Trellis-coded CPM for satellite-based mobile communications

NASA Technical Reports Server (NTRS)

Abrishamkar, Farrokh; Biglieri, Ezio

1988-01-01

Digital transmission for satellite-based land mobile communications is discussed. To satisfy the power and bandwidth limitations imposed on such systems, a combination of trellis coding and continuous-phase modulated signals are considered. Some schemes based on this idea are presented, and their performance is analyzed by computer simulation. The results obtained show that a scheme based on directional detection and Viterbi decoding appears promising for practical applications.

Efficient demodulation scheme for rolling-shutter-patterning of CMOS image sensor based visible light communications.

PubMed

Chen, Chia-Wei; Chow, Chi-Wai; Liu, Yang; Yeh, Chien-Hung

2017-10-02

Recently even the low-end mobile-phones are equipped with a high-resolution complementary-metal-oxide-semiconductor (CMOS) image sensor. This motivates using a CMOS image sensor for visible light communication (VLC). Here we propose and demonstrate an efficient demodulation scheme to synchronize and demodulate the rolling shutter pattern in image sensor based VLC. The implementation algorithm is discussed. The bit-error-rate (BER) performance and processing latency are evaluated and compared with other thresholding schemes.

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks.

PubMed

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-02-24

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption.

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks

PubMed Central

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-01-01

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption. PMID:26927104

Efficient decentralized consensus protocols

NASA Technical Reports Server (NTRS)

Lakshman, T. V.; Agrawala, A. K.

1986-01-01

Decentralized consensus protocols are characterized by successive rounds of message interchanges. Protocols which achieve a consensus in one round of message interchange require O(N-squared) messages, where N is the number of participants. In this paper, a communication scheme, based on finite projective planes, which requires only O(N sq rt N) messages for each round is presented. Using this communication scheme, decentralized consensus protocols which achieve a consensus within two rounds of message interchange are developed. The protocols are symmetric, and the communication scheme does not impose any hierarchical structure. The scheme is illustrated using blocking and nonblocking commit protocols, decentralized extrema finding, and computation of the sum function.

All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

PubMed

Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

2011-11-21

We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. © 2011 Optical Society of America

Turbulence mitigation scheme based on multiple-user detection in an orbital-angular-momentum multiplexed system

NASA Astrophysics Data System (ADS)

Zou, Li; Wang, Le; Zhao, Sheng-Mei; Chen, Han-Wu

2016-11-01

Atmospheric turbulence (AT) induced crosstalk can significantly impair the performance of a free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. In this paper, we propose a multiple-user detection (MUD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link. First, we present a MUD equivalent communication model for an OAM-multiplexed FSO communication link under AT. In the equivalent model, each input bit stream represents one user’s information. The deformed OAM spatial modes caused by AT, instead of the pure OAM spatial modes, are used as information carriers, and the overlapping between the deformed OAM spatial modes are computed as the correlation coefficients between the users. Then, we present a turbulence mitigation scheme based on MUD idea to enhance AT tolerance of the OAM-multiplexed FSO communication link. In the proposed scheme, the crosstalk caused by AT is used as a useful component to deduce users’ information. The numerical results show that the performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme. When the turbulence strength is 1 × 10-15 m-2/3, the transmission distance is 1000 m and the channel signal-to-noise ratio (SNR) is 26 dB, the bit-error-rate (BER) performance of four spatial multiplexed OAM modes lm = +1,+2,+3,+4 are all close to 10-5, and there is a 2-3 fold increase in the BER performance in comparison with those results without the proposed scheme. In addition, the proposed scheme is more effective for an OAM-multiplexed FSO communication link with a larger OAM mode topological charge interval. The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271238 and 61475075), the Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, China (Grant No. NYKL2015011), the Postgraduate Innovation Research Plan of Jiangsu Province, China (Grant No. CXZZ13_0489), and the University Natural Science Foundation of Jiangsu Province, China (Grant No. 16KJB510037).

Effects of partitioning and scheduling sparse matrix factorization on communication and load balance

NASA Technical Reports Server (NTRS)

Venugopal, Sesh; Naik, Vijay K.

1991-01-01

A block based, automatic partitioning and scheduling methodology is presented for sparse matrix factorization on distributed memory systems. Using experimental results, this technique is analyzed for communication and load imbalance overhead. To study the performance effects, these overheads were compared with those obtained from a straightforward 'wrap mapped' column assignment scheme. All experimental results were obtained using test sparse matrices from the Harwell-Boeing data set. The results show that there is a communication and load balance tradeoff. The block based method results in lower communication cost whereas the wrap mapped scheme gives better load balance.

Power adaptive multi-filter carrierless amplitude and phase access scheme for visible light communication network

NASA Astrophysics Data System (ADS)

Li, Wei; Huang, Zhitong; Li, Haoyue; Ji, Yuefeng

2018-04-01

Visible light communication (VLC) is a promising candidate for short-range broadband access due to its integration of advantages for both optical communication and wireless communication, whereas multi-user access is a key problem because of the intra-cell and inter-cell interferences. In addition, the non-flat channel effect results in higher losses for users in high frequency bands, which leads to unfair qualities. To solve those issues, we propose a power adaptive multi-filter carrierless amplitude and phase access (PA-MF-CAPA) scheme, and in the first step of this scheme, the MF-CAPA scheme utilizing multiple filters as different CAP dimensions is used to realize multi-user access. The character of orthogonality among the filters in different dimensions can mitigate the effect of intra-cell and inter-cell interferences. Moreover, the MF-CAPA scheme provides different channels modulated on the same frequency bands, which further increases the transmission rate. Then, the power adaptive procedure based on MF-CAPA scheme is presented to realize quality fairness. As demonstrated in our experiments, the MF-CAPA scheme yields an improved throughput compared with multi-band CAP access scheme, and the PA-MF-CAPA scheme enhances the quality fairness and further improves the throughput compared with the MF-CAPA scheme.

Improving Biometric-Based Authentication Schemes with Smart Card Revocation/Reissue for Wireless Sensor Networks.

PubMed

Moon, Jongho; Lee, Donghoon; Lee, Youngsook; Won, Dongho

2017-04-25

User authentication in wireless sensor networks is more difficult than in traditional networks owing to sensor network characteristics such as unreliable communication, limited resources, and unattended operation. For these reasons, various authentication schemes have been proposed to provide secure and efficient communication. In 2016, Park et al. proposed a secure biometric-based authentication scheme with smart card revocation/reissue for wireless sensor networks. However, we found that their scheme was still insecure against impersonation attack, and had a problem in the smart card revocation/reissue phase. In this paper, we show how an adversary can impersonate a legitimate user or sensor node, illegal smart card revocation/reissue and prove that Park et al.'s scheme fails to provide revocation/reissue. In addition, we propose an enhanced scheme that provides efficiency, as well as anonymity and security. Finally, we provide security and performance analysis between previous schemes and the proposed scheme, and provide formal analysis based on the random oracle model. The results prove that the proposed scheme can solve the weaknesses of impersonation attack and other security flaws in the security analysis section. Furthermore, performance analysis shows that the computational cost is lower than the previous scheme.

Improving Biometric-Based Authentication Schemes with Smart Card Revocation/Reissue for Wireless Sensor Networks

PubMed Central

Moon, Jongho; Lee, Donghoon; Lee, Youngsook; Won, Dongho

2017-01-01

User authentication in wireless sensor networks is more difficult than in traditional networks owing to sensor network characteristics such as unreliable communication, limited resources, and unattended operation. For these reasons, various authentication schemes have been proposed to provide secure and efficient communication. In 2016, Park et al. proposed a secure biometric-based authentication scheme with smart card revocation/reissue for wireless sensor networks. However, we found that their scheme was still insecure against impersonation attack, and had a problem in the smart card revocation/reissue phase. In this paper, we show how an adversary can impersonate a legitimate user or sensor node, illegal smart card revocation/reissue and prove that Park et al.’s scheme fails to provide revocation/reissue. In addition, we propose an enhanced scheme that provides efficiency, as well as anonymity and security. Finally, we provide security and performance analysis between previous schemes and the proposed scheme, and provide formal analysis based on the random oracle model. The results prove that the proposed scheme can solve the weaknesses of impersonation attack and other security flaws in the security analysis section. Furthermore, performance analysis shows that the computational cost is lower than the previous scheme. PMID:28441331

A Hybrid Key Management Scheme for WSNs Based on PPBR and a Tree-Based Path Key Establishment Method

PubMed Central

Zhang, Ying; Liang, Jixing; Zheng, Bingxin; Chen, Wei

2016-01-01

With the development of wireless sensor networks (WSNs), in most application scenarios traditional WSNs with static sink nodes will be gradually replaced by Mobile Sinks (MSs), and the corresponding application requires a secure communication environment. Current key management researches pay less attention to the security of sensor networks with MS. This paper proposes a hybrid key management schemes based on a Polynomial Pool-based key pre-distribution and Basic Random key pre-distribution (PPBR) to be used in WSNs with MS. The scheme takes full advantages of these two kinds of methods to improve the cracking difficulty of the key system. The storage effectiveness and the network resilience can be significantly enhanced as well. The tree-based path key establishment method is introduced to effectively solve the problem of communication link connectivity. Simulation clearly shows that the proposed scheme performs better in terms of network resilience, connectivity and storage effectiveness compared to other widely used schemes. PMID:27070624

PAPR reduction based on tone reservation scheme for DCO-OFDM indoor visible light communications.

PubMed

Bai, Jurong; Li, Yong; Yi, Yang; Cheng, Wei; Du, Huimin

2017-10-02

High peak-to-average power ratio (PAPR) leads to out-of-band power and in-band distortion in the direct current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) systems. In order to effectively reduce the PAPR with faster convergence and lower complexity, this paper proposes a tone reservation based scheme, which is the combination of the signal-to-clipping noise ratio (SCR) procedure and the least squares approximation (LSA) procedure. In the proposed scheme, the transmitter of the DCO-OFDM indoor visible light communication (VLC) system is designed to transform the PAPR reduced signal into real-valued positive OFDM signal without doubling the transmission bandwidth. Moreover, the communication distance and the light emitting diode (LED) irradiance angle are taking into consideration in the evaluation of the system bit error rate (BER). The PAPR reduction efficiency of the proposed scheme is remarkable for DCO-OFDM indoor VLC systems.

Improved Iterative Decoding of Network-Channel Codes for Multiple-Access Relay Channel.

PubMed

Majumder, Saikat; Verma, Shrish

2015-01-01

Cooperative communication using relay nodes is one of the most effective means of exploiting space diversity for low cost nodes in wireless network. In cooperative communication, users, besides communicating their own information, also relay the information of other users. In this paper we investigate a scheme where cooperation is achieved using a common relay node which performs network coding to provide space diversity for two information nodes transmitting to a base station. We propose a scheme which uses Reed-Solomon error correcting code for encoding the information bit at the user nodes and convolutional code as network code, instead of XOR based network coding. Based on this encoder, we propose iterative soft decoding of joint network-channel code by treating it as a concatenated Reed-Solomon convolutional code. Simulation results show significant improvement in performance compared to existing scheme based on compound codes.

Secure Communications in CIoT Networks with a Wireless Energy Harvesting Untrusted Relay

PubMed Central

Hu, Hequn; Liao, Xuewen

2017-01-01

The Internet of Things (IoT) represents a bright prospect that a variety of common appliances can connect to one another, as well as with the rest of the Internet, to vastly improve our lives. Unique communication and security challenges have been brought out by the limited hardware, low-complexity, and severe energy constraints of IoT devices. In addition, a severe spectrum scarcity problem has also been stimulated by the use of a large number of IoT devices. In this paper, cognitive IoT (CIoT) is considered where an IoT network works as the secondary system using underlay spectrum sharing. A wireless energy harvesting (EH) node is used as a relay to improve the coverage of an IoT device. However, the relay could be a potential eavesdropper to intercept the IoT device’s messages. This paper considers the problem of secure communication between the IoT device (e.g., sensor) and a destination (e.g., controller) via the wireless EH untrusted relay. Since the destination can be equipped with adequate energy supply, secure schemes based on destination-aided jamming are proposed based on power splitting (PS) and time splitting (TS) policies, called intuitive secure schemes based on PS (Int-PS), precoded secure scheme based on PS (Pre-PS), intuitive secure scheme based on TS (Int-TS) and precoded secure scheme based on TS (Pre-TS), respectively. The secure performances of the proposed schemes are evaluated through the metric of probability of successfully secure transmission (PSST), which represents the probability that the interference constraint of the primary user is satisfied and the secrecy rate is positive. PSST is analyzed for the proposed secure schemes, and the closed form expressions of PSST for Pre-PS and Pre-TS are derived and validated through simulation results. Numerical results show that the precoded secure schemes have better PSST than the intuitive secure schemes under similar power consumption. When the secure schemes based on PS and TS polices have similar PSST, the average transmit power consumption of the secure scheme based on TS is lower. The influences of power splitting and time slitting ratios are also discussed through simulations. PMID:28869540

Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.

PubMed

Mahfuz, Mohammad Upal

2016-10-01

In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.

Protection of autonomous microgrids using agent-based distributed communication

DOE PAGES

Cintuglu, Mehmet H.; Ma, Tan; Mohammed, Osama A.

2016-04-06

This study presents a real-time implementation of autonomous microgrid protection using agent-based distributed communication. Protection of an autonomous microgrid requires special considerations compared to large scale distribution net-works due to the presence of power converters and relatively low inertia. In this work, we introduce a practical overcurrent and a frequency selectivity method to overcome conventional limitations. The proposed overcurrent scheme defines a selectivity mechanism considering the remedial action scheme (RAS) of the microgrid after a fault instant based on feeder characteristics and the location of the intelligent electronic devices (IEDs). A synchrophasor-based online frequency selectivity approach is proposed to avoidmore » pulse loading effects in low inertia microgrids. Experimental results are presented for verification of the pro-posed schemes using a laboratory based microgrid. The setup was composed of actual generation units and IEDs using IEC 61850 protocol. The experimental results were in excellent agreement with the proposed protection scheme.« less

Protection of autonomous microgrids using agent-based distributed communication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cintuglu, Mehmet H.; Ma, Tan; Mohammed, Osama A.

This study presents a real-time implementation of autonomous microgrid protection using agent-based distributed communication. Protection of an autonomous microgrid requires special considerations compared to large scale distribution net-works due to the presence of power converters and relatively low inertia. In this work, we introduce a practical overcurrent and a frequency selectivity method to overcome conventional limitations. The proposed overcurrent scheme defines a selectivity mechanism considering the remedial action scheme (RAS) of the microgrid after a fault instant based on feeder characteristics and the location of the intelligent electronic devices (IEDs). A synchrophasor-based online frequency selectivity approach is proposed to avoidmore » pulse loading effects in low inertia microgrids. Experimental results are presented for verification of the pro-posed schemes using a laboratory based microgrid. The setup was composed of actual generation units and IEDs using IEC 61850 protocol. The experimental results were in excellent agreement with the proposed protection scheme.« less

A new precoding scheme for spectral efficient optical OFDM systems

NASA Astrophysics Data System (ADS)

Hardan, Saad Mshhain; Bayat, Oguz; Abdulkafi, Ayad Atiyah

2018-07-01

Achieving high spectral efficiency is the key requirement of 5G and optical wireless communication systems and has recently attracted much attention, aiming to satisfy the ever increasing demand for high data rates in communications systems. In this paper, we propose a new precoding/decoding algorithm for spectral efficient optical orthogonal frequency division multiplexing (OFDM) scheme based visible light communication (VLC) systems. The proposed coded modulated optical (CMO) based OFDM system can be applied for both single input single output (SISO) and multiple input multiple-output (MIMO) architectures. Firstly, the real OFDM time domain signal is obtained through invoking the precoding/decoding algorithm without the Hermitian symmetry. After that, the positive signal is achieved either by adding a DC-bias or by using the spatial multiplexing technique. The proposed CMO-OFDM scheme efficiently improves the spectral efficiency of the VLC system as it does not require the Hermitian symmetry constraint to yield real signals. A comparison of the performance improvement of the proposed scheme with other OFDM approaches is also presented in this work. Simulation results show that the proposed CMO-OFDM scheme can not only enhance the spectral efficiency of OFDM-based VLC systems but also improve bit error rate (BER) performance compared with other optical OFDM schemes.

PS-CARA: Context-Aware Resource Allocation Scheme for Mobile Public Safety Networks.

PubMed

Kaleem, Zeeshan; Khaliq, Muhammad Zubair; Khan, Ajmal; Ahmad, Ishtiaq; Duong, Trung Q

2018-05-08

The fifth-generation (5G) communications systems are expecting to support users with diverse quality-of-service (QoS) requirements. Beside these requirements, the task with utmost importance is to support the emergency communication services during natural or man-made disasters. Most of the conventional base stations are not properly functional during a disaster situation, so deployment of emergency base stations such as mobile personal cell (mPC) is crucial. An mPC having moving capability can move in the disaster area to provide emergency communication services. However, mPC deployment causes severe co-channel interference to the users in its vicinity. The problem in the existing resource allocation schemes is its support for static environment, that does not fit well for mPC. So, a resource allocation scheme for mPC users is desired that can dynamically allocate resources based on users’ location and its connection establishment priority. In this paper, we propose a public safety users priority-based context-aware resource allocation (PS-CARA) scheme for users sum-rate maximization in disaster environment. Simulations results demonstrate that the proposed PS-CARA scheme can increase the user average and edge rate around 10.3% and 32.8% , respectively because of context information availability and by prioritizing the public safety users. The simulation results ensure that call blocking probability is also reduced considerably under the PS-CARA scheme.

PS-CARA: Context-Aware Resource Allocation Scheme for Mobile Public Safety Networks

PubMed Central

Khaliq, Muhammad Zubair; Khan, Ajmal; Ahmad, Ishtiaq

2018-01-01

The fifth-generation (5G) communications systems are expecting to support users with diverse quality-of-service (QoS) requirements. Beside these requirements, the task with utmost importance is to support the emergency communication services during natural or man-made disasters. Most of the conventional base stations are not properly functional during a disaster situation, so deployment of emergency base stations such as mobile personal cell (mPC) is crucial. An mPC having moving capability can move in the disaster area to provide emergency communication services. However, mPC deployment causes severe co-channel interference to the users in its vicinity. The problem in the existing resource allocation schemes is its support for static environment, that does not fit well for mPC. So, a resource allocation scheme for mPC users is desired that can dynamically allocate resources based on users’ location and its connection establishment priority. In this paper, we propose a public safety users priority-based context-aware resource allocation (PS-CARA) scheme for users sum-rate maximization in disaster environment. Simulations results demonstrate that the proposed PS-CARA scheme can increase the user average and edge rate around 10.3% and 32.8% , respectively because of context information availability and by prioritizing the public safety users. The simulation results ensure that call blocking probability is also reduced considerably under the PS-CARA scheme. PMID:29738499

Chain-Based Communication in Cylindrical Underwater Wireless Sensor Networks

PubMed Central

Javaid, Nadeem; Jafri, Mohsin Raza; Khan, Zahoor Ali; Alrajeh, Nabil; Imran, Muhammad; Vasilakos, Athanasios

2015-01-01

Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate. PMID:25658394

Experimental demonstration of OFDM/OQAM transmission with DFT-based channel estimation for visible laser light communications

NASA Astrophysics Data System (ADS)

He, Jing; Shi, Jin; Deng, Rui; Chen, Lin

2017-08-01

Recently, visible light communication (VLC) based on light-emitting diodes (LEDs) is considered as a candidate technology for fifth-generation (5G) communications, VLC is free of electromagnetic interference and it can simplify the integration of VLC into heterogeneous wireless networks. Due to the data rates of VLC system limited by the low pumping efficiency, small output power and narrow modulation bandwidth, visible laser light communication (VLLC) system with laser diode (LD) has paid more attention. In addition, orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM) is currently attracting attention in optical communications. Due to the non-requirement of cyclic prefix (CP) and time-frequency domain well-localized pulse shapes, it can achieve high spectral efficiency. Moreover, OFDM/OQAM has lower out-of-band power leakage so that it increases the system robustness against inter-carrier interference (ICI) and frequency offset. In this paper, a Discrete Fourier Transform (DFT)-based channel estimation scheme combined with the interference approximation method (IAM) is proposed and experimentally demonstrated for VLLC OFDM/OQAM system. The performance of VLLC OFDM/OQAM system with and without DFT-based channel estimation is investigated. Moreover, the proposed DFT-based channel estimation scheme and the intra-symbol frequency-domain averaging (ISFA)-based method are also compared for the VLLC OFDM/OQAM system. The experimental results show that, the performance of EVM using the DFT-based channel estimation scheme is improved about 3dB compared with the conventional IAM method. In addition, the DFT-based channel estimation scheme can resist the channel noise effectively than that of the ISFA-based method.

College Communicative Teaching and E-Learning: A Training Scheme

ERIC Educational Resources Information Center

Ong, Charito G.

2017-01-01

This study sought to design and try out a training scheme for college teachers on e-learning use as a classroom strategy in a communicative teaching mode. Based on needs analysis the teachers of English were reoriented so that they became equipped with the rationale, strategies and assessment techniques of e-learning alongside communicative…

12.5 Gb/s multi-channel broadcasting transmission for free-space optical communication based on the optical frequency comb module.

PubMed

Tan, Jun; Zhao, Zeping; Wang, Yuehui; Zhang, Zhike; Liu, Jianguo; Zhu, Ninghua

2018-01-22

A wide-spectrum, ultra-stable optical frequency comb (OFC) module with 100 GHz frequency intervals based on a quantum dot mode locked (QDML) laser is fabricated by our lab, and a scheme with 12.5 Gb/s multi-channel broadcasting transmission for free-space optical (FSO) communication is proposed based on the OFC module. The output power of the OFC is very stable, with the specially designed circuit and the flatness of the frequency comb over the span of 6 nm, which can be limited to 1.5 dB. Four channel wavelengths are chosen to demonstrate one-to-many channels for FSO communication, like optical wireless broadcast. The outdoor experiment is established to test the bit error rate (BER) and eye diagrams with 12.5 Gb/s on-off keying (OOK). The indoor experiment is used to test the highest traffic rate, which is up to 21 Gb/s for one-hop FSO communication. To the best of our knowledge, this scheme is the first to propose the realization of one-to-many broadcasting transmission for FSO communication based on the OFC module. The advantages of integration, miniaturization, channelization, low power consumption, and unlimited bandwidth of one-to-many broadcasting communication scheme, shows promising results on constructing the future space-air-ground-ocean (SAGO) FSO communication networks.

A broadcast-based key agreement scheme using set reconciliation for wireless body area networks.

PubMed

Ali, Aftab; Khan, Farrukh Aslam

2014-05-01

Information and communication technologies have thrived over the last few years. Healthcare systems have also benefited from this progression. A wireless body area network (WBAN) consists of small, low-power sensors used to monitor human physiological values remotely, which enables physicians to remotely monitor the health of patients. Communication security in WBANs is essential because it involves human physiological data. Key agreement and authentication are the primary issues in the security of WBANs. To agree upon a common key, the nodes exchange information with each other using wireless communication. This information exchange process must be secure enough or the information exchange should be minimized to a certain level so that if information leak occurs, it does not affect the overall system. Most of the existing solutions for this problem exchange too much information for the sake of key agreement; getting this information is sufficient for an attacker to reproduce the key. Set reconciliation is a technique used to reconcile two similar sets held by two different hosts with minimal communication complexity. This paper presents a broadcast-based key agreement scheme using set reconciliation for secure communication in WBANs. The proposed scheme allows the neighboring nodes to agree upon a common key with the personal server (PS), generated from the electrocardiogram (EKG) feature set of the host body. Minimal information is exchanged in a broadcast manner, and even if every node is missing a different subset, by reconciling these feature sets, the whole network will still agree upon a single common key. Because of the limited information exchange, if an attacker gets the information in any way, he/she will not be able to reproduce the key. The proposed scheme mitigates replay, selective forwarding, and denial of service attacks using a challenge-response authentication mechanism. The simulation results show that the proposed scheme has a great deal of adoptability in terms of security, communication overhead, and running time complexity, as compared to the existing EKG-based key agreement scheme.

Unequal error control scheme for dimmable visible light communication systems

NASA Astrophysics Data System (ADS)

Deng, Keyan; Yuan, Lei; Wan, Yi; Li, Huaan

2017-01-01

Visible light communication (VLC), which has the advantages of a very large bandwidth, high security, and freedom from license-related restrictions and electromagnetic-interference, has attracted much interest. Because a VLC system simultaneously performs illumination and communication functions, dimming control, efficiency, and reliable transmission are significant and challenging issues of such systems. In this paper, we propose a novel unequal error control (UEC) scheme in which expanding window fountain (EWF) codes in an on-off keying (OOK)-based VLC system are used to support different dimming target values. To evaluate the performance of the scheme for various dimming target values, we apply it to H.264 scalable video coding bitstreams in a VLC system. The results of the simulations that are performed using additive white Gaussian noises (AWGNs) with different signal-to-noise ratios (SNRs) are used to compare the performance of the proposed scheme for various dimming target values. It is found that the proposed UEC scheme enables earlier base layer recovery compared to the use of the equal error control (EEC) scheme for different dimming target values and therefore afford robust transmission for scalable video multicast over optical wireless channels. This is because of the unequal error protection (UEP) and unequal recovery time (URT) of the EWF code in the proposed scheme.

On the security flaws in ID-based password authentication schemes for telecare medical information systems.

PubMed

Mishra, Dheerendra

2015-01-01

Telecare medical information systems (TMIS) enable healthcare delivery services. However, access of these services via public channel raises security and privacy issues. In recent years, several smart card based authentication schemes have been introduced to ensure secure and authorized communication between remote entities over the public channel for the (TMIS). We analyze the security of some of the recently proposed authentication schemes of Lin, Xie et al., Cao and Zhai, and Wu and Xu's for TMIS. Unfortunately, we identify that these schemes failed to satisfy desirable security attributes. In this article we briefly discuss four dynamic ID-based authentication schemes and demonstrate their failure to satisfy desirable security attributes. The study is aimed to demonstrate how inefficient password change phase can lead to denial of server scenario for an authorized user, and how an inefficient login phase causes the communication and computational overhead and decrease the performance of the system. Moreover, we show the vulnerability of Cao and Zhai's scheme to known session specific temporary information attack, vulnerability of Wu and Xu's scheme to off-line password guessing attack, and vulnerability of Xie et al.'s scheme to untraceable on-line password guessing attack.

A Hierarchical Modulation Coherent Communication Scheme for Simultaneous Four-State Continuous-Variable Quantum Key Distribution and Classical Communication

NASA Astrophysics Data System (ADS)

Yang, Can; Ma, Cheng; Hu, Linxi; He, Guangqiang

2018-06-01

We present a hierarchical modulation coherent communication protocol, which simultaneously achieves classical optical communication and continuous-variable quantum key distribution. Our hierarchical modulation scheme consists of a quadrature phase-shifting keying modulation for classical communication and a four-state discrete modulation for continuous-variable quantum key distribution. The simulation results based on practical parameters show that it is feasible to transmit both quantum information and classical information on a single carrier. We obtained a secure key rate of 10^{-3} bits/pulse to 10^{-1} bits/pulse within 40 kilometers, and in the meantime the maximum bit error rate for classical information is about 10^{-7}. Because continuous-variable quantum key distribution protocol is compatible with standard telecommunication technology, we think our hierarchical modulation scheme can be used to upgrade the digital communication systems to extend system function in the future.

An Efficient Identity-Based Key Management Scheme for Wireless Sensor Networks Using the Bloom Filter

PubMed Central

Qin, Zhongyuan; Zhang, Xinshuai; Feng, Kerong; Zhang, Qunfang; Huang, Jie

2014-01-01

With the rapid development and widespread adoption of wireless sensor networks (WSNs), security has become an increasingly prominent problem. How to establish a session key in node communication is a challenging task for WSNs. Considering the limitations in WSNs, such as low computing capacity, small memory, power supply limitations and price, we propose an efficient identity-based key management (IBKM) scheme, which exploits the Bloom filter to authenticate the communication sensor node with storage efficiency. The security analysis shows that IBKM can prevent several attacks effectively with acceptable computation and communication overhead. PMID:25264955

Integration of quantum key distribution and private classical communication through continuous variable

NASA Astrophysics Data System (ADS)

Wang, Tianyi; Gong, Feng; Lu, Anjiang; Zhang, Damin; Zhang, Zhengping

2017-12-01

In this paper, we propose a scheme that integrates quantum key distribution and private classical communication via continuous variables. The integrated scheme employs both quadratures of a weak coherent state, with encrypted bits encoded on the signs and Gaussian random numbers encoded on the values of the quadratures. The integration enables quantum and classical data to share the same physical and logical channel. Simulation results based on practical system parameters demonstrate that both classical communication and quantum communication can be implemented over distance of tens of kilometers, thus providing a potential solution for simultaneous transmission of quantum communication and classical communication.

Color-Space-Based Visual-MIMO for V2X Communication †

PubMed Central

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-01-01

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance. PMID:27120603

Color-Space-Based Visual-MIMO for V2X Communication.

PubMed

Kim, Jai-Eun; Kim, Ji-Won; Park, Youngil; Kim, Ki-Doo

2016-04-23

In this paper, we analyze the applicability of color-space-based, color-independent visual-MIMO for V2X. We aim to achieve a visual-MIMO scheme that can maintain the original color and brightness while performing seamless communication. We consider two scenarios of GCM based visual-MIMO for V2X. One is a multipath transmission using visual-MIMO networking and the other is multi-node V2X communication. In the scenario of multipath transmission, we analyze the channel capacity numerically and we illustrate the significance of networking information such as distance, reference color (symbol), and multiplexing-diversity mode transitions. In addition, in the V2X scenario of multiple access, we may achieve the simultaneous multiple access communication without node interferences by dividing the communication area using image processing. Finally, through numerical simulation, we show the superior SER performance of the visual-MIMO scheme compared with LED-PD communication and show the numerical result of the GCM based visual-MIMO channel capacity versus distance.

The synchronisation of fractional-order hyperchaos compound system

NASA Astrophysics Data System (ADS)

Noghredani, Naeimadeen; Riahi, Aminreza; Pariz, Naser; Karimpour, Ali

2018-02-01

This paper presents a new compound synchronisation scheme among four hyperchaotic memristor system with incommensurate fractional-order derivatives. First a new controller was designed based on adaptive technique to minimise the errors and guarantee compound synchronisation of four fractional-order memristor chaotic systems. According to the suitability of compound synchronisation as a reliable solution for secure communication, we then examined the application of the proposed adaptive compound synchronisation scheme in the presence of noise for secure communication. In addition, the unpredictability and complexity of the drive systems enhance the security of secure communication. The corresponding theoretical analysis and results of simulation validated the effectiveness of the proposed synchronisation scheme using MATLAB.

Secure communication in fiber optic systems via transmission of broad-band optical noise.

PubMed

Buskila, O; Eyal, A; Shtaif, M

2008-03-03

We propose a new scheme for data encryption in the physical layer. Our scheme is based on the distribution of a broadband optical noise-like signal between Alice and Bob. The broadband signal is used for the establishment of a secret key that can be used for the secure transmission of information by using the one-time-pad method. We characterize the proposed scheme and study its applicability to the existing fiber-optics communications infrastructure.

Schemes generating entangled states and entanglement swapping between photons and three-level atoms inside optical cavities for quantum communication

NASA Astrophysics Data System (ADS)

Heo, Jino; Kang, Min-Sung; Hong, Chang-Ho; Yang, Hyeon; Choi, Seong-Gon

2017-01-01

We propose quantum information processing schemes based on cavity quantum electrodynamics (QED) for quantum communication. First, to generate entangled states (Bell and Greenberger-Horne-Zeilinger [GHZ] states) between flying photons and three-level atoms inside optical cavities, we utilize a controlled phase flip (CPF) gate that can be implemented via cavity QED). Subsequently, we present an entanglement swapping scheme that can be realized using single-qubit measurements and CPF gates via optical cavities. These schemes can be directly applied to construct an entanglement channel for a communication system between two users. Consequently, it is possible for the trust center, having quantum nodes, to accomplish the linked channel (entanglement channel) between the two separate long-distance users via the distribution of Bell states and entanglement swapping. Furthermore, in our schemes, the main physical component is the CPF gate between the photons and the three-level atoms in cavity QED, which is feasible in practice. Thus, our schemes can be experimentally realized with current technology.

Semi-quantum Secure Direct Communication Scheme Based on Bell States

NASA Astrophysics Data System (ADS)

Xie, Chen; Li, Lvzhou; Situ, Haozhen; He, Jianhao

2018-06-01

Recently, the idea of semi-quantumness has been often used in designing quantum cryptographic schemes, which allows some of the participants of a quantum cryptographic scheme to remain classical. One of the reasons why this idea is popular is that it allows a quantum information processing task to be accomplished by using quantum resources as few as possible. In this paper, we extend the idea to quantum secure direct communication(QSDC) by proposing a semi-quantum secure direct communication scheme. In the scheme, the message sender, Alice, encodes each bit into a Bell state |φ+> = 1/{√2}(|00> +|11> ) or |{Ψ }+> = 1/{√ 2}(|01> +|10> ), and the message receiver, Bob, who is classical in the sense that he can either let the qubit he received reflect undisturbed, or measure the qubit in the computational basis |0>, |1> and then resend it in the state he found. Moreover, the security analysis of our scheme is also given.

A CDMA system implementation with dimming control for visible light communication

NASA Astrophysics Data System (ADS)

Chen, Danyang; Wang, Jianping; Jin, Jianli; Lu, Huimin; Feng, Lifang

2018-04-01

Visible light communication (VLC), using solid-state lightings to transmit information, has become a complement technology to wireless radio communication. As a realistic multiple access scheme for VLC system, code division multiple access (CDMA) has attracted more and more attentions in recent years. In this paper, we address and implement an improved CDMA scheme for VLC system. The simulation results reveal that the improved CDMA scheme not only supports multi-users' transmission but also maintains dimming value at about 50% and enhances the system efficiency. It can also realize the flexible dimming control by adjusting some parameters of system structure, which rarely affects the system BER performance. A real-time experimental VLC system with improved CDMA scheme is performed based on field programmable gate array (FPGA), reaching a good BER performance.

A Scheme to Optimize Flow Routing and Polling Switch Selection of Software Defined Networks.

PubMed

Chen, Huan; Li, Lemin; Ren, Jing; Wang, Yang; Zhao, Yangming; Wang, Xiong; Wang, Sheng; Xu, Shizhong

2015-01-01

This paper aims at minimizing the communication cost for collecting flow information in Software Defined Networks (SDN). Since flow-based information collecting method requires too much communication cost, and switch-based method proposed recently cannot benefit from controlling flow routing, jointly optimize flow routing and polling switch selection is proposed to reduce the communication cost. To this end, joint optimization problem is formulated as an Integer Linear Programming (ILP) model firstly. Since the ILP model is intractable in large size network, we also design an optimal algorithm for the multi-rooted tree topology and an efficient heuristic algorithm for general topology. According to extensive simulations, it is found that our method can save up to 55.76% communication cost compared with the state-of-the-art switch-based scheme.

Verifier-based three-party authentication schemes using extended chaotic maps for data exchange in telecare medicine information systems.

PubMed

Lee, Tian-Fu

2014-12-01

Telecare medicine information systems provide a communicating platform for accessing remote medical resources through public networks, and help health care workers and medical personnel to rapidly making correct clinical decisions and treatments. An authentication scheme for data exchange in telecare medicine information systems enables legal users in hospitals and medical institutes to establish a secure channel and exchange electronic medical records or electronic health records securely and efficiently. This investigation develops an efficient and secure verified-based three-party authentication scheme by using extended chaotic maps for data exchange in telecare medicine information systems. The proposed scheme does not require server's public keys and avoids time-consuming modular exponential computations and scalar multiplications on elliptic curve used in previous related approaches. Additionally, the proposed scheme is proven secure in the random oracle model, and realizes the lower bounds of messages and rounds in communications. Compared to related verified-based approaches, the proposed scheme not only possesses higher security, but also has lower computational cost and fewer transmissions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

An enhanced password authentication scheme for session initiation protocol with perfect forward secrecy.

PubMed

Qiu, Shuming; Xu, Guoai; Ahmad, Haseeb; Guo, Yanhui

2018-01-01

The Session Initiation Protocol (SIP) is an extensive and esteemed communication protocol employed to regulate signaling as well as for controlling multimedia communication sessions. Recently, Kumari et al. proposed an improved smart card based authentication scheme for SIP based on Farash's scheme. Farash claimed that his protocol is resistant against various known attacks. But, we observe some accountable flaws in Farash's protocol. We point out that Farash's protocol is prone to key-compromise impersonation attack and is unable to provide pre-verification in the smart card, efficient password change and perfect forward secrecy. To overcome these limitations, in this paper we present an enhanced authentication mechanism based on Kumari et al.'s scheme. We prove that the proposed protocol not only overcomes the issues in Farash's scheme, but it can also resist against all known attacks. We also provide the security analysis of the proposed scheme with the help of widespread AVISPA (Automated Validation of Internet Security Protocols and Applications) software. At last, comparing with the earlier proposals in terms of security and efficiency, we conclude that the proposed protocol is efficient and more secure.

Secure Communications in CIoT Networks with a Wireless Energy Harvesting Untrusted Relay.

PubMed

Hu, Hequn; Gao, Zhenzhen; Liao, Xuewen; Leung, Victor C M

2017-09-04

The Internet of Things (IoT) represents a bright prospect that a variety of common appliances can connect to one another, as well as with the rest of the Internet, to vastly improve our lives. Unique communication and security challenges have been brought out by the limited hardware, low-complexity, and severe energy constraints of IoT devices. In addition, a severe spectrum scarcity problem has also been stimulated by the use of a large number of IoT devices. In this paper, cognitive IoT (CIoT) is considered where an IoT network works as the secondary system using underlay spectrum sharing. A wireless energy harvesting (EH) node is used as a relay to improve the coverage of an IoT device. However, the relay could be a potential eavesdropper to intercept the IoT device's messages. This paper considers the problem of secure communication between the IoT device (e.g., sensor) and a destination (e.g., controller) via the wireless EH untrusted relay. Since the destination can be equipped with adequate energy supply, secure schemes based on destination-aided jamming are proposed based on power splitting (PS) and time splitting (TS) policies, called intuitive secure schemes based on PS (Int-PS), precoded secure scheme based on PS (Pre-PS), intuitive secure scheme based on TS (Int-TS) and precoded secure scheme based on TS (Pre-TS), respectively. The secure performances of the proposed schemes are evaluated through the metric of probability of successfully secure transmission ( P S S T ), which represents the probability that the interference constraint of the primary user is satisfied and the secrecy rate is positive. P S S T is analyzed for the proposed secure schemes, and the closed form expressions of P S S T for Pre-PS and Pre-TS are derived and validated through simulation results. Numerical results show that the precoded secure schemes have better P S S T than the intuitive secure schemes under similar power consumption. When the secure schemes based on PS and TS polices have similar P S S T , the average transmit power consumption of the secure scheme based on TS is lower. The influences of power splitting and time slitting ratios are also discussed through simulations.

An adaptive critic-based scheme for consensus control of nonlinear multi-agent systems

NASA Astrophysics Data System (ADS)

Heydari, Ali; Balakrishnan, S. N.

2014-12-01

The problem of decentralised consensus control of a network of heterogeneous nonlinear systems is formulated as an optimal tracking problem and a solution is proposed using an approximate dynamic programming based neurocontroller. The neurocontroller training comprises an initial offline training phase and an online re-optimisation phase to account for the fact that the reference signal subject to tracking is not fully known and available ahead of time, i.e., during the offline training phase. As long as the dynamics of the agents are controllable, and the communication graph has a directed spanning tree, this scheme guarantees the synchronisation/consensus even under switching communication topology and directed communication graph. Finally, an aerospace application is selected for the evaluation of the performance of the method. Simulation results demonstrate the potential of the scheme.

Role of memory errors in quantum repeaters

NASA Astrophysics Data System (ADS)

Hartmann, L.; Kraus, B.; Briegel, H.-J.; Dür, W.

2007-03-01

We investigate the influence of memory errors in the quantum repeater scheme for long-range quantum communication. We show that the communication distance is limited in standard operation mode due to memory errors resulting from unavoidable waiting times for classical signals. We show how to overcome these limitations by (i) improving local memory and (ii) introducing two operational modes of the quantum repeater. In both operational modes, the repeater is run blindly, i.e., without waiting for classical signals to arrive. In the first scheme, entanglement purification protocols based on one-way classical communication are used allowing to communicate over arbitrary distances. However, the error thresholds for noise in local control operations are very stringent. The second scheme makes use of entanglement purification protocols with two-way classical communication and inherits the favorable error thresholds of the repeater run in standard mode. One can increase the possible communication distance by an order of magnitude with reasonable overhead in physical resources. We outline the architecture of a quantum repeater that can possibly ensure intercontinental quantum communication.

Advanced Protection & Service Restoration for FREEDM Systems

NASA Astrophysics Data System (ADS)

Singh, Urvir

A smart electric power distribution system (FREEDM system) that incorporates DERs (Distributed Energy Resources), SSTs (Solid State Transformers - that can limit the fault current to two times of the rated current) & RSC (Reliable & Secure Communication) capabilities has been studied in this work in order to develop its appropriate protection & service restoration techniques. First, a solution is proposed that can make conventional protective devices be able to provide effective protection for FREEDM systems. Results show that although this scheme can provide required protection but it can be quite slow. Using the FREEDM system's communication capabilities, a communication assisted Overcurrent (O/C) protection scheme is proposed & results show that by using communication (blocking signals) very fast operating times are achieved thereby, mitigating the problem of conventional O/C scheme. Using the FREEDM System's DGI (Distributed Grid Intelligence) capability, an automated FLISR (Fault Location, Isolation & Service Restoration) scheme is proposed that is based on the concept of 'software agents' & uses lesser data (than conventional centralized approaches). Test results illustrated that this scheme is able to provide a global optimal system reconfiguration for service restoration.

The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

NASA Technical Reports Server (NTRS)

Ansari, Nirwan; Liu, Dequan

1991-01-01

A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

Distributed polar-coded OFDM based on Plotkin's construction for half duplex wireless communication

NASA Astrophysics Data System (ADS)

Umar, Rahim; Yang, Fengfan; Mughal, Shoaib; Xu, HongJun

2018-07-01

A Plotkin-based polar-coded orthogonal frequency division multiplexing (P-PC-OFDM) scheme is proposed and its bit error rate (BER) performance over additive white gaussian noise (AWGN), frequency selective Rayleigh, Rician and Nakagami-m fading channels has been evaluated. The considered Plotkin's construction possesses a parallel split in its structure, which motivated us to extend the proposed P-PC-OFDM scheme in a coded cooperative scenario. As the relay's effective collaboration has always been pivotal in the design of cooperative communication therefore, an efficient selection criterion for choosing the information bits has been inculcated at the relay node. To assess the BER performance of the proposed cooperative scheme, we have also upgraded conventional polar-coded cooperative scheme in the context of OFDM as an appropriate bench marker. The Monte Carlo simulated results revealed that the proposed Plotkin-based polar-coded cooperative OFDM scheme convincingly outperforms the conventional polar-coded cooperative OFDM scheme by 0.5 0.6 dBs over AWGN channel. This prominent gain in BER performance is made possible due to the bit-selection criteria and the joint successive cancellation decoding adopted at the relay and the destination nodes, respectively. Furthermore, the proposed coded cooperative schemes outperform their corresponding non-cooperative schemes by a gain of 1 dB under an identical condition.

Continuous-Variable Measurement-Device-Independent Multipartite Quantum Communication Using Coherent States

NASA Astrophysics Data System (ADS)

Zhou, Jian; Guo, Ying

2017-02-01

A continuous-variable measurement-device-independent (CV-MDI) multipartite quantum communication protocol is designed to realize multipartite communication based on the GHZ state analysis using Gaussian coherent states. It can remove detector side attack as the multi-mode measurement is blindly done in a suitable Black Box. The entanglement-based CV-MDI multipartite communication scheme and the equivalent prepare-and-measurement scheme are proposed to analyze the security and guide experiment, respectively. The general eavesdropping and coherent attack are considered for the security analysis. Subsequently, all the attacks are ascribed to coherent attack against imperfect links. The asymptotic key rate of the asymmetric configuration is also derived with the numeric simulations illustrating the performance of the proposed protocol.

Wireless Instrumentation System and Power Management Scheme Therefore

NASA Technical Reports Server (NTRS)

Perotti, Jose (Inventor); Lucena, Angel (Inventor); Eckhoff, Anthony (Inventor); Mata, Carlos T. (Inventor); Blalock, Norman N. (Inventor); Medelius, Pedro J. (Inventor)

2007-01-01

A wireless instrumentation system enables a plurality of low power wireless transceivers to transmit measurement data from a plurality of remote station sensors to a central data station accurately and reliably. The system employs a relay based communications scheme where remote stations that cannot communicate directly with the central station due to interference, poor signal strength, etc., are instructed to communicate with other of the remote stations that act as relays to the central station. A unique power management scheme is also employed to minimize power usage at each remote station and thereby maximize battery life. Each of the remote stations prefembly employs a modular design to facilitate easy reconfiguration of the stations as required.

Experimental demonstration of an OFDM based visible light communication system using inter-block precoding and superimposed pilots

NASA Astrophysics Data System (ADS)

Zhang, Junwei; Hong, Xuezhi; Liu, Jie; Guo, Changjian

2018-04-01

In this work, we investigate and experimentally demonstrate an orthogonal frequency division multiplexing (OFDM) based high speed wavelength-division multiplexed (WDM) visible light communication (VLC) system using an inter-block data precoding and superimposed pilots (DP-SP) based channel estimation (CE) scheme. The residual signal-to-pilot interference (SPI) can be eliminated by using inter-block data precoding, resulting in a significant improvement in estimated accuracy and the overall system performance compared with uncoded SP based CE scheme. We also study the power allocation/overhead problem of the training for DP-SP, uncoded SP and conventional preamble based CE schemes, from which we obtain the optimum signal-to-pilot power ratio (SPR)/overhead percentage for all above cases. Intra-symbol frequency-domain averaging (ISFA) is also adopted to further enhance the accuracy of CE. By using the DP-SP based CE scheme, aggregate data rates of 1.87-Gbit/s and 1.57-Gbit/s are experimentally demonstrated over 0.8-m and 2-m indoor free space transmission, respectively, using a commercially available red, green and blue (RGB) light emitting diode (LED) with WDM. Experimental results show that the DP-SP based CE scheme is comparable to the conventional preamble based CE scheme in term of received Q factor and data rate while entailing a much smaller overhead-size.

Efficient and faithful remote preparation of arbitrary three- and four-particle -class entangled states

NASA Astrophysics Data System (ADS)

Wang, Dong; Hu, You-Di; Wang, Zhe-Qiang; Ye, Liu

2015-06-01

We develop two efficient measurement-based schemes for remotely preparing arbitrary three- and four-particle W-class entangled states by utilizing genuine tripartite Greenberg-Horn-Zeilinger-type states as quantum channels, respectively. Through appropriate local operations and classical communication, the desired states can be faithfully retrieved at the receiver's place with certain probability. Compared with the previously existing schemes, the success probability in current schemes is greatly increased. Moreover, the required classical communication cost is calculated as well. Further, several attractive discussions on the properties of the presented schemes, including the success probability and reducibility, are made. Remarkably, the proposed schemes can be faithfully achieved with unity total success probability when the employed channels are reduced into maximally entangled ones.

A Scheme to Optimize Flow Routing and Polling Switch Selection of Software Defined Networks

PubMed Central

Chen, Huan; Li, Lemin; Ren, Jing; Wang, Yang; Zhao, Yangming; Wang, Xiong; Wang, Sheng; Xu, Shizhong

2015-01-01

This paper aims at minimizing the communication cost for collecting flow information in Software Defined Networks (SDN). Since flow-based information collecting method requires too much communication cost, and switch-based method proposed recently cannot benefit from controlling flow routing, jointly optimize flow routing and polling switch selection is proposed to reduce the communication cost. To this end, joint optimization problem is formulated as an Integer Linear Programming (ILP) model firstly. Since the ILP model is intractable in large size network, we also design an optimal algorithm for the multi-rooted tree topology and an efficient heuristic algorithm for general topology. According to extensive simulations, it is found that our method can save up to 55.76% communication cost compared with the state-of-the-art switch-based scheme. PMID:26690571

High-dimensional free-space optical communications based on orbital angular momentum coding

NASA Astrophysics Data System (ADS)

Zou, Li; Gu, Xiaofan; Wang, Le

2018-03-01

In this paper, we propose a high-dimensional free-space optical communication scheme using orbital angular momentum (OAM) coding. In the scheme, the transmitter encodes N-bits information by using a spatial light modulator to convert a Gaussian beam to a superposition mode of N OAM modes and a Gaussian mode; The receiver decodes the information through an OAM mode analyser which consists of a MZ interferometer with a rotating Dove prism, a photoelectric detector and a computer carrying out the fast Fourier transform. The scheme could realize a high-dimensional free-space optical communication, and decodes the information much fast and accurately. We have verified the feasibility of the scheme by exploiting 8 (4) OAM modes and a Gaussian mode to implement a 256-ary (16-ary) coding free-space optical communication to transmit a 256-gray-scale (16-gray-scale) picture. The results show that a zero bit error rate performance has been achieved.

A Secure Dynamic Identity and Chaotic Maps Based User Authentication and Key Agreement Scheme for e-Healthcare Systems.

PubMed

Li, Chun-Ta; Lee, Cheng-Chi; Weng, Chi-Yao; Chen, Song-Jhih

2016-11-01

Secure user authentication schemes in many e-Healthcare applications try to prevent unauthorized users from intruding the e-Healthcare systems and a remote user and a medical server can establish session keys for securing the subsequent communications. However, many schemes does not mask the users' identity information while constructing a login session between two or more parties, even though personal privacy of users is a significant topic for e-Healthcare systems. In order to preserve personal privacy of users, dynamic identity based authentication schemes are hiding user's real identity during the process of network communications and only the medical server knows login user's identity. In addition, most of the existing dynamic identity based authentication schemes ignore the inputs verification during login condition and this flaw may subject to inefficiency in the case of incorrect inputs in the login phase. Regarding the use of secure authentication mechanisms for e-Healthcare systems, this paper presents a new dynamic identity and chaotic maps based authentication scheme and a secure data protection approach is employed in every session to prevent illegal intrusions. The proposed scheme can not only quickly detect incorrect inputs during the phases of login and password change but also can invalidate the future use of a lost/stolen smart card. Compared the functionality and efficiency with other authentication schemes recently, the proposed scheme satisfies desirable security attributes and maintains acceptable efficiency in terms of the computational overheads for e-Healthcare systems.

LDPC-PPM Coding Scheme for Optical Communication

NASA Technical Reports Server (NTRS)

Barsoum, Maged; Moision, Bruce; Divsalar, Dariush; Fitz, Michael

2009-01-01

In a proposed coding-and-modulation/demodulation-and-decoding scheme for a free-space optical communication system, an error-correcting code of the low-density parity-check (LDPC) type would be concatenated with a modulation code that consists of a mapping of bits to pulse-position-modulation (PPM) symbols. Hence, the scheme is denoted LDPC-PPM. This scheme could be considered a competitor of a related prior scheme in which an outer convolutional error-correcting code is concatenated with an interleaving operation, a bit-accumulation operation, and a PPM inner code. Both the prior and present schemes can be characterized as serially concatenated pulse-position modulation (SCPPM) coding schemes. Figure 1 represents a free-space optical communication system based on either the present LDPC-PPM scheme or the prior SCPPM scheme. At the transmitting terminal, the original data (u) are processed by an encoder into blocks of bits (a), and the encoded data are mapped to PPM of an optical signal (c). For the purpose of design and analysis, the optical channel in which the PPM signal propagates is modeled as a Poisson point process. At the receiving terminal, the arriving optical signal (y) is demodulated to obtain an estimate (a^) of the coded data, which is then processed by a decoder to obtain an estimate (u^) of the original data.

Dynamic neural network-based methods for compensation of nonlinear effects in multimode communication lines

NASA Astrophysics Data System (ADS)

Sidelnikov, O. S.; Redyuk, A. A.; Sygletos, S.

2017-12-01

We consider neural network-based schemes of digital signal processing. It is shown that the use of a dynamic neural network-based scheme of signal processing ensures an increase in the optical signal transmission quality in comparison with that provided by other methods for nonlinear distortion compensation.

Color coded multiple access scheme for bidirectional multiuser visible light communications in smart home technologies

NASA Astrophysics Data System (ADS)

Tiwari, Samrat Vikramaditya; Sewaiwar, Atul; Chung, Yeon-Ho

2015-10-01

In optical wireless communications, multiple channel transmission is an attractive solution to enhancing capacity and system performance. A new modulation scheme called color coded multiple access (CCMA) for bidirectional multiuser visible light communications (VLC) is presented for smart home applications. The proposed scheme uses red, green and blue (RGB) light emitting diodes (LED) for downlink and phosphor based white LED (P-LED) for uplink to establish a bidirectional VLC and also employs orthogonal codes to support multiple users and devices. The downlink transmission for data user devices and smart home devices is provided using red and green colors from the RGB LEDs, respectively, while uplink transmission from both types of devices is performed using the blue color from P-LEDs. Simulations are conducted to verify the performance of the proposed scheme. It is found that the proposed bidirectional multiuser scheme is efficient in terms of data rate and performance. In addition, since the proposed scheme uses RGB signals for downlink data transmission, it provides flicker-free illumination that would lend itself to multiuser VLC system for smart home applications.

Faithful One-way Trip Deterministic Secure Quantum Communication Scheme Against Collective Rotating Noise Based on Order Rearrangement of Photon Pairs

NASA Astrophysics Data System (ADS)

Yuan, Hao; Zhang, Qin; Hong, Liang; Yin, Wen-jie; Xu, Dong

2014-08-01

We present a novel scheme for deterministic secure quantum communication (DSQC) over collective rotating noisy channel. Four special two-qubit states are found can constitute a noise-free subspaces, and so are utilized as quantum information carriers. In this scheme, the information carriers transmite over the quantum channel only one time, which can effectively reduce the influence of other noise existing in quantum channel. The information receiver need only perform two single-photon collective measurements to decode the secret messages, which can make the present scheme more convenient in practical application. It will be showed that our scheme has a relatively high information capacity and intrisic efficiency. Foremostly, the decoy photon pair checking technique and the order rearrangement of photon pairs technique guarantee that the present scheme is unconditionally secure.

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkhatib, Mohamed; Ellis, Abraham; Milan Biswal

keywords : Microgrid Protection, Impedance Relay, Signal Processing-based Fault Detec- tion, Networked Microgrids, Communication-Assisted Protection In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The surveymore » concluded that there is a gap in the available microgrid protection methods. The only credible protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

Access Control Mechanism for IoT Environments Based on Modelling Communication Procedures as Resources.

PubMed

Cruz-Piris, Luis; Rivera, Diego; Marsa-Maestre, Ivan; de la Hoz, Enrique; Velasco, Juan R

2018-03-20

Internet growth has generated new types of services where the use of sensors and actuators is especially remarkable. These services compose what is known as the Internet of Things (IoT). One of the biggest current challenges is obtaining a safe and easy access control scheme for the data managed in these services. We propose integrating IoT devices in an access control system designed for Web-based services by modelling certain IoT communication elements as resources. This would allow us to obtain a unified access control scheme between heterogeneous devices (IoT devices, Internet-based services, etc.). To achieve this, we have analysed the most relevant communication protocols for these kinds of environments and then we have proposed a methodology which allows the modelling of communication actions as resources. Then, we can protect these resources using access control mechanisms. The validation of our proposal has been carried out by selecting a communication protocol based on message exchange, specifically Message Queuing Telemetry Transport (MQTT). As an access control scheme, we have selected User-Managed Access (UMA), an existing Open Authorization (OAuth) 2.0 profile originally developed for the protection of Internet services. We have performed tests focused on validating the proposed solution in terms of the correctness of the access control system. Finally, we have evaluated the energy consumption overhead when using our proposal.

Access Control Mechanism for IoT Environments Based on Modelling Communication Procedures as Resources

PubMed Central

2018-01-01

Internet growth has generated new types of services where the use of sensors and actuators is especially remarkable. These services compose what is known as the Internet of Things (IoT). One of the biggest current challenges is obtaining a safe and easy access control scheme for the data managed in these services. We propose integrating IoT devices in an access control system designed for Web-based services by modelling certain IoT communication elements as resources. This would allow us to obtain a unified access control scheme between heterogeneous devices (IoT devices, Internet-based services, etc.). To achieve this, we have analysed the most relevant communication protocols for these kinds of environments and then we have proposed a methodology which allows the modelling of communication actions as resources. Then, we can protect these resources using access control mechanisms. The validation of our proposal has been carried out by selecting a communication protocol based on message exchange, specifically Message Queuing Telemetry Transport (MQTT). As an access control scheme, we have selected User-Managed Access (UMA), an existing Open Authorization (OAuth) 2.0 profile originally developed for the protection of Internet services. We have performed tests focused on validating the proposed solution in terms of the correctness of the access control system. Finally, we have evaluated the energy consumption overhead when using our proposal. PMID:29558406

An enhanced password authentication scheme for session initiation protocol with perfect forward secrecy

PubMed Central

2018-01-01

The Session Initiation Protocol (SIP) is an extensive and esteemed communication protocol employed to regulate signaling as well as for controlling multimedia communication sessions. Recently, Kumari et al. proposed an improved smart card based authentication scheme for SIP based on Farash’s scheme. Farash claimed that his protocol is resistant against various known attacks. But, we observe some accountable flaws in Farash’s protocol. We point out that Farash’s protocol is prone to key-compromise impersonation attack and is unable to provide pre-verification in the smart card, efficient password change and perfect forward secrecy. To overcome these limitations, in this paper we present an enhanced authentication mechanism based on Kumari et al.’s scheme. We prove that the proposed protocol not only overcomes the issues in Farash’s scheme, but it can also resist against all known attacks. We also provide the security analysis of the proposed scheme with the help of widespread AVISPA (Automated Validation of Internet Security Protocols and Applications) software. At last, comparing with the earlier proposals in terms of security and efficiency, we conclude that the proposed protocol is efficient and more secure. PMID:29547619

A scheme for synchronizing clocks connected by a packet communication network

NASA Astrophysics Data System (ADS)

dos Santos, R. V.; Monteiro, L. H. A.

2012-07-01

Consider a communication system in which a transmitter equipment sends fixed-size packets of data at a uniform rate to a receiver equipment. Consider also that these equipments are connected by a packet-switched network, which introduces a random delay to each packet. Here we propose an adaptive clock recovery scheme able of synchronizing the frequencies and the phases of these devices, within specified limits of precision. This scheme for achieving frequency and phase synchronization is based on measurements of the packet arrival times at the receiver, which are used to control the dynamics of a digital phase-locked loop. The scheme performance is evaluated via numerical simulations performed by using realistic parameter values.

LDPC-coded orbital angular momentum (OAM) modulation for free-space optical communication.

PubMed

Djordjevic, Ivan B; Arabaci, Murat

2010-11-22

An orbital angular momentum (OAM) based LDPC-coded modulation scheme suitable for use in FSO communication is proposed. We demonstrate that the proposed scheme can operate under strong atmospheric turbulence regime and enable 100 Gb/s optical transmission while employing 10 Gb/s components. Both binary and nonbinary LDPC-coded OAM modulations are studied. In addition to providing better BER performance, the nonbinary LDPC-coded modulation reduces overall decoder complexity and latency. The nonbinary LDPC-coded OAM modulation provides a net coding gain of 9.3 dB at the BER of 10(-8). The maximum-ratio combining scheme outperforms the corresponding equal-gain combining scheme by almost 2.5 dB.

Experimental investigation of analog and digital dimming techniques on photometric performance of an indoor Visible Light Communication (VLC) system

NASA Astrophysics Data System (ADS)

Zafar, Fahad; Kalavally, Vineetha; Bakaul, Masuduzzaman; Parthiban, R.

2015-09-01

For making commercial implementation of light emitting diode (LED) based visible light communication (VLC) systems feasible, it is necessary to incorporate it with dimming schemes which will provide energy savings, moods and increase the aesthetic value of the places using this technology. There are two general methods which are used to dim LEDs commonly categorized as analog and digital dimming. Incorporating fast data transmission with these techniques is a key challenge in VLC. In this paper, digital and analog dimming for a 10 Mb/s non return to zero on-off keying (NRZ-OOK) based VLC system is experimentally investigated considering both photometric and communicative parameters. A spectrophotometer was used for photometric analysis and a line of sight (LOS) configuration in the presence of ambient light was used for analyzing communication parameters. Based on the experimental results, it was determined that digital dimming scheme is preferable for use in indoor VLC systems requiring high dimming precision and data transmission at lower brightness levels. On the other hand, analog dimming scheme is a cost effective solution for high speed systems where dimming precision is insignificant.

A New Hybrid Scheme for Preventing Channel Interference and Collision in Mobile Networks

NASA Astrophysics Data System (ADS)

Kim, Kyungjun; Han, Kijun

This paper proposes a new hybrid scheme based on a given set of channels for preventing channel interference and collision in mobile networks. The proposed scheme is designed for improving system performance, focusing on enhancement of performance related to path breakage and channel interference. The objective of this scheme is to improve the performance of inter-node communication. Simulation results from this paper show that the new hybrid scheme can reduce a more control message overhead than a conventional random scheme.

Simultaneous classical communication and quantum key distribution using continuous variables*

NASA Astrophysics Data System (ADS)

Qi, Bing

2016-10-01

Presently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters show that both deterministic classical communication with a bit error rate of 10-9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.

Image secure transmission for optical orthogonal frequency-division multiplexing visible light communication systems using chaotic discrete cosine transform

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Zhang, Shaozhong; Chen, Fangni; Wu, Ming-Wei; Qiu, Weiwei

2017-11-01

A physical encryption scheme for orthogonal frequency-division multiplexing (OFDM) visible light communication (VLC) systems using chaotic discrete cosine transform (DCT) is proposed. In the scheme, the row of the DCT matrix is permutated by a scrambling sequence generated by a three-dimensional (3-D) Arnold chaos map. Furthermore, two scrambling sequences, which are also generated from a 3-D Arnold map, are employed to encrypt the real and imaginary parts of the transmitted OFDM signal before the chaotic DCT operation. The proposed scheme enhances the physical layer security and improves the bit error rate (BER) performance for OFDM-based VLC. The simulation results prove the efficiency of the proposed encryption method. The experimental results show that the proposed security scheme not only protects image data from eavesdroppers but also keeps the good BER and peak-to-average power ratio performances for image-based OFDM-VLC systems.

Event-triggered H∞ state estimation for semi-Markov jumping discrete-time neural networks with quantization.

PubMed

Rakkiyappan, R; Maheswari, K; Velmurugan, G; Park, Ju H

2018-05-17

This paper investigates H ∞ state estimation problem for a class of semi-Markovian jumping discrete-time neural networks model with event-triggered scheme and quantization. First, a new event-triggered communication scheme is introduced to determine whether or not the current sampled sensor data should be broad-casted and transmitted to the quantizer, which can save the limited communication resource. Second, a novel communication framework is employed by the logarithmic quantizer that quantifies and reduces the data transmission rate in the network, which apparently improves the communication efficiency of networks. Third, a stabilization criterion is derived based on the sufficient condition which guarantees a prescribed H ∞ performance level in the estimation error system in terms of the linear matrix inequalities. Finally, numerical simulations are given to illustrate the correctness of the proposed scheme. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantum communication for satellite-to-ground networks with partially entangled states

NASA Astrophysics Data System (ADS)

Chen, Na; Quan, Dong-Xiao; Pei, Chang-Xing; Yang-Hong

2015-02-01

To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, the security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of an auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that the probability of successfully transferring a quantum bit in the presented scheme is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on the critical components that are presented in this article an efficient, secure, and practical wide-area quantum communication can be achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 61072067 and 61372076), the 111 Project (Grant No. B08038), the Fund from the State Key Laboratory of Integrated Services Networks (Grant No. ISN 1001004), and the Fundamental Research Funds for the Central Universities (Grant Nos. K5051301059 and K5051201021).

Gaussian entanglement distribution via satellite

NASA Astrophysics Data System (ADS)

Hosseinidehaj, Nedasadat; Malaney, Robert

2015-02-01

In this work we analyze three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme, the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the tradeoff between space-based engineering complexity and the rate of ground-station entanglement generation.

A New Privacy-Preserving Handover Authentication Scheme for Wireless Networks

PubMed Central

Wang, Changji; Yuan, Yuan; Wu, Jiayuan

2017-01-01

Handover authentication is a critical issue in wireless networks, which is being used to ensure mobile nodes wander over multiple access points securely and seamlessly. A variety of handover authentication schemes for wireless networks have been proposed in the literature. Unfortunately, existing handover authentication schemes are vulnerable to a few security attacks, or incur high communication and computation costs. Recently, He et al. proposed a handover authentication scheme PairHand and claimed it can resist various attacks without rigorous security proofs. In this paper, we show that PairHand does not meet forward secrecy and strong anonymity. More seriously, it is vulnerable to key compromise attack, where an adversary can recover the private key of any mobile node. Then, we propose a new efficient and provably secure handover authentication scheme for wireless networks based on elliptic curve cryptography. Compared with existing schemes, our proposed scheme can resist key compromise attack, and achieves forward secrecy and strong anonymity. Moreover, it is more efficient in terms of computation and communication. PMID:28632171

A New Privacy-Preserving Handover Authentication Scheme for Wireless Networks.

PubMed

Wang, Changji; Yuan, Yuan; Wu, Jiayuan

2017-06-20

Handover authentication is a critical issue in wireless networks, which is being used to ensure mobile nodes wander over multiple access points securely and seamlessly. A variety of handover authentication schemes for wireless networks have been proposed in the literature. Unfortunately, existing handover authentication schemes are vulnerable to a few security attacks, or incur high communication and computation costs. Recently, He et al. proposed a handover authentication scheme PairHand and claimed it can resist various attacks without rigorous security proofs. In this paper, we show that PairHand does not meet forward secrecy and strong anonymity. More seriously, it is vulnerable to key compromise attack, where an adversary can recover the private key of any mobile node. Then, we propose a new efficient and provably secure handover authentication scheme for wireless networks based on elliptic curve cryptography. Compared with existing schemes, our proposed scheme can resist key compromise attack, and achieves forward secrecy and strong anonymity. Moreover, it is more efficient in terms of computation and communication.

A Polynomial Subset-Based Efficient Multi-Party Key Management System for Lightweight Device Networks.

PubMed

Mahmood, Zahid; Ning, Huansheng; Ghafoor, AtaUllah

2017-03-24

Wireless Sensor Networks (WSNs) consist of lightweight devices to measure sensitive data that are highly vulnerable to security attacks due to their constrained resources. In a similar manner, the internet-based lightweight devices used in the Internet of Things (IoT) are facing severe security and privacy issues because of the direct accessibility of devices due to their connection to the internet. Complex and resource-intensive security schemes are infeasible and reduce the network lifetime. In this regard, we have explored the polynomial distribution-based key establishment schemes and identified an issue that the resultant polynomial value is either storage intensive or infeasible when large values are multiplied. It becomes more costly when these polynomials are regenerated dynamically after each node join or leave operation and whenever key is refreshed. To reduce the computation, we have proposed an Efficient Key Management (EKM) scheme for multiparty communication-based scenarios. The proposed session key management protocol is established by applying a symmetric polynomial for group members, and the group head acts as a responsible node. The polynomial generation method uses security credentials and secure hash function. Symmetric cryptographic parameters are efficient in computation, communication, and the storage required. The security justification of the proposed scheme has been completed by using Rubin logic, which guarantees that the protocol attains mutual validation and session key agreement property strongly among the participating entities. Simulation scenarios are performed using NS 2.35 to validate the results for storage, communication, latency, energy, and polynomial calculation costs during authentication, session key generation, node migration, secure joining, and leaving phases. EKM is efficient regarding storage, computation, and communication overhead and can protect WSN-based IoT infrastructure.

A Polynomial Subset-Based Efficient Multi-Party Key Management System for Lightweight Device Networks

PubMed Central

Mahmood, Zahid; Ning, Huansheng; Ghafoor, AtaUllah

2017-01-01

Wireless Sensor Networks (WSNs) consist of lightweight devices to measure sensitive data that are highly vulnerable to security attacks due to their constrained resources. In a similar manner, the internet-based lightweight devices used in the Internet of Things (IoT) are facing severe security and privacy issues because of the direct accessibility of devices due to their connection to the internet. Complex and resource-intensive security schemes are infeasible and reduce the network lifetime. In this regard, we have explored the polynomial distribution-based key establishment schemes and identified an issue that the resultant polynomial value is either storage intensive or infeasible when large values are multiplied. It becomes more costly when these polynomials are regenerated dynamically after each node join or leave operation and whenever key is refreshed. To reduce the computation, we have proposed an Efficient Key Management (EKM) scheme for multiparty communication-based scenarios. The proposed session key management protocol is established by applying a symmetric polynomial for group members, and the group head acts as a responsible node. The polynomial generation method uses security credentials and secure hash function. Symmetric cryptographic parameters are efficient in computation, communication, and the storage required. The security justification of the proposed scheme has been completed by using Rubin logic, which guarantees that the protocol attains mutual validation and session key agreement property strongly among the participating entities. Simulation scenarios are performed using NS 2.35 to validate the results for storage, communication, latency, energy, and polynomial calculation costs during authentication, session key generation, node migration, secure joining, and leaving phases. EKM is efficient regarding storage, computation, and communication overhead and can protect WSN-based IoT infrastructure. PMID:28338632

A new chaotic communication scheme based on adaptive synchronization.

PubMed

Xiang-Jun, Wu

2006-12-01

A new chaotic communication scheme using adaptive synchronization technique of two unified chaotic systems is proposed. Different from the existing secure communication methods, the transmitted signal is modulated into the parameter of chaotic systems. The adaptive synchronization technique is used to synchronize two identical chaotic systems embedded in the transmitter and the receiver. It is assumed that the parameter of the receiver system is unknown. Based on the Lyapunov stability theory, an adaptive control law is derived to make the states of two identical unified chaotic systems with unknown system parameters asymptotically synchronized; thus the parameter of the receiver system is identified. Then the recovery of the original information signal in the receiver is successfully achieved on the basis of the estimated parameter. It is noticed that the time required for recovering the information signal and the accuracy of the recovered signal very sensitively depends on the frequency of the information signal. Numerical results have verified the effectiveness of the proposed scheme.

Provably secure identity-based identification and signature schemes from code assumptions

PubMed Central

Zhao, Yiming

2017-01-01

Code-based cryptography is one of few alternatives supposed to be secure in a post-quantum world. Meanwhile, identity-based identification and signature (IBI/IBS) schemes are two of the most fundamental cryptographic primitives, so several code-based IBI/IBS schemes have been proposed. However, with increasingly profound researches on coding theory, the security reduction and efficiency of such schemes have been invalidated and challenged. In this paper, we construct provably secure IBI/IBS schemes from code assumptions against impersonation under active and concurrent attacks through a provably secure code-based signature technique proposed by Preetha, Vasant and Rangan (PVR signature), and a security enhancement Or-proof technique. We also present the parallel-PVR technique to decrease parameter values while maintaining the standard security level. Compared to other code-based IBI/IBS schemes, our schemes achieve not only preferable public parameter size, private key size, communication cost and signature length due to better parameter choices, but also provably secure. PMID:28809940

Provably secure identity-based identification and signature schemes from code assumptions.

PubMed

Song, Bo; Zhao, Yiming

2017-01-01

Code-based cryptography is one of few alternatives supposed to be secure in a post-quantum world. Meanwhile, identity-based identification and signature (IBI/IBS) schemes are two of the most fundamental cryptographic primitives, so several code-based IBI/IBS schemes have been proposed. However, with increasingly profound researches on coding theory, the security reduction and efficiency of such schemes have been invalidated and challenged. In this paper, we construct provably secure IBI/IBS schemes from code assumptions against impersonation under active and concurrent attacks through a provably secure code-based signature technique proposed by Preetha, Vasant and Rangan (PVR signature), and a security enhancement Or-proof technique. We also present the parallel-PVR technique to decrease parameter values while maintaining the standard security level. Compared to other code-based IBI/IBS schemes, our schemes achieve not only preferable public parameter size, private key size, communication cost and signature length due to better parameter choices, but also provably secure.

Adaptively loaded SP-offset-QAM OFDM for IM/DD communication systems.

PubMed

Zhao, Jian; Chan, Chun-Kit

2017-09-04

In this paper, we propose adaptively loaded set-partitioned offset quadrature amplitude modulation (SP-offset-QAM) orthogonal frequency division multiplexing (OFDM) for low-cost intensity-modulation direct-detection (IM/DD) communication systems. We compare this scheme with multi-band carrier-less amplitude phase modulation (CAP) and conventional OFDM, and demonstrate >40 Gbit/s transmission over 50-km single-mode fiber. It is shown that the use of SP-QAM formats, together with the adaptive loading algorithm specifically designed to this group of formats, results in significant performance improvement for all these three schemes. SP-offset-QAM OFDM exhibits greatly reduced complexity compared to SP-QAM based multi-band CAP, via parallelized implementation and minimized memory length for spectral shaping. On the other hand, this scheme shows better performance than SP-QAM based conventional OFDM at both back-to-back and after transmission. We also characterize the proposed scheme in terms of enhanced tolerance to fiber intra-channel nonlinearity and the potential to increase the communication security. The studies show that adaptive SP-offset-QAM OFDM is a promising IM/DD solution for medium- and long-reach optical access networks and data center connections.

Lightweight ECC based RFID authentication integrated with an ID verifier transfer protocol.

PubMed

He, Debiao; Kumar, Neeraj; Chilamkurti, Naveen; Lee, Jong-Hyouk

2014-10-01

The radio frequency identification (RFID) technology has been widely adopted and being deployed as a dominant identification technology in a health care domain such as medical information authentication, patient tracking, blood transfusion medicine, etc. With more and more stringent security and privacy requirements to RFID based authentication schemes, elliptic curve cryptography (ECC) based RFID authentication schemes have been proposed to meet the requirements. However, many recently published ECC based RFID authentication schemes have serious security weaknesses. In this paper, we propose a new ECC based RFID authentication integrated with an ID verifier transfer protocol that overcomes the weaknesses of the existing schemes. A comprehensive security analysis has been conducted to show strong security properties that are provided from the proposed authentication scheme. Moreover, the performance of the proposed authentication scheme is analyzed in terms of computational cost, communicational cost, and storage requirement.

Communicating physics and the design of textbooks

NASA Astrophysics Data System (ADS)

Barojas, J.; Trigueros, M.

1991-05-01

The cognitive domains of a communication scheme for learning physics are related to a framework based on epistemology, and the planning of an introductory calculus textbook in classical mechanics is shown as an example of application.

A Comprehensive Observational Coding Scheme for Analyzing Instrumental, Affective, and Relational Communication in Health Care Contexts

PubMed Central

SIMINOFF, LAURA A.; STEP, MARY M.

2011-01-01

Many observational coding schemes have been offered to measure communication in health care settings. These schemes fall short of capturing multiple functions of communication among providers, patients, and other participants. After a brief review of observational communication coding, the authors present a comprehensive scheme for coding communication that is (a) grounded in communication theory, (b) accounts for instrumental and relational communication, and (c) captures important contextual features with tailored coding templates: the Siminoff Communication Content & Affect Program (SCCAP). To test SCCAP reliability and validity, the authors coded data from two communication studies. The SCCAP provided reliable measurement of communication variables including tailored content areas and observer ratings of speaker immediacy, affiliation, confirmation, and disconfirmation behaviors. PMID:21213170

NetCoDer: A Retransmission Mechanism for WSNs Based on Cooperative Relays and Network Coding

PubMed Central

Valle, Odilson T.; Montez, Carlos; Medeiros de Araujo, Gustavo; Vasques, Francisco; Moraes, Ricardo

2016-01-01

Some of the most difficult problems to deal with when using Wireless Sensor Networks (WSNs) are related to the unreliable nature of communication channels. In this context, the use of cooperative diversity techniques and the application of network coding concepts may be promising solutions to improve the communication reliability. In this paper, we propose the NetCoDer scheme to address this problem. Its design is based on merging cooperative diversity techniques and network coding concepts. We evaluate the effectiveness of the NetCoDer scheme through both an experimental setup with real WSN nodes and a simulation assessment, comparing NetCoDer performance against state-of-the-art TDMA-based (Time Division Multiple Access) retransmission techniques: BlockACK, Master/Slave and Redundant TDMA. The obtained results highlight that the proposed NetCoDer scheme clearly improves the network performance when compared with other retransmission techniques. PMID:27258280

From Fault-Diagnosis and Performance Recovery of a Controlled System to Chaotic Secure Communication

NASA Astrophysics Data System (ADS)

Hsu, Wen-Teng; Tsai, Jason Sheng-Hong; Guo, Fang-Cheng; Guo, Shu-Mei; Shieh, Leang-San

Chaotic systems are often applied to encryption on secure communication, but they may not provide high-degree security. In order to improve the security of communication, chaotic systems may need to add other secure signals, but this may cause the system to diverge. In this paper, we redesign a communication scheme that could create secure communication with additional secure signals, and the proposed scheme could keep system convergence. First, we introduce the universal state-space adaptive observer-based fault diagnosis/estimator and the high-performance tracker for the sampled-data linear time-varying system with unanticipated decay factors in actuators/system states. Besides, robustness, convergence in the mean, and tracking ability are given in this paper. A residual generation scheme and a mechanism for auto-tuning switched gain is also presented, so that the introduced methodology is applicable for the fault detection and diagnosis (FDD) for actuator and state faults to yield a high tracking performance recovery. The evolutionary programming-based adaptive observer is then applied to the problem of secure communication. Whenever the tracker induces a large control input which might not conform to the input constraint of some physical systems, the proposed modified linear quadratic optimal tracker (LQT) can effectively restrict the control input within the specified constraint interval, under the acceptable tracking performance. The effectiveness of the proposed design methodology is illustrated through tracking control simulation examples.

Secure Communication Based on a Hybrid of Chaos and Ica Encryptions

NASA Astrophysics Data System (ADS)

Chen, Wei Ching; Yuan, John

Chaos and independent component analysis (ICA) encryptions are two novel schemes for secure communications. In this paper, a new scheme combining chaos and ICA techniques is proposed to enhance the security level during communication. In this scheme, a master chaotic system is embedded at the transmitter. The message signal is mixed with a chaotic signal and a Gaussian white noise into two mixed signals and then transmitted to the receiver through the public channels. A signal for synchronization is transmitted through another public channel to the receiver where a slave chaotic system is embedded to reproduce the chaotic signal. A modified ICA is used to recover the message signal at the receiver. Since only two of the three transmitted signals contain the information of message signal, a hacker would not be able to retrieve the message signal by using ICA even though all the transmitted signals are intercepted. Spectrum analyses are used to prove that the message signal can be securely hidden under this scheme.

Simultaneous classical communication and quantum key distribution using continuous variables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, Bing

Currently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters showmore » that both deterministic classical communication with a bit error rate of 10 –9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.« less

Simultaneous classical communication and quantum key distribution using continuous variables

DOE PAGES

Qi, Bing

2016-10-26

Currently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters showmore » that both deterministic classical communication with a bit error rate of 10 –9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.« less

A Novel Scheme for an Energy Efficient Internet of Things Based on Wireless Sensor Networks.

PubMed

Rani, Shalli; Talwar, Rajneesh; Malhotra, Jyoteesh; Ahmed, Syed Hassan; Sarkar, Mahasweta; Song, Houbing

2015-11-12

One of the emerging networking standards that gap between the physical world and the cyber one is the Internet of Things. In the Internet of Things, smart objects communicate with each other, data are gathered and certain requests of users are satisfied by different queried data. The development of energy efficient schemes for the IoT is a challenging issue as the IoT becomes more complex due to its large scale the current techniques of wireless sensor networks cannot be applied directly to the IoT. To achieve the green networked IoT, this paper addresses energy efficiency issues by proposing a novel deployment scheme. This scheme, introduces: (1) a hierarchical network design; (2) a model for the energy efficient IoT; (3) a minimum energy consumption transmission algorithm to implement the optimal model. The simulation results show that the new scheme is more energy efficient and flexible than traditional WSN schemes and consequently it can be implemented for efficient communication in the IoT.

A Novel Scheme for an Energy Efficient Internet of Things Based on Wireless Sensor Networks

PubMed Central

Rani, Shalli; Talwar, Rajneesh; Malhotra, Jyoteesh; Ahmed, Syed Hassan; Sarkar, Mahasweta; Song, Houbing

2015-01-01

One of the emerging networking standards that gap between the physical world and the cyber one is the Internet of Things. In the Internet of Things, smart objects communicate with each other, data are gathered and certain requests of users are satisfied by different queried data. The development of energy efficient schemes for the IoT is a challenging issue as the IoT becomes more complex due to its large scale the current techniques of wireless sensor networks cannot be applied directly to the IoT. To achieve the green networked IoT, this paper addresses energy efficiency issues by proposing a novel deployment scheme. This scheme, introduces: (1) a hierarchical network design; (2) a model for the energy efficient IoT; (3) a minimum energy consumption transmission algorithm to implement the optimal model. The simulation results show that the new scheme is more energy efficient and flexible than traditional WSN schemes and consequently it can be implemented for efficient communication in the IoT. PMID:26569260

A Secure ECC-based RFID Mutual Authentication Protocol to Enhance Patient Medication Safety.

PubMed

Jin, Chunhua; Xu, Chunxiang; Zhang, Xiaojun; Li, Fagen

2016-01-01

Patient medication safety is an important issue in patient medication systems. In order to prevent medication errors, integrating Radio Frequency Identification (RFID) technology into automated patient medication systems is required in hospitals. Based on RFID technology, such systems can provide medical evidence for patients' prescriptions and medicine doses, etc. Due to the mutual authentication between the medication server and the tag, RFID authentication scheme is the best choice for automated patient medication systems. In this paper, we present a RFID mutual authentication scheme based on elliptic curve cryptography (ECC) to enhance patient medication safety. Our scheme can achieve security requirements and overcome various attacks existing in other schemes. In addition, our scheme has better performance in terms of computational cost and communication overhead. Therefore, the proposed scheme is well suitable for patient medication systems.

Communication Optimizations for a Wireless Distributed Prognostic Framework

NASA Technical Reports Server (NTRS)

Saha, Sankalita; Saha, Bhaskar; Goebel, Kai

2009-01-01

Distributed architecture for prognostics is an essential step in prognostic research in order to enable feasible real-time system health management. Communication overhead is an important design problem for such systems. In this paper we focus on communication issues faced in the distributed implementation of an important class of algorithms for prognostics - particle filters. In spite of being computation and memory intensive, particle filters lend well to distributed implementation except for one significant step - resampling. We propose new resampling scheme called parameterized resampling that attempts to reduce communication between collaborating nodes in a distributed wireless sensor network. Analysis and comparison with relevant resampling schemes is also presented. A battery health management system is used as a target application. A new resampling scheme for distributed implementation of particle filters has been discussed in this paper. Analysis and comparison of this new scheme with existing resampling schemes in the context for minimizing communication overhead have also been discussed. Our proposed new resampling scheme performs significantly better compared to other schemes by attempting to reduce both the communication message length as well as number total communication messages exchanged while not compromising prediction accuracy and precision. Future work will explore the effects of the new resampling scheme in the overall computational performance of the whole system as well as full implementation of the new schemes on the Sun SPOT devices. Exploring different network architectures for efficient communication is an importance future research direction as well.

Robust and efficient biometrics based password authentication scheme for telecare medicine information systems using extended chaotic maps.

PubMed

Lu, Yanrong; Li, Lixiang; Peng, Haipeng; Xie, Dong; Yang, Yixian

2015-06-01

The Telecare Medicine Information Systems (TMISs) provide an efficient communicating platform supporting the patients access health-care delivery services via internet or mobile networks. Authentication becomes an essential need when a remote patient logins into the telecare server. Recently, many extended chaotic maps based authentication schemes using smart cards for TMISs have been proposed. Li et al. proposed a secure smart cards based authentication scheme for TMISs using extended chaotic maps based on Lee's and Jiang et al.'s scheme. In this study, we show that Li et al.'s scheme has still some weaknesses such as violation the session key security, vulnerability to user impersonation attack and lack of local verification. To conquer these flaws, we propose a chaotic maps and smart cards based password authentication scheme by applying biometrics technique and hash function operations. Through the informal and formal security analyses, we demonstrate that our scheme is resilient possible known attacks including the attacks found in Li et al.'s scheme. As compared with the previous authentication schemes, the proposed scheme is more secure and efficient and hence more practical for telemedical environments.

Energy Efficient In-network RFID Data Filtering Scheme in Wireless Sensor Networks

PubMed Central

Bashir, Ali Kashif; Lim, Se-Jung; Hussain, Chauhdary Sajjad; Park, Myong-Soon

2011-01-01

RFID (Radio frequency identification) and wireless sensor networks are backbone technologies for pervasive environments. In integration of RFID and WSN, RFID data uses WSN protocols for multi-hop communications. Energy is a critical issue in WSNs; however, RFID data contains a lot of duplication. These duplications can be eliminated at the base station, but unnecessary transmissions of duplicate data within the network still occurs, which consumes nodes’ energy and affects network lifetime. In this paper, we propose an in-network RFID data filtering scheme that efficiently eliminates the duplicate data. For this we use a clustering mechanism where cluster heads eliminate duplicate data and forward filtered data towards the base station. Simulation results prove that our approach saves considerable amounts of energy in terms of communication and computational cost, compared to existing filtering schemes. PMID:22163999

Enhanced smartcard-based password-authenticated key agreement using extended chaotic maps.

PubMed

Lee, Tian-Fu; Hsiao, Chia-Hung; Hwang, Shi-Han; Lin, Tsung-Hung

2017-01-01

A smartcard based password-authenticated key agreement scheme enables a legal user to log in to a remote authentication server and access remote services through public networks using a weak password and a smart card. Lin recently presented an improved chaotic maps-based password-authenticated key agreement scheme that used smartcards to eliminate the weaknesses of the scheme of Guo and Chang, which does not provide strong user anonymity and violates session key security. However, the improved scheme of Lin does not exhibit the freshness property and the validity of messages so it still fails to withstand denial-of-service and privileged-insider attacks. Additionally, a single malicious participant can predetermine the session key such that the improved scheme does not exhibit the contributory property of key agreements. This investigation discusses these weaknesses and proposes an enhanced smartcard-based password-authenticated key agreement scheme that utilizes extended chaotic maps. The session security of this enhanced scheme is based on the extended chaotic map-based Diffie-Hellman problem, and is proven in the real-or-random and the sequence of games models. Moreover, the enhanced scheme ensures the freshness of communicating messages by appending timestamps, and thereby avoids the weaknesses in previous schemes.

Enhanced smartcard-based password-authenticated key agreement using extended chaotic maps

PubMed Central

Lee, Tian-Fu; Hsiao, Chia-Hung; Hwang, Shi-Han

2017-01-01

A smartcard based password-authenticated key agreement scheme enables a legal user to log in to a remote authentication server and access remote services through public networks using a weak password and a smart card. Lin recently presented an improved chaotic maps-based password-authenticated key agreement scheme that used smartcards to eliminate the weaknesses of the scheme of Guo and Chang, which does not provide strong user anonymity and violates session key security. However, the improved scheme of Lin does not exhibit the freshness property and the validity of messages so it still fails to withstand denial-of-service and privileged-insider attacks. Additionally, a single malicious participant can predetermine the session key such that the improved scheme does not exhibit the contributory property of key agreements. This investigation discusses these weaknesses and proposes an enhanced smartcard-based password-authenticated key agreement scheme that utilizes extended chaotic maps. The session security of this enhanced scheme is based on the extended chaotic map-based Diffie-Hellman problem, and is proven in the real-or-random and the sequence of games models. Moreover, the enhanced scheme ensures the freshness of communicating messages by appending timestamps, and thereby avoids the weaknesses in previous schemes. PMID:28759615

The network and transmission of based on the principle of laser multipoint communication

NASA Astrophysics Data System (ADS)

Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

2014-11-01

Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical multiplexer more than four goals or more, the ratio of received power and volume weight will be Obvious advantages, and can track multiple moving targets in flexible.It would to provide reference for the construction of earth integrated information networks.

Power Terminal Communication Access Network Monitoring System Scheme Based on Design Patterns

NASA Astrophysics Data System (ADS)

Yan, Shengchao; Wu, Desheng; Zhu, Jiang

2018-01-01

In order to realize patterns design for terminal communication monitoring system, this paper introduces manager-workers, tasks-workers design patterns, based on common design patterns such as factory method, chain of responsibility, facade. Using these patterns, the communication monitoring system which combines module-groups like networking communication, business data processing and the peripheral support has been designed successfully. Using these patterns makes this system have great flexibility and scalability and improves the degree of systematic pattern design structure.

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks

PubMed Central

Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research. PMID:28135288

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks.

PubMed

Liu, Xin; Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research.

Network coding multiuser scheme for indoor visible light communications

NASA Astrophysics Data System (ADS)

Zhang, Jiankun; Dang, Anhong

2017-12-01

Visible light communication (VLC) is a unique alternative for indoor data transfer and developing beyond point-to-point. However, for realizing high-capacity networks, VLC is facing challenges including the constrained bandwidth of the optical access point and random occlusion. A network coding scheme for VLC (NC-VLC) is proposed, with increased throughput and system robustness. Based on the Lambertian illumination model, theoretical decoding failure probability of the multiuser NC-VLC system is derived, and the impact of the system parameters on the performance is analyzed. Experiments demonstrate the proposed scheme successfully in the indoor multiuser scenario. These results indicate that the NC-VLC system shows a good performance under the link loss and random occlusion.

Data rate enhancement of optical camera communications by compensating inter-frame gaps

NASA Astrophysics Data System (ADS)

Nguyen, Duy Thong; Park, Youngil

2017-07-01

Optical camera communications (OCC) is a convenient way of transmitting data between LED lamps and image sensors that are included in most smart devices. Although many schemes have been suggested to increase the data rate of the OCC system, it is still much lower than that of the photodiode-based LiFi system. One major reason of this low data rate is attributed to the inter-frame gap (IFG) of image sensor system, that is, the time gap between consecutive image frames. In this paper, we propose a way to compensate for this IFG efficiently by an interleaved Hamming coding scheme. The proposed scheme is implemented and the performance is measured.

Demonstration of micro-projection enabled short-range communication system for 5G.

PubMed

Chou, Hsi-Hsir; Tsai, Cheng-Yu

2016-06-13

A liquid crystal on silicon (LCoS) based polarization modulated image (PMI) system architecture using red-, green- and blue-based light-emitting diodes (LEDs), which offers simultaneous micro-projection and high-speed data transmission at nearly a gigabit, serving as an alternative short-range communication (SRC) approach for personal communication device (PCD) application in 5G, is proposed and experimentally demonstrated. In order to make the proposed system architecture transparent to the future possible wireless data modulation format, baseband modulation schemes such as multilevel pulse amplitude modulation (M-PAM), M-ary phase shift keying modulation (M-PSK) and M-ary quadrature amplitude modulation (M-QAM) which can be further employed by more advanced multicarrier modulation schemes (such as DMT, OFDM and CAP) were used to investigate the highest possible data transmission rate of the proposed system architecture. The results demonstrated that an aggregative data transmission rate of 892 Mb/s and 900 Mb/s at a BER of 10^(-3) can be achieved by using 16-QAM baseband modulation scheme when data transmission were performed with and without micro-projection simultaneously.

Bi-orthogonal Symbol Mapping and Detection in Optical CDMA Communication System

NASA Astrophysics Data System (ADS)

Liu, Maw-Yang

2017-12-01

In this paper, the bi-orthogonal symbol mapping and detection scheme is investigated in time-spreading wavelength-hopping optical CDMA communication system. The carrier-hopping prime code is exploited as signature sequence, whose put-of-phase autocorrelation is zero. Based on the orthogonality of carrier-hopping prime code, the equal weight orthogonal signaling scheme can be constructed, and the proposed scheme using bi-orthogonal symbol mapping and detection can be developed. The transmitted binary data bits are mapped into corresponding bi-orthogonal symbols, where the orthogonal matrix code and its complement are utilized. In the receiver, the received bi-orthogonal data symbol is fed into the maximum likelihood decoder for detection. Under such symbol mapping and detection, the proposed scheme can greatly enlarge the Euclidean distance; hence, the system performance can be drastically improved.

Interference-Assisted Techniques for Transmission and Multiple Access in Optical Communications

NASA Astrophysics Data System (ADS)

Guan, Xun

Optical communications can be in wired or wireless form. Fiber optics communication (FOC) connects transmitters and receivers with optical fiber. Benefiting from its high bandwidth, low cost per volume and stability, it gains a significant market share in long-haul networks, access networks and data centers. Meanwhile, optical wireless communication (OWC) is also emerging as a crucial player in the communication market. In OWC, free-space optical communication (FSO) and visible light communication (VLC) are being studied and commercially deployed extensively. Interference is a common phenomenon in multi-user communication systems. In both FOC and OWC, interference has long been treated as a detrimental effect. However, it could also be beneficial to system applications. The effort of harnessing interference has spurred numerous innovations. Interesting examples are physical-layer network coding (PNC) and non-orthogonal multiple access (NOMA). The first part of this thesis in on the topic of PNC. PNC was firstly proposed in wireless communication to improve the throughput of a two-way relay network (TWRN). As a variation of network coding (NC), PNC turns the common channel interference (CCI) as a natural network coding operation. In this thesis, PNC is introduced into optical communication. Three schemes are proposed in different scenarios. Firstly, PNC is applied to a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system so as to improve the throughput of the multicast network. The optical signal to noise ratio (OSNR) penalty is quite low. Secondly, we investigate the application of PNC in an OFDM passive optical network (OFDM-PON) supporting heterogeneous services. It is found that only minor receiver power penalties are observed to realize PNC-based virtual private networks (VPN), both in the wired service part and the wireless service part in an OFDM-PON with heterogeneous services. Thirdly, we innovate relay-based visible light communication (VLC) by adopting PNC, with a newly proposed phase-aligning method. PNC could improve the throughput at the bottlenecking relay node in a VLC system, and the proposed phase aligning method can improve the BER performance. The second part of this thesis discusses another interference-assisted technology in communication, that is, non-orthogonal multiple access (NOMA). NOMA multiplexes signals from multiple users in another dimension: power domain, with a non-orthogonal multiplexing in other dimensions such as time, frequency and code. Three schemes are proposed in this part. The first and the second schemes both realize NOMA in VLC, with different multiuser detection (MUD) techniques and a proposed phase pre-distortion method. Although both can decrease the system BER compared to conventional NOMA, the scheme using joint detection (JD) outperforms the one using successive interference cancellation (SIC). The third scheme investigated in this part is a combination of NOMA and a multicarrier precoding (MP) technology based on an orthogonal circulant transform matrix (OCT). This combination can avoid the complicated adaptive bit loading or electronic equalization, making NOMA more attractive in a practical system.

Efficiently sphere-decodable physical layer transmission schemes for wireless storage networks

NASA Astrophysics Data System (ADS)

Lu, Hsiao-Feng Francis; Barreal, Amaro; Karpuk, David; Hollanti, Camilla

2016-12-01

Three transmission schemes over a new type of multiple-access channel (MAC) model with inter-source communication links are proposed and investigated in this paper. This new channel model is well motivated by, e.g., wireless distributed storage networks, where communication to repair a lost node takes place from helper nodes to a repairing node over a wireless channel. Since in many wireless networks nodes can come and go in an arbitrary manner, there must be an inherent capability of inter-node communication between every pair of nodes. Assuming that communication is possible between every pair of helper nodes, the newly proposed schemes are based on various smart time-sharing and relaying strategies. In other words, certain helper nodes will be regarded as relays, thereby converting the conventional uncooperative multiple-access channel to a multiple-access relay channel (MARC). The diversity-multiplexing gain tradeoff (DMT) of the system together with efficient sphere-decodability and low structural complexity in terms of the number of antennas required at each end is used as the main design objectives. While the optimal DMT for the new channel model is fully open, it is shown that the proposed schemes outperform the DMT of the simple time-sharing protocol and, in some cases, even the optimal uncooperative MAC DMT. While using a wireless distributed storage network as a motivating example throughout the paper, the MAC transmission techniques proposed here are completely general and as such applicable to any MAC communication with inter-source communication links.

Efficient biometric authenticated key agreements based on extended chaotic maps for telecare medicine information systems.

PubMed

Lou, Der-Chyuan; Lee, Tian-Fu; Lin, Tsung-Hung

2015-05-01

Authenticated key agreements for telecare medicine information systems provide patients, doctors, nurses and health visitors with accessing medical information systems and getting remote services efficiently and conveniently through an open network. In order to have higher security, many authenticated key agreement schemes appended biometric keys to realize identification except for using passwords and smartcards. Due to too many transmissions and computational costs, these authenticated key agreement schemes are inefficient in communication and computation. This investigation develops two secure and efficient authenticated key agreement schemes for telecare medicine information systems by using biometric key and extended chaotic maps. One scheme is synchronization-based, while the other nonce-based. Compared to related approaches, the proposed schemes not only retain the same security properties with previous schemes, but also provide users with privacy protection and have fewer transmissions and lower computational cost.

An Improved and Secure Anonymous Biometric-Based User Authentication with Key Agreement Scheme for the Integrated EPR Information System.

PubMed

Jung, Jaewook; Kang, Dongwoo; Lee, Donghoon; Won, Dongho

2017-01-01

Nowadays, many hospitals and medical institutes employ an authentication protocol within electronic patient records (EPR) services in order to provide protected electronic transactions in e-medicine systems. In order to establish efficient and robust health care services, numerous studies have been carried out on authentication protocols. Recently, Li et al. proposed a user authenticated key agreement scheme according to EPR information systems, arguing that their scheme is able to resist various types of attacks and preserve diverse security properties. However, this scheme possesses critical vulnerabilities. First, the scheme cannot prevent off-line password guessing attacks and server spoofing attack, and cannot preserve user identity. Second, there is no password verification process with the failure to identify the correct password at the beginning of the login phase. Third, the mechanism of password change is incompetent, in that it induces inefficient communication in communicating with the server to change a user password. Therefore, we suggest an upgraded version of the user authenticated key agreement scheme that provides enhanced security. Our security and performance analysis shows that compared to other related schemes, our scheme not only improves the security level, but also ensures efficiency.

An Improved and Secure Anonymous Biometric-Based User Authentication with Key Agreement Scheme for the Integrated EPR Information System

PubMed Central

Kang, Dongwoo; Lee, Donghoon; Won, Dongho

2017-01-01

Nowadays, many hospitals and medical institutes employ an authentication protocol within electronic patient records (EPR) services in order to provide protected electronic transactions in e-medicine systems. In order to establish efficient and robust health care services, numerous studies have been carried out on authentication protocols. Recently, Li et al. proposed a user authenticated key agreement scheme according to EPR information systems, arguing that their scheme is able to resist various types of attacks and preserve diverse security properties. However, this scheme possesses critical vulnerabilities. First, the scheme cannot prevent off-line password guessing attacks and server spoofing attack, and cannot preserve user identity. Second, there is no password verification process with the failure to identify the correct password at the beginning of the login phase. Third, the mechanism of password change is incompetent, in that it induces inefficient communication in communicating with the server to change a user password. Therefore, we suggest an upgraded version of the user authenticated key agreement scheme that provides enhanced security. Our security and performance analysis shows that compared to other related schemes, our scheme not only improves the security level, but also ensures efficiency. PMID:28046075

Announcement/Subscription/Publication: Message Based Communication for Heterogeneous Mobile Environments

NASA Astrophysics Data System (ADS)

Ristau, Henry

Many tasks in smart environments can be implemented using message based communication paradigms that decouple applications in time, space, synchronization and semantics. Current solutions for decoupled message based communication either do not support message processing and thus semantic decoupling or rely on clearly defined network structures. In this paper we present ASP, a novel concept for such communication that can directly operate on neighbor relations between brokers and does not rely on a homogeneous addressing scheme or anymore than simple link layer communication. We show by simulation that ASP performs well in a heterogeneous scenario with mobile nodes and decreases network or processor load significantly compared to message flooding.

New hybrid reverse differential pulse position width modulation scheme for wireless optical communication

NASA Astrophysics Data System (ADS)

Liao, Renbo; Liu, Hongzhan; Qiao, Yaojun

2014-05-01

In order to improve the power efficiency and reduce the packet error rate of reverse differential pulse position modulation (RDPPM) for wireless optical communication (WOC), a hybrid reverse differential pulse position width modulation (RDPPWM) scheme is proposed, based on RDPPM and reverse pulse width modulation. Subsequently, the symbol structure of RDPPWM is briefly analyzed, and its performance is compared with that of other modulation schemes in terms of average transmitted power, bandwidth requirement, and packet error rate over ideal additive white Gaussian noise (AWGN) channels. Based on the given model, the simulation results show that the proposed modulation scheme has the advantages of improving the power efficiency and reducing the bandwidth requirement. Moreover, in terms of error probability performance, RDPPWM can achieve a much lower packet error rate than that of RDPPM. For example, at the same received signal power of -28 dBm, the packet error rate of RDPPWM can decrease to 2.6×10-12, while that of RDPPM is 2.2×10. Furthermore, RDPPWM does not need symbol synchronization at the receiving end. These considerations make RDPPWM a favorable candidate to select as the modulation scheme in the WOC systems.

A multihop key agreement scheme for wireless ad hoc networks based on channel characteristics.

PubMed

Hao, Zhuo; Zhong, Sheng; Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

A Multihop Key Agreement Scheme for Wireless Ad Hoc Networks Based on Channel Characteristics

PubMed Central

Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks. PMID:23766725

Evaluation of selective control information detection scheme in orthogonal frequency division multiplexing-based radio-over-fiber and visible light communication links

NASA Astrophysics Data System (ADS)

Dalarmelina, Carlos A.; Adegbite, Saheed A.; Pereira, Esequiel da V.; Nunes, Reginaldo B.; Rocha, Helder R. O.; Segatto, Marcelo E. V.; Silva, Jair A. L.

2017-05-01

Block-level detection is required to decode what may be classified as selective control information (SCI) such as control format indicator in 4G-long-term evolution systems. Using optical orthogonal frequency division multiplexing over radio-over-fiber (RoF) links, we report the experimental evaluation of an SCI detection scheme based on a time-domain correlation (TDC) technique in comparison with the conventional maximum likelihood (ML) approach. When compared with the ML method, it is shown that the TDC method improves detection performance over both 20 and 40 km of standard single mode fiber (SSMF) links. We also report a performance analysis of the TDC scheme in noisy visible light communication channel models after propagation through 40 km of SSMF. Experimental and simulation results confirm that the TDC method is attractive for practical orthogonal frequency division multiplexing-based RoF and fiber-wireless systems. Unlike the ML method, another key benefit of the TDC is that it requires no channel estimation.

High Speed Inter-Satellite Communication System by Incorporating Hybrid Polarization-Wavelength Division Multiplexing Scheme

NASA Astrophysics Data System (ADS)

Chaudhary, Sushank; Chaudhary, Neha; Sharma, Saurabh; Choudhary, BC

2017-12-01

Inter-Satellite communication is one of remarkable technologies that can be used to communicate between satellites. This work is focused to carry out the investigations of polarization scheme by incorporating dense wavelength division multiplexing (DWDM) scheme in inter-satellite communication system. A 20×6 Gbps data are transported over inter-satellite optical link having span of 5,000 km to realize the total data transmission of 120 Gbps. Moreover, results are also reported with the effect of RZ and NRZ modulation schemes. The performance of proposed inter-satellite communication link is measured in terms of signal-to-noise ratio, received power and eye diagrams.

Communication scheme using a hyperchaotic semiconductor laser model: Chaos shift key revisited

NASA Astrophysics Data System (ADS)

Fataf, N. A. A.; Palit, Sanjay Kumar; Mukherjee, Sayan; Said, M. R. M.; Son, Doan Hoai; Banerjee, Santo

2017-11-01

Based on the Maxwell-Bloch equations, we considered a five-dimensional ODE system, describing the dynamics of a semiconductor laser. The system has rich dynamics with multi-periodic, chaotic and hyperchaotic states. In this analysis, we have investigated the hyperchaotic nature of the aforesaid model and proposed a communication scheme, the generalized form of chaos shift keys, where the coupled systems do not need to be in the synchronized state. The results are implemented with the hyperchaotic laser model followed by a comprehensive security analysis.

A secure and efficient chaotic map-based authenticated key agreement scheme for telecare medicine information systems.

PubMed

Mishra, Dheerendra; Srinivas, Jangirala; Mukhopadhyay, Sourav

2014-10-01

Advancement in network technology provides new ways to utilize telecare medicine information systems (TMIS) for patient care. Although TMIS usually faces various attacks as the services are provided over the public network. Recently, Jiang et al. proposed a chaotic map-based remote user authentication scheme for TMIS. Their scheme has the merits of low cost and session key agreement using Chaos theory. It enhances the security of the system by resisting various attacks. In this paper, we analyze the security of Jiang et al.'s scheme and demonstrate that their scheme is vulnerable to denial of service attack. Moreover, we demonstrate flaws in password change phase of their scheme. Further, our aim is to propose a new chaos map-based anonymous user authentication scheme for TMIS to overcome the weaknesses of Jiang et al.'s scheme, while also retaining the original merits of their scheme. We also show that our scheme is secure against various known attacks including the attacks found in Jiang et al.'s scheme. The proposed scheme is comparable in terms of the communication and computational overheads with Jiang et al.'s scheme and other related existing schemes. Moreover, we demonstrate the validity of the proposed scheme through the BAN (Burrows, Abadi, and Needham) logic.

An improved anonymous authentication scheme for roaming in ubiquitous networks.

PubMed

Lee, Hakjun; Lee, Donghoon; Moon, Jongho; Jung, Jaewook; Kang, Dongwoo; Kim, Hyoungshick; Won, Dongho

2018-01-01

With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people's lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.'s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al's scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments.

An improved anonymous authentication scheme for roaming in ubiquitous networks

PubMed Central

Lee, Hakjun; Lee, Donghoon; Moon, Jongho; Jung, Jaewook; Kang, Dongwoo; Kim, Hyoungshick

2018-01-01

With the evolution of communication technology and the exponential increase of mobile devices, the ubiquitous networking allows people to use our data and computing resources anytime and everywhere. However, numerous security concerns and complicated requirements arise as these ubiquitous networks are deployed throughout people’s lives. To meet the challenge, the user authentication schemes in ubiquitous networks should ensure the essential security properties for the preservation of the privacy with low computational cost. In 2017, Chaudhry et al. proposed a password-based authentication scheme for the roaming in ubiquitous networks to enhance the security. Unfortunately, we found that their scheme remains insecure in its protection of the user privacy. In this paper, we prove that Chaudhry et al.’s scheme is vulnerable to the stolen-mobile device and user impersonation attacks, and its drawbacks comprise the absence of the incorrect login-input detection, the incorrectness of the password change phase, and the absence of the revocation provision. Moreover, we suggest a possible way to fix the security flaw in Chaudhry et al’s scheme by using the biometric-based authentication for which the bio-hash is applied in the implementation of a three-factor authentication. We prove the security of the proposed scheme with the random oracle model and formally verify its security properties using a tool named ProVerif, and analyze it in terms of the computational and communication cost. The analysis result shows that the proposed scheme is suitable for resource-constrained ubiquitous environments. PMID:29505575

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS).

PubMed

Hadley, Wendy; Stewart, Angela; Hunter, Heather L; Affleck, Katelyn; Donenberg, Geri; Diclemente, Ralph; Brown, Larry K

2013-02-01

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.

CP-ABE Based Privacy-Preserving User Profile Matching in Mobile Social Networks

PubMed Central

Cui, Weirong; Du, Chenglie; Chen, Jinchao

2016-01-01

Privacy-preserving profile matching, a challenging task in mobile social networks, is getting more attention in recent years. In this paper, we propose a novel scheme that is based on ciphertext-policy attribute-based encryption to tackle this problem. In our scheme, a user can submit a preference-profile and search for users with matching-profile in decentralized mobile social networks. In this process, no participant’s profile and the submitted preference-profile is exposed. Meanwhile, a secure communication channel can be established between the pair of successfully matched users. In contrast to existing related schemes which are mainly based on the secure multi-party computation, our scheme can provide verifiability (both the initiator and any unmatched user cannot cheat each other to pretend to be matched), and requires few interactions among users. We provide thorough security analysis and performance evaluation on our scheme, and show its advantages in terms of security, efficiency and usability over state-of-the-art schemes. PMID:27337001

CP-ABE Based Privacy-Preserving User Profile Matching in Mobile Social Networks.

PubMed

Cui, Weirong; Du, Chenglie; Chen, Jinchao

2016-01-01

Privacy-preserving profile matching, a challenging task in mobile social networks, is getting more attention in recent years. In this paper, we propose a novel scheme that is based on ciphertext-policy attribute-based encryption to tackle this problem. In our scheme, a user can submit a preference-profile and search for users with matching-profile in decentralized mobile social networks. In this process, no participant's profile and the submitted preference-profile is exposed. Meanwhile, a secure communication channel can be established between the pair of successfully matched users. In contrast to existing related schemes which are mainly based on the secure multi-party computation, our scheme can provide verifiability (both the initiator and any unmatched user cannot cheat each other to pretend to be matched), and requires few interactions among users. We provide thorough security analysis and performance evaluation on our scheme, and show its advantages in terms of security, efficiency and usability over state-of-the-art schemes.

Effective W-state fusion strategies for electronic and photonic qubits via the quantum-dot-microcavity coupled system.

PubMed

Han, Xue; Hu, Shi; Guo, Qi; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

2015-08-05

We propose effective fusion schemes for stationary electronic W state and flying photonic W state, respectively, by using the quantum-dot-microcavity coupled system. The present schemes can fuse a n-qubit W state and a m-qubit W state to a (m + n - 1)-qubit W state, that is, these schemes can be used to not only create large W state with small ones, but also to prepare 3-qubit W states with Bell states. The schemes are based on the optical selection rules and the transmission and reflection rules of the cavity and can be achieved with high probability. We evaluate the effect of experimental imperfections and the feasibility of the schemes, which shows that the present schemes can be realized with high fidelity in both the weak coupling and the strong coupling regimes. These schemes may be meaningful for the large-scale solid-state-based quantum computation and the photon-qubit-based quantum communication.

Photonic channels for quantum communication

PubMed

van Enk SJ; Cirac; Zoller

1998-01-09

A general photonic channel for quantum communication is defined. By means of local quantum computing with a few auxiliary atoms, this channel can be reduced to one with effectively less noise. A scheme based on quantum interference is proposed that iteratively improves the fidelity of distant entangled particles.

Simultaneous trilateral communication based on three mutually coupled chaotic semiconductor lasers with optical feedback.

PubMed

Li, Qiliang; Lu, Shanshan; Bao, Qi; Chen, Dewang; Hu, Miao; Zeng, Ran; Yang, Guowei; Li, Shuqin

2018-01-10

In this paper, we propose a chaos-based scheme allowing for trilateral communication among three mutually coupled chaotic semiconductor lasers. The coupling through a partially transparent optical mirror between two lasers induces the chaotic dynamics. We numerically solve the delay rate equations of three lasers and demonstrate that the dynamics is completely synchronous. Herein, each laser is not only a transmitter but a receiver; three different messages are encoded by simultaneously modulating bias current of the three lasers. By monitoring the synchronization error between transmitter and receiver, and comparing the error with the message of the local laser, we can decipher the message of the sender. The investigation indicates that these messages introduced on the two ends of each link among three lasers can be simultaneously transmitted and restored, so the system can realize simultaneous trilateral communication. In this scheme, an eavesdropper can monitor the synchronization error, but one has no way to obtain the bits that are being sent, so the trilateral communication is secure.

A privacy preserving secure and efficient authentication scheme for telecare medical information systems.

PubMed

Mishra, Raghavendra; Barnwal, Amit Kumar

2015-05-01

The Telecare medical information system (TMIS) presents effective healthcare delivery services by employing information and communication technologies. The emerging privacy and security are always a matter of great concern in TMIS. Recently, Chen at al. presented a password based authentication schemes to address the privacy and security. Later on, it is proved insecure against various active and passive attacks. To erase the drawbacks of Chen et al.'s anonymous authentication scheme, several password based authentication schemes have been proposed using public key cryptosystem. However, most of them do not present pre-smart card authentication which leads to inefficient login and password change phases. To present an authentication scheme with pre-smart card authentication, we present an improved anonymous smart card based authentication scheme for TMIS. The proposed scheme protects user anonymity and satisfies all the desirable security attributes. Moreover, the proposed scheme presents efficient login and password change phases where incorrect input can be quickly detected and a user can freely change his password without server assistance. Moreover, we demonstrate the validity of the proposed scheme by utilizing the widely-accepted BAN (Burrows, Abadi, and Needham) logic. The proposed scheme is also comparable in terms of computational overheads with relevant schemes.

Faraday-Michelson system for quantum cryptography.

PubMed

Mo, Xiao-Fan; Zhu, Bing; Han, Zheng-Fu; Gui, You-Zhen; Guo, Guang-Can

2005-10-01

Quantum key distribution provides unconditional security for communication. Unfortunately, current experimental schemes are not suitable for long-distance fiber transmission because of phase drift or Rayleigh backscattering. In this Letter we present a unidirectional intrinsically stable scheme that is based on Michelson-Faraday interferometers, in which ordinary mirrors are replaced with 90 degree Faraday mirrors. With the scheme, a demonstration setup was built and excellent stability of interference fringe visibility was achieved over a fiber length of 175 km. Through a 125 km long commercial communication fiber cable between Beijing and Tianjin, the key exchange was performed with a quantum bit-error rate of less than 6%, which is to our knowledge the longest reported quantum key distribution experiment under field conditions.

A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks

PubMed Central

Chen, Huifang; Ge, Linlin; Xie, Lei

2015-01-01

The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes. PMID:26184224

A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks.

PubMed

Chen, Huifang; Ge, Linlin; Xie, Lei

2015-07-14

The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes.

Symbol Synchronization for Diffusion-Based Molecular Communications.

PubMed

Jamali, Vahid; Ahmadzadeh, Arman; Schober, Robert

2017-12-01

Symbol synchronization refers to the estimation of the start of a symbol interval and is needed for reliable detection. In this paper, we develop several symbol synchronization schemes for molecular communication (MC) systems where we consider some practical challenges, which have not been addressed in the literature yet. In particular, we take into account that in MC systems, the transmitter may not be equipped with an internal clock and may not be able to emit molecules with a fixed release frequency. Such restrictions hold for practical nanotransmitters, e.g., modified cells, where the lengths of the symbol intervals may vary due to the inherent randomness in the availability of food and energy for molecule generation, the process for molecule production, and the release process. To address this issue, we develop two synchronization-detection frameworks which both employ two types of molecule. In the first framework, one type of molecule is used for symbol synchronization and the other one is used for data detection, whereas in the second framework, both types of molecule are used for joint symbol synchronization and data detection. For both frameworks, we first derive the optimal maximum likelihood (ML) symbol synchronization schemes as performance upper bounds. Since ML synchronization entails high complexity, for each framework, we also propose three low-complexity suboptimal schemes, namely a linear filter-based scheme, a peak observation-based scheme, and a threshold-trigger scheme, which are suitable for MC systems with limited computational capabilities. Furthermore, we study the relative complexity and the constraints associated with the proposed schemes and the impact of the insertion and deletion errors that arise due to imperfect synchronization. Our simulation results reveal the effectiveness of the proposed synchronization schemes and suggest that the end-to-end performance of MC systems significantly depends on the accuracy of the symbol synchronization.

An Enhanced Privacy-Preserving Authentication Scheme for Vehicle Sensor Networks.

PubMed

Zhou, Yousheng; Zhao, Xiaofeng; Jiang, Yi; Shang, Fengjun; Deng, Shaojiang; Wang, Xiaojun

2017-12-08

Vehicle sensor networks (VSNs) are ushering in a promising future by enabling more intelligent transportation systems and providing a more efficient driving experience. However, because of their inherent openness, VSNs are subject to a large number of potential security threats. Although various authentication schemes have been proposed for addressing security problems, they are not suitable for VSN applications because of their high computation and communication costs. Chuang and Lee have developed a trust-extended authentication mechanism (TEAM) for vehicle-to-vehicle communication using a transitive trust relationship, which they claim can resist various attacks. However, it fails to counter internal attacks because of the utilization of a shared secret key. In this paper, to eliminate the vulnerability of TEAM, an enhanced privacy-preserving authentication scheme for VSNs is constructed. The security of our proposed scheme is proven under the random oracle model based on the assumption of the computational Diffie-Hellman problem.

An Enhanced Privacy-Preserving Authentication Scheme for Vehicle Sensor Networks

PubMed Central

Zhou, Yousheng; Zhao, Xiaofeng; Jiang, Yi; Shang, Fengjun; Deng, Shaojiang; Wang, Xiaojun

2017-01-01

Vehicle sensor networks (VSNs) are ushering in a promising future by enabling more intelligent transportation systems and providing a more efficient driving experience. However, because of their inherent openness, VSNs are subject to a large number of potential security threats. Although various authentication schemes have been proposed for addressing security problems, they are not suitable for VSN applications because of their high computation and communication costs. Chuang and Lee have developed a trust-extended authentication mechanism (TEAM) for vehicle-to-vehicle communication using a transitive trust relationship, which they claim can resist various attacks. However, it fails to counter internal attacks because of the utilization of a shared secret key. In this paper, to eliminate the vulnerability of TEAM, an enhanced privacy-preserving authentication scheme for VSNs is constructed. The security of our proposed scheme is proven under the random oracle model based on the assumption of the computational Diffie–Hellman problem. PMID:29292792

Einstein-Podolsky-Rosen-steering swapping between two Gaussian multipartite entangled states

NASA Astrophysics Data System (ADS)

Wang, Meihong; Qin, Zhongzhong; Wang, Yu; Su, Xiaolong

2017-08-01

Multipartite Einstein-Podolsky-Rosen (EPR) steering is a useful quantum resource for quantum communication in quantum networks. It has potential applications in secure quantum communication, such as one-sided device-independent quantum key distribution and quantum secret sharing. By distributing optical modes of a multipartite entangled state to space-separated quantum nodes, a local quantum network can be established. Based on the existing multipartite EPR steering in a local quantum network, secure quantum communication protocol can be accomplished. In this manuscript, we present swapping schemes for EPR steering between two space-separated Gaussian multipartite entangled states, which can be used to connect two space-separated quantum networks. Two swapping schemes, including the swapping between a tripartite Greenberger-Horne-Zeilinger (GHZ) entangled state and an EPR entangled state and that between two tripartite GHZ entangled states, are analyzed. Various types of EPR steering are presented after the swapping of two space-separated independent multipartite entanglement states without direct interaction, which can be used to implement quantum communication between two quantum networks. The presented schemes provide technical reference for more complicated quantum networks with EPR steering.

An electromagnetic method for removing the communication blackout with a space vehicle upon re-entry into the atmosphere

NASA Astrophysics Data System (ADS)

Cheng, Jianjun; Jin, Ke; Kou, Yong; Hu, Ruifeng; Zheng, Xiaojing

2017-03-01

When a hypersonic vehicle travels in the Earth and Mars atmosphere, the surface of the vehicle is surrounded by a plasma layer, which is an envelope of ionized air, created from the compression and heat of the atmosphere by the shock wave. The vehicles will lose contact with ground stations known as the reentry communication blackout. Based on the magnetohydrodynamic framework and electromagnetic wave propagation theory, an analytical model is proposed to describe the effect of the effectiveness of electromagnetic mitigation scheme on removing the reentry communication blackout. C and Global Positioning System (GPS) bands, two commonly used radio bands for communication, are taken as the cases to discuss the effectiveness of the electromagnetic field mitigation scheme. The results show that the electron density near the antenna of vehicles can be reduced by the electromagnetic field, and the required external magnetic field strength is far below the one in the magnetic window method. The directions of the external electric field and magnetic field have a significant impact on the effectiveness of the mitigation scheme. Furthermore, the effect of electron collisions on the required applied electromagnetic field is discussed, and the result indicates that electron collisions are a key factor to analyze the electromagnetic mitigation scheme. Finally, the feasible regions of the applied electromagnetic field for eliminating blackout are given. These investigations could have a significant benefit on the design and optimization of electromagnetic mitigation scheme for the blackout problem.

Event-triggered attitude control of spacecraft

NASA Astrophysics Data System (ADS)

Wu, Baolin; Shen, Qiang; Cao, Xibin

2018-02-01

The problem of spacecraft attitude stabilization control system with limited communication and external disturbances is investigated based on an event-triggered control scheme. In the proposed scheme, information of attitude and control torque only need to be transmitted at some discrete triggered times when a defined measurement error exceeds a state-dependent threshold. The proposed control scheme not only guarantees that spacecraft attitude control errors converge toward a small invariant set containing the origin, but also ensures that there is no accumulation of triggering instants. The performance of the proposed control scheme is demonstrated through numerical simulation.

Automobile inspection system based on wireless communication

NASA Astrophysics Data System (ADS)

Miao, Changyun; Ye, Chunqing

2010-07-01

This paper aims to research the Automobile Inspection System based on Wireless Communication, and suggests an overall design scheme which uses GPS for speed detection and Bluetooth and GPRS for communication. The communication between PDA and PC was realized by means of GPRS and TCP/IP; and the hardware circuit and software for detection terminal were devised by means of JINOU-3264 Bluetooth Module after analyzing the Bluetooth and its communication protocol. According to the results of debugging test, this system accomplished GPRS based data communication and management as well as the real-time detection on auto safety performance parameters in crash test via PC, whereby the need for mobility and reliability was met and the efficiency and level of detection was improved.

Via generalized function projective synchronization in nonlinear Schrödinger equation for secure communication

NASA Astrophysics Data System (ADS)

Zhao, L. W.; Du, J. G.; Yin, J. L.

2018-05-01

This paper proposes a novel secured communication scheme in a chaotic system by applying generalized function projective synchronization of the nonlinear Schrödinger equation. This phenomenal approach guarantees a secured and convenient communication. Our study applied the Melnikov theorem with an active control strategy to suppress chaos in the system. The transmitted information signal is modulated into the parameter of the nonlinear Schrödinger equation in the transmitter and it is assumed that the parameter of the receiver system is unknown. Based on the Lyapunov stability theory and the adaptive control technique, the controllers are designed to make two identical nonlinear Schrödinger equation with the unknown parameter asymptotically synchronized. The numerical simulation results of our study confirmed the validity, effectiveness and the feasibility of the proposed novel synchronization method and error estimate for a secure communication. The Chaos masking signals of the information communication scheme, further guaranteed a safer and secured information communicated via this approach.

An Overview of Recent Advances in Event-Triggered Consensus of Multiagent Systems.

PubMed

Ding, Lei; Han, Qing-Long; Ge, Xiaohua; Zhang, Xian-Ming

2018-04-01

Event-triggered consensus of multiagent systems (MASs) has attracted tremendous attention from both theoretical and practical perspectives due to the fact that it enables all agents eventually to reach an agreement upon a common quantity of interest while significantly alleviating utilization of communication and computation resources. This paper aims to provide an overview of recent advances in event-triggered consensus of MASs. First, a basic framework of multiagent event-triggered operational mechanisms is established. Second, representative results and methodologies reported in the literature are reviewed and some in-depth analysis is made on several event-triggered schemes, including event-based sampling schemes, model-based event-triggered schemes, sampled-data-based event-triggered schemes, and self-triggered sampling schemes. Third, two examples are outlined to show applicability of event-triggered consensus in power sharing of microgrids and formation control of multirobot systems, respectively. Finally, some challenging issues on event-triggered consensus are proposed for future research.

All-optical conversion scheme from binary to its MTN form with the help of nonlinear material based tree-net architecture

NASA Astrophysics Data System (ADS)

Maiti, Anup Kumar; Nath Roy, Jitendra; Mukhopadhyay, Sourangshu

2007-08-01

In the field of optical computing and parallel information processing, several number systems have been used for different arithmetic and algebraic operations. Therefore an efficient conversion scheme from one number system to another is very important. Modified trinary number (MTN) has already taken a significant role towards carry and borrow free arithmetic operations. In this communication, we propose a tree-net architecture based all optical conversion scheme from binary number to its MTN form. Optical switch using nonlinear material (NLM) plays an important role.

FD/DAMA Scheme For Mobile/Satellite Communications

NASA Technical Reports Server (NTRS)

Yan, Tsun-Yee; Wang, Charles C.; Cheng, Unjeng; Rafferty, William; Dessouky, Khaled I.

1992-01-01

Integrated-Adaptive Mobile Access Protocol (I-AMAP) proposed to allocate communication channels to subscribers in first-generation MSAT-X mobile/satellite communication network. Based on concept of frequency-division/demand-assigned multiple access (FD/DAMA) where partition of available spectrum adapted to subscribers' demands for service. Requests processed, and competing requests resolved according to channel-access protocol, or free-access tree algorithm described in "Connection Protocol for Mobile/Satellite Communications" (NPO-17735). Assigned spectrum utilized efficiently.

The GIS map coloring support decision-making system based on case-based reasoning and simulated annealing algorithm

NASA Astrophysics Data System (ADS)

Deng, Shuang; Xiang, Wenting; Tian, Yangge

2009-10-01

Map coloring is a hard task even to the experienced map experts. In the GIS project, usually need to color map according to the customer, which make the work more complex. With the development of GIS, more and more programmers join the project team, which lack the training of cartology, their coloring map are harder to meet the requirements of customer. From the experience, customers with similar background usually have similar tastes for coloring map. So, we developed a GIS color scheme decision-making system which can select color schemes of similar customers from case base for customers to select and adjust. The system is a BS/CS mixed system, the client side use JSP and make it possible for the system developers to go on remote calling of the colors scheme cases in the database server and communicate with customers. Different with general case-based reasoning, even the customers are very similar, their selection may have difference, it is hard to provide a "best" option. So, we select the Simulated Annealing Algorithm (SAA) to arrange the emergence order of different color schemes. Customers can also dynamically adjust certain features colors based on existing case. The result shows that the system can facilitate the communication between the designers and the customers and improve the quality and efficiency of coloring map.

Data traffic reduction schemes for Cholesky factorization on asynchronous multiprocessor systems

NASA Technical Reports Server (NTRS)

Naik, Vijay K.; Patrick, Merrell L.

1989-01-01

Communication requirements of Cholesky factorization of dense and sparse symmetric, positive definite matrices are analyzed. The communication requirement is characterized by the data traffic generated on multiprocessor systems with local and shared memory. Lower bound proofs are given to show that when the load is uniformly distributed the data traffic associated with factoring an n x n dense matrix using n to the alpha power (alpha less than or equal 2) processors is omega(n to the 2 + alpha/2 power). For n x n sparse matrices representing a square root of n x square root of n regular grid graph the data traffic is shown to be omega(n to the 1 + alpha/2 power), alpha less than or equal 1. Partitioning schemes that are variations of block assignment scheme are described and it is shown that the data traffic generated by these schemes are asymptotically optimal. The schemes allow efficient use of up to O(n to the 2nd power) processors in the dense case and up to O(n) processors in the sparse case before the total data traffic reaches the maximum value of O(n to the 3rd power) and O(n to the 3/2 power), respectively. It is shown that the block based partitioning schemes allow a better utilization of the data accessed from shared memory and thus reduce the data traffic than those based on column-wise wrap around assignment schemes.

Opto-microwave Butler matrixes based front-end for a multi-beam large direct radiating array antenna

NASA Astrophysics Data System (ADS)

Piqueras, M. A.; Mengual, T.; Navasquillo, O.; Sotom, M.; Caille, G.

2017-09-01

The evolution of broadband communication satellites shows a clear trend towards beam forming and beam-switching systems with efficient multiple access schemes with wide bandwidths, for which to be economically viable, the communication price shall be as low as possible.

Design and Hardware Implementation of a New Chaotic Secure Communication Technique

PubMed Central

Xiong, Li; Lu, Yan-Jun; Zhang, Yong-Fang; Zhang, Xin-Guo; Gupta, Parag

2016-01-01

In this paper, a scheme for chaotic modulation secure communication is proposed based on chaotic synchronization of an improved Lorenz system. For the first time, the intensity limit and stability of the transmitted signal, the characteristics of broadband and the requirements for accuracy of electronic components are presented by Multisim simulation. In addition, some improvements are made on the measurement method and the proposed experimental circuit in order to facilitate the experiments of chaotic synchronization, chaotic non-synchronization, experiment without signal and experiment with signal. To illustrate the effectiveness of the proposed scheme, some numerical simulations are presented. Then, the proposed chaotic secure communication circuit is implemented through analog electronic circuit, which is characterized by its high accuracy and good robustness. PMID:27548385

Design and Hardware Implementation of a New Chaotic Secure Communication Technique.

PubMed

Xiong, Li; Lu, Yan-Jun; Zhang, Yong-Fang; Zhang, Xin-Guo; Gupta, Parag

2016-01-01

In this paper, a scheme for chaotic modulation secure communication is proposed based on chaotic synchronization of an improved Lorenz system. For the first time, the intensity limit and stability of the transmitted signal, the characteristics of broadband and the requirements for accuracy of electronic components are presented by Multisim simulation. In addition, some improvements are made on the measurement method and the proposed experimental circuit in order to facilitate the experiments of chaotic synchronization, chaotic non-synchronization, experiment without signal and experiment with signal. To illustrate the effectiveness of the proposed scheme, some numerical simulations are presented. Then, the proposed chaotic secure communication circuit is implemented through analog electronic circuit, which is characterized by its high accuracy and good robustness.

A group communication approach for mobile computing mobile channel: An ISIS tool for mobile services

NASA Astrophysics Data System (ADS)

Cho, Kenjiro; Birman, Kenneth P.

1994-05-01

This paper examines group communication as an infrastructure to support mobility of users, and presents a simple scheme to support user mobility by means of switching a control point between replicated servers. We describe the design and implementation of a set of tools, called Mobile Channel, for use with the ISIS system. Mobile Channel is based on a combination of the two replication schemes: the primary-backup approach and the state machine approach. Mobile Channel implements a reliable one-to-many FIFO channel, in which a mobile client sees a single reliable server; servers, acting as a state machine, see multicast messages from clients. Migrations of mobile clients are handled as an intentional primary switch, and hand-offs or server failures are completely masked to mobile clients. To achieve high performance, servers are replicated at a sliding-window level. Our scheme provides a simple abstraction of migration, eliminates complicated hand-off protocols, provides fault-tolerance and is implemented within the existing group communication mechanism.

A Fine-Grained and Privacy-Preserving Query Scheme for Fog Computing-Enhanced Location-Based Service

PubMed Central

Yin, Fan; Tang, Xiaohu

2017-01-01

Location-based services (LBS), as one of the most popular location-awareness applications, has been further developed to achieve low-latency with the assistance of fog computing. However, privacy issues remain a research challenge in the context of fog computing. Therefore, in this paper, we present a fine-grained and privacy-preserving query scheme for fog computing-enhanced location-based services, hereafter referred to as FGPQ. In particular, mobile users can obtain the fine-grained searching result satisfying not only the given spatial range but also the searching content. Detailed privacy analysis shows that our proposed scheme indeed achieves the privacy preservation for the LBS provider and mobile users. In addition, extensive performance analyses and experiments demonstrate that the FGPQ scheme can significantly reduce computational and communication overheads and ensure the low-latency, which outperforms existing state-of-the art schemes. Hence, our proposed scheme is more suitable for real-time LBS searching. PMID:28696395

A Fine-Grained and Privacy-Preserving Query Scheme for Fog Computing-Enhanced Location-Based Service.

PubMed

Yang, Xue; Yin, Fan; Tang, Xiaohu

2017-07-11

Location-based services (LBS), as one of the most popular location-awareness applications, has been further developed to achieve low-latency with the assistance of fog computing. However, privacy issues remain a research challenge in the context of fog computing. Therefore, in this paper, we present a fine-grained and privacy-preserving query scheme for fog computing-enhanced location-based services, hereafter referred to as FGPQ. In particular, mobile users can obtain the fine-grained searching result satisfying not only the given spatial range but also the searching content. Detailed privacy analysis shows that our proposed scheme indeed achieves the privacy preservation for the LBS provider and mobile users. In addition, extensive performance analyses and experiments demonstrate that the FGPQ scheme can significantly reduce computational and communication overheads and ensure the low-latency, which outperforms existing state-of-the art schemes. Hence, our proposed scheme is more suitable for real-time LBS searching.

Protection of Renewable-dominated Microgrids: Challenges and Potential Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkhatib, Mohamed; Ellis, Abraham; Biswal, Milan

In this report we address the challenge of designing efficient protection system for inverter- dominated microgrids. These microgrids are characterised with limited fault current capacity as a result of current-limiting protection functions of inverters. Typically, inverters limit their fault contribution in sub-cycle time frame to as low as 1.1 per unit. As a result, overcurrent protection could fail completely to detect faults in inverter-dominated microgrids. As part of this project a detailed literature survey of existing and proposed microgrid protection schemes were conducted. The survey concluded that there is a gap in the available microgrid protection methods. The only crediblemore » protection solution available in literature for low- fault inverter-dominated microgrids is the differential protection scheme which represents a robust transmission-grade protection solution but at a very high cost. Two non-overcurrent protection schemes were investigated as part of this project; impedance-based protection and transient-based protection. Impedance-based protection depends on monitoring impedance trajectories at feeder relays to detect faults. Two communication-based impedance-based protection schemes were developed. the first scheme utilizes directional elements and pilot signals to locate the fault. The second scheme depends on a Central Protection Unit that communicates with all feeder relays to locate the fault based on directional flags received from feeder relays. The later approach could potentially be adapted to protect networked microgrids and dynamic topology microgrids. Transient-based protection relies on analyzing high frequency transients to detect and locate faults. This approach is very promising but its implementation in the filed faces several challenges. For example, high frequency transients due to faults can be confused with transients due to other events such as capacitor switching. Additionally, while detecting faults by analyzing transients could be doable, locating faults based on analyzing transients is still an open question.« less

Advanced Multiple In-Multiple Out (MIMO) Antenna Communications for Airborne Networks

DTIC Science & Technology

2015-03-01

are airborne and both employ multiple antennas. On the other hand, the conventionally studied MIMO wireless communication is based on the premise that...architecture as the central idea, upon which our proposed solutions are based . Hence, to facilitate experiments, we also de- velop a GNU Radio/USRP based D...decoder. 2.2 Variable Rate MIMO In this part of the report we develop a variable rate MIMO scheme, based on D-BLAST transceiver architecture, to

Enhancing the Reliability of Head Nodes in Underwater Sensor Networks

PubMed Central

Min, Hong; Cho, Yookun; Heo, Junyoung

2012-01-01

Underwater environments are quite different from terrestrial environments in terms of the communication media and operating conditions associated with those environments. In underwater sensor networks, the probability of node failure is high because sensor nodes are deployed in harsher environments than ground-based networks. The sensor nodes are surrounded by salt water and moved around by waves and currents. Many studies have focused on underwater communication environments in an effort to improve the data transmission throughput. In this paper, we present a checkpointing scheme for the head nodes to quickly recover from a head node failure. Experimental results show that the proposed scheme enhances the reliability of the networks and makes them more efficient in terms of energy consumption and the recovery latency compared to the previous scheme without checkpointing. PMID:22438707

Multiple Access Schemes for Lunar Missions

NASA Technical Reports Server (NTRS)

Deutsch, Leslie; Hamkins, Jon; Stocklin, Frank J.

2010-01-01

Two years ago, the NASA Coding, Modulation, and Link Protocol (CMLP) study was completed. The study, led by the authors of this paper, recommended codes, modulation schemes, and desired attributes of link protocols for all space communication links in NASA's future space architecture. Portions of the NASA CMLP team were reassembled to resolve one open issue: the use of multiple access (MA) communication from the lunar surface. The CMLP-MA team analyzed and simulated two candidate multiple access schemes that were identified in the original CMLP study: Code Division MA (CDMA) and Frequency Division MA (FDMA) based on a bandwidth-efficient Continuous Phase Modulation (CPM) with a superimposed Pseudo-Noise (PN) ranging signal (CPM/PN). This paper summarizes the results of the analysis and simulation of the CMLP-MA study and describes the final recommendations.

Distributed computing for membrane-based modeling of action potential propagation.

PubMed

Porras, D; Rogers, J M; Smith, W M; Pollard, A E

2000-08-01

Action potential propagation simulations with physiologic membrane currents and macroscopic tissue dimensions are computationally expensive. We, therefore, analyzed distributed computing schemes to reduce execution time in workstation clusters by parallelizing solutions with message passing. Four schemes were considered in two-dimensional monodomain simulations with the Beeler-Reuter membrane equations. Parallel speedups measured with each scheme were compared to theoretical speedups, recognizing the relationship between speedup and code portions that executed serially. A data decomposition scheme based on total ionic current provided the best performance. Analysis of communication latencies in that scheme led to a load-balancing algorithm in which measured speedups at 89 +/- 2% and 75 +/- 8% of theoretical speedups were achieved in homogeneous and heterogeneous clusters of workstations. Speedups in this scheme with the Luo-Rudy dynamic membrane equations exceeded 3.0 with eight distributed workstations. Cluster speedups were comparable to those measured during parallel execution on a shared memory machine.

Effect of asynchrony on numerical simulations of fluid flow phenomena

NASA Astrophysics Data System (ADS)

Konduri, Aditya; Mahoney, Bryan; Donzis, Diego

2015-11-01

Designing scalable CFD codes on massively parallel computers is a challenge. This is mainly due to the large number of communications between processing elements (PEs) and their synchronization, leading to idling of PEs. Indeed, communication will likely be the bottleneck in the scalability of codes on Exascale machines. Our recent work on asynchronous computing for PDEs based on finite-differences has shown that it is possible to relax synchronization between PEs at a mathematical level. Computations then proceed regardless of the status of communication, reducing the idle time of PEs and improving the scalability. However, accuracy of the schemes is greatly affected. We have proposed asynchrony-tolerant (AT) schemes to address this issue. In this work, we study the effect of asynchrony on the solution of fluid flow problems using standard and AT schemes. We show that asynchrony creates additional scales with low energy content. The specific wavenumbers affected can be shown to be due to two distinct effects: the randomness in the arrival of messages and the corresponding switching between schemes. Understanding these errors allow us to effectively control them, rendering the method's feasibility in solving turbulent flows at realistic conditions on future computing systems.

An enhanced biometric-based authentication scheme for telecare medicine information systems using elliptic curve cryptosystem.

PubMed

Lu, Yanrong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2015-03-01

The telecare medical information systems (TMISs) enable patients to conveniently enjoy telecare services at home. The protection of patient's privacy is a key issue due to the openness of communication environment. Authentication as a typical approach is adopted to guarantee confidential and authorized interaction between the patient and remote server. In order to achieve the goals, numerous remote authentication schemes based on cryptography have been presented. Recently, Arshad et al. (J Med Syst 38(12): 2014) presented a secure and efficient three-factor authenticated key exchange scheme to remedy the weaknesses of Tan et al.'s scheme (J Med Syst 38(3): 2014). In this paper, we found that once a successful off-line password attack that results in an adversary could impersonate any user of the system in Arshad et al.'s scheme. In order to thwart these security attacks, an enhanced biometric and smart card based remote authentication scheme for TMISs is proposed. In addition, the BAN logic is applied to demonstrate the completeness of the enhanced scheme. Security and performance analyses show that our enhanced scheme satisfies more security properties and less computational cost compared with previously proposed schemes.

Adaptive power allocation schemes based on IAFS algorithm for OFDM-based cognitive radio systems

NASA Astrophysics Data System (ADS)

Zhang, Shuying; Zhao, Xiaohui; Liang, Cong; Ding, Xu

2017-01-01

In cognitive radio (CR) systems, reasonable power allocation can increase transmission rate of CR users or secondary users (SUs) as much as possible and at the same time insure normal communication among primary users (PUs). This study proposes an optimal power allocation scheme for the OFDM-based CR system with one SU influenced by multiple PU interference constraints. This scheme is based on an improved artificial fish swarm (IAFS) algorithm in combination with the advantage of conventional artificial fish swarm (ASF) algorithm and particle swarm optimisation (PSO) algorithm. In performance comparison of IAFS algorithm with other intelligent algorithms by simulations, the superiority of the IAFS algorithm is illustrated; this superiority results in better performance of our proposed scheme than that of the power allocation algorithms proposed by the previous studies in the same scenario. Furthermore, our proposed scheme can obtain higher transmission data rate under the multiple PU interference constraints and the total power constraint of SU than that of the other mentioned works.

Alternative Path Communication in Wide-Scale Cluster-Tree Wireless Sensor Networks Using Inactive Periods

PubMed Central

Leão, Erico; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

2017-01-01

The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable technology to deploy wide-scale Wireless Sensor Networks (WSNs). These networks are usually designed to support convergecast traffic, where all communication paths go through the PAN (Personal Area Network) coordinator. Nevertheless, peer-to-peer communication relationships may be also required for different types of WSN applications. That is the typical case of sensor and actuator networks, where local control loops must be closed using a reduced number of communication hops. The use of communication schemes optimised just for the support of convergecast traffic may result in higher network congestion and in a potentially higher number of communication hops. Within this context, this paper proposes an Alternative-Route Definition (ARounD) communication scheme for WSNs. The underlying idea of ARounD is to setup alternative communication paths between specific source and destination nodes, avoiding congested cluster-tree paths. These alternative paths consider shorter inter-cluster paths, using a set of intermediate nodes to relay messages during their inactive periods in the cluster-tree network. Simulation results show that the ARounD communication scheme can significantly decrease the end-to-end communication delay, when compared to the use of standard cluster-tree communication schemes. Moreover, the ARounD communication scheme is able to reduce the network congestion around the PAN coordinator, enabling the reduction of the number of message drops due to queue overflows in the cluster-tree network. PMID:28481245

Alternative Path Communication in Wide-Scale Cluster-Tree Wireless Sensor Networks Using Inactive Periods.

PubMed

Leão, Erico; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

2017-05-06

The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable technology to deploy wide-scale Wireless Sensor Networks (WSNs). These networks are usually designed to support convergecast traffic, where all communication paths go through the PAN (Personal Area Network) coordinator. Nevertheless, peer-to-peer communication relationships may be also required for different types of WSN applications. That is the typical case of sensor and actuator networks, where local control loops must be closed using a reduced number of communication hops. The use of communication schemes optimised just for the support of convergecast traffic may result in higher network congestion and in a potentially higher number of communication hops. Within this context, this paper proposes an Alternative-Route Definition (ARounD) communication scheme for WSNs. The underlying idea of ARounD is to setup alternative communication paths between specific source and destination nodes, avoiding congested cluster-tree paths. These alternative paths consider shorter inter-cluster paths, using a set of intermediate nodes to relay messages during their inactive periods in the cluster-tree network. Simulation results show that the ARounD communication scheme can significantly decrease the end-to-end communication delay, when compared to the use of standard cluster-tree communication schemes. Moreover, the ARounD communication scheme is able to reduce the network congestion around the PAN coordinator, enabling the reduction of the number of message drops due to queue overflows in the cluster-tree network.

Combined peak-to-average power ratio reduction and physical layer security enhancement in optical orthogonal frequency division multiplexing visible-light communication systems

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Shoufa

2016-07-01

A physical encryption scheme for discrete Hartley transform (DHT) precoded orthogonal frequency division multiplexing (OFDM) visible-light communication (VLC) systems using frequency domain chaos scrambling is proposed. In the scheme, the chaos scrambling, which is generated by a modified logistic mapping, is utilized to enhance the physical layer of security, and the DHT precoding is employed to reduce of OFDM signal for OFDM-based VLC. The influence of chaos scrambling on peak-to-average power ratio (PAPR) and bit error rate (BER) of systems is studied. The experimental simulation results prove the efficiency of the proposed encryption method for DHT-precoded, OFDM-based VLC systems. Furthermore, the influence of the proposed encryption to the PAPR and BER of systems is evaluated. The experimental results show that the proposed security scheme can protect the DHT-precoded, OFDM-based VLC from eavesdroppers, while keeping the good BER performance of DHT-precoded systems. The BER performance of the encrypted and DHT-precoded system is almost the same as that of the conventional DHT-precoded system without encryption.

All-IP wireless sensor networks for real-time patient monitoring.

PubMed

Wang, Xiaonan; Le, Deguang; Cheng, Hongbin; Xie, Conghua

2014-12-01

This paper proposes the all-IP WSNs (wireless sensor networks) for real-time patient monitoring. In this paper, the all-IP WSN architecture based on gateway trees is proposed and the hierarchical address structure is presented. Based on this architecture, the all-IP WSN can perform routing without route discovery. Moreover, a mobile node is always identified by a home address and it does not need to be configured with a care-of address during the mobility process, so the communication disruption caused by the address change is avoided. Through the proposed scheme, a physician can monitor the vital signs of a patient at any time and at any places, and according to the IPv6 address he can also obtain the location information of the patient in order to perform effective and timely treatment. Finally, the proposed scheme is evaluated based on the simulation, and the simulation data indicate that the proposed scheme might effectively reduce the communication delay and control cost, and lower the packet loss rate. Copyright © 2014 Elsevier Inc. All rights reserved.

Secure Image Transmission over DFT-precoded OFDM-VLC systems based on Chebyshev Chaos scrambling

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Qiu, Weiwei

2017-08-01

This paper proposes a physical layer image secure transmission scheme for discrete Fourier transform (DFT) precoded OFDM-based visible light communication systems by using Chebyshev chaos maps. In the proposed scheme, 256 subcarriers and QPSK modulation are employed. The transmitted digital signal of the image is encrypted with a Chebyshev chaos sequence. The encrypted signal is then transformed by a DFT precoding matrix to reduce the PAPR of the OFDM signal. After that, the encrypted and DFT-precoded OFDM are transmitted over a VLC channel. The simulation results show that the proposed image security transmission scheme can not only protect the DFT-precoded OFDM-based VLC from eavesdroppers but also improve BER performance.

Beamforming Based Full-Duplex for Millimeter-Wave Communication

PubMed Central

Liu, Xiao; Xiao, Zhenyu; Bai, Lin; Choi, Jinho; Xia, Pengfei; Xia, Xiang-Gen

2016-01-01

In this paper, we study beamforming based full-duplex (FD) systems in millimeter-wave (mmWave) communications. A joint transmission and reception (Tx/Rx) beamforming problem is formulated to maximize the achievable rate by mitigating self-interference (SI). Since the optimal solution is difficult to find due to the non-convexity of the objective function, suboptimal schemes are proposed in this paper. A low-complexity algorithm, which iteratively maximizes signal power while suppressing SI, is proposed and its convergence is proven. Moreover, two closed-form solutions, which do not require iterations, are also derived under minimum-mean-square-error (MMSE), zero-forcing (ZF), and maximum-ratio transmission (MRT) criteria. Performance evaluations show that the proposed iterative scheme converges fast (within only two iterations on average) and approaches an upper-bound performance, while the two closed-form solutions also achieve appealing performances, although there are noticeable differences from the upper bound depending on channel conditions. Interestingly, these three schemes show different robustness against the geometry of Tx/Rx antenna arrays and channel estimation errors. PMID:27455256

Modified PTS-based PAPR Reduction for FBMC-OQAM Systems

NASA Astrophysics Data System (ADS)

Deng, Honggui; Ren, Shuang; Liu, Yan; Tang, Chengying

2017-10-01

The filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) has been raised great concern in the 5G communication research. However FBMC-OQAM has also the inherent drawback of high peak-to-average power ratio (PAPR) that should be addressed. Due to the overlapping structure of FBMC-OQAM signals, it is proven that directly employing conventional partial transmit sequence (PTS) scheme proposed for OFDM to FBMC-OQAM is ineffective. In this paper, we propose a modified PTS-based scheme by employing phase rotation factors to optimize only the phase of the sparse peak signals, called as sparse PTS (S-PTS) scheme. Theoretical analysis and simulation results show that the proposed S-PTS scheme provides a significant PAPR reduction performance with lower computational complexity.

Distributed plug-and-play optimal generator and load control for power system frequency regulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Changhong; Mallada, Enrique; Low, Steven H.

A distributed control scheme, which can be implemented on generators and controllable loads in a plug-and-play manner, is proposed for power system frequency regulation. The proposed scheme is based on local measurements, local computation, and neighborhood information exchanges over a communication network with an arbitrary (but connected) topology. In the event of a sudden change in generation or load, the proposed scheme can restore the nominal frequency and the reference inter-area power flows, while minimizing the total cost of control for participating generators and loads. Power network stability under the proposed control is proved with a relatively realistic model whichmore » includes nonlinear power flow and a generic (potentially nonlinear or high-order) turbine-governor model, and further with first- and second-order turbine-governor models as special cases. Finally, in simulations, the proposed control scheme shows a comparable performance to the existing automatic generation control (AGC) when implemented only on the generator side, and demonstrates better dynamic characteristics than AGC when each scheme is implemented on both generators and controllable loads. Simulation results also show robustness of the proposed scheme to communication link failure.« less

Distributed plug-and-play optimal generator and load control for power system frequency regulation

DOE PAGES

Zhao, Changhong; Mallada, Enrique; Low, Steven H.; ...

2018-03-14

A distributed control scheme, which can be implemented on generators and controllable loads in a plug-and-play manner, is proposed for power system frequency regulation. The proposed scheme is based on local measurements, local computation, and neighborhood information exchanges over a communication network with an arbitrary (but connected) topology. In the event of a sudden change in generation or load, the proposed scheme can restore the nominal frequency and the reference inter-area power flows, while minimizing the total cost of control for participating generators and loads. Power network stability under the proposed control is proved with a relatively realistic model whichmore » includes nonlinear power flow and a generic (potentially nonlinear or high-order) turbine-governor model, and further with first- and second-order turbine-governor models as special cases. Finally, in simulations, the proposed control scheme shows a comparable performance to the existing automatic generation control (AGC) when implemented only on the generator side, and demonstrates better dynamic characteristics than AGC when each scheme is implemented on both generators and controllable loads. Simulation results also show robustness of the proposed scheme to communication link failure.« less

On the Study of Cognitive Bidirectional Relaying with Asymmetric Traffic Demands

NASA Astrophysics Data System (ADS)

Ji, Xiaodong

2015-05-01

In this paper, we consider a cognitive radio network scenario, where two primary users want to exchange information with each other and meanwhile, one secondary node wishes to send messages to a cognitive base station. To meet the target quality of service (QoS) of the primary users and raise the communication opportunity of the secondary nodes, a cognitive bidirectional relaying (BDR) scheme is examined. First, system outage probabilities of conventional direct transmission and BDR schemes are presented. Next, a new system parameter called operating region is defined and calculated, which indicates in which position a secondary node can be a cognitive relay to assist the primary users. Then, a cognitive BDR scheme is proposed, giving a transmission protocol along with a time-slot splitting algorithm between the primary and secondary transmissions. Information-theoretic metric of ergodic capacity is studied for the cognitive BDR scheme to evaluate its performance. Simulation results show that with the proposed scheme, the target QoS of the primary users can be guaranteed, while increasing the communication opportunity for the secondary nodes.

Inferring product healthfulness from nutrition labelling. The influence of reference points.

PubMed

van Herpen, Erica; Hieke, Sophie; van Trijp, Hans C M

2014-01-01

Despite considerable research on nutrition labelling, it has proven difficult to find a front-of-pack label which is informative about product healthfulness across various situations. This study examines the ability of different types of nutrition labelling schemes (multiple traffic light label, nutrition table, GDA, logo) to communicate product healthfulness (a) across different product categories, (b) between options from the same product category, and (c) when viewed in isolation and in comparison with another product. Results of two experiments in Germany and The Netherlands show that a labelling scheme with reference point information at the nutrient level (e.g., the traffic light label) can achieve all three objectives. Although other types of labelling schemes are also capable of communicating healthfulness, labelling schemes lacking reference point information (e.g., nutrition tables) are less effective when no comparison product is available, and labelling schemes based on overall product healthfulness within the category (e.g., logos) can diminish consumers' ability to differentiate between categories, leading to a potential misinterpretation of product healthfulness. None of the labels affected food preferences.

Inferring Product Healthfulness from Nutrition Labelling: The Influence of Reference Points.

PubMed

Herpen, Erica van; Hieke, Sophie; van Trijp, Hans C M

2013-10-25

Despite considerable research on nutrition labelling, it has proven difficult to find a front-of-pack label which is informative about product healthfulness across various situations. This study examines the ability of different types of nutrition labelling schemes (multiple traffic light label, nutrition table, GDA, logo) to communicate product healthfulness (a) across different product categories, (b) between options from the same product category, and (c) when viewed in isolation and in comparison with another product. Results of two experiments in Germany and The Netherlands show that a labelling scheme with reference point information at the nutrient level (e.g., the traffic light label) can achieve all three objectives. Although other types of labelling schemes are also capable of communicating healthfulness, labelling schemes lacking reference point information (e.g., nutrition tables) are less effective when no comparison product is available, and labelling schemes based on overall product healthfulness within the category (e.g., logos) can diminish consumers' ability to differentiate between categories, leading to a potential misinterpretation of product healthfulness. None of the labels affected food preferences. Copyright © 2013. Published by Elsevier Ltd.

On detection and visualization techniques for cyber security situation awareness

NASA Astrophysics Data System (ADS)

Yu, Wei; Wei, Shixiao; Shen, Dan; Blowers, Misty; Blasch, Erik P.; Pham, Khanh D.; Chen, Genshe; Zhang, Hanlin; Lu, Chao

2013-05-01

Networking technologies are exponentially increasing to meet worldwide communication requirements. The rapid growth of network technologies and perversity of communications pose serious security issues. In this paper, we aim to developing an integrated network defense system with situation awareness capabilities to present the useful information for human analysts. In particular, we implement a prototypical system that includes both the distributed passive and active network sensors and traffic visualization features, such as 1D, 2D and 3D based network traffic displays. To effectively detect attacks, we also implement algorithms to transform real-world data of IP addresses into images and study the pattern of attacks and use both the discrete wavelet transform (DWT) based scheme and the statistical based scheme to detect attacks. Through an extensive simulation study, our data validate the effectiveness of our implemented defense system.

Perfect quantum multiple-unicast network coding protocol

NASA Astrophysics Data System (ADS)

Li, Dan-Dan; Gao, Fei; Qin, Su-Juan; Wen, Qiao-Yan

2018-01-01

In order to realize long-distance and large-scale quantum communication, it is natural to utilize quantum repeater. For a general quantum multiple-unicast network, it is still puzzling how to complete communication tasks perfectly with less resources such as registers. In this paper, we solve this problem. By applying quantum repeaters to multiple-unicast communication problem, we give encoding-decoding schemes for source nodes, internal ones and target ones, respectively. Source-target nodes share EPR pairs by using our encoding-decoding schemes over quantum multiple-unicast network. Furthermore, quantum communication can be accomplished perfectly via teleportation. Compared with existed schemes, our schemes can reduce resource consumption and realize long-distance transmission of quantum information.

Advanced mobility handover for mobile IPv6 based wireless networks.

PubMed

Safa Sadiq, Ali; Fisal, Norsheila Binti; Ghafoor, Kayhan Zrar; Lloret, Jaime

2014-01-01

We propose an Advanced Mobility Handover scheme (AMH) in this paper for seamless mobility in MIPv6-based wireless networks. In the proposed scheme, the mobile node utilizes a unique home IPv6 address developed to maintain communication with other corresponding nodes without a care-of-address during the roaming process. The IPv6 address for each MN during the first round of AMH process is uniquely identified by HA using the developed MN-ID field as a global permanent, which is identifying uniquely the IPv6 address of MN. Moreover, a temporary MN-ID is generated by access point each time an MN is associated with a particular AP and temporarily saved in a developed table inside the AP. When employing the AMH scheme, the handover process in the network layer is performed prior to its default time. That is, the mobility handover process in the network layer is tackled by a trigger developed AMH message to the next access point. Thus, a mobile node keeps communicating with the current access point while the network layer handover is executed by the next access point. The mathematical analyses and simulation results show that the proposed scheme performs better as compared with the existing approaches.

Characterization of Impulse Radio Intrabody Communication System for Wireless Body Area Networks.

PubMed

Cai, Zibo; Seyedi, MirHojjat; Zhang, Weiwei; Rivet, Francois; Lai, Daniel T H

2017-01-01

Intrabody communication (IBC) is a promising data communication technique for body area networks. This short-distance communication approach uses human body tissue as the medium of signal propagation. IBC is defined as one of the physical layers for the new IEEE 802.15.6 or wireless body area network (WBAN) standard, which can provide a suitable data rate for real-time physiological data communication while consuming lower power compared to that of radio-frequency protocols such as Bluetooth. In this paper, impulse radio (IR) IBC (IR-IBC) is examined using a field-programmable gate array (FPGA) implementation of an IBC system. A carrier-free pulse position modulation (PPM) scheme is implemented using an IBC transmitter in an FPGA board. PPM is a modulation technique that uses time-based pulse characteristics to encode data based on IR concepts. The transmission performance of the scheme was evaluated through signal propagation measurements of the human arm using 4- and 8-PPM transmitters, respectively. 4 or 8 is the number of symbols during modulations. It was found that the received signal-to-noise ratio (SNR) decreases approximately 8.0 dB for a range of arm distances (5-50 cm) between the transmitter and receiver electrodes with constant noise power and various signal amplitudes. The SNR for the 4-PPM scheme is approximately 2 dB higher than that for the 8-PPM one. In addition, the bit error rate (BER) is theoretically analyzed for the human body channel with additive white Gaussian noise. The 4- and 8-PPM IBC systems have average BER values of 10 -5 and 10 -10 , respectively. The results indicate the superiority of the 8-PPM scheme compared to the 4-PPM one when implementing the IBC system. The performance evaluation of the proposed IBC system will improve further IBC transceiver design.

A hybrid quantum eraser scheme for characterization of free-space and fiber communication channels

NASA Astrophysics Data System (ADS)

Nape, Isaac; Kyeremah, Charlotte; Vallés, Adam; Rosales-Guzmán, Carmelo; Buah-Bassuah, Paul K.; Forbes, Andrew

2018-02-01

We demonstrate a simple projective measurement based on the quantum eraser concept that can be used to characterize the disturbances of any communication channel. Quantum erasers are commonly implemented as spatially separated path interferometric schemes. Here we exploit the advantages of redefining the which-path information in terms of spatial modes, replacing physical paths with abstract paths of orbital angular momentum (OAM). Remarkably, vector modes (natural modes of free-space and fiber) have a non-separable feature of spin-orbit coupled states, equivalent to the description of two independently marked paths. We explore the effects of fiber perturbations by probing a step-index optical fiber channel with a vector mode, relevant to high-order spatial mode encoding of information for ultra-fast fiber communications.

Rate adaptive multilevel coded modulation with high coding gain in intensity modulation direct detection optical communication

NASA Astrophysics Data System (ADS)

Xiao, Fei; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Tian, Qinghua; Tian, Feng; Wang, Yongjun; Rao, Lan; Ullah, Rahat; Zhao, Feng; Li, Deng'ao

2018-02-01

A rate-adaptive multilevel coded modulation (RA-MLC) scheme based on fixed code length and a corresponding decoding scheme is proposed. RA-MLC scheme combines the multilevel coded and modulation technology with the binary linear block code at the transmitter. Bits division, coding, optional interleaving, and modulation are carried out by the preset rule, then transmitted through standard single mode fiber span equal to 100 km. The receiver improves the accuracy of decoding by means of soft information passing through different layers, which enhances the performance. Simulations are carried out in an intensity modulation-direct detection optical communication system using MATLAB®. Results show that the RA-MLC scheme can achieve bit error rate of 1E-5 when optical signal-to-noise ratio is 20.7 dB. It also reduced the number of decoders by 72% and realized 22 rate adaptation without significantly increasing the computing time. The coding gain is increased by 7.3 dB at BER=1E-3.

Long-distance quantum communication with atomic ensembles and linear optics.

PubMed

Duan, L M; Lukin, M D; Cirac, J I; Zoller, P

2001-11-22

Quantum communication holds promise for absolutely secure transmission of secret messages and the faithful transfer of unknown quantum states. Photonic channels appear to be very attractive for the physical implementation of quantum communication. However, owing to losses and decoherence in the channel, the communication fidelity decreases exponentially with the channel length. Here we describe a scheme that allows the implementation of robust quantum communication over long lossy channels. The scheme involves laser manipulation of atomic ensembles, beam splitters, and single-photon detectors with moderate efficiencies, and is therefore compatible with current experimental technology. We show that the communication efficiency scales polynomially with the channel length, and hence the scheme should be operable over very long distances.

On The Evolutionary Origin of Symbolic Communication

NASA Astrophysics Data System (ADS)

Grouchy, Paul; D'Eleuterio, Gabriele M. T.; Christiansen, Morten H.; Lipson, Hod

2016-10-01

The emergence of symbolic communication is often cited as a critical step in the evolution of Homo sapiens, language, and human-level cognition. It is a widely held assumption that humans are the only species that possess natural symbolic communication schemes, although a variety of other species can be taught to use symbols. The origin of symbolic communication remains a controversial open problem, obfuscated by the lack of a fossil record. Here we demonstrate an unbroken evolutionary pathway from a population of initially noncommunicating robots to the spontaneous emergence of symbolic communication. Robots evolve in a simulated world and are supplied with only a single channel of communication. When their ability to reproduce is motivated by the need to find a mate, robots evolve indexical communication schemes from initially noncommunicating populations in 99% of all experiments. Furthermore, 9% of the populations evolve a symbolic communication scheme allowing pairs of robots to exchange information about two independent spatial dimensions over a one-dimensional channel, thereby increasing their chance of reproduction. These results suggest that the ability for symbolic communication could have emerged spontaneously under natural selection, without requiring cognitive preadaptations or preexisting iconic communication schemes as previously conjectured.

An Efficient Authenticated Key Transfer Scheme in Client-Server Networks

NASA Astrophysics Data System (ADS)

Shi, Runhua; Zhang, Shun

2017-10-01

In this paper, we presented a novel authenticated key transfer scheme in client-server networks, which can achieve two secure goals of remote user authentication and the session key establishment between the remote user and the server. Especially, the proposed scheme can subtly provide two fully different authentications: identity-base authentication and anonymous authentication, while the remote user only holds a private key. Furthermore, our scheme only needs to transmit 1-round messages from the remote user to the server, thus it is very efficient in communication complexity. In addition, the most time-consuming computation in our scheme is elliptic curve scalar point multiplication, so it is also feasible even for mobile devices.

Train integrity detection risk analysis based on PRISM

NASA Astrophysics Data System (ADS)

Wen, Yuan

2018-04-01

GNSS based Train Integrity Monitoring System (TIMS) is an effective and low-cost detection scheme for train integrity detection. However, as an external auxiliary system of CTCS, GNSS may be influenced by external environments, such as uncertainty of wireless communication channels, which may lead to the failure of communication and positioning. In order to guarantee the reliability and safety of train operation, a risk analysis method of train integrity detection based on PRISM is proposed in this article. First, we analyze the risk factors (in GNSS communication process and the on-board communication process) and model them. Then, we evaluate the performance of the model in PRISM based on the field data. Finally, we discuss how these risk factors influence the train integrity detection process.

All-optical OFDM network coding scheme for all-optical virtual private communication in PON

NASA Astrophysics Data System (ADS)

Li, Lijun; Gu, Rentao; Ji, Yuefeng; Bai, Lin; Huang, Zhitong

2014-03-01

A novel optical orthogonal frequency division multiplexing (OFDM) network coding scheme is proposed over passive optical network (PON) system. The proposed scheme for all-optical virtual private network (VPN) does not only improve transmission efficiency, but also realize full-duplex communication mode in a single fiber. Compared with the traditional all-optical VPN architectures, the all-optical OFDM network coding scheme can support higher speed, more flexible bandwidth allocation, and higher spectrum efficiency. In order to reduce the difficulty of alignment for encoding operation between inter-communication traffic, the width of OFDM subcarrier pulse is stretched in our proposed scheme. The feasibility of all-optical OFDM network coding scheme for VPN is verified, and the relevant simulation results show that the full-duplex inter-communication traffic stream can be transmitted successfully. Furthermore, the tolerance of misalignment existing in inter-ONUs traffic is investigated and analyzed for all-optical encoding operation, and the difficulty of pulse alignment is proved to be lower.

Experimentally feasible security check for n-qubit quantum secret sharing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schauer, Stefan; Huber, Marcus; Hiesmayr, Beatrix C.

In this article we present a general security strategy for quantum secret sharing (QSS) protocols based on the scheme presented by Hillery, Buzek, and Berthiaume (HBB) [Phys. Rev. A 59, 1829 (1999)]. We focus on a generalization of the HBB protocol to n communication parties thus including n-partite Greenberger-Horne-Zeilinger states. We show that the multipartite version of the HBB scheme is insecure in certain settings and impractical when going to large n. To provide security for such QSS schemes in general we use the framework presented by some of the authors [M. Huber, F. Mintert, A. Gabriel, B. C. Hiesmayr,more » Phys. Rev. Lett. 104, 210501 (2010)] to detect certain genuine n-partite entanglement between the communication parties. In particular, we present a simple inequality which tests the security.« less

On the quantum-channel capacity for orbital angular momentum-based free-space optical communications.

PubMed

Zhang, Yequn; Djordjevic, Ivan B; Gao, Xin

2012-08-01

Inspired by recent demonstrations of orbital angular momentum-(OAM)-based single-photon communications, we propose two quantum-channel models: (i) the multidimensional quantum-key distribution model and (ii) the quantum teleportation model. Both models employ operator-sum representation for Kraus operators derived from OAM eigenkets transition probabilities. These models are highly important for future development of quantum-error correction schemes to extend the transmission distance and improve date rates of OAM quantum communications. By using these models, we calculate corresponding quantum-channel capacities in the presence of atmospheric turbulence.

On a two-pass scheme without a faraday mirror for free-space relativistic quantum cryptography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kravtsov, K. S.; Radchenko, I. V.; Korol'kov, A. V.

2013-05-15

The stability of destructive interference independent of the input polarization and the state of a quantum communication channel in fiber optic systems used in quantum cryptography plays a principal role in providing the security of communicated keys. A novel optical scheme is proposed that can be used both in relativistic quantum cryptography for communicating keys in open space and for communicating them over fiber optic lines. The scheme ensures stability of destructive interference and admits simple automatic balancing of a fiber interferometer.

High-order asynchrony-tolerant finite difference schemes for partial differential equations

NASA Astrophysics Data System (ADS)

Aditya, Konduri; Donzis, Diego A.

2017-12-01

Synchronizations of processing elements (PEs) in massively parallel simulations, which arise due to communication or load imbalances between PEs, significantly affect the scalability of scientific applications. We have recently proposed a method based on finite-difference schemes to solve partial differential equations in an asynchronous fashion - synchronization between PEs is relaxed at a mathematical level. While standard schemes can maintain their stability in the presence of asynchrony, their accuracy is drastically affected. In this work, we present a general methodology to derive asynchrony-tolerant (AT) finite difference schemes of arbitrary order of accuracy, which can maintain their accuracy when synchronizations are relaxed. We show that there are several choices available in selecting a stencil to derive these schemes and discuss their effect on numerical and computational performance. We provide a simple classification of schemes based on the stencil and derive schemes that are representative of different classes. Their numerical error is rigorously analyzed within a statistical framework to obtain the overall accuracy of the solution. Results from numerical experiments are used to validate the performance of the schemes.

Security enhancement of a biometric based authentication scheme for telecare medicine information systems with nonce.

PubMed

Mishra, Dheerendra; Mukhopadhyay, Sourav; Kumari, Saru; Khan, Muhammad Khurram; Chaturvedi, Ankita

2014-05-01

Telecare medicine information systems (TMIS) present the platform to deliver clinical service door to door. The technological advances in mobile computing are enhancing the quality of healthcare and a user can access these services using its mobile device. However, user and Telecare system communicate via public channels in these online services which increase the security risk. Therefore, it is required to ensure that only authorized user is accessing the system and user is interacting with the correct system. The mutual authentication provides the way to achieve this. Although existing schemes are either vulnerable to attacks or they have higher computational cost while an scalable authentication scheme for mobile devices should be secure and efficient. Recently, Awasthi and Srivastava presented a biometric based authentication scheme for TMIS with nonce. Their scheme only requires the computation of the hash and XOR functions.pagebreak Thus, this scheme fits for TMIS. However, we observe that Awasthi and Srivastava's scheme does not achieve efficient password change phase. Moreover, their scheme does not resist off-line password guessing attack. Further, we propose an improvement of Awasthi and Srivastava's scheme with the aim to remove the drawbacks of their scheme.

RiPPAS: A Ring-Based Privacy-Preserving Aggregation Scheme in Wireless Sensor Networks

PubMed Central

Zhang, Kejia; Han, Qilong; Cai, Zhipeng; Yin, Guisheng

2017-01-01

Recently, data privacy in wireless sensor networks (WSNs) has been paid increased attention. The characteristics of WSNs determine that users’ queries are mainly aggregation queries. In this paper, the problem of processing aggregation queries in WSNs with data privacy preservation is investigated. A Ring-based Privacy-Preserving Aggregation Scheme (RiPPAS) is proposed. RiPPAS adopts ring structure to perform aggregation. It uses pseudonym mechanism for anonymous communication and uses homomorphic encryption technique to add noise to the data easily to be disclosed. RiPPAS can handle both sum() queries and min()/max() queries, while the existing privacy-preserving aggregation methods can only deal with sum() queries. For processing sum() queries, compared with the existing methods, RiPPAS has advantages in the aspects of privacy preservation and communication efficiency, which can be proved by theoretical analysis and simulation results. For processing min()/max() queries, RiPPAS provides effective privacy preservation and has low communication overhead. PMID:28178197

Cryptanalysis and improvement of a biometrics-based authentication and key agreement scheme for multi-server environments.

PubMed

Yang, Li; Zheng, Zhiming

2018-01-01

According to advancements in the wireless technologies, study of biometrics-based multi-server authenticated key agreement schemes has acquired a lot of momentum. Recently, Wang et al. presented a three-factor authentication protocol with key agreement and claimed that their scheme was resistant to several prominent attacks. Unfortunately, this paper indicates that their protocol is still vulnerable to the user impersonation attack, privileged insider attack and server spoofing attack. Furthermore, their protocol cannot provide the perfect forward secrecy. As a remedy of these aforementioned problems, we propose a biometrics-based authentication and key agreement scheme for multi-server environments. Compared with various related schemes, our protocol achieves the stronger security and provides more functionality properties. Besides, the proposed protocol shows the satisfactory performances in respect of storage requirement, communication overhead and computational cost. Thus, our protocol is suitable for expert systems and other multi-server architectures. Consequently, the proposed protocol is more appropriate in the distributed networks.

Cryptanalysis and improvement of a biometrics-based authentication and key agreement scheme for multi-server environments

PubMed Central

Zheng, Zhiming

2018-01-01

According to advancements in the wireless technologies, study of biometrics-based multi-server authenticated key agreement schemes has acquired a lot of momentum. Recently, Wang et al. presented a three-factor authentication protocol with key agreement and claimed that their scheme was resistant to several prominent attacks. Unfortunately, this paper indicates that their protocol is still vulnerable to the user impersonation attack, privileged insider attack and server spoofing attack. Furthermore, their protocol cannot provide the perfect forward secrecy. As a remedy of these aforementioned problems, we propose a biometrics-based authentication and key agreement scheme for multi-server environments. Compared with various related schemes, our protocol achieves the stronger security and provides more functionality properties. Besides, the proposed protocol shows the satisfactory performances in respect of storage requirement, communication overhead and computational cost. Thus, our protocol is suitable for expert systems and other multi-server architectures. Consequently, the proposed protocol is more appropriate in the distributed networks. PMID:29534085

Quantum attack-resistent certificateless multi-receiver signcryption scheme.

PubMed

Li, Huixian; Chen, Xubao; Pang, Liaojun; Shi, Weisong

2013-01-01

The existing certificateless signcryption schemes were designed mainly based on the traditional public key cryptography, in which the security relies on the hard problems, such as factor decomposition and discrete logarithm. However, these problems will be easily solved by the quantum computing. So the existing certificateless signcryption schemes are vulnerable to the quantum attack. Multivariate public key cryptography (MPKC), which can resist the quantum attack, is one of the alternative solutions to guarantee the security of communications in the post-quantum age. Motivated by these concerns, we proposed a new construction of the certificateless multi-receiver signcryption scheme (CLMSC) based on MPKC. The new scheme inherits the security of MPKC, which can withstand the quantum attack. Multivariate quadratic polynomial operations, which have lower computation complexity than bilinear pairing operations, are employed in signcrypting a message for a certain number of receivers in our scheme. Security analysis shows that our scheme is a secure MPKC-based scheme. We proved its security under the hardness of the Multivariate Quadratic (MQ) problem and its unforgeability under the Isomorphism of Polynomials (IP) assumption in the random oracle model. The analysis results show that our scheme also has the security properties of non-repudiation, perfect forward secrecy, perfect backward secrecy and public verifiability. Compared with the existing schemes in terms of computation complexity and ciphertext length, our scheme is more efficient, which makes it suitable for terminals with low computation capacity like smart cards.

Position-based quantum cryptography over untrusted networks

NASA Astrophysics Data System (ADS)

Nadeem, Muhammad

2014-08-01

In this article, we propose quantum position verification (QPV) schemes where all the channels are untrusted except the position of the prover and distant reference stations of verifiers. We review and analyze the existing QPV schemes containing some pre-shared data between the prover and verifiers. Most of these schemes are based on non-cryptographic assumptions, i.e. quantum/classical channels between the verifiers are secure. It seems impractical in an environment fully controlled by adversaries and would lead to security compromise in practical implementations. However, our proposed formula for QPV is more robust, secure and according to the standard assumptions of cryptography. Furthermore, once the position of the prover is verified, our schemes establish secret keys in parallel and can be used for authentication and secret communication between the prover and verifiers.

An advanced temporal credential-based security scheme with mutual authentication and key agreement for wireless sensor networks.

PubMed

Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi

2013-07-24

Wireless sensor networks (WSNs) can be quickly and randomly deployed in any harsh and unattended environment and only authorized users are allowed to access reliable sensor nodes in WSNs with the aid of gateways (GWNs). Secure authentication models among the users, the sensor nodes and GWN are important research issues for ensuring communication security and data privacy in WSNs. In 2013, Xue et al. proposed a temporal-credential-based mutual authentication and key agreement scheme for WSNs. However, in this paper, we point out that Xue et al.'s scheme cannot resist stolen-verifier, insider, off-line password guessing, smart card lost problem and many logged-in users' attacks and these security weaknesses make the scheme inapplicable to practical WSN applications. To tackle these problems, we suggest a simple countermeasure to prevent proposed attacks while the other merits of Xue et al.'s authentication scheme are left unchanged.

An Advanced Temporal Credential-Based Security Scheme with Mutual Authentication and Key Agreement for Wireless Sensor Networks

PubMed Central

Li, Chun-Ta; Weng, Chi-Yao; Lee, Cheng-Chi

2013-01-01

Wireless sensor networks (WSNs) can be quickly and randomly deployed in any harsh and unattended environment and only authorized users are allowed to access reliable sensor nodes in WSNs with the aid of gateways (GWNs). Secure authentication models among the users, the sensor nodes and GWN are important research issues for ensuring communication security and data privacy in WSNs. In 2013, Xue et al. proposed a temporal-credential-based mutual authentication and key agreement scheme for WSNs. However, in this paper, we point out that Xue et al.'s scheme cannot resist stolen-verifier, insider, off-line password guessing, smart card lost problem and many logged-in users' attacks and these security weaknesses make the scheme inapplicable to practical WSN applications. To tackle these problems, we suggest a simple countermeasure to prevent proposed attacks while the other merits of Xue et al.'s authentication scheme are left unchanged. PMID:23887085

Security analysis and enhanced user authentication in proxy mobile IPv6 networks.

PubMed

Kang, Dongwoo; Jung, Jaewook; Lee, Donghoon; Kim, Hyoungshick; Won, Dongho

2017-01-01

The Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management protocol that allows a Mobile Node(MN) connected to the PMIPv6 domain to move from one network to another without changing the assigned IPv6 address. The user authentication procedure in this protocol is not standardized, but many smartcard based authentication schemes have been proposed. Recently, Alizadeh et al. proposed an authentication scheme for the PMIPv6. However, it could allow an attacker to derive an encryption key that must be securely shared between MN and the Mobile Access Gate(MAG). As a result, outsider adversary can derive MN's identity, password and session key. In this paper, we analyze Alizadeh et al.'s scheme regarding security and propose an enhanced authentication scheme that uses a dynamic identity to satisfy anonymity. Furthermore, we use BAN logic to show that our scheme can successfully generate and communicate with the inter-entity session key.

Quantum Secure Conditional Direct Communication via EPR Pairs

NASA Astrophysics Data System (ADS)

Gao, Ting; Yan, Fengli; Wang, Zhixi

Two schemes for quantum secure conditional direct communication are proposed, where a set of EPR pairs of maximally entangled particles in Bell states, initially made by the supervisor Charlie, but shared by the sender Alice and the receiver Bob, functions as quantum information channels for faithful transmission. After insuring the security of the quantum channel and obtaining the permission of Charlie (i.e., Charlie is trustworthy and cooperative, which means the "conditional" in the two schemes), Alice and Bob begin their private communication under the control of Charlie. In the first scheme, Alice transmits secret message to Bob in a deterministic manner with the help of Charlie by means of Alice's local unitary transformations, both Alice and Bob's local measurements, and both of Alice and Charlie's public classical communication. In the second scheme, the secure communication between Alice and Bob can be achieved via public classical communication of Charlie and Alice, and the local measurements of both Alice and Bob. The common feature of these protocols is that the communications between two communication parties Alice and Bob depend on the agreement of the third side Charlie. Moreover, transmitting one bit secret message, the sender Alice only needs to apply a local operation on her one qubit and send one bit classical information. We also show that the two schemes are completely secure if quantum channels are perfect.

A Reliable TTP-Based Infrastructure with Low Sensor Resource Consumption for the Smart Home Multi-Platform

PubMed Central

Kang, Jungho; Kim, Mansik; Park, Jong Hyuk

2016-01-01

With the ICT technology making great progress in the smart home environment, the ubiquitous environment is rapidly emerging all over the world, but problems are also increasing proportionally to the rapid growth of the smart home market such as multiplatform heterogeneity and new security threats. In addition, the smart home sensors have so low computing resources that they cannot process complicated computation tasks, which is required to create a proper security environment. A service provider also faces overhead in processing data from a rapidly increasing number of sensors. This paper aimed to propose a scheme to build infrastructure in which communication entities can securely authenticate and design security channel with physically unclonable PUFs and the TTP that smart home communication entities can rely on. In addition, we analyze and evaluate the proposed scheme for security and performance and prove that it can build secure channels with low resources. Finally, we expect that the proposed scheme can be helpful for secure communication with low resources in future smart home multiplatforms. PMID:27399699

A Reliable TTP-Based Infrastructure with Low Sensor Resource Consumption for the Smart Home Multi-Platform.

PubMed

Kang, Jungho; Kim, Mansik; Park, Jong Hyuk

2016-07-05

With the ICT technology making great progress in the smart home environment, the ubiquitous environment is rapidly emerging all over the world, but problems are also increasing proportionally to the rapid growth of the smart home market such as multiplatform heterogeneity and new security threats. In addition, the smart home sensors have so low computing resources that they cannot process complicated computation tasks, which is required to create a proper security environment. A service provider also faces overhead in processing data from a rapidly increasing number of sensors. This paper aimed to propose a scheme to build infrastructure in which communication entities can securely authenticate and design security channel with physically unclonable PUFs and the TTP that smart home communication entities can rely on. In addition, we analyze and evaluate the proposed scheme for security and performance and prove that it can build secure channels with low resources. Finally, we expect that the proposed scheme can be helpful for secure communication with low resources in future smart home multiplatforms.

A Robust and Effective Smart-Card-Based Remote User Authentication Mechanism Using Hash Function

PubMed Central

Odelu, Vanga; Goswami, Adrijit

2014-01-01

In a remote user authentication scheme, a remote server verifies whether a login user is genuine and trustworthy, and also for mutual authentication purpose a login user validates whether the remote server is genuine and trustworthy. Several remote user authentication schemes using the password, the biometrics, and the smart card have been proposed in the literature. However, most schemes proposed in the literature are either computationally expensive or insecure against several known attacks. In this paper, we aim to propose a new robust and effective password-based remote user authentication scheme using smart card. Our scheme is efficient, because our scheme uses only efficient one-way hash function and bitwise XOR operations. Through the rigorous informal and formal security analysis, we show that our scheme is secure against possible known attacks. We perform the simulation for the formal security analysis using the widely accepted AVISPA (Automated Validation Internet Security Protocols and Applications) tool to ensure that our scheme is secure against passive and active attacks. Furthermore, our scheme supports efficiently the password change phase always locally without contacting the remote server and correctly. In addition, our scheme performs significantly better than other existing schemes in terms of communication, computational overheads, security, and features provided by our scheme. PMID:24892078

A robust and effective smart-card-based remote user authentication mechanism using hash function.

PubMed

Das, Ashok Kumar; Odelu, Vanga; Goswami, Adrijit

2014-01-01

In a remote user authentication scheme, a remote server verifies whether a login user is genuine and trustworthy, and also for mutual authentication purpose a login user validates whether the remote server is genuine and trustworthy. Several remote user authentication schemes using the password, the biometrics, and the smart card have been proposed in the literature. However, most schemes proposed in the literature are either computationally expensive or insecure against several known attacks. In this paper, we aim to propose a new robust and effective password-based remote user authentication scheme using smart card. Our scheme is efficient, because our scheme uses only efficient one-way hash function and bitwise XOR operations. Through the rigorous informal and formal security analysis, we show that our scheme is secure against possible known attacks. We perform the simulation for the formal security analysis using the widely accepted AVISPA (Automated Validation Internet Security Protocols and Applications) tool to ensure that our scheme is secure against passive and active attacks. Furthermore, our scheme supports efficiently the password change phase always locally without contacting the remote server and correctly. In addition, our scheme performs significantly better than other existing schemes in terms of communication, computational overheads, security, and features provided by our scheme.

Optimizing Scheme for Remote Preparation of Four-particle Cluster-like Entangled States

NASA Astrophysics Data System (ADS)

Wang, Dong; Ye, Liu

2011-09-01

Recently, Ma et al. (Opt. Commun. 283:2640, 2010) have proposed a novel scheme for preparing a class of cluster-like entangled states based on a four-particle projective measurement. In this paper, we put forward a new and optimal scheme to realize the remote preparation for this class of cluster-like states with the aid of two bipartite partially entangled channels. Different from the previous scheme, we employ a two-particle projective measurement instead of the four-particle projective measurement during the preparation. Besides, the resource consumptions are computed in our scheme, which include classical communication cost and quantum resource consumptions. Moreover, we have some discussions on the features of our scheme and make some comparisons on resource consumptions and operation complexity between the previous scheme and ours. The results show that our scheme is more economic and feasible compared with the previous.

Downlink Multihop Transmission Technique for Asymmetric Traffic Accommodation in DS-CDMA/FDD Cellular Communications

NASA Astrophysics Data System (ADS)

Mori, Kazuo; Naito, Katsuhiro; Kobayashi, Hideo

This paper proposes an asymmetric traffic accommodation scheme using a multihop transmission technique for CDMA/FDD cellular communication systems. The proposed scheme exploits the multihop transmission to downlink packet transmissions, which require the large transmission power at their single-hop transmissions, in order to increase the downlink capacity. In these multihop transmissions, vacant uplink band is used for the transmissions from relay stations to destination mobile stations, and this leads more capacity enhancement in the downlink communications. The relay route selection method and power control method for the multihop transmissions are also investigated in the proposed scheme. The proposed scheme is evaluated by computer simulation and the results show that the proposed scheme can achieve better system performance.

Optimal attacks on qubit-based Quantum Key Recycling

NASA Astrophysics Data System (ADS)

Leermakers, Daan; Škorić, Boris

2018-03-01

Quantum Key Recycling (QKR) is a quantum cryptographic primitive that allows one to reuse keys in an unconditionally secure way. By removing the need to repeatedly generate new keys, it improves communication efficiency. Škorić and de Vries recently proposed a QKR scheme based on 8-state encoding (four bases). It does not require quantum computers for encryption/decryption but only single-qubit operations. We provide a missing ingredient in the security analysis of this scheme in the case of noisy channels: accurate upper bounds on the required amount of privacy amplification. We determine optimal attacks against the message and against the key, for 8-state encoding as well as 4-state and 6-state conjugate coding. We provide results in terms of min-entropy loss as well as accessible (Shannon) information. We show that the Shannon entropy analysis for 8-state encoding reduces to the analysis of quantum key distribution, whereas 4-state and 6-state suffer from additional leaks that make them less effective. From the optimal attacks we compute the required amount of privacy amplification and hence the achievable communication rate (useful information per qubit) of qubit-based QKR. Overall, 8-state encoding yields the highest communication rates.

Digital Self-Interference Cancellation for Asynchronous In-Band Full-Duplex Underwater Acoustic Communication.

PubMed

Qiao, Gang; Gan, Shuwei; Liu, Songzuo; Ma, Lu; Sun, Zongxin

2018-05-24

To improve the throughput of underwater acoustic (UWA) networking, the In-band full-duplex (IBFD) communication is one of the most vital pieces of research. The major drawback of IBFD-UWA communication is Self-Interference (SI). This paper presents a digital SI cancellation algorithm for asynchronous IBFD-UWA communication system. We focus on two issues: one is asynchronous communication dissimilar to IBFD radio communication, the other is nonlinear distortion caused by power amplifier (PA). First, we discuss asynchronous IBFD-UWA signal model with the nonlinear distortion of PA. Then, we design a scheme for asynchronous IBFD-UWA communication utilizing the non-overlapping region between SI and intended signal to estimate the nonlinear SI channel. To cancel the nonlinear distortion caused by PA, we propose an Over-Parameterization based Recursive Least Squares (RLS) algorithm (OPRLS) to estimate the nonlinear SI channel. Furthermore, we present the OPRLS with a sparse constraint to estimate the SI channel, which reduces the requirement of the length of the non-overlapping region. Finally, we verify our concept through simulation and the pool experiment. Results demonstrate that the proposed digital SI cancellation scheme can cancel SI efficiently.

Adaptive synchronisation of memristor-based neural networks with leakage delays and applications in chaotic masking secure communication

NASA Astrophysics Data System (ADS)

Liu, Jian; Xu, Rui

2018-04-01

Chaotic synchronisation has caused extensive attention due to its potential application in secure communication. This paper is concerned with the problem of adaptive synchronisation for two different kinds of memristor-based neural networks with time delays in leakage terms. By applying set-valued maps and differential inclusions theories, synchronisation criteria are obtained via linear matrix inequalities technique, which guarantee drive system being synchronised with response system under adaptive control laws. Finally, a numerical example is given to illustrate the feasibility of our theoretical results, and two schemes for secure communication are introduced based on chaotic masking method.

Collaborative Scheduling Using JMS in a Mixed Java and .NET Environment

NASA Technical Reports Server (NTRS)

Wang, Yeou-Fang; Wax, Allan; Lam, Ray; Baldwin, John; Borden, Chet

2006-01-01

A collaborative framework/environment was proto-typed to prove the feasibility of scheduling space flight missions on NASA's Deep Space Network (DSN) in a distributed fashion. In this environment, effective collaboration relies on efficient communications among all flight mission and DSN scheduling users. There-fore, messaging becomes critical to timely event notification and data synchronization. In the prototype, a rapid messaging system using Java Message Service (JMS) in a mixed Java and .NET environment is established. This scheme allows both Java and .NET applications to communicate with each other for data synchronization and schedule negotiation. The JMS approach we used is based on a centralized messaging scheme. With proper use of a high speed messaging system, all users in this collaborative framework can communicate with each other to generate a schedule collaboratively to meet DSN and projects tracking needs.

Development and feasibility testing of the Pediatric Emergency Discharge Interaction Coding Scheme.

PubMed

Curran, Janet A; Taylor, Alexandra; Chorney, Jill; Porter, Stephen; Murphy, Andrea; MacPhee, Shannon; Bishop, Andrea; Haworth, Rebecca

2017-08-01

Discharge communication is an important aspect of high-quality emergency care. This study addresses the gap in knowledge on how to describe discharge communication in a paediatric emergency department (ED). The objective of this feasibility study was to develop and test a coding scheme to characterize discharge communication between health-care providers (HCPs) and caregivers who visit the ED with their children. The Pediatric Emergency Discharge Interaction Coding Scheme (PEDICS) and coding manual were developed following a review of the literature and an iterative refinement process involving HCP observations, inter-rater assessments and team consensus. The coding scheme was pilot-tested through observations of HCPs across a range of shifts in one urban paediatric ED. Overall, 329 patient observations were carried out across 50 observational shifts. Inter-rater reliability was evaluated in 16% of the observations. The final version of the PEDICS contained 41 communication elements. Kappa scores were greater than .60 for the majority of communication elements. The most frequently observed communication elements were under the Introduction node and the least frequently observed were under the Social Concerns node. HCPs initiated the majority of the communication. Pediatric Emergency Discharge Interaction Coding Scheme addresses an important gap in the discharge communication literature. The tool is useful for mapping patterns of discharge communication between HCPs and caregivers. Results from our pilot test identified deficits in specific areas of discharge communication that could impact adherence to discharge instructions. The PEDICS would benefit from further testing with a different sample of HCPs. © 2017 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Distributed Adaptive Finite-Time Approach for Formation-Containment Control of Networked Nonlinear Systems Under Directed Topology.

PubMed

Wang, Yujuan; Song, Yongduan; Ren, Wei

2017-07-06

This paper presents a distributed adaptive finite-time control solution to the formation-containment problem for multiple networked systems with uncertain nonlinear dynamics and directed communication constraints. By integrating the special topology feature of the new constructed symmetrical matrix, the technical difficulty in finite-time formation-containment control arising from the asymmetrical Laplacian matrix under single-way directed communication is circumvented. Based upon fractional power feedback of the local error, an adaptive distributed control scheme is established to drive the leaders into the prespecified formation configuration in finite time. Meanwhile, a distributed adaptive control scheme, independent of the unavailable inputs of the leaders, is designed to keep the followers within a bounded distance from the moving leaders and then to make the followers enter the convex hull shaped by the formation of the leaders in finite time. The effectiveness of the proposed control scheme is confirmed by the simulation.

Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

PubMed Central

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-01-01

A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed. PMID:28362328

Patients' Data Management System Protected by Identity-Based Authentication and Key Exchange.

PubMed

Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

2017-03-31

A secure and distributed framework for the management of patients' information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients' data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

Experimental quantum-cryptography scheme based on orthogonal states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avella, Alessio; Brida, Giorgio; Degiovanni, Ivo Pietro

2010-12-15

Since, in general, nonorthogonal states cannot be cloned, any eavesdropping attempt in a quantum-communication scheme using nonorthogonal states as carriers of information introduces some errors in the transmission, leading to the possibility of detecting the spy. Usually, orthogonal states are not used in quantum-cryptography schemes since they can be faithfully cloned without altering the transmitted data. Nevertheless, L. Goldberg and L. Vaidman [Phys. Rev. Lett. 75, 1239 (1995)] proposed a protocol in which, even if the data exchange is realized using two orthogonal states, any attempt to eavesdrop is detectable by the legal users. In this scheme the orthogonal statesmore » are superpositions of two localized wave packets traveling along separate channels. Here we present an experiment realizing this scheme.« less

Hierarchical scheme for detecting the rotating MIMO transmission of the in-door RGB-LED visible light wireless communications using mobile-phone camera

NASA Astrophysics Data System (ADS)

Chen, Shih-Hao; Chow, Chi-Wai

2015-01-01

Multiple-input and multiple-output (MIMO) scheme can extend the transmission capacity for the light-emitting-diode (LED) based visible light communication (VLC) systems. The MIMO VLC system that uses the mobile-phone camera as the optical receiver (Rx) to receive MIMO signal from the n×n Red-Green-Blue (RGB) LED array is desirable. The key step of decoding this signal is to detect the signal direction. If the LED transmitter (Tx) is rotated, the Rx may not realize the rotation and transmission error can occur. In this work, we propose and demonstrate a novel hierarchical transmission scheme which can reduce the computation complexity of rotation detection in LED array VLC system. We use the n×n RGB LED array as the MIMO Tx. In our study, a novel two dimensional Hadamard coding scheme is proposed. Using the different LED color layers to indicate the rotation, a low complexity rotation detection method can be used for improving the quality of received signal. The detection correction rate is above 95% in the indoor usage distance. Experimental results confirm the feasibility of the proposed scheme.

Consensus-based distributed cooperative learning from closed-loop neural control systems.

PubMed

Chen, Weisheng; Hua, Shaoyong; Zhang, Huaguang

2015-02-01

In this paper, the neural tracking problem is addressed for a group of uncertain nonlinear systems where the system structures are identical but the reference signals are different. This paper focuses on studying the learning capability of neural networks (NNs) during the control process. First, we propose a novel control scheme called distributed cooperative learning (DCL) control scheme, by establishing the communication topology among adaptive laws of NN weights to share their learned knowledge online. It is further proved that if the communication topology is undirected and connected, all estimated weights of NNs can converge to small neighborhoods around their optimal values over a domain consisting of the union of all state orbits. Second, as a corollary it is shown that the conclusion on the deterministic learning still holds in the decentralized adaptive neural control scheme where, however, the estimated weights of NNs just converge to small neighborhoods of the optimal values along their own state orbits. Thus, the learned controllers obtained by DCL scheme have the better generalization capability than ones obtained by decentralized learning method. A simulation example is provided to verify the effectiveness and advantages of the control schemes proposed in this paper.

CSI feedback-based CS for underwater acoustic adaptive modulation OFDM system with channel prediction

NASA Astrophysics Data System (ADS)

Kuai, Xiao-yan; Sun, Hai-xin; Qi, Jie; Cheng, En; Xu, Xiao-ka; Guo, Yu-hui; Chen, You-gan

2014-06-01

In this paper, we investigate the performance of adaptive modulation (AM) orthogonal frequency division multiplexing (OFDM) system in underwater acoustic (UWA) communications. The aim is to solve the problem of large feedback overhead for channel state information (CSI) in every subcarrier. A novel CSI feedback scheme is proposed based on the theory of compressed sensing (CS). We propose a feedback from the receiver that only feedback the sparse channel parameters. Additionally, prediction of the channel state is proposed every several symbols to realize the AM in practice. We describe a linear channel prediction algorithm which is used in adaptive transmission. This system has been tested in the real underwater acoustic channel. The linear channel prediction makes the AM transmission techniques more feasible for acoustic channel communications. The simulation and experiment show that significant improvements can be obtained both in bit error rate (BER) and throughput in the AM scheme compared with the fixed Quadrature Phase Shift Keying (QPSK) modulation scheme. Moreover, the performance with standard CS outperforms the Discrete Cosine Transform (DCT) method.

A Novel Certificateless Signature Scheme for Smart Objects in the Internet-of-Things.

PubMed

Yeh, Kuo-Hui; Su, Chunhua; Choo, Kim-Kwang Raymond; Chiu, Wayne

2017-05-01

Rapid advances in wireless communications and pervasive computing technologies have resulted in increasing interest and popularity of Internet-of-Things (IoT) architecture, ubiquitously providing intelligence and convenience to our daily life. In IoT-based network environments, smart objects are embedded everywhere as ubiquitous things connected in a pervasive manner. Ensuring security for interactions between these smart things is significantly more important, and a topic of ongoing interest. In this paper, we present a certificateless signature scheme for smart objects in IoT-based pervasive computing environments. We evaluate the utility of the proposed scheme in IoT-oriented testbeds, i.e., Arduino Uno and Raspberry PI 2. Experiment results present the practicability of the proposed scheme. Moreover, we revisit the scheme of Wang et al. (2015) and revealed that a malicious super type I adversary can easily forge a legitimate signature to cheat any receiver as he/she wishes in the scheme. The superiority of the proposed certificateless signature scheme over relevant studies is demonstrated in terms of the summarized security and performance comparisons.

A Novel Certificateless Signature Scheme for Smart Objects in the Internet-of-Things

PubMed Central

Yeh, Kuo-Hui; Su, Chunhua; Choo, Kim-Kwang Raymond; Chiu, Wayne

2017-01-01

Rapid advances in wireless communications and pervasive computing technologies have resulted in increasing interest and popularity of Internet-of-Things (IoT) architecture, ubiquitously providing intelligence and convenience to our daily life. In IoT-based network environments, smart objects are embedded everywhere as ubiquitous things connected in a pervasive manner. Ensuring security for interactions between these smart things is significantly more important, and a topic of ongoing interest. In this paper, we present a certificateless signature scheme for smart objects in IoT-based pervasive computing environments. We evaluate the utility of the proposed scheme in IoT-oriented testbeds, i.e., Arduino Uno and Raspberry PI 2. Experiment results present the practicability of the proposed scheme. Moreover, we revisit the scheme of Wang et al. (2015) and revealed that a malicious super type I adversary can easily forge a legitimate signature to cheat any receiver as he/she wishes in the scheme. The superiority of the proposed certificateless signature scheme over relevant studies is demonstrated in terms of the summarized security and performance comparisons. PMID:28468313

Sensor Based Framework for Secure Multimedia Communication in VANET

PubMed Central

Rahim, Aneel; Khan, Zeeshan Shafi; Bin Muhaya, Fahad T.; Sher, Muhammad; Kim, Tai-Hoon

2010-01-01

Secure multimedia communication enhances the safety of passengers by providing visual pictures of accidents and danger situations. In this paper we proposed a framework for secure multimedia communication in Vehicular Ad-Hoc Networks (VANETs). Our proposed framework is mainly divided into four components: redundant information, priority assignment, malicious data verification and malicious node verification. The proposed scheme jhas been validated with the help of the NS-2 network simulator and the Evalvid tool. PMID:22163462

Comment on: Supervisory Asymmetric Deterministic Secure Quantum Communication

NASA Astrophysics Data System (ADS)

Kao, Shih-Hung; Tsai, Chia-Wei; Hwang, Tzonelih

2012-12-01

In 2010, Xiu et al. (Optics Communications 284:2065-2069, 2011) proposed several applications based on a new secure four-site distribution scheme using χ-type entangled states. This paper points out that one of these applications, namely, supervisory asymmetric deterministic secure quantum communication, is subject to an information leakage problem, in which the receiver can extract two bits of a three-bit secret message without the supervisor's permission. An enhanced protocol is proposed to resolve this problem.

D-MSR: a distributed network management scheme for real-time monitoring and process control applications in wireless industrial automation.

PubMed

Zand, Pouria; Dilo, Arta; Havinga, Paul

2013-06-27

Current wireless technologies for industrial applications, such as WirelessHART and ISA100.11a, use a centralized management approach where a central network manager handles the requirements of the static network. However, such a centralized approach has several drawbacks. For example, it cannot cope with dynamicity/disturbance in large-scale networks in a real-time manner and it incurs a high communication overhead and latency for exchanging management traffic. In this paper, we therefore propose a distributed network management scheme, D-MSR. It enables the network devices to join the network, schedule their communications, establish end-to-end connections by reserving the communication resources for addressing real-time requirements, and cope with network dynamicity (e.g., node/edge failures) in a distributed manner. According to our knowledge, this is the first distributed management scheme based on IEEE 802.15.4e standard, which guides the nodes in different phases from joining until publishing their sensor data in the network. We demonstrate via simulation that D-MSR can address real-time and reliable communication as well as the high throughput requirements of industrial automation wireless networks, while also achieving higher efficiency in network management than WirelessHART, in terms of delay and overhead.

D-MSR: A Distributed Network Management Scheme for Real-Time Monitoring and Process Control Applications in Wireless Industrial Automation

PubMed Central

Zand, Pouria; Dilo, Arta; Havinga, Paul

2013-01-01

Current wireless technologies for industrial applications, such as WirelessHART and ISA100.11a, use a centralized management approach where a central network manager handles the requirements of the static network. However, such a centralized approach has several drawbacks. For example, it cannot cope with dynamicity/disturbance in large-scale networks in a real-time manner and it incurs a high communication overhead and latency for exchanging management traffic. In this paper, we therefore propose a distributed network management scheme, D-MSR. It enables the network devices to join the network, schedule their communications, establish end-to-end connections by reserving the communication resources for addressing real-time requirements, and cope with network dynamicity (e.g., node/edge failures) in a distributed manner. According to our knowledge, this is the first distributed management scheme based on IEEE 802.15.4e standard, which guides the nodes in different phases from joining until publishing their sensor data in the network. We demonstrate via simulation that D-MSR can address real-time and reliable communication as well as the high throughput requirements of industrial automation wireless networks, while also achieving higher efficiency in network management than WirelessHART, in terms of delay and overhead. PMID:23807687

Efficient authentication scheme based on near-ring root extraction problem

NASA Astrophysics Data System (ADS)

Muthukumaran, V.; Ezhilmaran, D.

2017-11-01

An authentication protocolis the type of computer communication protocol or cryptography protocol specifically designed for transfer of authentication data between two entities. We have planned a two new entity authentication scheme on the basis of root extraction problem near-ring in this article. We suggest that this problem is suitably difficult to serve as a cryptographic assumption over the platform of near-ring N. The security issues also discussed.

An in fiber experimental approach to photonic quantum digital signatures that does not require quantum memory

NASA Astrophysics Data System (ADS)

Collins, Robert J.; Donaldon, Ross J.; Dunjko, Vedran; Wallden, Petros; Clarke, Patrick J.; Andersson, Erika; Jeffers, John; Buller, Gerald S.

2014-10-01

Classical digital signatures are commonly used in e-mail, electronic financial transactions and other forms of electronic communications to ensure that messages have not been tampered with in transit, and that messages are transferrable. The security of commonly used classical digital signature schemes relies on the computational difficulty of inverting certain mathematical functions. However, at present, there are no such one-way functions which have been proven to be hard to invert. With enough computational resources certain implementations of classical public key cryptosystems can be, and have been, broken with current technology. It is nevertheless possible to construct information-theoretically secure signature schemes, including quantum digital signature schemes. Quantum signature schemes can be made information theoretically secure based on the laws of quantum mechanics, while classical comparable protocols require additional resources such as secret communication and a trusted authority. Early demonstrations of quantum digital signatures required quantum memory, rendering them impractical at present. Our present implementation is based on a protocol that does not require quantum memory. It also uses the new technique of unambiguous quantum state elimination, Here we report experimental results for a test-bed system, recorded with a variety of different operating parameters, along with a discussion of aspects of the system security.

Advanced Mobility Handover for Mobile IPv6 Based Wireless Networks

PubMed Central

Safa Sadiq, Ali; Fisal, Norsheila Binti; Ghafoor, Kayhan Zrar; Lloret, Jaime

2014-01-01

We propose an Advanced Mobility Handover scheme (AMH) in this paper for seamless mobility in MIPv6-based wireless networks. In the proposed scheme, the mobile node utilizes a unique home IPv6 address developed to maintain communication with other corresponding nodes without a care-of-address during the roaming process. The IPv6 address for each MN during the first round of AMH process is uniquely identified by HA using the developed MN-ID field as a global permanent, which is identifying uniquely the IPv6 address of MN. Moreover, a temporary MN-ID is generated by access point each time an MN is associated with a particular AP and temporarily saved in a developed table inside the AP. When employing the AMH scheme, the handover process in the network layer is performed prior to its default time. That is, the mobility handover process in the network layer is tackled by a trigger developed AMH message to the next access point. Thus, a mobile node keeps communicating with the current access point while the network layer handover is executed by the next access point. The mathematical analyses and simulation results show that the proposed scheme performs better as compared with the existing approaches. PMID:25614890

Policy-Based Negotiation Engine for Cross-Domain Interoperability

NASA Technical Reports Server (NTRS)

Vatan, Farrokh; Chow, Edward T.

2012-01-01

A successful policy negotiation scheme for Policy-Based Management (PBM) has been implemented. Policy negotiation is the process of determining the "best" communication policy that all of the parties involved can agree on. Specifically, the problem is how to reconcile the various (and possibly conflicting) communication protocols used by different divisions. The solution must use protocols available to all parties involved, and should attempt to do so in the best way possible. Which protocols are commonly available, and what the definition of "best" is will be dependent on the parties involved and their individual communications priorities.

Group consensus control for networked multi-agent systems with communication delays.

PubMed

An, Bao-Ran; Liu, Guo-Ping; Tan, Chong

2018-05-01

This paper investigates group consensus problems in networked multi-agent systems (NMAS) with communication delays. Based on the sed state prediction scheme, the group consensus control protocol is designed to compensate the communication delay actively. In light of algebraic graph theories and matrix theories, necessary and(or) sufficient conditions of group consensus with respect to a given admissible control set are obtained for the NMAS with communication delays under mild assumptions. Finally, simulations are performed to demonstrate the effectiveness of the theoretical results. Copyright © 2018 ISA. All rights reserved.

Effects of information, education, and communication campaign on a community-based health insurance scheme in Burkina Faso

PubMed Central

Cofie, Patience; De Allegri, Manuela; Kouyaté, Bocar; Sauerborn, Rainer

2013-01-01

Objective The study analysed the effect of Information, Education, and Communication (IEC) campaign activities on the adoption of a community-based health insurance (CHI) scheme in Nouna, Burkina Faso. It also identified the factors that enhanced or limited the campaign's effectiveness. Design Complementary data collection approaches were used. A survey was conducted with 250 randomly selected household heads, followed by in-depth interviews with 22 purposively selected community leaders, group discussions with the project management team, and field observations. Bivariate analysis and multivariate logistic regression models were used to assess the association between household exposure to campaign and acquisition of knowledge as well as household exposure to campaign and enrolment. Results The IEC campaign had a positive effect on households’ knowledge about the CHI and to a lesser extent on household enrolment in the scheme. The effectiveness of the IEC strategy was mainly influenced by: (1) frequent and consistent IEC messages from multiple media channels (mass and interpersonal channels), including the radio, a mobile information van, and CHI team, and (2) community heads’ participation in the CHI scheme promotion. Education was the only significantly influential socio-demographic determinant of knowledge and enrolment among household heads. The relatively low effects of the IEC campaign on CHI enrolment are indicative of other important IEC mediating factors, which should be taken into account in future CHI campaign evaluation. Conclusion The study concludes that an IEC campaign is crucial to improving the understanding of the CHI scheme concept, which is an enabler to enrolment, and should be integrated into scheme designs and evaluations. PMID:24314344

Effects of information, education, and communication campaign on a community-based health insurance scheme in Burkina Faso.

PubMed

Cofie, Patience; De Allegri, Manuela; Kouyaté, Bocar; Sauerborn, Rainer

2013-12-06

The study analysed the effect of Information, Education, and Communication (IEC) campaign activities on the adoption of a community-based health insurance (CHI) scheme in Nouna, Burkina Faso. It also identified the factors that enhanced or limited the campaign's effectiveness. Complementary data collection approaches were used. A survey was conducted with 250 randomly selected household heads, followed by in-depth interviews with 22 purposively selected community leaders, group discussions with the project management team, and field observations. Bivariate analysis and multivariate logistic regression models were used to assess the association between household exposure to campaign and acquisition of knowledge as well as household exposure to campaign and enrolment. The IEC campaign had a positive effect on households' knowledge about the CHI and to a lesser extent on household enrolment in the scheme. The effectiveness of the IEC strategy was mainly influenced by: (1) frequent and consistent IEC messages from multiple media channels (mass and interpersonal channels), including the radio, a mobile information van, and CHI team, and (2) community heads' participation in the CHI scheme promotion. Education was the only significantly influential socio-demographic determinant of knowledge and enrolment among household heads. The relatively low effects of the IEC campaign on CHI enrolment are indicative of other important IEC mediating factors, which should be taken into account in future CHI campaign evaluation. The study concludes that an IEC campaign is crucial to improving the understanding of the CHI scheme concept, which is an enabler to enrolment, and should be integrated into scheme designs and evaluations.

Performance analysis of fiber-based free-space optical communications with coherent detection spatial diversity.

PubMed

Li, Kangning; Ma, Jing; Tan, Liying; Yu, Siyuan; Zhai, Chao

2016-06-10

The performances of fiber-based free-space optical (FSO) communications over gamma-gamma distributed turbulence are studied for multiple aperture receiver systems. The equal gain combining (EGC) technique is considered as a practical scheme to mitigate the atmospheric turbulence. Bit error rate (BER) performances for binary-phase-shift-keying-modulated coherent detection fiber-based free-space optical communications are derived and analyzed for EGC diversity receptions through an approximation method. To show the net diversity gain of a multiple aperture receiver system, BER performances of EGC are compared with a single monolithic aperture receiver system with the same total aperture area (same average total incident optical power on the aperture surface) for fiber-based free-space optical communications. The analytical results are verified by Monte Carlo simulations. System performances are also compared for EGC diversity coherent FSO communications with or without considering fiber-coupling efficiencies.

A Key Pre-Distribution Scheme Based on µ-PBIBD for Enhancing Resilience in Wireless Sensor Networks.

PubMed

Yuan, Qi; Ma, Chunguang; Yu, Haitao; Bian, Xuefen

2018-05-12

Many key pre-distribution (KPD) schemes based on combinatorial design were proposed for secure communication of wireless sensor networks (WSNs). Due to complexity of constructing the combinatorial design, it is infeasible to generate key rings using the corresponding combinatorial design in large scale deployment of WSNs. In this paper, we present a definition of new combinatorial design, termed “µ-partially balanced incomplete block design (µ-PBIBD)”, which is a refinement of partially balanced incomplete block design (PBIBD), and then describe a 2-D construction of µ-PBIBD which is mapped to KPD in WSNs. Our approach is of simple construction which provides a strong key connectivity and a poor network resilience. To improve the network resilience of KPD based on 2-D µ-PBIBD, we propose a KPD scheme based on 3-D Ex-µ-PBIBD which is a construction of µ-PBIBD from 2-D space to 3-D space. Ex-µ-PBIBD KPD scheme improves network scalability and resilience while has better key connectivity. Theoretical analysis and comparison with the related schemes show that key pre-distribution scheme based on Ex-µ-PBIBD provides high network resilience and better key scalability, while it achieves a trade-off between network resilience and network connectivity.

A Key Pre-Distribution Scheme Based on µ-PBIBD for Enhancing Resilience in Wireless Sensor Networks

PubMed Central

Yuan, Qi; Ma, Chunguang; Yu, Haitao; Bian, Xuefen

2018-01-01

Many key pre-distribution (KPD) schemes based on combinatorial design were proposed for secure communication of wireless sensor networks (WSNs). Due to complexity of constructing the combinatorial design, it is infeasible to generate key rings using the corresponding combinatorial design in large scale deployment of WSNs. In this paper, we present a definition of new combinatorial design, termed “µ-partially balanced incomplete block design (µ-PBIBD)”, which is a refinement of partially balanced incomplete block design (PBIBD), and then describe a 2-D construction of µ-PBIBD which is mapped to KPD in WSNs. Our approach is of simple construction which provides a strong key connectivity and a poor network resilience. To improve the network resilience of KPD based on 2-D µ-PBIBD, we propose a KPD scheme based on 3-D Ex-µ-PBIBD which is a construction of µ-PBIBD from 2-D space to 3-D space. Ex-µ-PBIBD KPD scheme improves network scalability and resilience while has better key connectivity. Theoretical analysis and comparison with the related schemes show that key pre-distribution scheme based on Ex-µ-PBIBD provides high network resilience and better key scalability, while it achieves a trade-off between network resilience and network connectivity. PMID:29757244

Temporal characteristic analysis of laser-modulated pulsed X-ray source for space X-ray communication

NASA Astrophysics Data System (ADS)

Hang, Shuang; Liu, Yunpeng; Li, Huan; Tang, Xiaobin; Chen, Da

2018-04-01

X-ray communication (XCOM) is a new communication type and is expected to realize high-speed data transmission in some special communication scenarios, such as deep space communication and blackout communication. This study proposes a high-speed modulated X-ray source scheme based on the laser-to-X-ray conversion. The temporal characteristics of the essential components of the proposed laser-modulated pulsed X-ray source (LMPXS) were analyzed to evaluate its pulse emission performance. Results show that the LMPXS can provide a maximum modulation rate up to 100 Mbps which is expected to significantly improve the data rate of XCOM.

Coherent receiver design based on digital signal processing in optical high-speed intersatellite links with M-phase-shift keying

NASA Astrophysics Data System (ADS)

Schaefer, Semjon; Gregory, Mark; Rosenkranz, Werner

2016-11-01

We present simulative and experimental investigations of different coherent receiver designs for high-speed optical intersatellite links. We focus on frequency offset (FO) compensation in homodyne and intradyne detection systems. The considered laser communication terminal uses an optical phase-locked loop (OPLL), which ensures stable homodyne detection. However, the hardware complexity increases with the modulation order. Therefore, we show that software-based intradyne detection is an attractive alternative for OPLL-based homodyne systems. Our approach is based on digital FO and phase noise compensation, in order to achieve a more flexible coherent detection scheme. Analytic results will further show the theoretical impact of the different detection schemes on the receiver sensitivity. Finally, we compare the schemes in terms of bit error ratio measurements and optimal receiver design.

A Tree Based Self-routing Scheme for Mobility Support in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Kim, Young-Duk; Yang, Yeon-Mo; Kang, Won-Seok; Kim, Jin-Wook; An, Jinung

Recently, WSNs (Wireless Sensor Networks) with mobile robot is a growing technology that offer efficient communication services for anytime and anywhere applications. However, the tiny sensor node has very limited network resources due to its low battery power, low data rate, node mobility, and channel interference constraint between neighbors. Thus, in this paper, we proposed a tree based self-routing protocol for autonomous mobile robots based on beacon mode and implemented in real test-bed environments. The proposed scheme offers beacon based real-time scheduling for reliable association process between parent and child nodes. In addition, it supports smooth handover procedure by reducing flooding overhead of control packets. Throughout the performance evaluation by using a real test-bed system and simulation, we illustrate that our proposed scheme demonstrates promising performance for wireless sensor networks with mobile robots.

Microresonator-based solitons for massively parallel coherent optical communications

NASA Astrophysics Data System (ADS)

Marin-Palomo, Pablo; Kemal, Juned N.; Karpov, Maxim; Kordts, Arne; Pfeifle, Joerg; Pfeiffer, Martin H. P.; Trocha, Philipp; Wolf, Stefan; Brasch, Victor; Anderson, Miles H.; Rosenberger, Ralf; Vijayan, Kovendhan; Freude, Wolfgang; Kippenberg, Tobias J.; Koos, Christian

2017-06-01

Solitons are waveforms that preserve their shape while propagating, as a result of a balance of dispersion and nonlinearity. Soliton-based data transmission schemes were investigated in the 1980s and showed promise as a way of overcoming the limitations imposed by dispersion of optical fibres. However, these approaches were later abandoned in favour of wavelength-division multiplexing schemes, which are easier to implement and offer improved scalability to higher data rates. Here we show that solitons could make a comeback in optical communications, not as a competitor but as a key element of massively parallel wavelength-division multiplexing. Instead of encoding data on the soliton pulse train itself, we use continuous-wave tones of the associated frequency comb as carriers for communication. Dissipative Kerr solitons (DKSs) (solitons that rely on a double balance of parametric gain and cavity loss, as well as dispersion and nonlinearity) are generated as continuously circulating pulses in an integrated silicon nitride microresonator via four-photon interactions mediated by the Kerr nonlinearity, leading to low-noise, spectrally smooth, broadband optical frequency combs. We use two interleaved DKS frequency combs to transmit a data stream of more than 50 terabits per second on 179 individual optical carriers that span the entire telecommunication C and L bands (centred around infrared telecommunication wavelengths of 1.55 micrometres). We also demonstrate coherent detection of a wavelength-division multiplexing data stream by using a pair of DKS frequency combs—one as a multi-wavelength light source at the transmitter and the other as the corresponding local oscillator at the receiver. This approach exploits the scalability of microresonator-based DKS frequency comb sources for massively parallel optical communications at both the transmitter and the receiver. Our results demonstrate the potential of these sources to replace the arrays of continuous-wave lasers that are currently used in high-speed communications. In combination with advanced spatial multiplexing schemes and highly integrated silicon photonic circuits, DKS frequency combs could bring chip-scale petabit-per-second transceivers into reach.

Quantum Attack-Resistent Certificateless Multi-Receiver Signcryption Scheme

PubMed Central

Li, Huixian; Chen, Xubao; Pang, Liaojun; Shi, Weisong

2013-01-01

The existing certificateless signcryption schemes were designed mainly based on the traditional public key cryptography, in which the security relies on the hard problems, such as factor decomposition and discrete logarithm. However, these problems will be easily solved by the quantum computing. So the existing certificateless signcryption schemes are vulnerable to the quantum attack. Multivariate public key cryptography (MPKC), which can resist the quantum attack, is one of the alternative solutions to guarantee the security of communications in the post-quantum age. Motivated by these concerns, we proposed a new construction of the certificateless multi-receiver signcryption scheme (CLMSC) based on MPKC. The new scheme inherits the security of MPKC, which can withstand the quantum attack. Multivariate quadratic polynomial operations, which have lower computation complexity than bilinear pairing operations, are employed in signcrypting a message for a certain number of receivers in our scheme. Security analysis shows that our scheme is a secure MPKC-based scheme. We proved its security under the hardness of the Multivariate Quadratic (MQ) problem and its unforgeability under the Isomorphism of Polynomials (IP) assumption in the random oracle model. The analysis results show that our scheme also has the security properties of non-repudiation, perfect forward secrecy, perfect backward secrecy and public verifiability. Compared with the existing schemes in terms of computation complexity and ciphertext length, our scheme is more efficient, which makes it suitable for terminals with low computation capacity like smart cards. PMID:23967037

Adaptive Information Dissemination Control to Provide Diffdelay for the Internet of Things.

PubMed

Liu, Xiao; Liu, Anfeng; Huang, Changqin

2017-01-12

Applications running on the Internet of Things, such as the Wireless Sensor and Actuator Networks (WSANs) platform, generally have different quality of service (QoS) requirements. For urgent events, it is crucial that information be reported to the actuator quickly, and the communication cost is the second factor. However, for interesting events, communication costs, network lifetime and time all become important factors. In most situations, these different requirements cannot be satisfied simultaneously. In this paper, an adaptive communication control based on a differentiated delay (ACCDS) scheme is proposed to resolve this conflict. In an ACCDS, source nodes of events adaptively send various searching actuators routings (SARs) based on the degree of sensitivity to delay while maintaining the network lifetime. For a delay-sensitive event, the source node sends a large number of SARs to actuators to identify and inform the actuators in an extremely short time; thus, action can be taken quickly but at higher communication costs. For delay-insensitive events, the source node sends fewer SARs to reduce communication costs and improve network lifetime. Therefore, an ACCDS can meet the QoS requirements of different events using a differentiated delay framework. Theoretical analysis simulation results indicate that an ACCDS provides delay and communication costs and differentiated services; an ACCDS scheme can reduce the network delay by 11.111%-53.684% for a delay-sensitive event and reduce the communication costs by 5%-22.308% for interesting events, and reduce the network lifetime by about 28.713%.

Adaptive Information Dissemination Control to Provide Diffdelay for the Internet of Things

PubMed Central

Liu, Xiao; Liu, Anfeng; Huang, Changqin

2017-01-01

Applications running on the Internet of Things, such as the Wireless Sensor and Actuator Networks (WSANs) platform, generally have different quality of service (QoS) requirements. For urgent events, it is crucial that information be reported to the actuator quickly, and the communication cost is the second factor. However, for interesting events, communication costs, network lifetime and time all become important factors. In most situations, these different requirements cannot be satisfied simultaneously. In this paper, an adaptive communication control based on a differentiated delay (ACCDS) scheme is proposed to resolve this conflict. In an ACCDS, source nodes of events adaptively send various searching actuators routings (SARs) based on the degree of sensitivity to delay while maintaining the network lifetime. For a delay-sensitive event, the source node sends a large number of SARs to actuators to identify and inform the actuators in an extremely short time; thus, action can be taken quickly but at higher communication costs. For delay-insensitive events, the source node sends fewer SARs to reduce communication costs and improve network lifetime. Therefore, an ACCDS can meet the QoS requirements of different events using a differentiated delay framework. Theoretical analysis simulation results indicate that an ACCDS provides delay and communication costs and differentiated services; an ACCDS scheme can reduce the network delay by 11.111%–53.684% for a delay-sensitive event and reduce the communication costs by 5%–22.308% for interesting events, and reduce the network lifetime by about 28.713%. PMID:28085097

Combined guaranteed throughput and best effort network-on-chip

DOEpatents

Chen, Gregory K.; Anders, Mark A.; Kaul, Himanshu; Krishnamurthy, Ram K.; Stillmaker, Aaron T.

2018-05-22

A first packet-switched reservation request is received. Data associated with the first packet-switched reservation request is communicated through a first circuit-switched channel according to a best effort communication scheme. A second packet-switched reservation request is received. Data associated with the second packet-switched reservation request is communicated through a second circuit-switched channel according to a guaranteed throughput communication scheme.

An Efficient User Authentication and User Anonymity Scheme with Provably Security for IoT-Based Medical Care System.

PubMed

Li, Chun-Ta; Wu, Tsu-Yang; Chen, Chin-Ling; Lee, Cheng-Chi; Chen, Chien-Ming

2017-06-23

In recent years, with the increase in degenerative diseases and the aging population in advanced countries, demands for medical care of older or solitary people have increased continually in hospitals and healthcare institutions. Applying wireless sensor networks for the IoT-based telemedicine system enables doctors, caregivers or families to monitor patients' physiological conditions at anytime and anyplace according to the acquired information. However, transmitting physiological data through the Internet concerns the personal privacy of patients. Therefore, before users can access medical care services in IoT-based medical care system, they must be authenticated. Typically, user authentication and data encryption are most critical for securing network communications over a public channel between two or more participants. In 2016, Liu and Chung proposed a bilinear pairing-based password authentication scheme for wireless healthcare sensor networks. They claimed their authentication scheme cannot only secure sensor data transmission, but also resist various well-known security attacks. In this paper, we demonstrate that Liu-Chung's scheme has some security weaknesses, and we further present an improved secure authentication and data encryption scheme for the IoT-based medical care system, which can provide user anonymity and prevent the security threats of replay and password/sensed data disclosure attacks. Moreover, we modify the authentication process to reduce redundancy in protocol design, and the proposed scheme is more efficient in performance compared with previous related schemes. Finally, the proposed scheme is provably secure in the random oracle model under ECDHP.

FPGA implementation cost and performance evaluation of IEEE 802.11 protocol encryption security schemes

NASA Astrophysics Data System (ADS)

Sklavos, N.; Selimis, G.; Koufopavlou, O.

2005-01-01

The explosive growth of internet and consumer demand for mobility has fuelled the exponential growth of wireless communications and networks. Mobile users want access to services and information, from both internet and personal devices, from a range of locations without the use of a cable medium. IEEE 802.11 is one of the most widely used wireless standards of our days. The amount of access and mobility into wireless networks requires a security infrastructure that protects communication within that network. The security of this protocol is based on the wired equivalent privacy (WEP) scheme. Currently, all the IEEE 802.11 market products support WEP. But recently, the 802.11i working group introduced the advanced encryption standard (AES), as the security scheme for the future IEEE 802.11 applications. In this paper, the hardware integrations of WEP and AES are studied. A field programmable gate array (FPGA) device has been used as the hardware implementation platform, for a fair comparison between the two security schemes. Measurements for the FPGA implementation cost, operating frequency, power consumption and performance are given.

MPEG-compliant joint source/channel coding using discrete cosine transform and substream scheduling for visual communication over packet networks

NASA Astrophysics Data System (ADS)

Kim, Seong-Whan; Suthaharan, Shan; Lee, Heung-Kyu; Rao, K. R.

2001-01-01

Quality of Service (QoS)-guarantee in real-time communication for multimedia applications is significantly important. An architectural framework for multimedia networks based on substreams or flows is effectively exploited for combining source and channel coding for multimedia data. But the existing frame by frame approach which includes Moving Pictures Expert Group (MPEG) cannot be neglected because it is a standard. In this paper, first, we designed an MPEG transcoder which converts an MPEG coded stream into variable rate packet sequences to be used for our joint source/channel coding (JSCC) scheme. Second, we designed a classification scheme to partition the packet stream into multiple substreams which have their own QoS requirements. Finally, we designed a management (reservation and scheduling) scheme for substreams to support better perceptual video quality such as the bound of end-to-end jitter. We have shown that our JSCC scheme is better than two other two popular techniques by simulation and real video experiments on the TCP/IP environment.

DREAM: Classification scheme for dialog acts in clinical research query mediation.

PubMed

Hoxha, Julia; Chandar, Praveen; He, Zhe; Cimino, James; Hanauer, David; Weng, Chunhua

2016-02-01

Clinical data access involves complex but opaque communication between medical researchers and query analysts. Understanding such communication is indispensable for designing intelligent human-machine dialog systems that automate query formulation. This study investigates email communication and proposes a novel scheme for classifying dialog acts in clinical research query mediation. We analyzed 315 email messages exchanged in the communication for 20 data requests obtained from three institutions. The messages were segmented into 1333 utterance units. Through a rigorous process, we developed a classification scheme and applied it for dialog act annotation of the extracted utterances. Evaluation results with high inter-annotator agreement demonstrate the reliability of this scheme. This dataset is used to contribute preliminary understanding of dialog acts distribution and conversation flow in this dialog space. Copyright © 2015 Elsevier Inc. All rights reserved.

A Round-Efficient Authenticated Key Agreement Scheme Based on Extended Chaotic Maps for Group Cloud Meeting.

PubMed

Lin, Tsung-Hung; Tsung, Chen-Kun; Lee, Tian-Fu; Wang, Zeng-Bo

2017-12-03

The security is a critical issue for business purposes. For example, the cloud meeting must consider strong security to maintain the communication privacy. Considering the scenario with cloud meeting, we apply extended chaotic map to present passwordless group authentication key agreement, termed as Passwordless Group Authentication Key Agreement (PL-GAKA). PL-GAKA improves the computation efficiency for the simple group password-based authenticated key agreement (SGPAKE) proposed by Lee et al. in terms of computing the session key. Since the extended chaotic map has equivalent security level to the Diffie-Hellman key exchange scheme applied by SGPAKE, the security of PL-GAKA is not sacrificed when improving the computation efficiency. Moreover, PL-GAKA is a passwordless scheme, so the password maintenance is not necessary. Short-term authentication is considered, hence the communication security is stronger than other protocols by dynamically generating session key in each cloud meeting. In our analysis, we first prove that each meeting member can get the correct information during the meeting. We analyze common security issues for the proposed PL-GAKA in terms of session key security, mutual authentication, perfect forward security, and data integrity. Moreover, we also demonstrate that communicating in PL-GAKA is secure when suffering replay attacks, impersonation attacks, privileged insider attacks, and stolen-verifier attacks. Eventually, an overall comparison is given to show the performance between PL-GAKA, SGPAKE and related solutions.

Dynamic Resource Allocation and Access Class Barring Scheme for Delay-Sensitive Devices in Machine to Machine (M2M) Communications.

PubMed

Li, Ning; Cao, Chao; Wang, Cong

2017-06-15

Supporting simultaneous access of machine-type devices is a critical challenge in machine-to-machine (M2M) communications. In this paper, we propose an optimal scheme to dynamically adjust the Access Class Barring (ACB) factor and the number of random access channel (RACH) resources for clustered machine-to-machine (M2M) communications, in which Delay-Sensitive (DS) devices coexist with Delay-Tolerant (DT) ones. In M2M communications, since delay-sensitive devices share random access resources with delay-tolerant devices, reducing the resources consumed by delay-sensitive devices means that there will be more resources available to delay-tolerant ones. Our goal is to optimize the random access scheme, which can not only satisfy the requirements of delay-sensitive devices, but also take the communication quality of delay-tolerant ones into consideration. We discuss this problem from the perspective of delay-sensitive services by adjusting the resource allocation and ACB scheme for these devices dynamically. Simulation results show that our proposed scheme realizes good performance in satisfying the delay-sensitive services as well as increasing the utilization rate of the random access resources allocated to them.

Decoding mobile-phone image sensor rolling shutter effect for visible light communications

NASA Astrophysics Data System (ADS)

Liu, Yang

2016-01-01

Optical wireless communication (OWC) using visible lights, also known as visible light communication (VLC), has attracted significant attention recently. As the traditional OWC and VLC receivers (Rxs) are based on PIN photo-diode or avalanche photo-diode, deploying the complementary metal-oxide-semiconductor (CMOS) image sensor as the VLC Rx is attractive since nowadays nearly every person has a smart phone with embedded CMOS image sensor. However, deploying the CMOS image sensor as the VLC Rx is challenging. In this work, we propose and demonstrate two simple contrast ratio (CR) enhancement schemes to improve the contrast of the rolling shutter pattern. Then we describe their processing algorithms one by one. The experimental results show that both the proposed CR enhancement schemes can significantly mitigate the high-intensity fluctuations of the rolling shutter pattern and improve the bit-error-rate performance.

Multicellular Computing Using Conjugation for Wiring

PubMed Central

Goñi-Moreno, Angel; Amos, Martyn; de la Cruz, Fernando

2013-01-01

Recent efforts in synthetic biology have focussed on the implementation of logical functions within living cells. One aim is to facilitate both internal “re-programming” and external control of cells, with potential applications in a wide range of domains. However, fundamental limitations on the degree to which single cells may be re-engineered have led to a growth of interest in multicellular systems, in which a “computation” is distributed over a number of different cell types, in a manner analogous to modern computer networks. Within this model, individual cell type perform specific sub-tasks, the results of which are then communicated to other cell types for further processing. The manner in which outputs are communicated is therefore of great significance to the overall success of such a scheme. Previous experiments in distributed cellular computation have used global communication schemes, such as quorum sensing (QS), to implement the “wiring” between cell types. While useful, this method lacks specificity, and limits the amount of information that may be transferred at any one time. We propose an alternative scheme, based on specific cell-cell conjugation. This mechanism allows for the direct transfer of genetic information between bacteria, via circular DNA strands known as plasmids. We design a multi-cellular population that is able to compute, in a distributed fashion, a Boolean XOR function. Through this, we describe a general scheme for distributed logic that works by mixing different strains in a single population; this constitutes an important advantage of our novel approach. Importantly, the amount of genetic information exchanged through conjugation is significantly higher than the amount possible through QS-based communication. We provide full computational modelling and simulation results, using deterministic, stochastic and spatially-explicit methods. These simulations explore the behaviour of one possible conjugation-wired cellular computing system under different conditions, and provide baseline information for future laboratory implementations. PMID:23840385

A Scenario-Based Protocol Checker for Public-Key Authentication Scheme

NASA Astrophysics Data System (ADS)

Saito, Takamichi

Security protocol provides communication security for the internet. One of the important features of it is authentication with key exchange. Its correctness is a requirement of the whole of the communication security. In this paper, we introduce three attack models realized as their attack scenarios, and provide an authentication-protocol checker for applying three attack-scenarios based on the models. We also utilize it to check two popular security protocols: Secure SHell (SSH) and Secure Socket Layer/Transport Layer Security (SSL/TLS).

LWT Based Sensor Node Signal Processing in Vehicle Surveillance Distributed Sensor Network

NASA Astrophysics Data System (ADS)

Cha, Daehyun; Hwang, Chansik

Previous vehicle surveillance researches on distributed sensor network focused on overcoming power limitation and communication bandwidth constraints in sensor node. In spite of this constraints, vehicle surveillance sensor node must have signal compression, feature extraction, target localization, noise cancellation and collaborative signal processing with low computation and communication energy dissipation. In this paper, we introduce an algorithm for light-weight wireless sensor node signal processing based on lifting scheme wavelet analysis feature extraction in distributed sensor network.

Fundamental Limits of Delay and Security in Device-to-Device Communication

DTIC Science & Technology

2013-01-01

systematic MDS (maximum distance separable) codes and random binning strategies that achieve a Pareto optimal delayreconstruction tradeoff. The erasure MD...file, and a coding scheme based on erasure compression and Slepian-Wolf binning is presented. The coding scheme is shown to provide a Pareto optimal...ble) codes and random binning strategies that achieve a Pareto optimal delay- reconstruction tradeoff. The erasure MD setup is then used to propose a

Experimental quantum-cryptography scheme based on orthogonal states

NASA Astrophysics Data System (ADS)

Avella, Alessio; Brida, Giorgio; Degiovanni, Ivo Pietro; Genovese, Marco; Gramegna, Marco; Traina, Paolo

2010-12-01

Since, in general, nonorthogonal states cannot be cloned, any eavesdropping attempt in a quantum-communication scheme using nonorthogonal states as carriers of information introduces some errors in the transmission, leading to the possibility of detecting the spy. Usually, orthogonal states are not used in quantum-cryptography schemes since they can be faithfully cloned without altering the transmitted data. Nevertheless, L. Goldberg and L. Vaidman [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.75.1239 75, 1239 (1995)] proposed a protocol in which, even if the data exchange is realized using two orthogonal states, any attempt to eavesdrop is detectable by the legal users. In this scheme the orthogonal states are superpositions of two localized wave packets traveling along separate channels. Here we present an experiment realizing this scheme.

Evolvable mathematical models: A new artificial Intelligence paradigm

NASA Astrophysics Data System (ADS)

Grouchy, Paul

We develop a novel Artificial Intelligence paradigm to generate autonomously artificial agents as mathematical models of behaviour. Agent/environment inputs are mapped to agent outputs via equation trees which are evolved in a manner similar to Symbolic Regression in Genetic Programming. Equations are comprised of only the four basic mathematical operators, addition, subtraction, multiplication and division, as well as input and output variables and constants. From these operations, equations can be constructed that approximate any analytic function. These Evolvable Mathematical Models (EMMs) are tested and compared to their Artificial Neural Network (ANN) counterparts on two benchmarking tasks: the double-pole balancing without velocity information benchmark and the challenging discrete Double-T Maze experiments with homing. The results from these experiments show that EMMs are capable of solving tasks typically solved by ANNs, and that they have the ability to produce agents that demonstrate learning behaviours. To further explore the capabilities of EMMs, as well as to investigate the evolutionary origins of communication, we develop NoiseWorld, an Artificial Life simulation in which interagent communication emerges and evolves from initially noncommunicating EMM-based agents. Agents develop the capability to transmit their x and y position information over a one-dimensional channel via a complex, dialogue-based communication scheme. These evolved communication schemes are analyzed and their evolutionary trajectories examined, yielding significant insight into the emergence and subsequent evolution of cooperative communication. Evolved agents from NoiseWorld are successfully transferred onto physical robots, demonstrating the transferability of EMM-based AIs from simulation into physical reality.

Security analysis and enhanced user authentication in proxy mobile IPv6 networks

PubMed Central

Kang, Dongwoo; Jung, Jaewook; Lee, Donghoon; Kim, Hyoungshick

2017-01-01

The Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management protocol that allows a Mobile Node(MN) connected to the PMIPv6 domain to move from one network to another without changing the assigned IPv6 address. The user authentication procedure in this protocol is not standardized, but many smartcard based authentication schemes have been proposed. Recently, Alizadeh et al. proposed an authentication scheme for the PMIPv6. However, it could allow an attacker to derive an encryption key that must be securely shared between MN and the Mobile Access Gate(MAG). As a result, outsider adversary can derive MN’s identity, password and session key. In this paper, we analyze Alizadeh et al.’s scheme regarding security and propose an enhanced authentication scheme that uses a dynamic identity to satisfy anonymity. Furthermore, we use BAN logic to show that our scheme can successfully generate and communicate with the inter-entity session key. PMID:28719621

On the Study of a Quadrature DCSK Modulation Scheme for Cognitive Radio

NASA Astrophysics Data System (ADS)

Quyen, Nguyen Xuan

The past decade has witnessed a boom of wireless communications which necessitate an increasing improvement of data rate, error-rate performance, bandwidth efficiency, and information security. In this work, we propose a quadrature (IQ) differential chaos-shift keying (DCSK) modulation scheme for the application in cognitive radio (CR), named CR-IQ-DCSK, which offers the above improvement. Chaotic signal is generated in frequency domain and then converted into time domain via an inverse Fourier transform. The real and imaginary components of the frequency-based chaotic signal are simultaneously used in in-phase and quadrature branches of an IQ modulator, where each branch conveys two bits by means of a DCSK-based modulation. Schemes and operating principle of the modulator and demodulator are proposed and described. Analytical BER performance for the proposed schemes over a typical multipath Rayleigh fading channel is derived and verified by numerical simulations. Results show that the proposed scheme outperforms DCSK, CDSK and performs better with the increment of the number of channel paths.

A framework for implementing data services in multi-service mobile satellite systems

NASA Technical Reports Server (NTRS)

Ali, Mohammed O.; Leung, Victor C. M.; Spolsky, Andrew I.

1988-01-01

Mobile satellite systems being planned for introduction in the early 1990s are expected to be invariably of the multi-service type. Mobile Telephone Service (MTS), Mobile Radio Service (MRS), and Mobile Data Service (MDS) are the major classifications used to categorize the many user applications to be supported. The MTS and MRS services encompass circuit-switched voice communication applications, and may be efficiently implemented using a centralized Demand-Assigned Multiple Access (DAMA) scheme. Applications under the MDS category are, on the other hand, message-oriented and expected to vary widely in characteristics; from simplex mode short messaging applications to long duration, full-duplex interactive data communication and large file transfer applications. For some applications under this service category, the conventional circuit-based DAMA scheme may prove highly inefficient due to the long time required to set up and establish communication links relative to the actual message transmission time. It is proposed that by defining a set of basic bearer services to be supported in MDS and optimizing their transmission and access schemes independent of the MTS and MRS services, the MDS applications can be more efficiently integrated into the multi-service design of mobile satellite systems.

A framework for implementing data services in multi-service mobile satellite systems

NASA Astrophysics Data System (ADS)

Ali, Mohammed O.; Leung, Victor C. M.; Spolsky, Andrew I.

1988-05-01

Mobile satellite systems being planned for introduction in the early 1990s are expected to be invariably of the multi-service type. Mobile Telephone Service (MTS), Mobile Radio Service (MRS), and Mobile Data Service (MDS) are the major classifications used to categorize the many user applications to be supported. The MTS and MRS services encompass circuit-switched voice communication applications, and may be efficiently implemented using a centralized Demand-Assigned Multiple Access (DAMA) scheme. Applications under the MDS category are, on the other hand, message-oriented and expected to vary widely in characteristics; from simplex mode short messaging applications to long duration, full-duplex interactive data communication and large file transfer applications. For some applications under this service category, the conventional circuit-based DAMA scheme may prove highly inefficient due to the long time required to set up and establish communication links relative to the actual message transmission time. It is proposed that by defining a set of basic bearer services to be supported in MDS and optimizing their transmission and access schemes independent of the MTS and MRS services, the MDS applications can be more efficiently integrated into the multi-service design of mobile satellite systems.

Design and Analysis of a Dynamic Mobility Management Scheme for Wireless Mesh Network

PubMed Central

Roy, Sudipta

2013-01-01

Seamless mobility management of the mesh clients (MCs) in wireless mesh network (WMN) has drawn a lot of attention from the research community. A number of mobility management schemes such as mesh network with mobility management (MEMO), mesh mobility management (M3), and wireless mesh mobility management (WMM) have been proposed. The common problem with these schemes is that they impose uniform criteria on all the MCs for sending route update message irrespective of their distinct characteristics. This paper proposes a session-to-mobility ratio (SMR) based dynamic mobility management scheme for handling both internet and intranet traffic. To reduce the total communication cost, this scheme considers each MC's session and mobility characteristics by dynamically determining optimal threshold SMR value for each MC. A numerical analysis of the proposed scheme has been carried out. Comparison with other schemes shows that the proposed scheme outperforms MEMO, M3, and WMM with respect to total cost. PMID:24311982

Heralded quantum repeater based on the scattering of photons off single emitters using parametric down-conversion source.

PubMed

Song, Guo-Zhu; Wu, Fang-Zhou; Zhang, Mei; Yang, Guo-Jian

2016-06-28

Quantum repeater is the key element in quantum communication and quantum information processing. Here, we investigate the possibility of achieving a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We design the compact quantum circuits for nonlocal entanglement generation, entanglement swapping, and entanglement purification, and discuss the feasibility of our protocols with current experimental technology. In our scheme, we use a parametric down-conversion source instead of ideal single-photon sources to realize the heralded quantum repeater. Moreover, our protocols can turn faulty events into the detection of photon polarization, and the fidelity can reach 100% in principle. Our scheme is attractive and scalable, since it can be realized with artificial solid-state quantum systems. With developed experimental technique on controlling emitter-waveguide systems, the repeater may be very useful in long-distance quantum communication.

Heralded quantum repeater based on the scattering of photons off single emitters using parametric down-conversion source

PubMed Central

Song, Guo-Zhu; Wu, Fang-Zhou; Zhang, Mei; Yang, Guo-Jian

2016-01-01

Quantum repeater is the key element in quantum communication and quantum information processing. Here, we investigate the possibility of achieving a heralded quantum repeater based on the scattering of photons off single emitters in one-dimensional waveguides. We design the compact quantum circuits for nonlocal entanglement generation, entanglement swapping, and entanglement purification, and discuss the feasibility of our protocols with current experimental technology. In our scheme, we use a parametric down-conversion source instead of ideal single-photon sources to realize the heralded quantum repeater. Moreover, our protocols can turn faulty events into the detection of photon polarization, and the fidelity can reach 100% in principle. Our scheme is attractive and scalable, since it can be realized with artificial solid-state quantum systems. With developed experimental technique on controlling emitter-waveguide systems, the repeater may be very useful in long-distance quantum communication. PMID:27350159

A Suboptimal Power-Saving Transmission Scheme in Multiple Component Carrier Networks

NASA Astrophysics Data System (ADS)

Chung, Yao-Liang; Tsai, Zsehong

Power consumption due to transmissions in base stations (BSs) has been a major contributor to communication-related CO2 emissions. A power optimization model is developed in this study with respect to radio resource allocation and activation in a multiple Component Carrier (CC) environment. We formulate and solve the power-minimization problem of the BS transceivers for multiple-CC networks with carrier aggregation, while maintaining the overall system and respective users' utilities above minimum levels. The optimized power consumption based on this model can be viewed as a lower bound of that of other algorithms employed in practice. A suboptimal scheme with low computation complexity is proposed. Numerical results show that the power consumption of our scheme is much better than that of the conventional one in which all CCs are always active, if both schemes maintain the same required utilities.

Security enhanced multi-factor biometric authentication scheme using bio-hash function.

PubMed

Choi, Younsung; Lee, Youngsook; Moon, Jongho; Won, Dongho

2017-01-01

With the rapid development of personal information and wireless communication technology, user authentication schemes have been crucial to ensure that wireless communications are secure. As such, various authentication schemes with multi-factor authentication have been proposed to improve the security of electronic communications. Multi-factor authentication involves the use of passwords, smart cards, and various biometrics to provide users with the utmost privacy and data protection. Cao and Ge analyzed various authentication schemes and found that Younghwa An's scheme was susceptible to a replay attack where an adversary masquerades as a legal server and a user masquerading attack where user anonymity is not provided, allowing an adversary to execute a password change process by intercepting the user's ID during login. Cao and Ge improved upon Younghwa An's scheme, but various security problems remained. This study demonstrates that Cao and Ge's scheme is susceptible to a biometric recognition error, slow wrong password detection, off-line password attack, user impersonation attack, ID guessing attack, a DoS attack, and that their scheme cannot provide session key agreement. Then, to address all weaknesses identified in Cao and Ge's scheme, this study proposes a security enhanced multi-factor biometric authentication scheme and provides a security analysis and formal analysis using Burrows-Abadi-Needham logic. Finally, the efficiency analysis reveals that the proposed scheme can protect against several possible types of attacks with only a slightly high computational cost.

Demonstration of spatial-light-modulation-based four-wave mixing in cold atoms

NASA Astrophysics Data System (ADS)

Juo, Jz-Yuan; Lin, Jia-Kang; Cheng, Chin-Yao; Liu, Zi-Yu; Yu, Ite A.; Chen, Yong-Fan

2018-05-01

Long-distance quantum optical communications usually require efficient wave-mixing processes to convert the wavelengths of single photons. Many quantum applications based on electromagnetically induced transparency (EIT) have been proposed and demonstrated at the single-photon level, such as quantum memories, all-optical transistors, and cross-phase modulations. However, EIT-based four-wave mixing (FWM) in a resonant double-Λ configuration has a maximum conversion efficiency (CE) of 25% because of absorptive loss due to spontaneous emission. An improved scheme using spatially modulated intensities of two control fields has been theoretically proposed to overcome this conversion limit. In this study, we first demonstrate wavelength conversion from 780 to 795 nm with a 43% CE by using this scheme at an optical density (OD) of 19 in cold 87Rb atoms. According to the theoretical model, the CE in the proposed scheme can further increase to 96% at an OD of 240 under ideal conditions, thereby attaining an identical CE to that of the previous nonresonant double-Λ scheme at half the OD. This spatial-light-modulation-based FWM scheme can achieve a near-unity CE, thus providing an easy method of implementing an efficient quantum wavelength converter for all-optical quantum information processing.

A two layer chaotic encryption scheme of secure image transmission for DCT precoded OFDM-VLC transmission

NASA Astrophysics Data System (ADS)

Wang, Zhongpeng; Chen, Fangni; Qiu, Weiwei; Chen, Shoufa; Ren, Dongxiao

2018-03-01

In this paper, a two-layer image encryption scheme for a discrete cosine transform (DCT) precoded orthogonal frequency division multiplexing (OFDM) visible light communication (VLC) system is proposed. Firstly, in the proposed scheme the transmitted image is first encrypted by a chaos scrambling sequence,which is generated from the hybrid 4-D hyper- and Arnold map in the upper-layer. After that, the encrypted image is converted into digital QAM modulation signal, which is re-encrypted by chaos scrambling sequence based on Arnold map in physical layer to further enhance the security of the transmitted image. Moreover, DCT precoding is employed to improve BER performance of the proposed system and reduce the PAPR of OFDM signal. The BER and PAPR performances of the proposed system are evaluated by simulation experiments. The experiment results show that the proposed two-layer chaos scrambling schemes achieve image secure transmission for image-based OFDM VLC. Furthermore, DCT precoding can reduce the PAPR and improve the BER performance of OFDM-based VLC.

A low-complexity and high performance concatenated coding scheme for high-speed satellite communications

NASA Technical Reports Server (NTRS)

Lin, Shu; Rhee, Dojun; Rajpal, Sandeep

1993-01-01

This report presents a low-complexity and high performance concatenated coding scheme for high-speed satellite communications. In this proposed scheme, the NASA Standard Reed-Solomon (RS) code over GF(2(exp 8) is used as the outer code and the second-order Reed-Muller (RM) code of Hamming distance 8 is used as the inner code. The RM inner code has a very simple trellis structure and is decoded with the soft-decision Viterbi decoding algorithm. It is shown that the proposed concatenated coding scheme achieves an error performance which is comparable to that of the NASA TDRS concatenated coding scheme in which the NASA Standard rate-1/2 convolutional code of constraint length 7 and d sub free = 10 is used as the inner code. However, the proposed RM inner code has much smaller decoding complexity, less decoding delay, and much higher decoding speed. Consequently, the proposed concatenated coding scheme is suitable for reliable high-speed satellite communications, and it may be considered as an alternate coding scheme for the NASA TDRS system.

Evaluation of counterfactuality in counterfactual communication protocols

NASA Astrophysics Data System (ADS)

Arvidsson-Shukur, D. R. M.; Barnes, C. H. W.; Gottfries, A. N. O.

2017-12-01

We provide an in-depth investigation of parameter estimation in nested Mach-Zehnder interferometers (NMZIs) using two information measures: the Fisher information and the Shannon mutual information. Protocols for counterfactual communication have, so far, been based on two different definitions of counterfactuality. In particular, some schemes have been based on NMZI devices, and have recently been subject to criticism. We provide a methodology for evaluating the counterfactuality of these protocols, based on an information-theoretical framework. More specifically, we make the assumption that any realistic quantum channel in MZI structures will have some weak uncontrolled interaction. We then use the Fisher information of this interaction to measure counterfactual violations. The measure is used to evaluate the suggested counterfactual communication protocol of H. Salih et al. [Phys. Rev. Lett. 110, 170502 (2013), 10.1103/PhysRevLett.110.170502]. The protocol of D. R. M. Arvidsson-Shukur and C. H. W. Barnes [Phys. Rev. A 94, 062303 (2016), 10.1103/PhysRevA.94.062303], based on a different definition, is evaluated with a probability measure. Our results show that the definition of Arvidsson-Shukur and Barnes is satisfied by their scheme, while that of Salih et al. is only satisfied by perfect quantum channels. For realistic devices the latter protocol does not achieve its objective.

A joint precoding scheme for indoor downlink multi-user MIMO VLC systems

NASA Astrophysics Data System (ADS)

Zhao, Qiong; Fan, Yangyu; Kang, Bochao

2017-11-01

In this study, we aim to improve the system performance and reduce the implementation complexity of precoding scheme for visible light communication (VLC) systems. By incorporating the power-method algorithm and the block diagonalization (BD) algorithm, we propose a joint precoding scheme for indoor downlink multi-user multi-input-multi-output (MU-MIMO) VLC systems. In this scheme, we apply the BD algorithm to eliminate the co-channel interference (CCI) among users firstly. Secondly, the power-method algorithm is used to search the precoding weight for each user based on the optimal criterion of signal to interference plus noise ratio (SINR) maximization. Finally, the optical power restrictions of VLC systems are taken into account to constrain the precoding weight matrix. Comprehensive computer simulations in two scenarios indicate that the proposed scheme always has better bit error rate (BER) performance and lower computation complexity than that of the traditional scheme.

LDPC-coded MIMO optical communication over the atmospheric turbulence channel using Q-ary pulse-position modulation.

PubMed

Djordjevic, Ivan B

2007-08-06

We describe a coded power-efficient transmission scheme based on repetition MIMO principle suitable for communication over the atmospheric turbulence channel, and determine its channel capacity. The proposed scheme employs the Q-ary pulse-position modulation. We further study how to approach the channel capacity limits using low-density parity-check (LDPC) codes. Component LDPC codes are designed using the concept of pairwise-balanced designs. Contrary to the several recent publications, bit-error rates and channel capacities are reported assuming non-ideal photodetection. The atmospheric turbulence channel is modeled using the Gamma-Gamma distribution function due to Al-Habash et al. Excellent bit-error rate performance improvement, over uncoded case, is found.

Improved BDF Relaying Scheme Using Time Diversity over Atmospheric Turbulence and Misalignment Fading Channels

PubMed Central

García-Zambrana, Antonio; Castillo-Vázquez, Carmen; Castillo-Vázquez, Beatriz

2014-01-01

A novel bit-detect-and-forward (BDF) relaying scheme based on repetition coding with the relay is proposed, significantly improving the robustness to impairments proper to free-space optical (FSO) communications such as unsuitable alignment between transmitter and receiver as well as fluctuations in the irradiance of the transmitted optical beam due to the atmospheric turbulence. Closed-form asymptotic bit-error-rate (BER) expressions are derived for a 3-way FSO communication setup. Fully exploiting the potential time-diversity available in the relay turbulent channel, a relevant better performance is achieved, showing a greater robustness to the relay location since a high diversity gain is provided regardless of the source-destination link distance. PMID:24587711

OptoRadio: a method of wireless communication using orthogonal M-ary PSK (OMPSK) modulation

NASA Astrophysics Data System (ADS)

Gaire, Sunil Kumar; Faruque, Saleh; Ahamed, Md. Maruf

2016-09-01

Laser based radio communication system, i.e. OptoRadio, using Orthogonal M-ary PSK Modulation scheme is presented in this paper. In this scheme, when a block of data needs to be transmitted, the corresponding block of biorthogonal code is transmitted by means of multi-phase shift keying. At the receiver, two photo diodes are cross coupled. The effect is that the net output power due to ambient light is close to zero. The laser signal is then transmitted only into one of the receivers. With all other signals being cancelled out, the laser signal is an overwhelmingly dominant signal. The detailed design, bit error correction capabilities, and bandwidth efficiency are presented to illustrate the concept.

A Chaos MIMO-OFDM Scheme for Mobile Communication with Physical-Layer Security

NASA Astrophysics Data System (ADS)

Okamoto, Eiji

Chaos communications enable a physical-layer security, which can enhance the transmission security in combining with upper-layer encryption techniques, or can omit the upper-layer secure protocol and enlarges the transmission efficiency. However, the chaos communication usually degrades the error rate performance compared to unencrypted digital modulations. To achieve both physical-layer security and channel coding gain, we have proposed a chaos multiple-input multiple-output (MIMO) scheme in which a rate-one chaos convolution is applied to MIMO multiplexing. However, in the conventional study only flat fading is considered. To apply this scheme to practical mobile environments, i.e., multipath fading channels, we propose a chaos MIMO-orthogonal frequency division multi-plexing (OFDM) scheme and show its effectiveness through computer simulations.

Controlled quantum secure direct communication by entanglement distillation or generalized measurement

NASA Astrophysics Data System (ADS)

Tan, Xiaoqing; Zhang, Xiaoqian

2016-05-01

We propose two controlled quantum secure communication schemes by entanglement distillation or generalized measurement. The sender Alice, the receiver Bob and the controllers David and Cliff take part in the whole schemes. The supervisors David and Cliff can control the information transmitted from Alice to Bob by adjusting the local measurement angles θ _4 and θ _3. Bob can verify his secret information by classical one-way function after communication. The average amount of information is analyzed and compared for these two methods by MATLAB. The generalized measurement is a better scheme. Our schemes are secure against some well-known attacks because classical encryption and decoy states are used to ensure the security of the classical channel and the quantum channel.

AIB-OR: improving onion routing circuit construction using anonymous identity-based cryptosystems.

PubMed

Wang, Changji; Shi, Dongyuan; Xu, Xilei

2015-01-01

The rapid growth of Internet applications has made communication anonymity an increasingly important or even indispensable security requirement. Onion routing has been employed as an infrastructure for anonymous communication over a public network, which provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. However, existing onion routing protocols usually exhibit poor performance due to repeated encryption operations. In this paper, we first present an improved anonymous multi-receiver identity-based encryption (AMRIBE) scheme, and an improved identity-based one-way anonymous key agreement (IBOWAKE) protocol. We then propose an efficient onion routing protocol named AIB-OR that provides provable security and strong anonymity. Our main approach is to use our improved AMRIBE scheme and improved IBOWAKE protocol in onion routing circuit construction. Compared with other onion routing protocols, AIB-OR provides high efficiency, scalability, strong anonymity and fault tolerance. Performance measurements from a prototype implementation show that our proposed AIB-OR can achieve high bandwidths and low latencies when deployed over the Internet.

AIB-OR: Improving Onion Routing Circuit Construction Using Anonymous Identity-Based Cryptosystems

PubMed Central

Wang, Changji; Shi, Dongyuan; Xu, Xilei

2015-01-01

The rapid growth of Internet applications has made communication anonymity an increasingly important or even indispensable security requirement. Onion routing has been employed as an infrastructure for anonymous communication over a public network, which provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. However, existing onion routing protocols usually exhibit poor performance due to repeated encryption operations. In this paper, we first present an improved anonymous multi-receiver identity-based encryption (AMRIBE) scheme, and an improved identity-based one-way anonymous key agreement (IBOWAKE) protocol. We then propose an efficient onion routing protocol named AIB-OR that provides provable security and strong anonymity. Our main approach is to use our improved AMRIBE scheme and improved IBOWAKE protocol in onion routing circuit construction. Compared with other onion routing protocols, AIB-OR provides high efficiency, scalability, strong anonymity and fault tolerance. Performance measurements from a prototype implementation show that our proposed AIB-OR can achieve high bandwidths and low latencies when deployed over the Internet. PMID:25815879

Quantum money with classical verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavinsky, Dmitry

We propose and construct a quantum money scheme that allows verification through classical communication with a bank. This is the first demonstration that a secure quantum money scheme exists that does not require quantum communication for coin verification. Our scheme is secure against adaptive adversaries - this property is not directly related to the possibility of classical verification, nevertheless none of the earlier quantum money constructions is known to possess it.

Quantum money with classical verification

NASA Astrophysics Data System (ADS)

Gavinsky, Dmitry

2014-12-01

We propose and construct a quantum money scheme that allows verification through classical communication with a bank. This is the first demonstration that a secure quantum money scheme exists that does not require quantum communication for coin verification. Our scheme is secure against adaptive adversaries - this property is not directly related to the possibility of classical verification, nevertheless none of the earlier quantum money constructions is known to possess it.

Bluetooth based chaos synchronization using particle swarm optimization and its applications to image encryption.

PubMed

Yau, Her-Terng; Hung, Tzu-Hsiang; Hsieh, Chia-Chun

2012-01-01

This study used the complex dynamic characteristics of chaotic systems and Bluetooth to explore the topic of wireless chaotic communication secrecy and develop a communication security system. The PID controller for chaos synchronization control was applied, and the optimum parameters of this PID controller were obtained using a Particle Swarm Optimization (PSO) algorithm. Bluetooth was used to realize wireless transmissions, and a chaotic wireless communication security system was developed in the design concept of a chaotic communication security system. The experimental results show that this scheme can be used successfully in image encryption.

n-body simulations using message passing parallel computers.

NASA Astrophysics Data System (ADS)

Grama, A. Y.; Kumar, V.; Sameh, A.

The authors present new parallel formulations of the Barnes-Hut method for n-body simulations on message passing computers. These parallel formulations partition the domain efficiently incurring minimal communication overhead. This is in contrast to existing schemes that are based on sorting a large number of keys or on the use of global data structures. The new formulations are augmented by alternate communication strategies which serve to minimize communication overhead. The impact of these communication strategies is experimentally studied. The authors report on experimental results obtained from an astrophysical simulation on an nCUBE2 parallel computer.

Superframe Duration Allocation Schemes to Improve the Throughput of Cluster-Tree Wireless Sensor Networks

PubMed Central

Leão, Erico; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco

2017-01-01

The use of Wireless Sensor Network (WSN) technologies is an attractive option to support wide-scale monitoring applications, such as the ones that can be found in precision agriculture, environmental monitoring and industrial automation. The IEEE 802.15.4/ZigBee cluster-tree topology is a suitable topology to build wide-scale WSNs. Despite some of its known advantages, including timing synchronisation and duty-cycle operation, cluster-tree networks may suffer from severe network congestion problems due to the convergecast pattern of its communication traffic. Therefore, the careful adjustment of transmission opportunities (superframe durations) allocated to the cluster-heads is an important research issue. This paper proposes a set of proportional Superframe Duration Allocation (SDA) schemes, based on well-defined protocol and timing models, and on the message load imposed by child nodes (Load-SDA scheme), or by number of descendant nodes (Nodes-SDA scheme) of each cluster-head. The underlying reasoning is to adequately allocate transmission opportunities (superframe durations) and parametrize buffer sizes, in order to improve the network throughput and avoid typical problems, such as: network congestion, high end-to-end communication delays and discarded messages due to buffer overflows. Simulation assessments show how proposed allocation schemes may clearly improve the operation of wide-scale cluster-tree networks. PMID:28134822

Coded throughput performance simulations for the time-varying satellite channel. M.S. Thesis

NASA Technical Reports Server (NTRS)

Han, LI

1995-01-01

The design of a reliable satellite communication link involving the data transfer from a small, low-orbit satellite to a ground station, but through a geostationary satellite, was examined. In such a scenario, the received signal power to noise density ratio increases as the transmitting low-orbit satellite comes into view, and then decreases as it then departs, resulting in a short-duration, time-varying communication link. The optimal values of the small satellite antenna beamwidth, signaling rate, modulation scheme and the theoretical link throughput (in bits per day) have been determined. The goal of this thesis is to choose a practical coding scheme which maximizes the daily link throughput while satisfying a prescribed probability of error requirement. We examine the throughput of both fixed rate and variable rate concatenated forward error correction (FEC) coding schemes for the additive white Gaussian noise (AWGN) channel, and then examine the effect of radio frequency interference (RFI) on the best coding scheme among them. Interleaving is used to mitigate degradation due to RFI. It was found that the variable rate concatenated coding scheme could achieve 74 percent of the theoretical throughput, equivalent to 1.11 Gbits/day based on the cutoff rate R(sub 0). For comparison, 87 percent is achievable for AWGN-only case.

A Secure Key Distribution System of Quantum Cryptography Based on the Coherent State

NASA Technical Reports Server (NTRS)

Guo, Guang-Can; Zhang, Xiao-Yu

1996-01-01

The cryptographic communication has a lot of important applications, particularly in the magnificent prospects of private communication. As one knows, the security of cryptographic channel depends crucially on the secrecy of the key. The Vernam cipher is the only cipher system which has guaranteed security. In that system the key must be as long as the message and most be used only once. Quantum cryptography is a method whereby key secrecy can be guaranteed by a physical law. So it is impossible, even in principle, to eavesdrop on such channels. Quantum cryptography has been developed in recent years. Up to now, many schemes of quantum cryptography have been proposed. Now one of the main problems in this field is how to increase transmission distance. In order to use quantum nature of light, up to now proposed schemes all use very dim light pulses. The average photon number is about 0.1. Because of the loss of the optical fiber, it is difficult for the quantum cryptography based on one photon level or on dim light to realize quantum key-distribution over long distance. A quantum key distribution based on coherent state is introduced in this paper. Here we discuss the feasibility and security of this scheme.

Compound synchronization of four memristor chaotic oscillator systems and secure communication.

PubMed

Sun, Junwei; Shen, Yi; Yin, Quan; Xu, Chengjie

2013-03-01

In this paper, a novel kind of compound synchronization among four chaotic systems is investigated, where the drive systems have been conceptually divided into two categories: scaling drive systems and base drive systems. Firstly, a sufficient condition is obtained to ensure compound synchronization among four memristor chaotic oscillator systems based on the adaptive technique. Secondly, a secure communication scheme via adaptive compound synchronization of four memristor chaotic oscillator systems is presented. The corresponding theoretical proofs and numerical simulations are given to demonstrate the validity and feasibility of the proposed control technique. The unpredictability of scaling drive systems can additionally enhance the security of communication. The transmitted signals can be split into several parts loaded in the drive systems to improve the reliability of communication.

Hybrid architecture for encoded measurement-based quantum computation

PubMed Central

Zwerger, M.; Briegel, H. J.; Dür, W.

2014-01-01

We present a hybrid scheme for quantum computation that combines the modular structure of elementary building blocks used in the circuit model with the advantages of a measurement-based approach to quantum computation. We show how to construct optimal resource states of minimal size to implement elementary building blocks for encoded quantum computation in a measurement-based way, including states for error correction and encoded gates. The performance of the scheme is determined by the quality of the resource states, where within the considered error model a threshold of the order of 10% local noise per particle for fault-tolerant quantum computation and quantum communication. PMID:24946906

An Efficient User Authentication and User Anonymity Scheme with Provably Security for IoT-Based Medical Care System

PubMed Central

Wu, Tsu-Yang; Chen, Chin-Ling; Lee, Cheng-Chi; Chen, Chien-Ming

2017-01-01

In recent years, with the increase in degenerative diseases and the aging population in advanced countries, demands for medical care of older or solitary people have increased continually in hospitals and healthcare institutions. Applying wireless sensor networks for the IoT-based telemedicine system enables doctors, caregivers or families to monitor patients’ physiological conditions at anytime and anyplace according to the acquired information. However, transmitting physiological data through the Internet concerns the personal privacy of patients. Therefore, before users can access medical care services in IoT-based medical care system, they must be authenticated. Typically, user authentication and data encryption are most critical for securing network communications over a public channel between two or more participants. In 2016, Liu and Chung proposed a bilinear pairing-based password authentication scheme for wireless healthcare sensor networks. They claimed their authentication scheme cannot only secure sensor data transmission, but also resist various well-known security attacks. In this paper, we demonstrate that Liu–Chung’s scheme has some security weaknesses, and we further present an improved secure authentication and data encryption scheme for the IoT-based medical care system, which can provide user anonymity and prevent the security threats of replay and password/sensed data disclosure attacks. Moreover, we modify the authentication process to reduce redundancy in protocol design, and the proposed scheme is more efficient in performance compared with previous related schemes. Finally, the proposed scheme is provably secure in the random oracle model under ECDHP. PMID:28644381

Research Topics on Cluttered Environments Interrogation and Propagation

DTIC Science & Technology

2014-11-04

propagation in random and complex media and looked at specific applications associated with imaging and communication through a cluttered medium...imaging and communication schemes. We have used the results on the fourth moment to analyze wavefront correction schemes and obtained novel...and com- plex media and looked at specific applications associated with imaging and communication through a cluttered medium. The main new

An up-link power control for demand assignment International Business Satellite Communications Network

NASA Astrophysics Data System (ADS)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio

Up-link power control (UPC) is one of the essential technologies to provide efficient satellite communication systems operated at frequency bands above 10 GHz. A simple and cost-effective UPC scheme applicable to a demand assignment international business satellite communications system has been developed. This paper presents the UPC scheme, including the hardware implementation and its performance.

Analysis of synchronous digital-modulation schemes for satellite communication

NASA Technical Reports Server (NTRS)

Takhar, G. S.; Gupta, S. C.

1975-01-01

The multipath communication channel for space communications is modeled as a multiplicative channel. This paper discusses the effects of multiplicative channel processes on the symbol error rate for quadrature modulation (QM) digital modulation schemes. An expression for the upper bound on the probability of error is derived and numerically evaluated. The results are compared with those obtained for additive channels.

An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks.

PubMed

Jung, Jaewook; Kim, Jiye; Choi, Younsung; Won, Dongho

2016-08-16

In wireless sensor networks (WSNs), a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.'s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.'s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes.

End-User Tools Towards AN Efficient Electricity Consumption: the Dynamic Smart Grid

NASA Astrophysics Data System (ADS)

Kamel, Fouad; Kist, Alexander A.

2010-06-01

Growing uncontrolled electrical demands have caused increased supply requirements. This causes volatile electrical markets and has detrimental unsustainable environmental impacts. The market is presently characterized by regular daily peak demand conditions associated with high electricity prices. A demand-side response system can limit peak demands to an acceptable level. The proposed scheme is based on energy demand and price information which is available online. An online server is used to communicate the information of electricity suppliers to users, who are able to use the information to manage and control their own demand. A configurable, intelligent switching system is used to control local loads during peak events and mange the loads at other times as necessary. The aim is to shift end user loads towards periods where energy demand and therefore also prices are at the lowest. As a result, this will flatten the load profile and avoiding load peeks which are costly for suppliers. The scheme is an endeavour towards achieving a dynamic smart grid demand-side-response environment using information-based communication and computer-controlled switching. Diffusing the scheme shall lead to improved electrical supply services and controlled energy consumption and prices.

Modulation aware cluster size optimisation in wireless sensor networks

NASA Astrophysics Data System (ADS)

Sriram Naik, M.; Kumar, Vinay

2017-07-01

Wireless sensor networks (WSNs) play a great role because of their numerous advantages to the mankind. The main challenge with WSNs is the energy efficiency. In this paper, we have focused on the energy minimisation with the help of cluster size optimisation along with consideration of modulation effect when the nodes are not able to communicate using baseband communication technique. Cluster size optimisations is important technique to improve the performance of WSNs. It provides improvement in energy efficiency, network scalability, network lifetime and latency. We have proposed analytical expression for cluster size optimisation using traditional sensing model of nodes for square sensing field with consideration of modulation effects. Energy minimisation can be achieved by changing the modulation schemes such as BPSK, 16-QAM, QPSK, 64-QAM, etc., so we are considering the effect of different modulation techniques in the cluster formation. The nodes in the sensing fields are random and uniformly deployed. It is also observed that placement of base station at centre of scenario enables very less number of modulation schemes to work in energy efficient manner but when base station placed at the corner of the sensing field, it enable large number of modulation schemes to work in energy efficient manner.

Experimental on-demand recovery of entanglement by local operations within non-Markovian dynamics

PubMed Central

Orieux, Adeline; D'Arrigo, Antonio; Ferranti, Giacomo; Franco, Rosario Lo; Benenti, Giuliano; Paladino, Elisabetta; Falci, Giuseppe; Sciarrino, Fabio; Mataloni, Paolo

2015-01-01

In many applications entanglement must be distributed through noisy communication channels that unavoidably degrade it. Entanglement cannot be generated by local operations and classical communication (LOCC), implying that once it has been distributed it is not possible to recreate it by LOCC. Recovery of entanglement by purely local control is however not forbidden in the presence of non-Markovian dynamics, and here we demonstrate in two all-optical experiments that such entanglement restoration can even be achieved on-demand. First, we implement an open-loop control scheme based on a purely local operation, without acquiring any information on the environment; then, we use a closed-loop scheme in which the environment is measured, the outcome controling the local operations on the system. The restored entanglement is a manifestation of “hidden” quantum correlations resumed by the local control. Relying on local control, both schemes improve the efficiency of entanglement sharing in distributed quantum networks. PMID:25712406

Toward an endovascular internal carotid artery classification system.

PubMed

Shapiro, M; Becske, T; Riina, H A; Raz, E; Zumofen, D; Jafar, J J; Huang, P P; Nelson, P K

2014-02-01

Does the world need another ICA classification scheme? We believe so. The purpose of proposed angiography-driven classification is to optimize description of the carotid artery from the endovascular perspective. A review of existing, predominantly surgically-driven classifications is performed, and a new scheme, based on the study of NYU aneurysm angiographic and cross-sectional databases is proposed. Seven segments - cervical, petrous, cavernous, paraophthlamic, posterior communicating, choroidal, and terminus - are named. This nomenclature recognizes intrinsic uncertainty in precise angiographic and cross-sectional localization of aneurysms adjacent to the dural rings, regarding all lesions distal to the cavernous segment as potentially intradural. Rather than subdividing various transitional, ophthalmic, and hypophyseal aneurysm subtypes, as necessitated by their varied surgical approaches and risks, the proposed classification emphasizes their common endovascular treatment features, while recognizing that many complex, trans-segmental, and fusiform aneurysms not readily classifiable into presently available, saccular aneurysm-driven schemes, are being increasingly addressed by endovascular means. We believe this classification may find utility in standardizing nomenclature for outcome tracking, treatment trials and physician communication.

Controlled Secure Direct Communication with Seven-Qubit Entangled States

NASA Astrophysics Data System (ADS)

Wang, Shu-Kai; Zha, Xin-Wei; Wu, Hao

2018-01-01

In this paper, a new controlled secure direct communication protocol based on a maximally seven-qubit entangled state is proposed. the outcomes of measurement is performed by the sender and the controller, the receiver can obtain different secret messages in a deterministic way with unit successful probability.In this scheme,by using entanglement swapping, no qubits carrying secret messages are transmitted.Therefore, the protocol is completely secure.

Authentication Binding between SSL/TLS and HTTP

NASA Astrophysics Data System (ADS)

Saito, Takamichi; Sekiguchi, Kiyomi; Hatsugai, Ryosuke

While the Secure Socket Layer or Transport Layer Security (SSL/TLS) is assumed to provide secure communications over the Internet, many web applications utilize basic or digest authentication of Hyper Text Transport Protocol (HTTP) over SSL/TLS. Namely, in the scheme, there are two different authentication schemes in a session. Since they are separated by a layer, these are not convenient for a web application. Moreover, the scheme may also cause problems in establishing secure communication. Then we provide a scheme of authentication binding between SSL/TLS and HTTP without modifying SSL/TLS protocols and its implementation, and we show the effectiveness of our proposed scheme.

Unconditionally Secure Credit/Debit Card Chip Scheme and Physical Unclonable Function

NASA Astrophysics Data System (ADS)

Kish, Laszlo B.; Entesari, Kamran; Granqvist, Claes-Göran; Kwan, Chiman

The statistical-physics-based Kirchhoff-law-Johnson-noise (KLJN) key exchange offers a new and simple unclonable system for credit/debit card chip authentication and payment. The key exchange, the authentication and the communication are unconditionally secure so that neither mathematics- nor statistics-based attacks are able to crack the scheme. The ohmic connection and the short wiring lengths between the chips in the card and the terminal constitute an ideal setting for the KLJN protocol, and even its simplest versions offer unprecedented security and privacy for credit/debit card chips and applications of physical unclonable functions (PUFs).

Leap Frog and Time Step Sub-Cycle Scheme for Coupled Neutronics and Thermal-Hydraulic Codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, S.

2002-07-01

As the result of the advancing TCP/IP based inter-process communication technology, more and more legacy thermal-hydraulic codes have been coupled with neutronics codes to provide best-estimate capabilities for reactivity related reactor transient analysis. Most of the coupling schemes are based on closely coupled serial or parallel approaches. Therefore, the execution of the coupled codes usually requires significant CPU time, when a complicated system is analyzed. Leap Frog scheme has been used to reduce the run time. The extent of the decoupling is usually determined based on a trial and error process for a specific analysis. It is the intent ofmore » this paper to develop a set of general criteria, which can be used to invoke the automatic Leap Frog algorithm. The algorithm will not only provide the run time reduction but also preserve the accuracy. The criteria will also serve as the base of an automatic time step sub-cycle scheme when a sudden reactivity change is introduced and the thermal-hydraulic code is marching with a relatively large time step. (authors)« less

A secure chaotic maps and smart cards based password authentication and key agreement scheme with user anonymity for telecare medicine information systems.

PubMed

Li, Chun-Ta; Lee, Cheng-Chi; Weng, Chi-Yao

2014-09-01

Telecare medicine information system (TMIS) is widely used for providing a convenient and efficient communicating platform between patients at home and physicians at medical centers or home health care (HHC) organizations. To ensure patient privacy, in 2013, Hao et al. proposed a chaotic map based authentication scheme with user anonymity for TMIS. Later, Lee showed that Hao et al.'s scheme is in no provision for providing fairness in session key establishment and gave an efficient user authentication and key agreement scheme using smart cards, in which only few hashing and Chebyshev chaotic map operations are required. In addition, Jiang et al. discussed that Hao et al.'s scheme can not resist stolen smart card attack and they further presented an improved scheme which attempts to repair the security pitfalls found in Hao et al.'s scheme. In this paper, we found that both Lee's and Jiang et al.'s authentication schemes have a serious security problem in that a registered user's secret parameters may be intentionally exposed to many non-registered users and this problem causing the service misuse attack. Therefore, we propose a slight modification on Lee's scheme to prevent the shortcomings. Compared with previous schemes, our improved scheme not only inherits the advantages of Lee's and Jiang et al.'s authentication schemes for TMIS but also remedies the serious security weakness of not being able to withstand service misuse attack.

Application of Kalman filter in frequency offset estimation for coherent optical quadrature phase-shift keying communication system

NASA Astrophysics Data System (ADS)

Jiang, Wen; Yang, Yanfu; Zhang, Qun; Sun, Yunxu; Zhong, Kangping; Zhou, Xian; Yao, Yong

2016-09-01

The frequency offset estimation (FOE) schemes based on Kalman filter are proposed and investigated in detail via numerical simulation and experiment. The schemes consist of a modulation phase removing stage and Kalman filter estimation stage. In the second stage, the Kalman filters are employed for tracking either differential angles or differential data between two successive symbols. Several implementations of the proposed FOE scheme are compared by employing different modulation removing methods and two Kalman algorithms. The optimal FOE implementation is suggested for different operating conditions including optical signal-to-noise ratio and the number of the available data symbols.

SPECS: Secure and Privacy Enhancing Communications Schemes for VANETs

NASA Astrophysics Data System (ADS)

Chim, T. W.; Yiu, S. M.; Hui, L. C. K.; Jiang, Zoe L.; Li, Victor O. K.

Vehicular ad hoc network (VANET) is an emerging type of networks which facilitates vehicles on roads to communicate for driving safety. The basic idea is to allow arbitrary vehicles to broadcast ad hoc messages (e.g. traffic accidents) to other vehicles. However, this raises the concern of security and privacy. Messages should be signed and verified before they are trusted while the real identity of vehicles should not be revealed, but traceable by authorized party. Existing solutions either rely heavily on a tamper-proof hardware device, or cannot satisfy the privacy requirement and do not have an effective message verification scheme. In this paper, we provide a software-based solution which makes use of only two shared secrets to satisfy the privacy requirement and gives lower message overhead and at least 45% higher successful rate than previous solutions in the message verification phase using the bloom filter and the binary search techniques. We also provide the first group communication protocol to allow vehicles to authenticate and securely communicate with others in a group of known vehicles.

Security enhanced multi-factor biometric authentication scheme using bio-hash function

PubMed Central

Lee, Youngsook; Moon, Jongho

2017-01-01

With the rapid development of personal information and wireless communication technology, user authentication schemes have been crucial to ensure that wireless communications are secure. As such, various authentication schemes with multi-factor authentication have been proposed to improve the security of electronic communications. Multi-factor authentication involves the use of passwords, smart cards, and various biometrics to provide users with the utmost privacy and data protection. Cao and Ge analyzed various authentication schemes and found that Younghwa An’s scheme was susceptible to a replay attack where an adversary masquerades as a legal server and a user masquerading attack where user anonymity is not provided, allowing an adversary to execute a password change process by intercepting the user’s ID during login. Cao and Ge improved upon Younghwa An’s scheme, but various security problems remained. This study demonstrates that Cao and Ge’s scheme is susceptible to a biometric recognition error, slow wrong password detection, off-line password attack, user impersonation attack, ID guessing attack, a DoS attack, and that their scheme cannot provide session key agreement. Then, to address all weaknesses identified in Cao and Ge’s scheme, this study proposes a security enhanced multi-factor biometric authentication scheme and provides a security analysis and formal analysis using Burrows-Abadi-Needham logic. Finally, the efficiency analysis reveals that the proposed scheme can protect against several possible types of attacks with only a slightly high computational cost. PMID:28459867

A Round-Efficient Authenticated Key Agreement Scheme Based on Extended Chaotic Maps for Group Cloud Meeting

PubMed Central

Lee, Tian-Fu; Wang, Zeng-Bo

2017-01-01

The security is a critical issue for business purposes. For example, the cloud meeting must consider strong security to maintain the communication privacy. Considering the scenario with cloud meeting, we apply extended chaotic map to present passwordless group authentication key agreement, termed as Passwordless Group Authentication Key Agreement (PL-GAKA). PL-GAKA improves the computation efficiency for the simple group password-based authenticated key agreement (SGPAKE) proposed by Lee et al. in terms of computing the session key. Since the extended chaotic map has equivalent security level to the Diffie–Hellman key exchange scheme applied by SGPAKE, the security of PL-GAKA is not sacrificed when improving the computation efficiency. Moreover, PL-GAKA is a passwordless scheme, so the password maintenance is not necessary. Short-term authentication is considered, hence the communication security is stronger than other protocols by dynamically generating session key in each cloud meeting. In our analysis, we first prove that each meeting member can get the correct information during the meeting. We analyze common security issues for the proposed PL-GAKA in terms of session key security, mutual authentication, perfect forward security, and data integrity. Moreover, we also demonstrate that communicating in PL-GAKA is secure when suffering replay attacks, impersonation attacks, privileged insider attacks, and stolen-verifier attacks. Eventually, an overall comparison is given to show the performance between PL-GAKA, SGPAKE and related solutions. PMID:29207509

A security and privacy preserving e-prescription system based on smart cards.

PubMed

Hsu, Chien-Lung; Lu, Chung-Fu

2012-12-01

In 2002, Ateniese and Medeiros proposed an e-prescription system, in which the patient can store e-prescription and related information using smart card. Latter, Yang et al. proposed a novel smart-card based e-prescription system based on Ateniese and Medeiros's system in 2004. Yang et al. considered the privacy issues of prescription data and adopted the concept of a group signature to provide patient's privacy protection. To make the e-prescription system more realistic, they further applied a proxy signature to allow a patient to delegate his signing capability to other people. This paper proposed a novel security and privacy preserving e-prescription system model based on smart cards. A new role, chemist, is included in the system model for settling the medicine dispute. We further presented a concrete identity-based (ID-based) group signature scheme and an ID-based proxy signature scheme to realize the proposed model. Main property of an ID-based system is that public key is simple user's identity and can be verified without extra public key certificates. Our ID-based group signature scheme can allow doctors to sign e-prescription anonymously. In a case of a medical dispute, identities of the doctors can be identified. The proposed ID-based proxy signature scheme can improve signing delegation and allows a delegation chain. The proposed e-prescription system based on our proposed two cryptographic schemes is more practical and efficient than Yang et al.'s system in terms of security, communication overheads, computational costs, practical considerations.

Enhanced Two-Factor Authentication and Key Agreement Using Dynamic Identities in Wireless Sensor Networks.

PubMed

Chang, I-Pin; Lee, Tian-Fu; Lin, Tsung-Hung; Liu, Chuan-Ming

2015-11-30

Key agreements that use only password authentication are convenient in communication networks, but these key agreement schemes often fail to resist possible attacks, and therefore provide poor security compared with some other authentication schemes. To increase security, many authentication and key agreement schemes use smartcard authentication in addition to passwords. Thus, two-factor authentication and key agreement schemes using smartcards and passwords are widely adopted in many applications. Vaidya et al. recently presented a two-factor authentication and key agreement scheme for wireless sensor networks (WSNs). Kim et al. observed that the Vaidya et al. scheme fails to resist gateway node bypassing and user impersonation attacks, and then proposed an improved scheme for WSNs. This study analyzes the weaknesses of the two-factor authentication and key agreement scheme of Kim et al., which include vulnerability to impersonation attacks, lost smartcard attacks and man-in-the-middle attacks, violation of session key security, and failure to protect user privacy. An efficient and secure authentication and key agreement scheme for WSNs based on the scheme of Kim et al. is then proposed. The proposed scheme not only solves the weaknesses of previous approaches, but also increases security requirements while maintaining low computational cost.

Secure anonymity-preserving password-based user authentication and session key agreement scheme for telecare medicine information systems.

PubMed

Sutrala, Anil Kumar; Das, Ashok Kumar; Odelu, Vanga; Wazid, Mohammad; Kumari, Saru

2016-10-01

Information and communication and technology (ICT) has changed the entire paradigm of society. ICT facilitates people to use medical services over the Internet, thereby reducing the travel cost, hospitalization cost and time to a greater extent. Recent advancements in Telecare Medicine Information System (TMIS) facilitate users/patients to access medical services over the Internet by gaining health monitoring facilities at home. Amin and Biswas recently proposed a RSA-based user authentication and session key agreement protocol usable for TMIS, which is an improvement over Giri et al.'s RSA-based user authentication scheme for TMIS. In this paper, we show that though Amin-Biswas's scheme considerably improves the security drawbacks of Giri et al.'s scheme, their scheme has security weaknesses as it suffers from attacks such as privileged insider attack, user impersonation attack, replay attack and also offline password guessing attack. A new RSA-based user authentication scheme for TMIS is proposed, which overcomes the security pitfalls of Amin-Biswas's scheme and also preserves user anonymity property. The careful formal security analysis using the two widely accepted Burrows-Abadi-Needham (BAN) logic and the random oracle models is done. Moreover, the informal security analysis of the scheme is also done. These security analyses show the robustness of our new scheme against the various known attacks as well as attacks found in Amin-Biswas's scheme. The simulation of the proposed scheme using the widely accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool is also done. We present a new user authentication and session key agreement scheme for TMIS, which fixes the mentioned security pitfalls found in Amin-Biswas's scheme, and we also show that the proposed scheme provides better security than other existing schemes through the rigorous security analysis and verification tool. Furthermore, we present the formal security verification of our scheme using the widely accepted AVISPA tool. High security and extra functionality features allow our proposed scheme to be applicable for telecare medicine information systems which is used for e-health care medical applications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Interactive educational technologies as a method of communicative competency development of optical and fiber optic communication systems specialists

NASA Astrophysics Data System (ADS)

Matveeva, Tatiana U.; Osadchiy, Igor S.; Husnutdinova, Marina N.

2017-04-01

The article examines the process of formation of communicative competencies of optic and fiber optic communication systems specialists; the role of communicative competencies is examined in the structure of professionally important skills, together with the contents of professional activity. The stages of empirical research into formation of communicative competencies have been presented, and the values of statistical reliability of data have been provided. The model of formation of communicative competency using interactive technology has been developed based on the research done, and main stages of model implementation and motives of formation of communicative competency have been highlighted. A scheme of "Communicative competence as a base of future success" training session has been suggested as one of the basic interactive technologies. Main components of education that are used during the stages of the training cycle have been examined. The statistical data on the effectiveness of use of interactive educational technologies has been presented; it allowed development of communicative competency of specialists in the field of optical and fiber optic communication system.

An Extended Chaotic Maps-Based Three-Party Password-Authenticated Key Agreement with User Anonymity

PubMed Central

Lu, Yanrong; Li, Lixiang; Zhang, Hao; Yang, Yixian

2016-01-01

User anonymity is one of the key security features of an authenticated key agreement especially for communicating messages via an insecure network. Owing to the better properties and higher performance of chaotic theory, the chaotic maps have been introduced into the security schemes, and hence numerous key agreement schemes have been put forward under chaotic-maps. Recently, Xie et al. released an enhanced scheme under Farash et al.’s scheme and claimed their improvements could withstand the security loopholes pointed out in the scheme of Farash et al., i.e., resistance to the off-line password guessing and user impersonation attacks. Nevertheless, through our careful analysis, the improvements were released by Xie et al. still could not solve the problems troubled in Farash et al‥ Besides, Xie et al.’s improvements failed to achieve the user anonymity and the session key security. With the purpose of eliminating the security risks of the scheme of Xie et al., we design an anonymous password-based three-party authenticated key agreement under chaotic maps. Both the formal analysis and the formal security verification using AVISPA are presented. Also, BAN logic is used to show the correctness of the enhancements. Furthermore, we also demonstrate that the design thwarts most of the common attacks. We also make a comparison between the recent chaotic-maps based schemes and our enhancements in terms of performance. PMID:27101305

Local distinguishability of Dicke states in quantum secret sharing

NASA Astrophysics Data System (ADS)

Wang, Jing-Tao; Xu, Gang; Chen, Xiu-Bo; Sun, Xing-Ming; Jia, Heng-Yue

2017-03-01

We comprehensively investigate the local distinguishability of orthogonal Dicke states under local operations and classical communication (LOCC) from both qualitative and quantitative aspects. Based on our work, defects in the LOCC-quantum secret sharing (QSS) scheme can be complemented, and the information leakage can be quantified. For (k1 ,k2 , k , n)-threshold LOCC-QSS scheme, more intuitive formulas for unambiguous probability and guessing probability were established, which can be used for determining the parameter k1 and k2 directly.

Image communication scheme based on dynamic visual cryptography and computer generated holography

NASA Astrophysics Data System (ADS)

Palevicius, Paulius; Ragulskis, Minvydas

2015-01-01

Computer generated holograms are often exploited to implement optical encryption schemes. This paper proposes the integration of dynamic visual cryptography (an optical technique based on the interplay of visual cryptography and time-averaging geometric moiré) with Gerchberg-Saxton algorithm. A stochastic moiré grating is used to embed the secret into a single cover image. The secret can be visually decoded by a naked eye if only the amplitude of harmonic oscillations corresponds to an accurately preselected value. The proposed visual image encryption scheme is based on computer generated holography, optical time-averaging moiré and principles of dynamic visual cryptography. Dynamic visual cryptography is used both for the initial encryption of the secret image and for the final decryption. Phase data of the encrypted image are computed by using Gerchberg-Saxton algorithm. The optical image is decrypted using the computationally reconstructed field of amplitudes.

Asynchronous Communication Scheme For Hypercube Computer

NASA Technical Reports Server (NTRS)

Madan, Herb S.

1988-01-01

Scheme devised for asynchronous-message communication system for Mark III hypercube concurrent-processor network. Network consists of up to 1,024 processing elements connected electrically as though were at corners of 10-dimensional cube. Each node contains two Motorola 68020 processors along with Motorola 68881 floating-point processor utilizing up to 4 megabytes of shared dynamic random-access memory. Scheme intended to support applications requiring passage of both polled or solicited and unsolicited messages.

Numerical Simulations of Reacting Flows Using Asynchrony-Tolerant Schemes for Exascale Computing

NASA Astrophysics Data System (ADS)

Cleary, Emmet; Konduri, Aditya; Chen, Jacqueline

2017-11-01

Communication and data synchronization between processing elements (PEs) are likely to pose a major challenge in scalability of solvers at the exascale. Recently developed asynchrony-tolerant (AT) finite difference schemes address this issue by relaxing communication and synchronization between PEs at a mathematical level while preserving accuracy, resulting in improved scalability. The performance of these schemes has been validated for simple linear and nonlinear homogeneous PDEs. However, many problems of practical interest are governed by highly nonlinear PDEs with source terms, whose solution may be sensitive to perturbations caused by communication asynchrony. The current work applies the AT schemes to combustion problems with chemical source terms, yielding a stiff system of PDEs with nonlinear source terms highly sensitive to temperature. Examples shown will use single-step and multi-step CH4 mechanisms for 1D premixed and nonpremixed flames. Error analysis will be discussed both in physical and spectral space. Results show that additional errors introduced by the AT schemes are negligible and the schemes preserve their accuracy. We acknowledge funding from the DOE Computational Science Graduate Fellowship administered by the Krell Institute.

A review and evaluation of research on the deaf-blind from perceptual, communicative, social and rehabilitative perspectives.

PubMed

Rönnberg, J; Borg, E

2001-01-01

This paper reviews research on deaf-blind individuals, primarily from behavioral and communicative points of view. Inclusion in the population of deaf-blind is qualified by describing a variety of subgroups and genetically based syndromes associated with deaf-blindness. Sensory assessment procedures--based primarily on residual capacities--are appraised. Consequences for everyday life are described briefly. Non-sensory, alternative classificatory schemes and procedures are presented and the results from behavior modification procedures used for correcting maladaptive behaviors are summarized. Methods for communicating tactilely are described and evaluated. Attention is also drawn to some suggestions regarding learning of alphabetic codes and sign acquisition. Finally, suggestions for future research are proposed.

Schemes for Hybrid Bidirectional Controlled Quantum Communication via Multi-qubit Entangled States

NASA Astrophysics Data System (ADS)

Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

2018-02-01

We present two schemes for hybrid bidirectional controlled quantum communication (HBCQC) via six- and nine-qubit entangled states as the quantum channel, respectively. In these schemes, two distant parties, Alice and Bob are not only senders but also receivers, and Alice wants to teleport an unknown single-qubit state to Bob, at the same time, Bob wishes to help Alice remotely prepares an arbitrary single- and two- qubit state, respectively. It is shown that, only if the two senders and the controller collaborate with each other, the HBCQC can be completed successfully. We demonstrate, in our both schemes, the total success probability of the HBCQC can reach 1, that is, the schemes are deterministic.

High data rate modem simulation for the space station multiple-access communications system

NASA Technical Reports Server (NTRS)

Horan, Stephen

1987-01-01

The communications system for the space station will require a space based multiple access component to provide communications between the space based program elements and the station. A study was undertaken to investigate two of the concerns of this multiple access system, namely, the issues related to the frequency spectrum utilization and the possibilities for higher order (than QPSK) modulation schemes for use in possible modulators and demodulators (modems). As a result of the investigation, many key questions about the frequency spectrum utilization were raised. At this point, frequency spectrum utilization is seen as an area requiring further work. Simulations were conducted using a computer aided communications system design package to provide a straw man modem structure to be used for both QPSK and 8-PSK channels.

Mutual information of optical communication in phase-conjugating Gaussian channels

NASA Astrophysics Data System (ADS)

Schäfermeier, Clemens; Andersen, Ulrik L.

2018-03-01

In all practical communication channels, the code word consists of Gaussian states and the measurement strategy is often a Gaussian detector such as homodyning or heterodyning. We investigate the communication performance using a phase-conjugated alphabet and joint Gaussian detection in a phase-insensitive amplifying channel. We find that a communication scheme consisting of a phase-conjugating alphabet of coherent states and a joint detection strategy significantly outperforms a standard coherent-state strategy based in individual detection. Moreover, we show that the performance can be further enhanced by using entanglement and that the performance is completely independent of the gain of the phase-insensitively amplifying channel.

Quantum secret sharing via local operations and classical communication.

PubMed

Yang, Ying-Hui; Gao, Fei; Wu, Xia; Qin, Su-Juan; Zuo, Hui-Juan; Wen, Qiao-Yan

2015-11-20

We investigate the distinguishability of orthogonal multipartite entangled states in d-qudit system by restricted local operations and classical communication. According to these properties, we propose a standard (2, n)-threshold quantum secret sharing scheme (called LOCC-QSS scheme), which solves the open question in [Rahaman et al., Phys. Rev. A, 91, 022330 (2015)]. On the other hand, we find that all the existing (k, n)-threshold LOCC-QSS schemes are imperfect (or "ramp"), i.e., unauthorized groups can obtain some information about the shared secret. Furthermore, we present a (3, 4)-threshold LOCC-QSS scheme which is close to perfect.

Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network

PubMed Central

Yang, Bin; Zhang, Jianfeng

2017-01-01

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme. PMID:28657588

Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network.

PubMed

Yang, Bin; Zhang, Jianfeng

2017-06-28

Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme.

Quantum-secret-sharing scheme based on local distinguishability of orthogonal multiqudit entangled states

NASA Astrophysics Data System (ADS)

Wang, Jingtao; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-02-01

In this study, we propose the concept of judgment space to investigate the quantum-secret-sharing scheme based on local distinguishability (called LOCC-QSS). Because of the proposing of this conception, the property of orthogonal mutiqudit entangled states under restricted local operation and classical communication (LOCC) can be described more clearly. According to these properties, we reveal that, in the previous (k ,n )-threshold LOCC-QSS scheme, there are two required conditions for the selected quantum states to resist the unambiguous attack: (i) their k -level judgment spaces are orthogonal, and (ii) their (k -1 )-level judgment spaces are equal. Practically, if k

Multi-Gbit/s optical phase chaos communications using a time-delayed optoelectronic oscillator with a three-wave interferometer nonlinearity.

PubMed

Oden, Jérémy; Lavrov, Roman; Chembo, Yanne K; Larger, Laurent

2017-11-01

We propose a chaos communication scheme based on a chaotic optical phase carrier generated with an optoelectronic oscillator with nonlinear time-delay feedback. The system includes a dedicated non-local nonlinearity, which is a customized three-wave imbalanced interferometer. This particular feature increases the complexity of the chaotic waveform and thus the security of the transmitted information, as these interferometers are characterized by four independent parameters which are part of the secret key for the chaos encryption scheme. We first analyze the route to chaos in the system, and evidence a sequence of period doubling bifurcations from the steady-state to fully developed chaos. Then, in the chaotic regime, we study the synchronization between the emitter and the receiver, and achieve chaotic carrier cancellation with a signal-to-noise ratio up to 20 dB. We finally demonstrate error-free chaos communications at a data rate of 3 Gbit/s.

Multi-Gbit/s optical phase chaos communications using a time-delayed optoelectronic oscillator with a three-wave interferometer nonlinearity

NASA Astrophysics Data System (ADS)

Oden, Jérémy; Lavrov, Roman; Chembo, Yanne K.; Larger, Laurent

2017-11-01

We propose a chaos communication scheme based on a chaotic optical phase carrier generated with an optoelectronic oscillator with nonlinear time-delay feedback. The system includes a dedicated non-local nonlinearity, which is a customized three-wave imbalanced interferometer. This particular feature increases the complexity of the chaotic waveform and thus the security of the transmitted information, as these interferometers are characterized by four independent parameters which are part of the secret key for the chaos encryption scheme. We first analyze the route to chaos in the system, and evidence a sequence of period doubling bifurcations from the steady-state to fully developed chaos. Then, in the chaotic regime, we study the synchronization between the emitter and the receiver, and achieve chaotic carrier cancellation with a signal-to-noise ratio up to 20 dB. We finally demonstrate error-free chaos communications at a data rate of 3 Gbit/s.

Enhanced Security and Pairing-free Handover Authentication Scheme for Mobile Wireless Networks

NASA Astrophysics Data System (ADS)

Chen, Rui; Shu, Guangqiang; Chen, Peng; Zhang, Lijun

2017-10-01

With the widely deployment of mobile wireless networks, we aim to propose a secure and seamless handover authentication scheme that allows users to roam freely in wireless networks without worrying about security and privacy issues. Given the open characteristic of wireless networks, safety and efficiency should be considered seriously. Several previous protocols are designed based on a bilinear pairing mapping, which is time-consuming and inefficient work, as well as unsuitable for practical situations. To address these issues, we designed a new pairing-free handover authentication scheme for mobile wireless networks. This scheme is an effective improvement of the protocol by Xu et al., which is suffer from the mobile node impersonation attack. Security analysis and simulation experiment indicate that the proposed protocol has many excellent security properties when compared with other recent similar handover schemes, such as mutual authentication and resistance to known network threats, as well as requiring lower computation and communication cost.

Controlled Bidirectional Quantum Secure Direct Communication

PubMed Central

Chou, Yao-Hsin; Lin, Yu-Ting; Zeng, Guo-Jyun; Lin, Fang-Jhu; Chen, Chi-Yuan

2014-01-01

We propose a novel protocol for controlled bidirectional quantum secure communication based on a nonlocal swap gate scheme. Our proposed protocol would be applied to a system in which a controller (supervisor/Charlie) controls the bidirectional communication with quantum information or secret messages between legitimate users (Alice and Bob). In this system, the legitimate users must obtain permission from the controller in order to exchange their respective quantum information or secret messages simultaneously; the controller is unable to obtain any quantum information or secret messages from the decoding process. Moreover, the presence of the controller also avoids the problem of one legitimate user receiving the quantum information or secret message before the other, and then refusing to help the other user decode the quantum information or secret message. Our proposed protocol is aimed at protecting against external and participant attacks on such a system, and the cost of transmitting quantum bits using our protocol is less than that achieved in other studies. Based on the nonlocal swap gate scheme, the legitimate users exchange their quantum information or secret messages without transmission in a public channel, thus protecting against eavesdroppers stealing the secret messages. PMID:25006596

Assurance of energy efficiency and data security for ECG transmission in BASNs.

PubMed

Ma, Tao; Shrestha, Pradhumna Lal; Hempel, Michael; Peng, Dongming; Sharif, Hamid; Chen, Hsiao-Hwa

2012-04-01

With the technological advancement in body area sensor networks (BASNs), low cost high quality electrocardiographic (ECG) diagnosis systems have become important equipment for healthcare service providers. However, energy consumption and data security with ECG systems in BASNs are still two major challenges to tackle. In this study, we investigate the properties of compressed ECG data for energy saving as an effort to devise a selective encryption mechanism and a two-rate unequal error protection (UEP) scheme. The proposed selective encryption mechanism provides a simple and yet effective security solution for an ECG sensor-based communication platform, where only one percent of data is encrypted without compromising ECG data security. This part of the encrypted data is essential to ECG data quality due to its unequally important contribution to distortion reduction. The two-rate UEP scheme achieves a significant additional energy saving due to its unequal investment of communication energy to the outcomes of the selective encryption, and thus, it maintains a high ECG data transmission quality. Our results show the improvements in communication energy saving of about 40%, and demonstrate a higher transmission quality and security measured in terms of wavelet-based weighted percent root-mean-squared difference.

Secure SCADA communication by using a modified key management scheme.

PubMed

Rezai, Abdalhossein; Keshavarzi, Parviz; Moravej, Zahra

2013-07-01

This paper presents and evaluates a new cryptographic key management scheme which increases the efficiency and security of the Supervisory Control And Data Acquisition (SCADA) communication. In the proposed key management scheme, two key update phases are used: session key update and master key update. In the session key update phase, session keys are generated in the master station. In the master key update phase, the Elliptic Curve Diffie-Hellman (ECDH) protocol is used. The Poisson process is also used to model the Security Index (SI) and Quality of Service (QoS). Our analysis shows that the proposed key management not only supports the required speed in the MODBUS implementation but also has several advantages compared to other key management schemes for secure communication in SCADA networks. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Location-assured, multifactor authentication on smartphones via LTE communication

NASA Astrophysics Data System (ADS)

Kuseler, Torben; Lami, Ihsan A.; Al-Assam, Hisham

2013-05-01

With the added security provided by LTE, geographical location has become an important factor for authentication to enhance the security of remote client authentication during mCommerce applications using Smartphones. Tight combination of geographical location with classic authentication factors like PINs/Biometrics in a real-time, remote verification scheme over the LTE layer connection assures the authenticator about the client itself (via PIN/biometric) as well as the client's current location, thus defines the important aspects of "who", "when", and "where" of the authentication attempt without eaves dropping or man on the middle attacks. To securely integrate location as an authentication factor into the remote authentication scheme, client's location must be verified independently, i.e. the authenticator should not solely rely on the location determined on and reported by the client's Smartphone. The latest wireless data communication technology for mobile phones (4G LTE, Long-Term Evolution), recently being rolled out in various networks, can be employed to enhance this location-factor requirement of independent location verification. LTE's Control Plane LBS provisions, when integrated with user-based authentication and independent source of localisation factors ensures secure efficient, continuous location tracking of the Smartphone. This feature can be performed during normal operation of the LTE-based communication between client and network operator resulting in the authenticator being able to verify the client's claimed location more securely and accurately. Trials and experiments show that such algorithm implementation is viable for nowadays Smartphone-based banking via LTE communication.

Demonstration of flexible and reconfigurable WDM multicast scheme supporting downstream emergency multicast communication for WDM optical access network

NASA Astrophysics Data System (ADS)

Li, Ze; Zhang, Min; Wang, Danshi; Cui, Yue

2017-09-01

We propose a flexible and reconfigurable wavelength-division multiplexing (WDM) multicast scheme supporting downstream emergency multicast communication for WDM optical access network (WDM-OAN) via a multicast module (MM) based on four-wave mixing (FWM) in a semiconductor optical amplifier. It serves as an emergency measure to dispose of the burst, large bandwidth, and real-time multicast service with fast service provisioning and high resource efficiency. It also plays the role of physical backup in cases of big data migration or network disaster caused by invalid lasers or modulator failures. It provides convenient and reliable multicast service and emergency protection for WDM-OAN without modifying WDM-OAN structure. The strategies of an MM setting at the optical line terminal and remote node are discussed to apply this scheme to passive optical networks and active optical networks, respectively. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment in which one-to-six/eight 10-Gbps nonreturn-to-zero-differential phase-shift keying WDM multicasts in both strategies are successfully transmitted over single-mode fiber of 20.2 km. One-to-many reconfigurable WDM multicasts dealing with higher data rate and other modulation formats of multicast service are possible through the proposed scheme. It can be applied to different WDM access technologies, e.g., time-wavelength-division multiplexing-OAN and coherent WDM-OAN, and upgraded smoothly.

An Anonymous User Authentication and Key Agreement Scheme Based on a Symmetric Cryptosystem in Wireless Sensor Networks

PubMed Central

Jung, Jaewook; Kim, Jiye; Choi, Younsung; Won, Dongho

2016-01-01

In wireless sensor networks (WSNs), a registered user can login to the network and use a user authentication protocol to access data collected from the sensor nodes. Since WSNs are typically deployed in unattended environments and sensor nodes have limited resources, many researchers have made considerable efforts to design a secure and efficient user authentication process. Recently, Chen et al. proposed a secure user authentication scheme using symmetric key techniques for WSNs. They claim that their scheme assures high efficiency and security against different types of attacks. After careful analysis, however, we find that Chen et al.’s scheme is still vulnerable to smart card loss attack and is susceptible to denial of service attack, since it is invalid for verification to simply compare an entered ID and a stored ID in smart card. In addition, we also observe that their scheme cannot preserve user anonymity. Furthermore, their scheme cannot quickly detect an incorrect password during login phase, and this flaw wastes both communication and computational overheads. In this paper, we describe how these attacks work, and propose an enhanced anonymous user authentication and key agreement scheme based on a symmetric cryptosystem in WSNs to address all of the aforementioned vulnerabilities in Chen et al.’s scheme. Our analysis shows that the proposed scheme improves the level of security, and is also more efficient relative to other related schemes. PMID:27537890

An Energy Efficient Cooperative Hierarchical MIMO Clustering Scheme for Wireless Sensor Networks

PubMed Central

Nasim, Mehwish; Qaisar, Saad; Lee, Sungyoung

2012-01-01

In this work, we present an energy efficient hierarchical cooperative clustering scheme for wireless sensor networks. Communication cost is a crucial factor in depleting the energy of sensor nodes. In the proposed scheme, nodes cooperate to form clusters at each level of network hierarchy ensuring maximal coverage and minimal energy expenditure with relatively uniform distribution of load within the network. Performance is enhanced by cooperative multiple-input multiple-output (MIMO) communication ensuring energy efficiency for WSN deployments over large geographical areas. We test our scheme using TOSSIM and compare the proposed scheme with cooperative multiple-input multiple-output (CMIMO) clustering scheme and traditional multihop Single-Input-Single-Output (SISO) routing approach. Performance is evaluated on the basis of number of clusters, number of hops, energy consumption and network lifetime. Experimental results show significant energy conservation and increase in network lifetime as compared to existing schemes. PMID:22368459

Working in a Hose Building Factory. Youth Training Scheme. Core Exemplar Work Based Project.

ERIC Educational Resources Information Center

Further Education Staff Coll., Blagdon (England).

This trainer's guide is intended to assist supervisors of work-based career training projects in helping students learn about the operations of a marine hose factory, requisition supplies, rewarp nylon binders, determine the cost of material depreciation, communicate with coworkers, and learn about health and safety procedures. Though specific to…

Compressive Sampling based Image Coding for Resource-deficient Visual Communication.

PubMed

Liu, Xianming; Zhai, Deming; Zhou, Jiantao; Zhang, Xinfeng; Zhao, Debin; Gao, Wen

2016-04-14

In this paper, a new compressive sampling based image coding scheme is developed to achieve competitive coding efficiency at lower encoder computational complexity, while supporting error resilience. This technique is particularly suitable for visual communication with resource-deficient devices. At the encoder, compact image representation is produced, which is a polyphase down-sampled version of the input image; but the conventional low-pass filter prior to down-sampling is replaced by a local random binary convolution kernel. The pixels of the resulting down-sampled pre-filtered image are local random measurements and placed in the original spatial configuration. The advantages of local random measurements are two folds: 1) preserve high-frequency image features that are otherwise discarded by low-pass filtering; 2) remain a conventional image and can therefore be coded by any standardized codec to remove statistical redundancy of larger scales. Moreover, measurements generated by different kernels can be considered as multiple descriptions of the original image and therefore the proposed scheme has the advantage of multiple description coding. At the decoder, a unified sparsity-based soft-decoding technique is developed to recover the original image from received measurements in a framework of compressive sensing. Experimental results demonstrate that the proposed scheme is competitive compared with existing methods, with a unique strength of recovering fine details and sharp edges at low bit-rates.

Magnetic resonance image compression using scalar-vector quantization

NASA Astrophysics Data System (ADS)

Mohsenian, Nader; Shahri, Homayoun

1995-12-01

A new coding scheme based on the scalar-vector quantizer (SVQ) is developed for compression of medical images. SVQ is a fixed-rate encoder and its rate-distortion performance is close to that of optimal entropy-constrained scalar quantizers (ECSQs) for memoryless sources. The use of a fixed-rate quantizer is expected to eliminate some of the complexity issues of using variable-length scalar quantizers. When transmission of images over noisy channels is considered, our coding scheme does not suffer from error propagation which is typical of coding schemes which use variable-length codes. For a set of magnetic resonance (MR) images, coding results obtained from SVQ and ECSQ at low bit-rates are indistinguishable. Furthermore, our encoded images are perceptually indistinguishable from the original, when displayed on a monitor. This makes our SVQ based coder an attractive compression scheme for picture archiving and communication systems (PACS), currently under consideration for an all digital radiology environment in hospitals, where reliable transmission, storage, and high fidelity reconstruction of images are desired.

An Experimental Realization of a Chaos-Based Secure Communication Using Arduino Microcontrollers.

PubMed

Zapateiro De la Hoz, Mauricio; Acho, Leonardo; Vidal, Yolanda

2015-01-01

Security and secrecy are some of the important concerns in the communications world. In the last years, several encryption techniques have been proposed in order to improve the secrecy of the information transmitted. Chaos-based encryption techniques are being widely studied as part of the problem because of the highly unpredictable and random-look nature of the chaotic signals. In this paper we propose a digital-based communication system that uses the logistic map which is a mathematically simple model that is chaotic under certain conditions. The input message signal is modulated using a simple Delta modulator and encrypted using a logistic map. The key signal is also encrypted using the same logistic map with different initial conditions. In the receiver side, the binary-coded message is decrypted using the encrypted key signal that is sent through one of the communication channels. The proposed scheme is experimentally tested using Arduino shields which are simple yet powerful development kits that allows for the implementation of the communication system for testing purposes.

Spectrum Sharing Based on a Bertrand Game in Cognitive Radio Sensor Networks

PubMed Central

Zeng, Biqing; Zhang, Chi; Hu, Pianpian; Wang, Shengyu

2017-01-01

In the study of power control and allocation based on pricing, the utility of secondary users is usually studied from the perspective of the signal to noise ratio. The study of secondary user utility from the perspective of communication demand can not only promote the secondary users to meet the maximum communication needs, but also to maximize the utilization of spectrum resources, however, research in this area is lacking, so from the viewpoint of meeting the demand of network communication, this paper designs a two stage model to solve spectrum leasing and allocation problem in cognitive radio sensor networks (CRSNs). In the first stage, the secondary base station collects the secondary network communication requirements, and rents spectrum resources from several primary base stations using the Bertrand game to model the transaction behavior of the primary base station and secondary base station. The second stage, the subcarriers and power allocation problem of secondary base stations is defined as a nonlinear programming problem to be solved based on Nash bargaining. The simulation results show that the proposed model can satisfy the communication requirements of each user in a fair and efficient way compared to other spectrum sharing schemes. PMID:28067850

Twisted Acoustics: Metasurface-Enabled Multiplexing and Demultiplexing.

PubMed

Jiang, Xue; Liang, Bin; Cheng, Jian-Chun; Qiu, Cheng-Wei

2018-05-01

Metasurfaces are used to enable acoustic orbital angular momentum (a-OAM)-based multiplexing in real-time, postprocess-free, and sensor-scanning-free fashions to improve the bandwidth of acoustic communication, with intrinsic compatibility and expandability to cooperate with other multiplexing schemes. The metasurface-based communication relying on encoding information onto twisted beams is numerically and experimentally demonstrated by realizing real-time picture transfer, which differs from existing static data transfer by encoding data onto OAM states. With the advantages of real-time transmission, passive and instantaneous data decoding, vanishingly low loss, compact size, and high transmitting accuracy, the study of a-OAM-based information transfer with metasurfaces offers new route to boost the capacity of acoustic communication and great potential to profoundly advance relevant fields. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simple Peer-to-Peer SIP Privacy

NASA Astrophysics Data System (ADS)

Koskela, Joakim; Tarkoma, Sasu

In this paper, we introduce a model for enhancing privacy in peer-to-peer communication systems. The model is based on data obfuscation, preventing intermediate nodes from tracking calls, while still utilizing the shared resources of the peer network. This increases security when moving between untrusted, limited and ad-hoc networks, when the user is forced to rely on peer-to-peer schemes. The model is evaluated using a Host Identity Protocol-based prototype on mobile devices, and is found to provide good privacy, especially when combined with a source address hiding scheme. The contribution of this paper is to present the model and results obtained from its use, including usability considerations.

Pricing Models and Payment Schemes for Library Collections.

ERIC Educational Resources Information Center

Stern, David

2002-01-01

Discusses new pricing and payment options for libraries in light of online products. Topics include alternative cost models rather than traditional subscriptions; use-based pricing; changes in scholarly communication due to information technology; methods to determine appropriate charges for different organizations; consortial plans; funding; and…

Cultivation of students' engineering designing ability based on optoelectronic system course project

NASA Astrophysics Data System (ADS)

Cao, Danhua; Wu, Yubin; Li, Jingping

2017-08-01

We carry out teaching based on optoelectronic related course group, aiming at junior students majored in Optoelectronic Information Science and Engineering. " Optoelectronic System Course Project " is product-designing-oriented and lasts for a whole semester. It provides a chance for students to experience the whole process of product designing, and improve their abilities to search literature, proof schemes, design and implement their schemes. In teaching process, each project topic is carefully selected and repeatedly refined to guarantee the projects with the knowledge integrity, engineering meanings and enjoyment. Moreover, we set up a top team with professional and experienced teachers, and build up learning community. Meanwhile, the communication between students and teachers as well as the interaction among students are taken seriously in order to improve their team-work ability and communicational skills. Therefore, students are not only able to have a chance to review the knowledge hierarchy of optics, electronics, and computer sciences, but also are able to improve their engineering mindset and innovation consciousness.

Generating the Local Oscillator "Locally" in Continuous-Variable Quantum Key Distribution Based on Coherent Detection

NASA Astrophysics Data System (ADS)

Qi, Bing; Lougovski, Pavel; Pooser, Raphael; Grice, Warren; Bobrek, Miljko

2015-10-01

Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In this paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a "locally" generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct a coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad2 ), which is small enough to enable secure key distribution. This technology also opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.

Coordination between primary and secondary care: the role of electronic messages and economic incentives.

PubMed

La Rocca, Antonella; Hoholm, Thomas

2017-02-17

In Norway, a government reform has recently been introduced to enhance coordination between primary and secondary care. This paper examines the effects of two newly introduced measures to improve the coordination: an ICT-based communication tool/standard and an economic incentive scheme. This qualitative study is based primarily on 27 open-ended interviews. We interviewed nine employees at a hospital (the focal actor), 17 employees from seven different municipalities, and a representative of a Regional Health Authority. ICT-based communication is perceived to facilitate information exchange between primary and secondary care, thus positively affecting coordination. However, the economic incentive scheme appears to have the opposite effect by creating tensions between the two organizations and accentuating power asymmetry in favor of secondary care. The inter-organizational nature of coordination in health care makes it crucial for policymakers and management of care organizations to conceive incentives and instruments that work jointly across organizations rather than at only one of the health care organizations involved. Such an approach is likely to favor a more symmetrical pattern of collaboration between primary and secondary care.

Soldier communication net for the 21st century digitized battlespace

NASA Astrophysics Data System (ADS)

Mu, Libo; Zhang, Yutian

1999-07-01

This paper present soldier communication net scheme, which survives and operates in the 21st century battlefield environment. First, it analyzes the features, the need, function of the soldier communication net on the 21st century battlefield environment. Secondly it presents a layered model of the soldier communication net, derived from the OSI theory, and discusses the design of the 3 layers, link layer, link controller and input/output applications layer. Thirdly, it present some key technical discussion concerning with the direct-sequence-spread-spectrum communication, code/decode and low power consumption. Finally, it gives the conclusion that spread spectrum time division system is the best scheme of soldier communication net.

Quantum secret sharing using orthogonal multiqudit entangled states

NASA Astrophysics Data System (ADS)

Bai, Chen-Ming; Li, Zhi-Hui; Liu, Cheng-Ji; Li, Yong-Ming

2017-12-01

In this work, we investigate the distinguishability of orthogonal multiqudit entangled states under restricted local operations and classical communication. According to these properties, we propose a quantum secret sharing scheme to realize three types of access structures, i.e., the ( n, n)-threshold, the restricted (3, n)-threshold and restricted (4, n)-threshold schemes (called LOCC-QSS scheme). All cooperating players in the restricted threshold schemes are from two disjoint groups. In the proposed protocol, the participants use the computational basis measurement and classical communication to distinguish between those orthogonal states and reconstruct the original secret. Furthermore, we also analyze the security of our scheme in four primary quantum attacks and give a simple encoding method in order to better prevent the participant conspiracy attack.

Observer-based consensus of networked thrust-propelled vehicles with directed graphs.

PubMed

Cang, Weiye; Li, Zhongkui; Wang, Hanlei

2017-11-01

In this paper, we investigate the consensus problem for networked underactuated thrust-propelled vehicles (TPVs) interacting on directed graphs. We propose distributed observer-based consensus protocols, which avoid the reliance on the measurements of translational velocities and accelerations. Using the input-output analysis, we present necessary and sufficient conditions to ensure that the observer-based protocols can achieve consensus for both the cases without and with constant communication delays, provided that the communication graph contains a directed spanning tree. Simulation examples are finally provided to illustrate the effectiveness of the control schemes. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Progress in Y-00 physical cipher for Giga bit/sec optical data communications (intensity modulation method)

NASA Astrophysics Data System (ADS)

Hirota, Osamu; Futami, Fumio

2014-10-01

To guarantee a security of Cloud Computing System is urgent problem. Although there are several threats in a security problem, the most serious problem is cyber attack against an optical fiber transmission among data centers. In such a network, an encryption scheme on Layer 1(physical layer) with an ultimately strong security, a small delay, and a very high speed should be employed, because a basic optical link is operated at 10 Gbit/sec/wavelength. We have developed a quantum noise randomied stream cipher so called Yuen- 2000 encryption scheme (Y-00) during a decade. This type of cipher is a completely new type random cipher in which ciphertext for a legitimate receiver and eavesdropper are different. This is a condition to break the Shannon limit in theory of cryptography. In addition, this scheme has a good balance on a security, a speed and a cost performance. To realize such an encryption, several modulation methods are candidates such as phase-modulation, intensity-modulation, quadrature amplitude modulation, and so on. Northwestern university group demonstrated a phase modulation system (α=η) in 2003. In 2005, we reported a demonstration of 1 Gbit/sec system based on intensity modulation scheme(ISK-Y00), and gave a design method for quadratic amplitude modulation (QAM-Y00) in 2005 and 2010. An intensity modulation scheme promises a real application to a secure fiber communication of current data centers. This paper presents a progress in quantum noise randomized stream cipher based on ISK-Y00, integrating our theoretical and experimental achievements in the past and recent 100 Gbit/sec(10Gbit/sec × 10 wavelengths) experiment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chertkov, Michael; Turitsyn, Konstantin; Sulc, Petr

The anticipated increase in the number of plug-in electric vehicles (EV) will put additional strain on electrical distribution circuits. Many control schemes have been proposed to control EV charging. Here, we develop control algorithms based on randomized EV charging start times and simple one-way broadcast communication allowing for a time delay between communication events. Using arguments from queuing theory and statistical analysis, we seek to maximize the utilization of excess distribution circuit capacity while keeping the probability of a circuit overload negligible.

Establishing rational networking using the DL04 quantum secure direct communication protocol

NASA Astrophysics Data System (ADS)

Qin, Huawang; Tang, Wallace K. S.; Tso, Raylin

2018-06-01

The first rational quantum secure direct communication scheme is proposed, in which we use the game theory with incomplete information to model the rational behavior of the participant, and give the strategy space and utility function. The rational participant can get his maximal utility when he performs the protocol faithfully, and then the Nash equilibrium of the protocol can be achieved. Compared to the traditional schemes, our scheme will be more practical in the presence of rational participant.

Physical-Layer Network Coding for VPN in TDM-PON

NASA Astrophysics Data System (ADS)

Wang, Qike; Tse, Kam-Hon; Chen, Lian-Kuan; Liew, Soung-Chang

2012-12-01

We experimentally demonstrate a novel optical physical-layer network coding (PNC) scheme over time-division multiplexing (TDM) passive optical network (PON). Full-duplex error-free communications between optical network units (ONUs) at 2.5 Gb/s are shown for all-optical virtual private network (VPN) applications. Compared to the conventional half-duplex communications set-up, our scheme can increase the capacity by 100% with power penalty smaller than 3 dB. Synchronization of two ONUs is not required for the proposed VPN scheme

Robust Timing Synchronization in Aeronautical Mobile Communication Systems

NASA Technical Reports Server (NTRS)

Xiong, Fu-Qin; Pinchak, Stanley

2004-01-01

This work details a study of robust synchronization schemes suitable for satellite to mobile aeronautical applications. A new scheme, the Modified Sliding Window Synchronizer (MSWS), is devised and compared with existing schemes, including the traditional Early-Late Gate Synchronizer (ELGS), the Gardner Zero-Crossing Detector (GZCD), and the Sliding Window Synchronizer (SWS). Performance of the synchronization schemes is evaluated by a set of metrics that indicate performance in digital communications systems. The metrics are convergence time, mean square phase error (or root mean-square phase error), lowest SNR for locking, initial frequency offset performance, midstream frequency offset performance, and system complexity. The performance of the synchronizers is evaluated by means of Matlab simulation models. A simulation platform is devised to model the satellite to mobile aeronautical channel, consisting of a Quadrature Phase Shift Keying modulator, an additive white Gaussian noise channel, and a demodulator front end. Simulation results show that the MSWS provides the most robust performance at the cost of system complexity. The GZCD provides a good tradeoff between robustness and system complexity for communication systems that require high symbol rates or low overall system costs. The ELGS has a high system complexity despite its average performance. Overall, the SWS, originally designed for multi-carrier systems, performs very poorly in single-carrier communications systems. Table 5.1 in Section 5 provides a ranking of each of the synchronization schemes in terms of the metrics set forth in Section 4.1. Details of comparison are given in Section 5. Based on the results presented in Table 5, it is safe to say that the most robust synchronization scheme examined in this work is the high-sample-rate Modified Sliding Window Synchronizer. A close second is its low-sample-rate cousin. The tradeoff between complexity and lowest mean-square phase error determines the rankings of the Gardner Zero-Crossing Detector and both versions of the Early-Late Gate Synchronizer. The least robust models are the high and low-sample-rate Sliding Window Synchronizers. Consequently, the recommended replacement synchronizer for NASA's Advanced Air Transportation Technologies mobile aeronautical communications system is the high-sample-rate Modified Sliding Window Synchronizer. By incorporating this synchronizer into their system, NASA can be assured that their system will be operational in extremely adverse conditions. The quick convergence time of the MSWS should allow the use of high-level protocols. However, if NASA feels that reduced system complexity is the most important aspect of their replacement synchronizer, the Gardner Zero-Crossing Detector would be the best choice.

A satellite-based personal communication system for the 21st century

NASA Technical Reports Server (NTRS)

Sue, Miles K.; Dessouky, Khaled; Levitt, Barry; Rafferty, William

1990-01-01

Interest in personal communications (PCOMM) has been stimulated by recent developments in satellite and terrestrial mobile communications. A personal access satellite system (PASS) concept was developed at the Jet Propulsion Laboratory (JPL) which has many attractive user features, including service diversity and a handheld terminal. Significant technical challenges addressed in formulating the PASS space and ground segments are discussed. PASS system concept and basic design features, high risk enabling technologies, an optimized multiple access scheme, alternative antenna coverage concepts, the use of non-geostationary orbits, user terminal radiation constraints, and user terminal frequency reference are covered.

Quantum secret sharing via local operations and classical communication

PubMed Central

Yang, Ying-Hui; Gao, Fei; Wu, Xia; Qin, Su-Juan; Zuo, Hui-Juan; Wen, Qiao-Yan

2015-01-01

We investigate the distinguishability of orthogonal multipartite entangled states in d-qudit system by restricted local operations and classical communication. According to these properties, we propose a standard (2, n)-threshold quantum secret sharing scheme (called LOCC-QSS scheme), which solves the open question in [Rahaman et al., Phys. Rev. A, 91, 022330 (2015)]. On the other hand, we find that all the existing (k, n)-threshold LOCC-QSS schemes are imperfect (or “ramp”), i.e., unauthorized groups can obtain some information about the shared secret. Furthermore, we present a (3, 4)-threshold LOCC-QSS scheme which is close to perfect. PMID:26586412

On the Adaptive Protection of Microgrids: A Review on How to Mitigate Cyber Attacks and Communication Failures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habib, Hany F; Lashway, Christopher R; Mohammed, Osama A

One main challenge in the practical implementation of a microgrid is the design of an adequate protection scheme in both grid connected and islanded modes. Conventional overcurrent protection schemes face selectivity and sensitivity issues during grid and microgrid faults since the fault current level is different in both cases for the same relay. Various approaches have been implemented in the past to deal with this problem, yet the most promising ones are the implementation of adaptive protection techniques abiding by the IEC 61850 communication standard. This paper presents a critical review of existing adaptive protection schemes, the technical challenges formore » the use of classical protection techniques and the need for an adaptive, smart protection system. However, the risk of communication link failures and cyber security threats still remain a challenge in implementing a reliable adaptive protection scheme. A contingency is needed where a communication issue prevents the relay from adjusting to a lower current level during islanded mode. An adaptive protection scheme is proposed that utilizes energy storage (ES) and hybrid ES (HESS) already available in the network as a mechanism to source the higher fault current. Four common grid ES and HESS are reviewed for their suitability in feeding the fault while some solutions are proposed.« less

Enhanced Two-Factor Authentication and Key Agreement Using Dynamic Identities in Wireless Sensor Networks

PubMed Central

Chang, I-Pin; Lee, Tian-Fu; Lin, Tsung-Hung; Liu, Chuan-Ming

2015-01-01

Key agreements that use only password authentication are convenient in communication networks, but these key agreement schemes often fail to resist possible attacks, and therefore provide poor security compared with some other authentication schemes. To increase security, many authentication and key agreement schemes use smartcard authentication in addition to passwords. Thus, two-factor authentication and key agreement schemes using smartcards and passwords are widely adopted in many applications. Vaidya et al. recently presented a two-factor authentication and key agreement scheme for wireless sensor networks (WSNs). Kim et al. observed that the Vaidya et al. scheme fails to resist gateway node bypassing and user impersonation attacks, and then proposed an improved scheme for WSNs. This study analyzes the weaknesses of the two-factor authentication and key agreement scheme of Kim et al., which include vulnerability to impersonation attacks, lost smartcard attacks and man-in-the-middle attacks, violation of session key security, and failure to protect user privacy. An efficient and secure authentication and key agreement scheme for WSNs based on the scheme of Kim et al. is then proposed. The proposed scheme not only solves the weaknesses of previous approaches, but also increases security requirements while maintaining low computational cost. PMID:26633396

CCS-DTN: clustering and network coding-based efficient routing in social DTNs.

PubMed

Zhang, Zhenjing; Ma, Maode; Jin, Zhigang

2014-12-25

With the development of mobile Internet, wireless communication via mobile devices has become a hot research topic, which is typically in the form of Delay Tolerant Networks (DTNs). One critical issue in the development of DTNs is routing. Although there is a lot research work addressing routing issues in DTNs, they cannot produce an advanced solution to the comprehensive challenges since only one or two aspects (nodes' movements, clustering, centricity and so on) are considered when the routing problem is handled. In view of these defects in the existing works, we propose a novel solution to address the routing issue in social DTNs. By this solution, mobile nodes are divided into different clusters. The scheme, Spray and Wait, is used for the intra-cluster communication while a new forwarding mechanism is designed for the inter-cluster version. In our solution, the characteristics of nodes and the relation between nodes are fully considered. The simulation results show that our proposed scheme can significantly improve the performance of the routing scheme in social DTNs.

CCS-DTN: Clustering and Network Coding-Based Efficient Routing in Social DTNs

PubMed Central

Zhang, Zhenjing; Ma, Maode; Jin, Zhigang

2015-01-01

With the development of mobile Internet, wireless communication via mobile devices has become a hot research topic, which is typically in the form of Delay Tolerant Networks (DTNs). One critical issue in the development of DTNs is routing. Although there is a lot research work addressing routing issues in DTNs, they cannot produce an advanced solution to the comprehensive challenges since only one or two aspects (nodes' movements, clustering, centricity and so on) are considered when the routing problem is handled. In view of these defects in the existing works, we propose a novel solution to address the routing issue in social DTNs. By this solution, mobile nodes are divided into different clusters. The scheme, Spray and Wait, is used for the intra-cluster communication while a new forwarding mechanism is designed for the inter-cluster version. In our solution, the characteristics of nodes and the relation between nodes are fully considered. The simulation results show that our proposed scheme can significantly improve the performance of the routing scheme in social DTNs. PMID:25609047

Communication channels secured from eavesdropping via transmission of photonic Bell states

NASA Astrophysics Data System (ADS)

Shimizu, Kaoru; Imoto, Nobuyuki

1999-07-01

This paper proposes a quantum communication scheme for sending a definite binary sequence while confirming the security of the transmission. The scheme is very suitable for sending a ciphertext in a secret-key cryptosystem so that we can detect any eavesdropper who attempts to decipher the key. Thus we can continue to use a secret key unless we detect eavesdropping and the security of a key that is used repeatedly can be enhanced to the level of one-time-pad cryptography. In our scheme, a pair of entangled photon twins is employed as a bit carrier which is encoded in a two-term superposition of four Bell states. Different bases are employed for encoding the binary sequence of a ciphertext and a random test bit. The photon twins are measured with a Bell state analyzer and any bit can be decoded from the resultant Bell state when the receiver is later notified of the coding basis through a classical channel. By opening the positions and the values of test bits, ciphertext can be read and eavesdropping is simultaneously detected.

PCPA: A Practical Certificateless Conditional Privacy Preserving Authentication Scheme for Vehicular Ad Hoc Networks

PubMed Central

2018-01-01

Vehicle ad hoc networks (VANETs) is a promising network scenario for greatly improving traffic efficiency and safety, in which smart vehicles can communicate with other vehicles or roadside units. For the availability of VANETs, it is very important to deal with the security and privacy problems for VANETs. In this paper, based on certificateless cryptography and elliptic curve cryptography, we present a certificateless signature with message recovery (CLS-MR), which we believe are of independent interest. Then, a practical certificateless conditional privacy preserving authentication (PCPA) scheme is proposed by incorporating the proposed CLS-MR scheme. Furthermore, the security analysis shows that PCPA satisfies all security and privacy requirements. The evaluation results indicate that PCPA achieves low computation and communication costs because there is no need to use the bilinear pairing and map-to-point hash operations. Moreover, extensive simulations show that PCPA is feasible and achieves prominent performances in terms of message delay and message loss ratio, and thus is more suitable for the deployment and adoption of VANETs. PMID:29762511

Security Encryption Scheme for Communication of Web Based Control Systems

NASA Astrophysics Data System (ADS)

Robles, Rosslin John; Kim, Tai-Hoon

A control system is a device or set of devices to manage, command, direct or regulate the behavior of other devices or systems. The trend in most systems is that they are connected through the Internet. Traditional Supervisory Control and Data Acquisition Systems (SCADA) is connected only in a limited private network Since the internet Supervisory Control and Data Acquisition Systems (SCADA) facility has brought a lot of advantages in terms of control, data viewing and generation. Along with these advantages, are security issues regarding web SCADA, operators are pushed to connect Control Systems through the internet. Because of this, many issues regarding security surfaced. In this paper, we discuss web SCADA and the issues regarding security. As a countermeasure, a web SCADA security solution using crossed-crypto-scheme is proposed to be used in the communication of SCADA components.

Design and analysis of multihypothesis motion-compensated prediction (MHMCP) codec for error-resilient visual communications

NASA Astrophysics Data System (ADS)

Kung, Wei-Ying; Kim, Chang-Su; Kuo, C.-C. Jay

2004-10-01

A multi-hypothesis motion compensated prediction (MHMCP) scheme, which predicts a block from a weighted superposition of more than one reference blocks in the frame buffer, is proposed and analyzed for error resilient visual communication in this research. By combining these reference blocks effectively, MHMCP can enhance the error resilient capability of compressed video as well as achieve a coding gain. In particular, we investigate the error propagation effect in the MHMCP coder and analyze the rate-distortion performance in terms of the hypothesis number and hypothesis coefficients. It is shown that MHMCP suppresses the short-term effect of error propagation more effectively than the intra refreshing scheme. Simulation results are given to confirm the analysis. Finally, several design principles for the MHMCP coder are derived based on the analytical and experimental results.

A new communication protocol family for a distributed spacecraft control system

NASA Technical Reports Server (NTRS)

Baldi, Andrea; Pace, Marco

1994-01-01

In this paper we describe the concepts behind and architecture of a communication protocol family, which was designed to fulfill the communication requirements of ESOC's new distributed spacecraft control system SCOS 2. A distributed spacecraft control system needs a data delivery subsystem to be used for telemetry (TLM) distribution, telecommand (TLC) dispatch and inter-application communication, characterized by the following properties: reliability, so that any operational workstation is guaranteed to receive the data it needs to accomplish its role; efficiency, so that the telemetry distribution, even for missions with high telemetry rates, does not cause a degradation of the overall control system performance; scalability, so that the network is not the bottleneck both in terms of bandwidth and reconfiguration; flexibility, so that it can be efficiently used in many different situations. The new protocol family which satisfies the above requirements is built on top of widely used communication protocols (UDP and TCP), provides reliable point-to-point and broadcast communication (UDP+) and is implemented in C++. Reliability is achieved using a retransmission mechanism based on a sequence numbering scheme. Such a scheme allows to have cost-effective performances compared to the traditional protocols, because retransmission is only triggered by applications which explicitly need reliability. This flexibility enables applications with different profiles to take advantage of the available protocols, so that the best rate between sped and reliability can be achieved case by case.

Optimal Quantization Scheme for Data-Efficient Target Tracking via UWSNs Using Quantized Measurements.

PubMed

Zhang, Senlin; Chen, Huayan; Liu, Meiqin; Zhang, Qunfei

2017-11-07

Target tracking is one of the broad applications of underwater wireless sensor networks (UWSNs). However, as a result of the temporal and spatial variability of acoustic channels, underwater acoustic communications suffer from an extremely limited bandwidth. In order to reduce network congestion, it is important to shorten the length of the data transmitted from local sensors to the fusion center by quantization. Although quantization can reduce bandwidth cost, it also brings about bad tracking performance as a result of information loss after quantization. To solve this problem, this paper proposes an optimal quantization-based target tracking scheme. It improves the tracking performance of low-bit quantized measurements by minimizing the additional covariance caused by quantization. The simulation demonstrates that our scheme performs much better than the conventional uniform quantization-based target tracking scheme and the increment of the data length affects our scheme only a little. Its tracking performance improves by only 4.4% from 2- to 3-bit, which means our scheme weakly depends on the number of data bits. Moreover, our scheme also weakly depends on the number of participate sensors, and it can work well in sparse sensor networks. In a 6 × 6 × 6 sensor network, compared with 4 × 4 × 4 sensor networks, the number of participant sensors increases by 334.92%, while the tracking accuracy using 1-bit quantized measurements improves by only 50.77%. Overall, our optimal quantization-based target tracking scheme can achieve the pursuit of data-efficiency, which fits the requirements of low-bandwidth UWSNs.

Efficient eNB inter-communication scheme in converged mobile and NG-PON2 system

NASA Astrophysics Data System (ADS)

Xiao, Simiao; Sun, Xiao; Zhang, Kaibin

2016-02-01

In LTE, a new X2-interface is defined to facilitate direct communication between neighboring eNBs. Since LTE is an all-IP network, the X2-interface traffic currently needs to be routed and transponded in L3 at the edge router by IP addressing. As mobile data increases, it is a promising trend to backhaul mobile services based on PON. In this paper, an effective approach for eNB inter-communication over TWDM-PON is proposed. By associating the IP address of eNB and the MAC address of ONU, the "inter-eNB communication in L3" can be mapped into "inter-ONU communication in L2" and transponded via the protocol of PON at the OLT. Thus, fast and cost-effective eNB inter-communication can be realized based on TWDM-PON within one wavelength channel and between different wavelength channels. The increasing data traffic pressure to the core network can also be alleviated.

BossPro: a biometrics-based obfuscation scheme for software protection

NASA Astrophysics Data System (ADS)

Kuseler, Torben; Lami, Ihsan A.; Al-Assam, Hisham

2013-05-01

This paper proposes to integrate biometric-based key generation into an obfuscated interpretation algorithm to protect authentication application software from illegitimate use or reverse-engineering. This is especially necessary for mCommerce because application programmes on mobile devices, such as Smartphones and Tablet-PCs are typically open for misuse by hackers. Therefore, the scheme proposed in this paper ensures that a correct interpretation / execution of the obfuscated program code of the authentication application requires a valid biometric generated key of the actual person to be authenticated, in real-time. Without this key, the real semantics of the program cannot be understood by an attacker even if he/she gains access to this application code. Furthermore, the security provided by this scheme can be a vital aspect in protecting any application running on mobile devices that are increasingly used to perform business/financial or other security related applications, but are easily lost or stolen. The scheme starts by creating a personalised copy of any application based on the biometric key generated during an enrolment process with the authenticator as well as a nuance created at the time of communication between the client and the authenticator. The obfuscated code is then shipped to the client's mobile devise and integrated with real-time biometric extracted data of the client to form the unlocking key during execution. The novelty of this scheme is achieved by the close binding of this application program to the biometric key of the client, thus making this application unusable for others. Trials and experimental results on biometric key generation, based on client's faces, and an implemented scheme prototype, based on the Android emulator, prove the concept and novelty of this proposed scheme.

An Efficient Buyer-Seller Watermarking Protocol Based on Chameleon Encryption

NASA Astrophysics Data System (ADS)

Poh, Geong Sen; Martin, Keith M.

Buyer-seller watermarking protocols are designed to deter clients from illegally distributing copies of digital content. This is achieved by allowing a distributor to insert a unique watermark into content in such a way that the distributor does not know the final watermarked copy that is given to the client. This protects both the client and distributor from attempts by one to falsely accuse the other of misuse. Buyer-seller watermarking protocols are normally based on asymmetric cryptographic primitives known as homomorphic encryption schemes. However, the computational and communication overhead of this conventional approach is high. In this paper we propose a different approach, based on the symmetric Chameleon encryption scheme. We show that this leads to significant gains in computational and operational efficiency.

Energy Savings in Cellular Networks Based on Space-Time Structure of Traffic Loads

NASA Astrophysics Data System (ADS)

Sun, Jingbo; Wang, Yue; Yuan, Jian; Shan, Xiuming

Since most of energy consumed by the telecommunication infrastructure is due to the Base Transceiver Station (BTS), switching off BTSs when traffic load is low has been recognized as an effective way of saving energy. In this letter, an energy saving scheme is proposed to minimize the number of active BTSs based on the space-time structure of traffic loads as determined by principal component analysis. Compared to existing methods, our approach models traffic loads more accurately, and has a much smaller input size. As it is implemented in an off-line manner, our scheme also avoids excessive communications and computing overheads. Simulation results show that the proposed method has a comparable performance in energy savings.

Implementation of a web-based, interactive polytrauma tutorial in computed tomography for radiology residents: how we do it.

PubMed

Schlorhaufer, C; Behrends, M; Diekhaus, G; Keberle, M; Weidemann, J

2012-12-01

Due to the time factor in polytraumatized patients all relevant pathologies in a polytrauma computed tomography (CT) scan have to be read and communicated very quickly. During radiology residency acquisition of effective reading schemes based on typical polytrauma pathologies is very important. Thus, an online tutorial for the structured diagnosis of polytrauma CT was developed. Based on current multimedia theories like the cognitive load theory a didactic concept was developed. As a web-environment the learning management system ILIAS was chosen. CT data sets were converted into online scrollable QuickTime movies. Audiovisual tutorial movies with guided image analyses by a consultant radiologist were recorded. The polytrauma tutorial consists of chapterized text content and embedded interactive scrollable CT data sets. Selected trauma pathologies are demonstrated to the user by guiding tutor movies. Basic reading schemes are communicated with the help of detailed commented movies of normal data sets. Common and important pathologies could be explored in a self-directed manner. Ambitious didactic concepts can be supported by a web based application on the basis of cognitive load theory and currently available software tools. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A Novel Addressing Scheme for PMIPv6 Based Global IP-WSNs

PubMed Central

Islam, Md. Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are being used in healthcare, home automation, industrial control and agricultural monitoring. In most of these applications global addressing of individual IP-WSN nodes and layer-three routing for mobility enabled IP-WSN with special attention to reliability, energy efficiency and end to end delay minimization are a few of the major issues to be addressed. Most of the routing protocols in WSN are based on layer-two approaches. For reliability and end to end communication enhancement the necessity of layer-three routing for IP-WSNs is generating significant attention among the research community, but due to the hurdle of maintaining routing state and other communication overhead, it was not possible to introduce a layer-three routing protocol for IP-WSNs. To address this issue we propose in this paper a global addressing scheme and layer-three based hierarchical routing protocol. The proposed addressing and routing approach focuses on all the above mentioned issues. Simulation results show that the proposed addressing and routing approach significantly enhances the reliability, energy efficiency and end to end delay minimization. We also present architecture, message formats and different routing scenarios in this paper. PMID:22164084

A novel addressing scheme for PMIPv6 based global IP-WSNs.

PubMed

Islam, Md Motaharul; Huh, Eui-Nam

2011-01-01

IP based Wireless Sensor Networks (IP-WSNs) are being used in healthcare, home automation, industrial control and agricultural monitoring. In most of these applications global addressing of individual IP-WSN nodes and layer-three routing for mobility enabled IP-WSN with special attention to reliability, energy efficiency and end to end delay minimization are a few of the major issues to be addressed. Most of the routing protocols in WSN are based on layer-two approaches. For reliability and end to end communication enhancement the necessity of layer-three routing for IP-WSNs is generating significant attention among the research community, but due to the hurdle of maintaining routing state and other communication overhead, it was not possible to introduce a layer-three routing protocol for IP-WSNs. To address this issue we propose in this paper a global addressing scheme and layer-three based hierarchical routing protocol. The proposed addressing and routing approach focuses on all the above mentioned issues. Simulation results show that the proposed addressing and routing approach significantly enhances the reliability, energy efficiency and end to end delay minimization. We also present architecture, message formats and different routing scenarios in this paper.

Secure and Efficient Two-Factor User Authentication Scheme with User Anonymity for Network Based E-Health Care Applications.

PubMed

Li, Xiong; Niu, Jianwei; Karuppiah, Marimuthu; Kumari, Saru; Wu, Fan

2016-12-01

Benefited from the development of network and communication technologies, E-health care systems and telemedicine have got the fast development. By using the E-health care systems, patient can enjoy the remote medical service provided by the medical server. Medical data are important privacy information for patient, so it is an important issue to ensure the secure of transmitted medical data through public network. Authentication scheme can thwart unauthorized users from accessing services via insecure network environments, so user authentication with privacy protection is an important mechanism for the security of E-health care systems. Recently, based on three factors (password, biometric and smart card), an user authentication scheme for E-health care systems was been proposed by Amin et al., and they claimed that their scheme can withstand most of common attacks. Unfortunate, we find that their scheme cannot achieve the untraceability feature of the patient. Besides, their scheme lacks a password check mechanism such that it is inefficient to find the unauthorized login by the mistake of input a wrong password. Due to the same reason, their scheme is vulnerable to Denial of Service (DoS) attack if the patient updates the password mistakenly by using a wrong password. In order improve the security level of authentication scheme for E-health care application, a robust user authentication scheme with privacy protection is proposed for E-health care systems. Then, security prove of our scheme are analysed. Security and performance analyses show that our scheme is more powerful and secure for E-health care systems when compared with other related schemes.

Coding for reliable satellite communications

NASA Technical Reports Server (NTRS)

Gaarder, N. T.; Lin, S.

1986-01-01

This research project was set up to study various kinds of coding techniques for error control in satellite and space communications for NASA Goddard Space Flight Center. During the project period, researchers investigated the following areas: (1) decoding of Reed-Solomon codes in terms of dual basis; (2) concatenated and cascaded error control coding schemes for satellite and space communications; (3) use of hybrid coding schemes (error correction and detection incorporated with retransmission) to improve system reliability and throughput in satellite communications; (4) good codes for simultaneous error correction and error detection, and (5) error control techniques for ring and star networks.

A Synchronous Digital Duplexing Technique for OFDMA-Based Indoor Communications

NASA Astrophysics Data System (ADS)

Park, Chang-Hwan; Ko, Yo-Han; Kim, Yeong-Jun; Park, Kyung-Won; Jeon, Won-Gi; Paik, Jong-Ho; Lee, Seok-Pil; Cho, Yong-Soo

In this paper, we propose a new digital duplexing scheme, called synchronous digital duplexing (SDD), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously in wireless communication. In order to transmit uplink and downlink signals simultaneously, the proposed SDD obtains mutual information among subscriber stations (SSs) with a mutual ranging symbol. This information is used for selection of transmission time, decision on cyclic suffix (CS) insertion, determination of CS length, and re-establishment of FFT starting point.

Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things.

PubMed

Martín-Fernández, Francisco; Caballero-Gil, Pino; Caballero-Gil, Cándido

2016-01-07

This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie-Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes.

Authentication Based on Non-Interactive Zero-Knowledge Proofs for the Internet of Things

PubMed Central

Martín-Fernández, Francisco; Caballero-Gil, Pino; Caballero-Gil, Cándido

2016-01-01

This paper describes the design and analysis of a new scheme for the authenticated exchange of confidential information in insecure environments within the Internet of Things, which allows a receiver of a message to authenticate the sender and compute a secret key shared with it. The proposal is based on the concept of a non-interactive zero-knowledge proof, so that in a single communication, relevant data may be inferred to verify the legitimacy of the sender. Besides, the new scheme uses the idea under the Diffie–Hellman protocol for the establishment of a shared secret key. The proposal has been fully developed for platforms built on the Android Open Source Project, so it can be used in any device or sensor with this operating system. This work provides a performance study of the implementation and a comparison between its promising results and others obtained with similar schemes. PMID:26751454

Decision algorithm for data center vortex beam receiver

NASA Astrophysics Data System (ADS)

Kupferman, Judy; Arnon, Shlomi

2017-12-01

We present a new scheme for a vortex beam communications system which exploits the radial component p of Laguerre-Gauss modes in addition to the azimuthal component l generally used. We derive a new encoding algorithm which makes use of the spatial distribution of intensity to create an alphabet dictionary for communication. We suggest an application of the scheme as part of an optical wireless link for intra data center communication. We investigate the probability of error in decoding, for several detector options.

A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes.

PubMed

Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme.

Quasi-disjoint pentadiagonal matrix systems for the parallelization of compact finite-difference schemes and filters

NASA Astrophysics Data System (ADS)

Kim, Jae Wook

2013-05-01

This paper proposes a novel systematic approach for the parallelization of pentadiagonal compact finite-difference schemes and filters based on domain decomposition. The proposed approach allows a pentadiagonal banded matrix system to be split into quasi-disjoint subsystems by using a linear-algebraic transformation technique. As a result the inversion of pentadiagonal matrices can be implemented within each subdomain in an independent manner subject to a conventional halo-exchange process. The proposed matrix transformation leads to new subdomain boundary (SB) compact schemes and filters that require three halo terms to exchange with neighboring subdomains. The internode communication overhead in the present approach is equivalent to that of standard explicit schemes and filters based on seven-point discretization stencils. The new SB compact schemes and filters demand additional arithmetic operations compared to the original serial ones. However, it is shown that the additional cost becomes sufficiently low by choosing optimal sizes of their discretization stencils. Compared to earlier published results, the proposed SB compact schemes and filters successfully reduce parallelization artifacts arising from subdomain boundaries to a level sufficiently negligible for sophisticated aeroacoustic simulations without degrading parallel efficiency. The overall performance and parallel efficiency of the proposed approach are demonstrated by stringent benchmark tests.

Quantum Communication Using Coherent Rejection Sampling

NASA Astrophysics Data System (ADS)

Anshu, Anurag; Devabathini, Vamsi Krishna; Jain, Rahul

2017-09-01

Compression of a message up to the information it carries is key to many tasks involved in classical and quantum information theory. Schumacher [B. Schumacher, Phys. Rev. A 51, 2738 (1995), 10.1103/PhysRevA.51.2738] provided one of the first quantum compression schemes and several more general schemes have been developed ever since [M. Horodecki, J. Oppenheim, and A. Winter, Commun. Math. Phys. 269, 107 (2007); , 10.1007/s00220-006-0118-xI. Devetak and J. Yard, Phys. Rev. Lett. 100, 230501 (2008); , 10.1103/PhysRevLett.100.230501A. Abeyesinghe, I. Devetak, P. Hayden, and A. Winter, Proc. R. Soc. A 465, 2537 (2009), 10.1098/rspa.2009.0202]. However, the one-shot characterization of these quantum tasks is still under development, and often lacks a direct connection with analogous classical tasks. Here we show a new technique for the compression of quantum messages with the aid of entanglement. We devise a new tool that we call the convex split lemma, which is a coherent quantum analogue of the widely used rejection sampling procedure in classical communication protocols. As a consequence, we exhibit new explicit protocols with tight communication cost for quantum state merging, quantum state splitting, and quantum state redistribution (up to a certain optimization in the latter case). We also present a port-based teleportation scheme which uses a fewer number of ports in the presence of information about input.

An efficient biometric and password-based remote user authentication using smart card for Telecare Medical Information Systems in multi-server environment.

PubMed

Maitra, Tanmoy; Giri, Debasis

2014-12-01

The medical organizations have introduced Telecare Medical Information System (TMIS) to provide a reliable facility by which a patient who is unable to go to a doctor in critical or urgent period, can communicate to a doctor through a medical server via internet from home. An authentication mechanism is needed in TMIS to hide the secret information of both parties, namely a server and a patient. Recent research includes patient's biometric information as well as password to design a remote user authentication scheme that enhances the security level. In a single server environment, one server is responsible for providing services to all the authorized remote patients. However, the problem arises if a patient wishes to access several branch servers, he/she needs to register to the branch servers individually. In 2014, Chuang and Chen proposed an remote user authentication scheme for multi-server environment. In this paper, we have shown that in their scheme, an non-register adversary can successfully logged-in into the system as a valid patient. To resist the weaknesses, we have proposed an authentication scheme for TMIS in multi-server environment where the patients can register to a root telecare server called registration center (RC) in one time to get services from all the telecare branch servers through their registered smart card. Security analysis and comparison shows that our proposed scheme provides better security with low computational and communication cost.

Spatial-Temporal Data Collection with Compressive Sensing in Mobile Sensor Networks

PubMed Central

Li, Jiayin; Guo, Wenzhong; Chen, Zhonghui; Xiong, Neal

2017-01-01

Compressive sensing (CS) provides an energy-efficient paradigm for data gathering in wireless sensor networks (WSNs). However, the existing work on spatial-temporal data gathering using compressive sensing only considers either multi-hop relaying based or multiple random walks based approaches. In this paper, we exploit the mobility pattern for spatial-temporal data collection and propose a novel mobile data gathering scheme by employing the Metropolis-Hastings algorithm with delayed acceptance, an improved random walk algorithm for a mobile collector to collect data from a sensing field. The proposed scheme exploits Kronecker compressive sensing (KCS) for spatial-temporal correlation of sensory data by allowing the mobile collector to gather temporal compressive measurements from a small subset of randomly selected nodes along a random routing path. More importantly, from the theoretical perspective we prove that the equivalent sensing matrix constructed from the proposed scheme for spatial-temporal compressible signal can satisfy the property of KCS models. The simulation results demonstrate that the proposed scheme can not only significantly reduce communication cost but also improve recovery accuracy for mobile data gathering compared to the other existing schemes. In particular, we also show that the proposed scheme is robust in unreliable wireless environment under various packet losses. All this indicates that the proposed scheme can be an efficient alternative for data gathering application in WSNs. PMID:29117152

Spatial-Temporal Data Collection with Compressive Sensing in Mobile Sensor Networks.

PubMed

Zheng, Haifeng; Li, Jiayin; Feng, Xinxin; Guo, Wenzhong; Chen, Zhonghui; Xiong, Neal

2017-11-08

Compressive sensing (CS) provides an energy-efficient paradigm for data gathering in wireless sensor networks (WSNs). However, the existing work on spatial-temporal data gathering using compressive sensing only considers either multi-hop relaying based or multiple random walks based approaches. In this paper, we exploit the mobility pattern for spatial-temporal data collection and propose a novel mobile data gathering scheme by employing the Metropolis-Hastings algorithm with delayed acceptance, an improved random walk algorithm for a mobile collector to collect data from a sensing field. The proposed scheme exploits Kronecker compressive sensing (KCS) for spatial-temporal correlation of sensory data by allowing the mobile collector to gather temporal compressive measurements from a small subset of randomly selected nodes along a random routing path. More importantly, from the theoretical perspective we prove that the equivalent sensing matrix constructed from the proposed scheme for spatial-temporal compressible signal can satisfy the property of KCS models. The simulation results demonstrate that the proposed scheme can not only significantly reduce communication cost but also improve recovery accuracy for mobile data gathering compared to the other existing schemes. In particular, we also show that the proposed scheme is robust in unreliable wireless environment under various packet losses. All this indicates that the proposed scheme can be an efficient alternative for data gathering application in WSNs .

Multistage Estimation Of Frequency And Phase

NASA Technical Reports Server (NTRS)

Kumar, Rajendra

1991-01-01

Conceptual two-stage software scheme serves as prototype of multistage scheme for digital estimation of phase, frequency, and rate of change of frequency ("Doppler rate") of possibly phase-modulated received sinusoidal signal in communication system in which transmitter and/or receiver traveling rapidly, accelerating, and/or jerking severely. Each additional stage of multistage scheme provides increasingly refined estimate of frequency and phase of signal. Conceived for use in estimating parameters of signals from spacecraft and high dynamic GPS signal parameters, also applicable, to terrestrial stationary/mobile (e.g., cellular radio) and land-mobile/satellite communication systems.

Privacy-Aware Image Encryption Based on Logistic Map and Data Hiding

NASA Astrophysics Data System (ADS)

Sun, Jianglin; Liao, Xiaofeng; Chen, Xin; Guo, Shangwei

The increasing need for image communication and storage has created a great necessity for securely transforming and storing images over a network. Whereas traditional image encryption algorithms usually consider the security of the whole plain image, region of interest (ROI) encryption schemes, which are of great importance in practical applications, protect the privacy regions of plain images. Existing ROI encryption schemes usually adopt approximate techniques to detect the privacy region and measure the quality of encrypted images; however, their performance is usually inconsistent with a human visual system (HVS) and is sensitive to statistical attacks. In this paper, we propose a novel privacy-aware ROI image encryption (PRIE) scheme based on logistical mapping and data hiding. The proposed scheme utilizes salient object detection to automatically, adaptively and accurately detect the privacy region of a given plain image. After private pixels have been encrypted using chaotic cryptography, the significant bits are embedded into the nonprivacy region of the plain image using data hiding. Extensive experiments are conducted to illustrate the consistency between our automatic ROI detection and HVS. Our experimental results also demonstrate that the proposed scheme exhibits satisfactory security performance.

Optical Implementation of the Optimal Universal and Phase-Covariant Quantum Cloning Machines

NASA Astrophysics Data System (ADS)

Ye, Liu; Song, Xue-Ke; Yang, Jie; Yang, Qun; Ma, Yang-Cheng

Quantum cloning relates to the security of quantum computation and quantum communication. In this paper, firstly we propose a feasible unified scheme to implement optimal 1 → 2 universal, 1 → 2 asymmetric and symmetric phase-covariant cloning, and 1 → 2 economical phase-covariant quantum cloning machines only via a beam splitter. Then 1 → 3 economical phase-covariant quantum cloning machines also can be realized by adding another beam splitter in context of linear optics. The scheme is based on the interference of two photons on a beam splitter with different splitting ratios for vertical and horizontal polarization components. It is shown that under certain condition, the scheme is feasible by current experimental technology.

An Experimental Study of a Micro-Projection Enabled Optical Terminal for Short-Range Bidirectional Multi-Wavelength Visible Light Communications

PubMed Central

Tsai, Cheng-Yu; Jiang, Jhih-Shan

2018-01-01

A micro-projection enabled short-range communication (SRC) approach using red-, green- and blue-based light-emitting diodes (RGB-LEDs) has experimentally demonstrated recently that micro-projection and high-speed data transmission can be performed simultaneously. In this research, a reconfigurable design of a polarization modulated image system based on the use of a Liquid Crystal on Silicon based Spatial Light Modulator (LCoS-based SLM) serving as a portable optical terminal capable of micro-projection and bidirectional multi-wavelength communications is proposed and experimentally demonstrated. For the proof of concept, the system performance was evaluated through a bidirectional communication link at a transmission distance over 0.65 m. In order to make the proposed communication system architecture compatible with the data modulation format of future possible wireless communication system, baseband modulation scheme, i.e., Non-Return-to-Zero On-Off-Keying (NRZ_OOK), M-ary Phase Shift Keying (M-PSK) and M-ary Quadrature Amplitude Modulation (M-QAM) were used to investigate the system transmission performance. The experimental results shown that an acceptable BER (satisfying the limitation of Forward Error Correction, FEC standard) and crosstalk can all be achieved in the bidirectional multi-wavelength communication scenario. PMID:29587457

A Multi-layer Dynamic Model for Coordination Based Group Decision Making in Water Resource Allocation and Scheduling

NASA Astrophysics Data System (ADS)

Huang, Wei; Zhang, Xingnan; Li, Chenming; Wang, Jianying

Management of group decision-making is an important issue in water source management development. In order to overcome the defects in lacking of effective communication and cooperation in the existing decision-making models, this paper proposes a multi-layer dynamic model for coordination in water resource allocation and scheduling based group decision making. By introducing the scheme-recognized cooperative satisfaction index and scheme-adjusted rationality index, the proposed model can solve the problem of poor convergence of multi-round decision-making process in water resource allocation and scheduling. Furthermore, the problem about coordination of limited resources-based group decision-making process can be solved based on the effectiveness of distance-based group of conflict resolution. The simulation results show that the proposed model has better convergence than the existing models.

Spatial and temporal accuracy of asynchrony-tolerant finite difference schemes for partial differential equations at extreme scales

NASA Astrophysics Data System (ADS)

Kumari, Komal; Donzis, Diego

2017-11-01

Highly resolved computational simulations on massively parallel machines are critical in understanding the physics of a vast number of complex phenomena in nature governed by partial differential equations. Simulations at extreme levels of parallelism present many challenges with communication between processing elements (PEs) being a major bottleneck. In order to fully exploit the computational power of exascale machines one needs to devise numerical schemes that relax global synchronizations across PEs. This asynchronous computations, however, have a degrading effect on the accuracy of standard numerical schemes.We have developed asynchrony-tolerant (AT) schemes that maintain order of accuracy despite relaxed communications. We show, analytically and numerically, that these schemes retain their numerical properties with multi-step higher order temporal Runge-Kutta schemes. We also show that for a range of optimized parameters,the computation time and error for AT schemes is less than their synchronous counterpart. Stability of the AT schemes which depends upon history and random nature of delays, are also discussed. Support from NSF is gratefully acknowledged.

Investigation of advanced pre- and post-equalization schemes in high-order CAP modulation based high-speed indoor VLC transmission system

NASA Astrophysics Data System (ADS)

Wang, Yiguang; Chi, Nan

2016-10-01

Light emitting diodes (LEDs) based visible light communication (VLC) has been considered as a promising technology for indoor high-speed wireless access, due to its unique advantages, such as low cost, license free and high security. To achieve high-speed VLC transmission, carrierless amplitude and phase (CAP) modulation has been utilized for its lower complexity and high spectral efficiency. Moreover, to compensate the linear and nonlinear distortions such as frequency attenuation, sampling time offset, LED nonlinearity etc., series of pre- and post-equalization schemes should be employed in high-speed VLC systems. In this paper, we make an investigation on several advanced pre- and postequalization schemes for high-order CAP modulation based VLC systems. We propose to use a weighted preequalization technique to compensate the LED frequency attenuation. In post-equalization, a hybrid post equalizer is proposed, which consists of a linear equalizer, a Volterra series based nonlinear equalizer, and a decision-directed least mean square (DD-LMS) equalizer. Modified cascaded multi-modulus algorithm (M-CMMA) is employed to update the weights of the linear and the nonlinear equalizer, while DD-LMS can further improve the performance after the preconvergence. Based on high-order CAP modulation and these equalization schemes, we have experimentally demonstrated a 1.35-Gb/s, a 4.5-Gb/s and a 8-Gb/s high-speed indoor VLC transmission systems. The results show the benefit and feasibility of the proposed equalization schemes for high-speed VLC systems.

Cost-Efficient and Multi-Functional Secure Aggregation in Large Scale Distributed Application

PubMed Central

Zhang, Ping; Li, Wenjun; Sun, Hua

2016-01-01

Secure aggregation is an essential component of modern distributed applications and data mining platforms. Aggregated statistical results are typically adopted in constructing a data cube for data analysis at multiple abstraction levels in data warehouse platforms. Generating different types of statistical results efficiently at the same time (or referred to as enabling multi-functional support) is a fundamental requirement in practice. However, most of the existing schemes support a very limited number of statistics. Securely obtaining typical statistical results simultaneously in the distribution system, without recovering the original data, is still an open problem. In this paper, we present SEDAR, which is a SEcure Data Aggregation scheme under the Range segmentation model. Range segmentation model is proposed to reduce the communication cost by capturing the data characteristics, and different range uses different aggregation strategy. For raw data in the dominant range, SEDAR encodes them into well defined vectors to provide value-preservation and order-preservation, and thus provides the basis for multi-functional aggregation. A homomorphic encryption scheme is used to achieve data privacy. We also present two enhanced versions. The first one is a Random based SEDAR (REDAR), and the second is a Compression based SEDAR (CEDAR). Both of them can significantly reduce communication cost with the trade-off lower security and lower accuracy, respectively. Experimental evaluations, based on six different scenes of real data, show that all of them have an excellent performance on cost and accuracy. PMID:27551747

Cost-Efficient and Multi-Functional Secure Aggregation in Large Scale Distributed Application.

PubMed

Zhang, Ping; Li, Wenjun; Sun, Hua

2016-01-01

Secure aggregation is an essential component of modern distributed applications and data mining platforms. Aggregated statistical results are typically adopted in constructing a data cube for data analysis at multiple abstraction levels in data warehouse platforms. Generating different types of statistical results efficiently at the same time (or referred to as enabling multi-functional support) is a fundamental requirement in practice. However, most of the existing schemes support a very limited number of statistics. Securely obtaining typical statistical results simultaneously in the distribution system, without recovering the original data, is still an open problem. In this paper, we present SEDAR, which is a SEcure Data Aggregation scheme under the Range segmentation model. Range segmentation model is proposed to reduce the communication cost by capturing the data characteristics, and different range uses different aggregation strategy. For raw data in the dominant range, SEDAR encodes them into well defined vectors to provide value-preservation and order-preservation, and thus provides the basis for multi-functional aggregation. A homomorphic encryption scheme is used to achieve data privacy. We also present two enhanced versions. The first one is a Random based SEDAR (REDAR), and the second is a Compression based SEDAR (CEDAR). Both of them can significantly reduce communication cost with the trade-off lower security and lower accuracy, respectively. Experimental evaluations, based on six different scenes of real data, show that all of them have an excellent performance on cost and accuracy.

Provably Secure Heterogeneous Access Control Scheme for Wireless Body Area Network.

PubMed

Omala, Anyembe Andrew; Mbandu, Angolo Shem; Mutiria, Kamenyi Domenic; Jin, Chunhua; Li, Fagen

2018-04-28

Wireless body area network (WBAN) provides a medium through which physiological information could be harvested and transmitted to application provider (AP) in real time. Integrating WBAN in a heterogeneous Internet of Things (IoT) ecosystem would enable an AP to monitor patients from anywhere and at anytime. However, the IoT roadmap of interconnected 'Things' is still faced with many challenges. One of the challenges in healthcare is security and privacy of streamed medical data from heterogeneously networked devices. In this paper, we first propose a heterogeneous signcryption scheme where a sender is in a certificateless cryptographic (CLC) environment while a receiver is in identity-based cryptographic (IBC) environment. We then use this scheme to design a heterogeneous access control protocol. Formal security proof for indistinguishability against adaptive chosen ciphertext attack and unforgeability against adaptive chosen message attack in random oracle model is presented. In comparison with some of the existing access control schemes, our scheme has lower computation and communication cost.

Experimental extraction of an entangled photon pair from two identically decohered pairs.

PubMed

Yamamoto, Takashi; Koashi, Masato; Ozdemir, Sahin Kaya; Imoto, Nobuyuki

2003-01-23

Entanglement is considered to be one of the most important resources in quantum information processing schemes, including teleportation, dense coding and entanglement-based quantum key distribution. Because entanglement cannot be generated by classical communication between distant parties, distribution of entangled particles between them is necessary. During the distribution process, entanglement between the particles is degraded by the decoherence and dissipation processes that result from unavoidable coupling with the environment. Entanglement distillation and concentration schemes are therefore needed to extract pairs with a higher degree of entanglement from these less-entangled pairs; this is accomplished using local operations and classical communication. Here we report an experimental demonstration of extraction of a polarization-entangled photon pair from two decohered photon pairs. Two polarization-entangled photon pairs are generated by spontaneous parametric down-conversion and then distributed through a channel that induces identical phase fluctuations to both pairs; this ensures that no entanglement is available as long as each pair is manipulated individually. Then, through collective local operations and classical communication we extract from the two decohered pairs a photon pair that is observed to be polarization-entangled.

Deep Space Network and Lunar Network Communication Coverage of the Moon

NASA Technical Reports Server (NTRS)

Lee, Charles H.; Cheung, Kar-Ming

2006-01-01

In this article, we describe the communication coverage analysis for the lunar network and the Earth ground stations. The first part of this article focuses on the direct communication coverage of the Moon from the Earth's ground stations. In particular, we assess the coverage performance of the Moon based on the existing Deep Space Network (DSN) antennas and the complimentary coverage of other potential stations at Hartebeesthoek, South Africa and at Santiago, Chile. We also address the coverage sensitivity based on different DSN antenna scenarios and their capability to provide single and redundant coverage of the Moon. The second part of this article focuses on the framework of the constrained optimization scheme to seek a stable constellation six relay satellites in two planes that not only can provide continuous communication coverage to any users on the Moon surface, but can also deliver data throughput in a highly efficient manner.

Cryptanalysis of a chaotic communication scheme using adaptive observer.

PubMed

Liu, Ying; Tang, Wallace K S

2008-12-01

This paper addresses the cryptanalysis of a secure communication scheme recently proposed by Wu [Chaos 16, 043118 (2006)], where the information signal is modulated into a system parameter of a unified chaotic system. With the Kerckhoff principle, assuming that the structure of the cryptosystem is known, an adaptive observer can be designed to synchronize the targeted system, so that the transmitted information and the user-specific parameters are obtained. The success of adaptive synchronization is mathematically proved with the use of Lyapunov stability theory, based on the original assumption, i.e., the dynamical evolution of the information signal is available. A more practical case, but yet much more difficult, is also considered. As demonstrated with simulations, generalized synchronization is still possible, even if the derivative of the information signal is kept secret. Hence, the message can be coarsely estimated, making the security of the considered system questionable.

Photonic ultra-wideband pulse generation, hybrid modulation and dispersion-compensation-free transmission in multi-access communication systems.

PubMed

Tan, Kang; Shao, Jing; Sun, Junqiang; Wang, Jian

2012-01-16

We propose and demonstrate a scheme for optical ultrawideband (UWB) pulse generation by exploiting a half-carrier-suppressed Mach-Zehnder modulator (MZM) and a delay-interferometer- and wavelength-division-multiplexer-based, reconfigurable and multi-channel differentiator (DWRMD). Multi-wavelength, polarity- and shape-switchable UWB pulses of monocycle, doublet, triplet, and quadruplet are experimentally generated simply by tuning two bias voltages to modify the carrier-suppression ratio of MZM and the differential order of DWRMD respectively. The pulse position modulation, pulse shape modulation, pulse amplitude modulation and binary phase-shift keying modulation of UWB pulses can also be conveniently realized with the same scheme structure, which indicates that the hybrid modulation of those four formats can be achieved. Consequently, the proposed approach has potential applications in multi-shape, multi-modulation and multi-access UWB-over-fiber communication systems.

On-board congestion control for satellite packet switching networks

NASA Technical Reports Server (NTRS)

Chu, Pong P.

1991-01-01

It is desirable to incorporate packet switching capability on-board for future communication satellites. Because of the statistical nature of packet communication, incoming traffic fluctuates and may cause congestion. Thus, it is necessary to incorporate a congestion control mechanism as part of the on-board processing to smooth and regulate the bursty traffic. Although there are extensive studies on congestion control for both baseband and broadband terrestrial networks, these schemes are not feasible for space based switching networks because of the unique characteristics of satellite link. Here, we propose a new congestion control method for on-board satellite packet switching. This scheme takes into consideration the long propagation delay in satellite link and takes advantage of the the satellite's broadcasting capability. It divides the control between the ground terminals and satellite, but distributes the primary responsibility to ground terminals and only requires minimal hardware resource on-board satellite.

Telidon Videotex presentation level protocol: Augmented picture description instructions

NASA Astrophysics Data System (ADS)

Obrien, C. D.; Brown, H. G.; Smirle, J. C.; Lum, Y. F.; Kukulka, J. Z.; Kwan, A.

1982-02-01

The Telidon Videotex system is a method by which graphic and textual information and transactional services can be accessed from information sources by the general public. In order to transmit information to a Telidon terminal at a minimum bandwidth, and in a manner independent of the type of communications channel, a coding scheme was devised which permits the encoding of a picture into the geometric drawing elements which compose it. These picture description instructions are an alpha geometric coding model and are based on the primitives of POINT, LINE, ARC, RECTANGLE, POLYGON, and INCREMENT. Text is encoded as (ASCII) characters along with a supplementary table of accents and special characters. A mosaic shape table is included for compatibility. A detailed specification of the coding scheme and a description of the principles which make it independent of communications channel and display hardware are provided.

Quantum photonic network and physical layer security

NASA Astrophysics Data System (ADS)

Sasaki, Masahide; Endo, Hiroyuki; Fujiwara, Mikio; Kitamura, Mitsuo; Ito, Toshiyuki; Shimizu, Ryosuke; Toyoshima, Morio

2017-06-01

Quantum communication and quantum cryptography are expected to enhance the transmission rate and the security (confidentiality of data transmission), respectively. We study a new scheme which can potentially bridge an intermediate region covered by these two schemes, which is referred to as quantum photonic network. The basic framework is information theoretically secure communications in a free space optical (FSO) wiretap channel, in which an eavesdropper has physically limited access to the main channel between the legitimate sender and receiver. We first review a theoretical framework to quantify the optimal balance of the transmission efficiency and the security level under power constraint and at finite code length. We then present experimental results on channel characterization based on 10 MHz on-off keying transmission in a 7.8 km terrestrial FSO wiretap channel. This article is part of the themed issue 'Quantum technology for the 21st century'.

Continuous variable quantum key distribution with modulated entangled states.

PubMed

Madsen, Lars S; Usenko, Vladyslav C; Lassen, Mikael; Filip, Radim; Andersen, Ulrik L

2012-01-01

Quantum key distribution enables two remote parties to grow a shared key, which they can use for unconditionally secure communication over a certain distance. The maximal distance depends on the loss and the excess noise of the connecting quantum channel. Several quantum key distribution schemes based on coherent states and continuous variable measurements are resilient to high loss in the channel, but are strongly affected by small amounts of channel excess noise. Here we propose and experimentally address a continuous variable quantum key distribution protocol that uses modulated fragile entangled states of light to greatly enhance the robustness to channel noise. We experimentally demonstrate that the resulting quantum key distribution protocol can tolerate more noise than the benchmark set by the ideal continuous variable coherent state protocol. Our scheme represents a very promising avenue for extending the distance for which secure communication is possible.

Quantum photonic network and physical layer security.

PubMed

Sasaki, Masahide; Endo, Hiroyuki; Fujiwara, Mikio; Kitamura, Mitsuo; Ito, Toshiyuki; Shimizu, Ryosuke; Toyoshima, Morio

2017-08-06

Quantum communication and quantum cryptography are expected to enhance the transmission rate and the security (confidentiality of data transmission), respectively. We study a new scheme which can potentially bridge an intermediate region covered by these two schemes, which is referred to as quantum photonic network. The basic framework is information theoretically secure communications in a free space optical (FSO) wiretap channel, in which an eavesdropper has physically limited access to the main channel between the legitimate sender and receiver. We first review a theoretical framework to quantify the optimal balance of the transmission efficiency and the security level under power constraint and at finite code length. We then present experimental results on channel characterization based on 10 MHz on-off keying transmission in a 7.8 km terrestrial FSO wiretap channel.This article is part of the themed issue 'Quantum technology for the 21st century'. © 2017 The Author(s).

A family of chaotic pure analog coding schemes based on baker's map function

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Jing; Lu, Xuanxuan; Yuen, Chau; Wu, Jun

2015-12-01

This paper considers a family of pure analog coding schemes constructed from dynamic systems which are governed by chaotic functions—baker's map function and its variants. Various decoding methods, including maximum likelihood (ML), minimum mean square error (MMSE), and mixed ML-MMSE decoding algorithms, have been developed for these novel encoding schemes. The proposed mirrored baker's and single-input baker's analog codes perform a balanced protection against the fold error (large distortion) and weak distortion and outperform the classical chaotic analog coding and analog joint source-channel coding schemes in literature. Compared to the conventional digital communication system, where quantization and digital error correction codes are used, the proposed analog coding system has graceful performance evolution, low decoding latency, and no quantization noise. Numerical results show that under the same bandwidth expansion, the proposed analog system outperforms the digital ones over a wide signal-to-noise (SNR) range.

Event generators for address event representation transmitters

NASA Astrophysics Data System (ADS)

Serrano-Gotarredona, Rafael; Serrano-Gotarredona, Teresa; Linares Barranco, Bernabe

2005-06-01

Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. In a typical AER transmitter chip, there is an array of neurons that generate events. They send events to a peripheral circuitry (let's call it "AER Generator") that transforms those events to neurons coordinates (addresses) which are put sequentially on an interchip high speed digital bus. This bus includes a parallel multi-bit address word plus a Rqst (request) and Ack (acknowledge) handshaking signals for asynchronous data exchange. There have been two main approaches published in the literature for implementing such "AER Generator" circuits. They differ on the way of handling event collisions coming from the array of neurons. One approach is based on detecting and discarding collisions, while the other incorporates arbitration for sequencing colliding events . The first approach is supposed to be simpler and faster, while the second is able to handle much higher event traffic. In this article we will concentrate on the second arbiter-based approach. Boahen has been publishing several techniques for implementing and improving the arbiter based approach. Originally, he proposed an arbitration squeme by rows, followed by a column arbitration. In this scheme, while one neuron was selected by the arbiters to transmit his event out of the chip, the rest of neurons in the array were freezed to transmit any further events during this time window. This limited the maximum transmission speed. In order to improve this speed, Boahen proposed an improved 'burst mode' scheme. In this scheme after the row arbitration, a complete row of events is pipelined out of the array and arbitered out of the chip at higher speed. During this single row event arbitration, the array is free to generate new events and communicate to the row arbiter, in a pipelined mode. This scheme significantly improves maximum event transmission speed, specially for high traffic situations were speed is more critical. We have analyzed and studied this approach and have detected some shortcomings in the circuits reported by Boahen, which may render some false situations under some statistical conditions. The present paper proposes some improvements to overcome such situations. The improved "AER Generator" has been implemented in an AER transmitter system

Network coding based joint signaling and dynamic bandwidth allocation scheme for inter optical network unit communication in passive optical networks

NASA Astrophysics Data System (ADS)

Wei, Pei; Gu, Rentao; Ji, Yuefeng

2014-06-01

As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.

Working towards a clearer and more helpful hazard map: investigating the influence of hazard map design on hazard communication

NASA Astrophysics Data System (ADS)

Thompson, M. A.; Lindsay, J. M.; Gaillard, J.

2015-12-01

Globally, geological hazards are communicated using maps. In traditional hazard mapping practice, scientists analyse data about a hazard, and then display the results on a map for stakeholder and public use. However, this one-way, top-down approach to hazard communication is not necessarily effective or reliable. The messages which people take away will be dependent on the way in which they read, interpret, and understand the map, a facet of hazard communication which has been relatively unexplored. Decades of cartographic studies suggest that variables in the visual representation of data on maps, such as colour and symbology, can have a powerful effect on how people understand map content. In practice, however, there is little guidance or consistency in how hazard information is expressed and represented on maps. Accordingly, decisions are often made based on subjective preference, rather than research-backed principles. Here we present the results of a study in which we explore how hazard map design features can influence hazard map interpretation, and we propose a number of considerations for hazard map design. A series of hazard maps were generated, with each one showing the same probabilistic volcanic ashfall dataset, but using different verbal and visual variables (e.g., different colour schemes, data classifications, probabilistic formats). Following a short pilot study, these maps were used in an online survey of 110 stakeholders and scientists in New Zealand. Participants answered 30 open-ended and multiple choice questions about ashfall hazard based on the different maps. Results suggest that hazard map design can have a significant influence on the messages readers take away. For example, diverging colour schemes were associated with concepts of "risk" and decision-making more than sequential schemes, and participants made more precise estimates of hazard with isarithmic data classifications compared to binned or gradational shading. Based on such findings, we make a number of suggestions for communicating hazard using maps. Most importantly, we emphasise that multiple meanings may be taken away from a map, and this may have important implications in a crisis. We propose that engaging with map audiences in a two-way dialogue in times of peace may help prevent miscommunications in the event of a crisis.

An Experimental Realization of a Chaos-Based Secure Communication Using Arduino Microcontrollers

PubMed Central

Zapateiro De la Hoz, Mauricio; Vidal, Yolanda

2015-01-01

Security and secrecy are some of the important concerns in the communications world. In the last years, several encryption techniques have been proposed in order to improve the secrecy of the information transmitted. Chaos-based encryption techniques are being widely studied as part of the problem because of the highly unpredictable and random-look nature of the chaotic signals. In this paper we propose a digital-based communication system that uses the logistic map which is a mathematically simple model that is chaotic under certain conditions. The input message signal is modulated using a simple Delta modulator and encrypted using a logistic map. The key signal is also encrypted using the same logistic map with different initial conditions. In the receiver side, the binary-coded message is decrypted using the encrypted key signal that is sent through one of the communication channels. The proposed scheme is experimentally tested using Arduino shields which are simple yet powerful development kits that allows for the implementation of the communication system for testing purposes. PMID:26413563

A lightweight and secure two factor anonymous authentication protocol for Global Mobility Networks.

PubMed

Baig, Ahmed Fraz; Hassan, Khwaja Mansoor Ul; Ghani, Anwar; Chaudhry, Shehzad Ashraf; Khan, Imran; Ashraf, Muhammad Usman

2018-01-01

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.'s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols.

A lightweight and secure two factor anonymous authentication protocol for Global Mobility Networks

PubMed Central

2018-01-01

Global Mobility Networks(GLOMONETs) in wireless communication permits the global roaming services that enable a user to leverage the mobile services in any foreign country. Technological growth in wireless communication is also accompanied by new security threats and challenges. A threat-proof authentication protocol in wireless communication may overcome the security flaws by allowing only legitimate users to access a particular service. Recently, Lee et al. found Mun et al. scheme vulnerable to different attacks and proposed an advanced secure scheme to overcome the security flaws. However, this article points out that Lee et al. scheme lacks user anonymity, inefficient user authentication, vulnerable to replay and DoS attacks and Lack of local password verification. Furthermore, this article presents a more robust anonymous authentication scheme to handle the threats and challenges found in Lee et al.’s protocol. The proposed protocol is formally verified with an automated tool(ProVerif). The proposed protocol has superior efficiency in comparison to the existing protocols. PMID:29702675

Communication: Spin densities within a unitary group based spin-adapted open-shell coupled-cluster theory: Analytic evaluation of isotropic hyperfine-coupling constants for the combinatoric open-shell coupled-cluster scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Datta, Dipayan, E-mail: datta.dipayan@gmail.com; Gauss, Jürgen, E-mail: gauss@uni-mainz.de

We report analytical calculations of isotropic hyperfine-coupling constants in radicals using a spin-adapted open-shell coupled-cluster theory, namely, the unitary group based combinatoric open-shell coupled-cluster (COSCC) approach within the singles and doubles approximation. A scheme for the evaluation of the one-particle spin-density matrix required in these calculations is outlined within the spin-free formulation of the COSCC approach. In this scheme, the one-particle spin-density matrix for an open-shell state with spin S and M{sub S} = + S is expressed in terms of the one- and two-particle spin-free (charge) density matrices obtained from the Lagrangian formulation that is used for calculating themore » analytic first derivatives of the energy. Benchmark calculations are presented for NO, NCO, CH{sub 2}CN, and two conjugated π-radicals, viz., allyl and 1-pyrrolyl in order to demonstrate the performance of the proposed scheme.« less

Design of an anti-Rician-fading modem for mobile satellite communication systems

NASA Technical Reports Server (NTRS)

Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

1995-01-01

To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

An event-triggered control approach for the leader-tracking problem with heterogeneous agents

NASA Astrophysics Data System (ADS)

Garcia, Eloy; Cao, Yongcan; Casbeer, David W.

2018-05-01

This paper presents an event-triggered control and communication framework for the cooperative leader-tracking problem with communication constraints. Continuous communication among agents is not assumed in this work and decentralised event-based strategies are proposed for agents with heterogeneous linear dynamics. Also, the leader dynamics are unknown and only intermittent measurements of its states are obtained by a subset of the followers. The event-based method not only represents a way to restrict communication among agents, but it also provides a decentralised scheme for scheduling information broadcasts. Notably, each agent is able to determine its own broadcasting instants independently of any other agent in the network. In an extension, the case where transmission of information is affected by time-varying communication delays is addressed. Finally, positive lower-bounds on the inter-event time intervals are obtained in order to show that Zeno behaviour does not exist and, therefore, continuous exchange of information is never needed in this framework.

Highly Scalable Asynchronous Computing Method for Partial Differential Equations: A Path Towards Exascale

NASA Astrophysics Data System (ADS)

Konduri, Aditya

Many natural and engineering systems are governed by nonlinear partial differential equations (PDEs) which result in a multiscale phenomena, e.g. turbulent flows. Numerical simulations of these problems are computationally very expensive and demand for extreme levels of parallelism. At realistic conditions, simulations are being carried out on massively parallel computers with hundreds of thousands of processing elements (PEs). It has been observed that communication between PEs as well as their synchronization at these extreme scales take up a significant portion of the total simulation time and result in poor scalability of codes. This issue is likely to pose a bottleneck in scalability of codes on future Exascale systems. In this work, we propose an asynchronous computing algorithm based on widely used finite difference methods to solve PDEs in which synchronization between PEs due to communication is relaxed at a mathematical level. We show that while stability is conserved when schemes are used asynchronously, accuracy is greatly degraded. Since message arrivals at PEs are random processes, so is the behavior of the error. We propose a new statistical framework in which we show that average errors drop always to first-order regardless of the original scheme. We propose new asynchrony-tolerant schemes that maintain accuracy when synchronization is relaxed. The quality of the solution is shown to depend, not only on the physical phenomena and numerical schemes, but also on the characteristics of the computing machine. A novel algorithm using remote memory access communications has been developed to demonstrate excellent scalability of the method for large-scale computing. Finally, we present a path to extend this method in solving complex multi-scale problems on Exascale machines.

Efficient entanglement distribution over 200 kilometers.

PubMed

Dynes, J F; Takesue, H; Yuan, Z L; Sharpe, A W; Harada, K; Honjo, T; Kamada, H; Tadanaga, O; Nishida, Y; Asobe, M; Shields, A J

2009-07-06

Here we report the first demonstration of entanglement distribution over a record distance of 200 km which is of sufficient fidelity to realize secure communication. In contrast to previous entanglement distribution schemes, we use detection elements based on practical avalanche photodiodes (APDs) operating in a self-differencing mode. These APDs are low-cost, compact and easy to operate requiring only electrical cooling to achieve high single photon detection efficiency. The self-differencing APDs in combination with a reliable parametric down-conversion source demonstrate that entanglement distribution over ultra-long distances has become both possible and practical. Consequently the outlook is extremely promising for real world entanglement-based communication between distantly separated parties.

Intelligent fault isolation and diagnosis for communication satellite systems

NASA Technical Reports Server (NTRS)

Tallo, Donald P.; Durkin, John; Petrik, Edward J.

1992-01-01

Discussed here is a prototype diagnosis expert system to provide the Advanced Communication Technology Satellite (ACTS) System with autonomous diagnosis capability. The system, the Fault Isolation and Diagnosis EXpert (FIDEX) system, is a frame-based system that uses hierarchical structures to represent such items as the satellite's subsystems, components, sensors, and fault states. This overall frame architecture integrates the hierarchical structures into a lattice that provides a flexible representation scheme and facilitates system maintenance. FIDEX uses an inexact reasoning technique based on the incrementally acquired evidence approach developed by Shortliffe. The system is designed with a primitive learning ability through which it maintains a record of past diagnosis studies.

PIYAS-proceeding to intelligent service oriented memory allocation for flash based data centric sensor devices in wireless sensor networks.

PubMed

Rizvi, Sanam Shahla; Chung, Tae-Sun

2010-01-01

Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks.

An assessment of innovative pricing schemes for the communication of value: is price discrimination and two-part pricing a way forward?

PubMed

Hertzman, Peter; Miller, Paul; Tolley, Keith

2018-02-01

With the introduction of new expensive medicines, traditional pricing schemes based on constructs such as price per pill/vial have been challenged. Potential innovative schemes could be either financial-based or performance-based. Within financial-based schemes the use of price discrimination is an emerging option, which we explore in this assessment. Areas covered: In the short term the price per indication approach is likely to become more prevalent for high cost, high benefit new pharmaceuticals, such as those emerging in oncology (e.g. new combination immunotherapies). 'Two-Part Pricing' (2PP) is a frequently used payment method in other industries, which consists of an Entry Fee, giving the buyer the right to use the product, and a Usage Price charged every time the product is purchased. Introducing 2PP into biopharma could have cross-stakeholder benefits including broader patient access, and improvement in budget/revenue predictability. A concern however is the potential complexity of the negotiation between manufacturer and payer. Expert commentary: We believe 'price discrimination' and 2PP in particular can be relevant for some new, expensive specialist medicines. A recommended first step would be to initiate pilots to test to what degree the 2PP approach meets stakeholder objectives and is practical to implement within specialty care.

Optimally Distributed Kalman Filtering with Data-Driven Communication †

PubMed Central

Dormann, Katharina

2018-01-01

For multisensor data fusion, distributed state estimation techniques that enable a local processing of sensor data are the means of choice in order to minimize storage and communication costs. In particular, a distributed implementation of the optimal Kalman filter has recently been developed. A significant disadvantage of this algorithm is that the fusion center needs access to each node so as to compute a consistent state estimate, which requires full communication each time an estimate is requested. In this article, different extensions of the optimally distributed Kalman filter are proposed that employ data-driven transmission schemes in order to reduce communication expenses. As a first relaxation of the full-rate communication scheme, it can be shown that each node only has to transmit every second time step without endangering consistency of the fusion result. Also, two data-driven algorithms are introduced that even allow for lower transmission rates, and bounds are derived to guarantee consistent fusion results. Simulations demonstrate that the data-driven distributed filtering schemes can outperform a centralized Kalman filter that requires each measurement to be sent to the center node. PMID:29596392

Image watermarking capacity analysis based on Hopfield neural network

NASA Astrophysics Data System (ADS)

Zhang, Fan; Zhang, Hongbin

2004-11-01

In watermarking schemes, watermarking can be viewed as a form of communication problems. Almost all of previous works on image watermarking capacity are based on information theory, using Shannon formula to calculate the capacity of watermarking. In this paper, we present a blind watermarking algorithm using Hopfield neural network, and analyze watermarking capacity based on neural network. In our watermarking algorithm, watermarking capacity is decided by attraction basin of associative memory.

Enhancing LoRaWAN Security through a Lightweight and Authenticated Key Management Approach.

PubMed

Sanchez-Iborra, Ramon; Sánchez-Gómez, Jesús; Pérez, Salvador; Fernández, Pedro J; Santa, José; Hernández-Ramos, José L; Skarmeta, Antonio F

2018-06-05

Luckily, new communication technologies and protocols are nowadays designed considering security issues. A clear example of this can be found in the Internet of Things (IoT) field, a quite recent area where communication technologies such as ZigBee or IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) already include security features to guarantee authentication, confidentiality and integrity. More recent technologies are Low-Power Wide-Area Networks (LP-WAN), which also consider security, but present initial approaches that can be further improved. An example of this can be found in Long Range (LoRa) and its layer-two supporter LoRa Wide Area Network (LoRaWAN), which include a security scheme based on pre-shared cryptographic material lacking flexibility when a key update is necessary. Because of this, in this work, we evaluate the security vulnerabilities of LoRaWAN in the area of key management and propose different alternative schemes. Concretely, the application of an approach based on the recently specified Ephemeral Diffie⁻Hellman Over COSE (EDHOC) is found as a convenient solution, given its flexibility in the update of session keys, its low computational cost and the limited message exchanges needed. A comparative conceptual analysis considering the overhead of different security schemes for LoRaWAN is carried out in order to evaluate their benefits in the challenging area of LP-WAN.

An Efficient and Practical Smart Card Based Anonymity Preserving User Authentication Scheme for TMIS using Elliptic Curve Cryptography.

PubMed

Amin, Ruhul; Islam, S K Hafizul; Biswas, G P; Khan, Muhammad Khurram; Kumar, Neeraj

2015-11-01

In the last few years, numerous remote user authentication and session key agreement schemes have been put forwarded for Telecare Medical Information System, where the patient and medical server exchange medical information using Internet. We have found that most of the schemes are not usable for practical applications due to known security weaknesses. It is also worth to note that unrestricted number of patients login to the single medical server across the globe. Therefore, the computation and maintenance overhead would be high and the server may fail to provide services. In this article, we have designed a medical system architecture and a standard mutual authentication scheme for single medical server, where the patient can securely exchange medical data with the doctor(s) via trusted central medical server over any insecure network. We then explored the security of the scheme with its resilience to attacks. Moreover, we formally validated the proposed scheme through the simulation using Automated Validation of Internet Security Schemes and Applications software whose outcomes confirm that the scheme is protected against active and passive attacks. The performance comparison demonstrated that the proposed scheme has lower communication cost than the existing schemes in literature. In addition, the computation cost of the proposed scheme is nearly equal to the exiting schemes. The proposed scheme not only efficient in terms of different security attacks, but it also provides an efficient login, mutual authentication, session key agreement and verification and password update phases along with password recovery.

Hardware accelerator design for change detection in smart camera

NASA Astrophysics Data System (ADS)

Singh, Sanjay; Dunga, Srinivasa Murali; Saini, Ravi; Mandal, A. S.; Shekhar, Chandra; Chaudhury, Santanu; Vohra, Anil

2011-10-01

Smart Cameras are important components in Human Computer Interaction. In any remote surveillance scenario, smart cameras have to take intelligent decisions to select frames of significant changes to minimize communication and processing overhead. Among many of the algorithms for change detection, one based on clustering based scheme was proposed for smart camera systems. However, such an algorithm could achieve low frame rate far from real-time requirements on a general purpose processors (like PowerPC) available on FPGAs. This paper proposes the hardware accelerator capable of detecting real time changes in a scene, which uses clustering based change detection scheme. The system is designed and simulated using VHDL and implemented on Xilinx XUP Virtex-IIPro FPGA board. Resulted frame rate is 30 frames per second for QVGA resolution in gray scale.

Highly Efficient Coherent Optical Memory Based on Electromagnetically Induced Transparency

NASA Astrophysics Data System (ADS)

Hsiao, Ya-Fen; Tsai, Pin-Ju; Chen, Hung-Shiue; Lin, Sheng-Xiang; Hung, Chih-Chiao; Lee, Chih-Hsi; Chen, Yi-Hsin; Chen, Yong-Fan; Yu, Ite A.; Chen, Ying-Cheng

2018-05-01

Quantum memory is an important component in the long-distance quantum communication based on the quantum repeater protocol. To outperform the direct transmission of photons with quantum repeaters, it is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we achieve a storage efficiency of 92.0 (1.5)% for a coherent optical memory based on the electromagnetically induced transparency scheme in optically dense cold atomic media. We also obtain a useful time-bandwidth product of 1200, considering only storage where the retrieval efficiency remains above 50%. Both are the best record to date in all kinds of schemes for the realization of optical memory. Our work significantly advances the pursuit of a high-performance optical memory and should have important applications in quantum information science.

A Novel Fast and Secure Approach for Voice Encryption Based on DNA Computing

NASA Astrophysics Data System (ADS)

Kakaei Kate, Hamidreza; Razmara, Jafar; Isazadeh, Ayaz

2018-06-01

Today, in the world of information communication, voice information has a particular importance. One way to preserve voice data from attacks is voice encryption. The encryption algorithms use various techniques such as hashing, chaotic, mixing, and many others. In this paper, an algorithm is proposed for voice encryption based on three different schemes to increase flexibility and strength of the algorithm. The proposed algorithm uses an innovative encoding scheme, the DNA encryption technique and a permutation function to provide a secure and fast solution for voice encryption. The algorithm is evaluated based on various measures including signal to noise ratio, peak signal to noise ratio, correlation coefficient, signal similarity and signal frequency content. The results demonstrate applicability of the proposed method in secure and fast encryption of voice files

Highly Efficient Coherent Optical Memory Based on Electromagnetically Induced Transparency.

PubMed

Hsiao, Ya-Fen; Tsai, Pin-Ju; Chen, Hung-Shiue; Lin, Sheng-Xiang; Hung, Chih-Chiao; Lee, Chih-Hsi; Chen, Yi-Hsin; Chen, Yong-Fan; Yu, Ite A; Chen, Ying-Cheng

2018-05-04

Quantum memory is an important component in the long-distance quantum communication based on the quantum repeater protocol. To outperform the direct transmission of photons with quantum repeaters, it is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we achieve a storage efficiency of 92.0 (1.5)% for a coherent optical memory based on the electromagnetically induced transparency scheme in optically dense cold atomic media. We also obtain a useful time-bandwidth product of 1200, considering only storage where the retrieval efficiency remains above 50%. Both are the best record to date in all kinds of schemes for the realization of optical memory. Our work significantly advances the pursuit of a high-performance optical memory and should have important applications in quantum information science.

Deep-space and near-Earth optical communications by coded orbital angular momentum (OAM) modulation.

PubMed

Djordjevic, Ivan B

2011-07-18

In order to achieve multi-gigabit transmission (projected for 2020) for the use in interplanetary communications, the usage of large number of time slots in pulse-position modulation (PPM), typically used in deep-space applications, is needed, which imposes stringent requirements on system design and implementation. As an alternative satisfying high-bandwidth demands of future interplanetary communications, while keeping the system cost and power consumption reasonably low, in this paper, we describe the use of orbital angular momentum (OAM) as an additional degree of freedom. The OAM is associated with azimuthal phase of the complex electric field. Because OAM eigenstates are orthogonal the can be used as basis functions for N-dimensional signaling. The OAM modulation and multiplexing can, therefore, be used, in combination with other degrees of freedom, to solve the high-bandwidth requirements of future deep-space and near-Earth optical communications. The main challenge for OAM deep-space communication represents the link between a spacecraft probe and the Earth station because in the presence of atmospheric turbulence the orthogonality between OAM states is no longer preserved. We will show that in combination with LDPC codes, the OAM-based modulation schemes can operate even under strong atmospheric turbulence regime. In addition, the spectral efficiency of proposed scheme is N2/log₂N times better than that of PPM.

Angle and Context Free Grammar Based Precarious Node Detection and Secure Data Transmission in MANETs.

PubMed

Veerasamy, Anitha; Madane, Srinivasa Rao; Sivakumar, K; Sivaraman, Audithan

2016-01-01

Growing attractiveness of Mobile Ad Hoc Networks (MANETs), its features, and usage has led to the launching of threats and attacks to bring negative consequences in the society. The typical features of MANETs, especially with dynamic topology and open wireless medium, may leave MANETs vulnerable. Trust management using uncertain reasoning scheme has previously attempted to solve this problem. However, it produces additional overhead while securing the network. Hence, a Location and Trust-based secure communication scheme (L&TS) is proposed to overcome this limitation. Since the design securing requires more than two data algorithms, the cost of the system goes up. Another mechanism proposed in this paper, Angle and Context Free Grammar (ACFG) based precarious node elimination and secure communication in MANETs, intends to secure data transmission and detect precarious nodes in a MANET at a comparatively lower cost. The Elliptic Curve function is used to isolate a malicious node, thereby incorporating secure data transfer. Simulation results show that the dynamic estimation of the metrics improves throughput by 26% in L&TS when compared to the TMUR. ACFG achieves 33% and 51% throughput increase when compared to L&TS and TMUR mechanisms, respectively.

Data-Gathering Scheme Using AUVs in Large-Scale Underwater Sensor Networks: A Multihop Approach

PubMed Central

Khan, Jawaad Ullah; Cho, Ho-Shin

2016-01-01

In this paper, we propose a data-gathering scheme for hierarchical underwater sensor networks, where multiple Autonomous Underwater Vehicles (AUVs) are deployed over large-scale coverage areas. The deployed AUVs constitute an intermittently connected multihop network through inter-AUV synchronization (in this paper, synchronization means an interconnection between nodes for communication) for forwarding data to the designated sink. In such a scenario, the performance of the multihop communication depends upon the synchronization among the vehicles. The mobility parameters of the vehicles vary continuously because of the constantly changing underwater currents. The variations in the AUV mobility parameters reduce the inter-AUV synchronization frequency contributing to delays in the multihop communication. The proposed scheme improves the AUV synchronization frequency by permitting neighboring AUVs to share their status information via a pre-selected node called an agent-node at the static layer of the network. We evaluate the proposed scheme in terms of the AUV synchronization frequency, vertical delay (node→AUV), horizontal delay (AUV→AUV), end-to-end delay, and the packet loss ratio. Simulation results show that the proposed scheme significantly reduces the aforementioned delays without the synchronization time-out process employed in conventional works. PMID:27706042

Data-Gathering Scheme Using AUVs in Large-Scale Underwater Sensor Networks: A Multihop Approach.

PubMed

Khan, Jawaad Ullah; Cho, Ho-Shin

2016-09-30

In this paper, we propose a data-gathering scheme for hierarchical underwater sensor networks, where multiple Autonomous Underwater Vehicles (AUVs) are deployed over large-scale coverage areas. The deployed AUVs constitute an intermittently connected multihop network through inter-AUV synchronization (in this paper, synchronization means an interconnection between nodes for communication) for forwarding data to the designated sink. In such a scenario, the performance of the multihop communication depends upon the synchronization among the vehicles. The mobility parameters of the vehicles vary continuously because of the constantly changing underwater currents. The variations in the AUV mobility parameters reduce the inter-AUV synchronization frequency contributing to delays in the multihop communication. The proposed scheme improves the AUV synchronization frequency by permitting neighboring AUVs to share their status information via a pre-selected node called an agent-node at the static layer of the network. We evaluate the proposed scheme in terms of the AUV synchronization frequency, vertical delay (node→AUV), horizontal delay (AUV→AUV), end-to-end delay, and the packet loss ratio. Simulation results show that the proposed scheme significantly reduces the aforementioned delays without the synchronization time-out process employed in conventional works.

An Overview and Analysis of Mobile Internet Protocols in Cellular Environments.

ERIC Educational Resources Information Center

Chao, Han-Chieh

2001-01-01

Notes that cellular is the inevitable future architecture for the personal communication service system. Discusses the current cellular support based on Mobile Internet Protocol version 6 (Ipv6) and points out the shortfalls of using Mobile IP. Highlights protocols especially for mobile management schemes which can optimize a high-speed mobile…

Generating the local oscillator "locally" in continuous-variable quantum key distribution based on coherent detection

DOE PAGES

Qi, Bing; Lougovski, Pavel; Pooser, Raphael C.; ...

2015-10-21

Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In our paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a “locally” generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct amore » coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad 2), which is small enough to enable secure key distribution. This technology opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.« less

Data Delivery Method Based on Neighbor Nodes' Information in a Mobile Ad Hoc Network

PubMed Central

Hayashi, Takuma; Taenaka, Yuzo; Okuda, Takeshi; Yamaguchi, Suguru

2014-01-01

This paper proposes a data delivery method based on neighbor nodes' information to achieve reliable communication in a mobile ad hoc network (MANET). In a MANET, it is difficult to deliver data reliably due to instabilities in network topology and wireless network condition which result from node movement. To overcome such unstable communication, opportunistic routing and network coding schemes have lately attracted considerable attention. Although an existing method that employs such schemes, MAC-independent opportunistic routing and encoding (MORE), Chachulski et al. (2007), improves the efficiency of data delivery in an unstable wireless mesh network, it does not address node movement. To efficiently deliver data in a MANET, the method proposed in this paper thus first employs the same opportunistic routing and network coding used in MORE and also uses the location information and transmission probabilities of neighbor nodes to adapt to changeable network topology and wireless network condition. The simulation experiments showed that the proposed method can achieve efficient data delivery with low network load when the movement speed is relatively slow. PMID:24672371

Data delivery method based on neighbor nodes' information in a mobile ad hoc network.

PubMed

Kashihara, Shigeru; Hayashi, Takuma; Taenaka, Yuzo; Okuda, Takeshi; Yamaguchi, Suguru

2014-01-01

This paper proposes a data delivery method based on neighbor nodes' information to achieve reliable communication in a mobile ad hoc network (MANET). In a MANET, it is difficult to deliver data reliably due to instabilities in network topology and wireless network condition which result from node movement. To overcome such unstable communication, opportunistic routing and network coding schemes have lately attracted considerable attention. Although an existing method that employs such schemes, MAC-independent opportunistic routing and encoding (MORE), Chachulski et al. (2007), improves the efficiency of data delivery in an unstable wireless mesh network, it does not address node movement. To efficiently deliver data in a MANET, the method proposed in this paper thus first employs the same opportunistic routing and network coding used in MORE and also uses the location information and transmission probabilities of neighbor nodes to adapt to changeable network topology and wireless network condition. The simulation experiments showed that the proposed method can achieve efficient data delivery with low network load when the movement speed is relatively slow.

Integer cosine transform for image compression

NASA Technical Reports Server (NTRS)

Cheung, K.-M.; Pollara, F.; Shahshahani, M.

1991-01-01

This article describes a recently introduced transform algorithm called the integer cosine transform (ICT), which is used in transform-based data compression schemes. The ICT algorithm requires only integer operations on small integers and at the same time gives a rate-distortion performance comparable to that offered by the floating-point discrete cosine transform (DCT). The article addresses the issue of implementation complexity, which is of prime concern for source coding applications of interest in deep-space communications. Complexity reduction in the transform stage of the compression scheme is particularly relevant, since this stage accounts for most (typically over 80 percent) of the computational load.

Bridging the integration gap between imaging and information systems: a uniform data concept for content-based image retrieval in computer-aided diagnosis.

PubMed

Welter, Petra; Riesmeier, Jörg; Fischer, Benedikt; Grouls, Christoph; Kuhl, Christiane; Deserno, Thomas M

2011-01-01

It is widely accepted that content-based image retrieval (CBIR) can be extremely useful for computer-aided diagnosis (CAD). However, CBIR has not been established in clinical practice yet. As a widely unattended gap of integration, a unified data concept for CBIR-based CAD results and reporting is lacking. Picture archiving and communication systems and the workflow of radiologists must be considered for successful data integration to be achieved. We suggest that CBIR systems applied to CAD should integrate their results in a picture archiving and communication systems environment such as Digital Imaging and Communications in Medicine (DICOM) structured reporting documents. A sample DICOM structured reporting template adaptable to CBIR and an appropriate integration scheme is presented. The proposed CBIR data concept may foster the promulgation of CBIR systems in clinical environments and, thereby, improve the diagnostic process.

Bridging the integration gap between imaging and information systems: a uniform data concept for content-based image retrieval in computer-aided diagnosis

PubMed Central

Riesmeier, Jörg; Fischer, Benedikt; Grouls, Christoph; Kuhl, Christiane; Deserno (né Lehmann), Thomas M

2011-01-01

It is widely accepted that content-based image retrieval (CBIR) can be extremely useful for computer-aided diagnosis (CAD). However, CBIR has not been established in clinical practice yet. As a widely unattended gap of integration, a unified data concept for CBIR-based CAD results and reporting is lacking. Picture archiving and communication systems and the workflow of radiologists must be considered for successful data integration to be achieved. We suggest that CBIR systems applied to CAD should integrate their results in a picture archiving and communication systems environment such as Digital Imaging and Communications in Medicine (DICOM) structured reporting documents. A sample DICOM structured reporting template adaptable to CBIR and an appropriate integration scheme is presented. The proposed CBIR data concept may foster the promulgation of CBIR systems in clinical environments and, thereby, improve the diagnostic process. PMID:21672913

Bidirectional chaos communication between two outer semiconductor lasers coupled mutually with a central semiconductor laser.

PubMed

Li, Ping; Wu, Jia-Gui; Wu, Zheng-Mao; Lin, Xiao-Dong; Deng, Dao; Liu, Yu-Ran; Xia, Guang-Qiong

2011-11-21

Based on a linear chain composed of a central semiconductor laser and two outer semiconductor lasers, chaos synchronization and bidirectional communication between two outer lasers have been investigated under the case that the central laser and the two outer lasers are coupled mutually, whereas there exists no coupling between the two outer lasers. The simulation results show that high-quality and stable isochronal synchronization between the two outer lasers can be achieved, while the cross-correlation coefficients between the two outer lasers and the central laser are very low under proper operation condition. Based on the high performance chaos synchronization between the two outer lasers, message bidirectional transmissions of bit rates up to 20 Gbit/s can be realized through adopting a novel decoding scheme which is different from that based on chaos pass filtering effect. Furthermore, the security of bidirectional communication is also analyzed. © 2011 Optical Society of America

A potent approach for the development of FPGA based DAQ system for HEP experiments

NASA Astrophysics Data System (ADS)

Khan, Shuaib Ahmad; Mitra, Jubin; David, Erno; Kiss, Tivadar; Nayak, Tapan Kumar

2017-10-01

With ever increasing particle beam energies and interaction rates in modern High Energy Physics (HEP) experiments in the present and future accelerator facilities, there has always been the demand for robust Data Acquisition (DAQ) schemes which perform in the harsh radiation environment and handle high data volume. The scheme is required to be flexible enough to adapt to the demands of future detector and electronics upgrades, and at the same time keeping the cost factor in mind. To address these challenges, in the present work, we discuss an efficient DAQ scheme for error resilient, high speed data communication on commercially available state-of-the-art FPGA with optical links. The scheme utilises GigaBit Transceiver (GBT) protocol to establish radiation tolerant communication link between on-detector front-end electronics situated in harsh radiation environment to the back-end Data Processing Unit (DPU) placed in a low radiation zone. The acquired data are reconstructed in DPU which reduces the data volume significantly, and then transmitted to the computing farms through high speed optical links using 10 Gigabit Ethernet (10GbE). In this study, we focus on implementation and testing of GBT protocol and 10GbE links on an Intel FPGA. Results of the measurements of resource utilisation, critical path delays, signal integrity, eye diagram and Bit Error Rate (BER) are presented, which are the indicators for efficient system performance.

Long-distance quantum communication over noisy networks without long-time quantum memory

NASA Astrophysics Data System (ADS)

Mazurek, Paweł; Grudka, Andrzej; Horodecki, Michał; Horodecki, Paweł; Łodyga, Justyna; Pankowski, Łukasz; PrzysieŻna, Anna

2014-12-01

The problem of sharing entanglement over large distances is crucial for implementations of quantum cryptography. A possible scheme for long-distance entanglement sharing and quantum communication exploits networks whose nodes share Einstein-Podolsky-Rosen (EPR) pairs. In Perseguers et al. [Phys. Rev. A 78, 062324 (2008), 10.1103/PhysRevA.78.062324] the authors put forward an important isomorphism between storing quantum information in a dimension D and transmission of quantum information in a D +1 -dimensional network. We show that it is possible to obtain long-distance entanglement in a noisy two-dimensional (2D) network, even when taking into account that encoding and decoding of a state is exposed to an error. For 3D networks we propose a simple encoding and decoding scheme based solely on syndrome measurements on 2D Kitaev topological quantum memory. Our procedure constitutes an alternative scheme of state injection that can be used for universal quantum computation on 2D Kitaev code. It is shown that the encoding scheme is equivalent to teleporting the state, from a specific node into a whole two-dimensional network, through some virtual EPR pair existing within the rest of network qubits. We present an analytic lower bound on fidelity of the encoding and decoding procedure, using as our main tool a modified metric on space-time lattice, deviating from a taxicab metric at the first and the last time slices.

An Efficient Location Verification Scheme for Static Wireless Sensor Networks.

PubMed

Kim, In-Hwan; Kim, Bo-Sung; Song, JooSeok

2017-01-24

In wireless sensor networks (WSNs), the accuracy of location information is vital to support many interesting applications. Unfortunately, sensors have difficulty in estimating their location when malicious sensors attack the location estimation process. Even though secure localization schemes have been proposed to protect location estimation process from attacks, they are not enough to eliminate the wrong location estimations in some situations. The location verification can be the solution to the situations or be the second-line defense. The problem of most of the location verifications is the explicit involvement of many sensors in the verification process and requirements, such as special hardware, a dedicated verifier and the trusted third party, which causes more communication and computation overhead. In this paper, we propose an efficient location verification scheme for static WSN called mutually-shared region-based location verification (MSRLV), which reduces those overheads by utilizing the implicit involvement of sensors and eliminating several requirements. In order to achieve this, we use the mutually-shared region between location claimant and verifier for the location verification. The analysis shows that MSRLV reduces communication overhead by 77% and computation overhead by 92% on average, when compared with the other location verification schemes, in a single sensor verification. In addition, simulation results for the verification of the whole network show that MSRLV can detect the malicious sensors by over 90% when sensors in the network have five or more neighbors.

An Efficient Location Verification Scheme for Static Wireless Sensor Networks

PubMed Central

Kim, In-hwan; Kim, Bo-sung; Song, JooSeok

2017-01-01

In wireless sensor networks (WSNs), the accuracy of location information is vital to support many interesting applications. Unfortunately, sensors have difficulty in estimating their location when malicious sensors attack the location estimation process. Even though secure localization schemes have been proposed to protect location estimation process from attacks, they are not enough to eliminate the wrong location estimations in some situations. The location verification can be the solution to the situations or be the second-line defense. The problem of most of the location verifications is the explicit involvement of many sensors in the verification process and requirements, such as special hardware, a dedicated verifier and the trusted third party, which causes more communication and computation overhead. In this paper, we propose an efficient location verification scheme for static WSN called mutually-shared region-based location verification (MSRLV), which reduces those overheads by utilizing the implicit involvement of sensors and eliminating several requirements. In order to achieve this, we use the mutually-shared region between location claimant and verifier for the location verification. The analysis shows that MSRLV reduces communication overhead by 77% and computation overhead by 92% on average, when compared with the other location verification schemes, in a single sensor verification. In addition, simulation results for the verification of the whole network show that MSRLV can detect the malicious sensors by over 90% when sensors in the network have five or more neighbors. PMID:28125007

A power-efficient ZF precoding scheme for multi-user indoor visible light communication systems

NASA Astrophysics Data System (ADS)

Zhao, Qiong; Fan, Yangyu; Deng, Lijun; Kang, Bochao

2017-02-01

In this study, we propose a power-efficient ZF precoding scheme for visible light communication (VLC) downlink multi-user multiple-input-single-output (MU-MISO) systems, which incorporates the zero-forcing (ZF) and the characteristics of VLC systems. The main idea of this scheme is that the channel matrix used to perform pseudoinverse comes from the set of optical Access Points (APs) shared by more than one user, instead of the set of all involved serving APs as the existing ZF precoding schemes often used. By doing this, the waste of power, which is caused by the transmission of one user's data in the un-serving APs, can be avoided. In addition, the size of the channel matrix needs to perform pseudoinverse becomes smaller, which helps to reduce the computation complexity. Simulation results in two scenarios show that the proposed ZF precoding scheme has higher power efficiency, better bit error rate (BER) performance and lower computation complexity compared with traditional ZF precoding schemes.

Efficient bit sifting scheme of post-processing in quantum key distribution

NASA Astrophysics Data System (ADS)

Li, Qiong; Le, Dan; Wu, Xianyan; Niu, Xiamu; Guo, Hong

2015-10-01

Bit sifting is an important step in the post-processing of quantum key distribution (QKD). Its function is to sift out the undetected original keys. The communication traffic of bit sifting has essential impact on the net secure key rate of a practical QKD system. In this paper, an efficient bit sifting scheme is presented, of which the core is a lossless source coding algorithm. Both theoretical analysis and experimental results demonstrate that the performance of the scheme is approaching the Shannon limit. The proposed scheme can greatly decrease the communication traffic of the post-processing of a QKD system, which means the proposed scheme can decrease the secure key consumption for classical channel authentication and increase the net secure key rate of the QKD system, as demonstrated by analyzing the improvement on the net secure key rate. Meanwhile, some recommendations on the application of the proposed scheme to some representative practical QKD systems are also provided.

4.5-Gb/s RGB-LED based WDM visible light communication system employing CAP modulation and RLS based adaptive equalization.

PubMed

Wang, Yiguang; Huang, Xingxing; Tao, Li; Shi, Jianyang; Chi, Nan

2015-05-18

Inter-symbol interference (ISI) is one of the key problems that seriously limit transmission data rate in high-speed VLC systems. To eliminate ISI and further improve the system performance, series of equalization schemes have been widely investigated. As an adaptive algorithm commonly used in wireless communication, RLS is also suitable for visible light communication due to its quick convergence and better performance. In this paper, for the first time we experimentally demonstrate a high-speed RGB-LED based WDM VLC system employing carrier-less amplitude and phase (CAP) modulation and recursive least square (RLS) based adaptive equalization. An aggregate data rate of 4.5Gb/s is successfully achieved over 1.5-m indoor free space transmission with the bit error rate (BER) below the 7% forward error correction (FEC) limit of 3.8x10(-3). To the best of our knowledge, this is the highest data rate ever achieved in RGB-LED based VLC systems.

EDOVE: Energy and Depth Variance-Based Opportunistic Void Avoidance Scheme for Underwater Acoustic Sensor Networks

PubMed Central

Eun, Yongsoon

2017-01-01

Underwater Acoustic Sensor Network (UASN) comes with intrinsic constraints because it is deployed in the aquatic environment and uses the acoustic signals to communicate. The examples of those constraints are long propagation delay, very limited bandwidth, high energy cost for transmission, very high signal attenuation, costly deployment and battery replacement, and so forth. Therefore, the routing schemes for UASN must take into account those characteristics to achieve energy fairness, avoid energy holes, and improve the network lifetime. The depth based forwarding schemes in literature use node’s depth information to forward data towards the sink. They minimize the data packet duplication by employing the holding time strategy. However, to avoid void holes in the network, they use two hop node proximity information. In this paper, we propose the Energy and Depth variance-based Opportunistic Void avoidance (EDOVE) scheme to gain energy balancing and void avoidance in the network. EDOVE considers not only the depth parameter, but also the normalized residual energy of the one-hop nodes and the normalized depth variance of the second hop neighbors. Hence, it avoids the void regions as well as balances the network energy and increases the network lifetime. The simulation results show that the EDOVE gains more than 15% packet delivery ratio, propagates 50% less copies of data packet, consumes less energy, and has more lifetime than the state of the art forwarding schemes. PMID:28954395

EDOVE: Energy and Depth Variance-Based Opportunistic Void Avoidance Scheme for Underwater Acoustic Sensor Networks.

PubMed

Bouk, Safdar Hussain; Ahmed, Syed Hassan; Park, Kyung-Joon; Eun, Yongsoon

2017-09-26

Underwater Acoustic Sensor Network (UASN) comes with intrinsic constraints because it is deployed in the aquatic environment and uses the acoustic signals to communicate. The examples of those constraints are long propagation delay, very limited bandwidth, high energy cost for transmission, very high signal attenuation, costly deployment and battery replacement, and so forth. Therefore, the routing schemes for UASN must take into account those characteristics to achieve energy fairness, avoid energy holes, and improve the network lifetime. The depth based forwarding schemes in literature use node's depth information to forward data towards the sink. They minimize the data packet duplication by employing the holding time strategy. However, to avoid void holes in the network, they use two hop node proximity information. In this paper, we propose the Energy and Depth variance-based Opportunistic Void avoidance (EDOVE) scheme to gain energy balancing and void avoidance in the network. EDOVE considers not only the depth parameter, but also the normalized residual energy of the one-hop nodes and the normalized depth variance of the second hop neighbors. Hence, it avoids the void regions as well as balances the network energy and increases the network lifetime. The simulation results show that the EDOVE gains more than 15 % packet delivery ratio, propagates 50 % less copies of data packet, consumes less energy, and has more lifetime than the state of the art forwarding schemes.

A Spectrum Access Based on Quality of Service (QoS) in Cognitive Radio Networks.

PubMed

Zhai, Linbo; Wang, Hua; Gao, Chuangen

2016-01-01

The quality of service (QoS) is important issue for cognitive radio networks. In the cognitive radio system, the licensed users, also called primary users (PUs), are authorized to utilize the wireless spectrum, while unlicensed users, also called secondary users (SUs), are not authorized to use the wireless spectrum. SUs access the wireless spectrum opportunistically when the spectrum is idle. While SUs use an idle channel, the instance that PUs come back makes SUs terminate their communications and leave the current channel. Therefore, quality of service (QoS) is difficult to be ensured for SUs. In this paper, we first propose an analysis model to obtain QoS for cognitive radio networks such as blocking probability, completed traffic and termination probability of SUs. When the primary users use the channels frequently, QoS of SUs is difficult to be ensured, especially the termination probability. Then, we propose a channel reservation scheme to improve QoS of SUs. The scheme makes the terminated SUs move to the reserved channels and keep on communications. Simulation results show that our scheme can improve QoS of SUs especially the termination probability with a little cost of blocking probability in dynamic environment.

Cooperative MIMO communication at wireless sensor network: an error correcting code approach.

PubMed

Islam, Mohammad Rakibul; Han, Young Shin

2011-01-01

Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error p(b). It is observed that C-MIMO performs more efficiently when the targeted p(b) is smaller. Also the lower encoding rate for LDPC code offers better error characteristics.

Cooperative MIMO Communication at Wireless Sensor Network: An Error Correcting Code Approach

PubMed Central

Islam, Mohammad Rakibul; Han, Young Shin

2011-01-01

Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error pb. It is observed that C-MIMO performs more efficiently when the targeted pb is smaller. Also the lower encoding rate for LDPC code offers better error characteristics. PMID:22163732

From Theory to Practice: Measuring end-of-life communication quality using multiple goals theory.

PubMed

Van Scoy, L J; Scott, A M; Reading, J M; Chuang, C H; Chinchilli, V M; Levi, B H; Green, M J

2017-05-01

To describe how multiple goals theory can be used as a reliable and valid measure (i.e., coding scheme) of the quality of conversations about end-of-life issues. We analyzed conversations from 17 conversations in which 68 participants (mean age=51years) played a game that prompted discussion in response to open-ended questions about end-of-life issues. Conversations (mean duration=91min) were audio-recorded and transcribed. Communication quality was assessed by three coders who assigned numeric scores rating how well individuals accomplished task, relational, and identity goals in the conversation. The coding measure, which results in a quantifiable outcome, yielded strong reliability (intra-class correlation range=0.73-0.89 and Cronbach's alpha range=0.69-0.89 for each of the coded domains) and validity (using multilevel nonlinear modeling, we detected significant variability in scores between games for each of the coded domains, all p-values <0.02). Our coding scheme provides a theory-based measure of end-of-life conversation quality that is superior to other methods of measuring communication quality. Our description of the coding method enables researches to adapt and apply this measure to communication interventions in other clinical contexts. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Hierarchical auto-configuration addressing in mobile ad hoc networks (HAAM)

NASA Astrophysics Data System (ADS)

Ram Srikumar, P.; Sumathy, S.

2017-11-01

Addressing plays a vital role in networking to identify devices uniquely. A device must be assigned with a unique address in order to participate in the data communication in any network. Different protocols defining different types of addressing are proposed in literature. Address auto-configuration is a key requirement for self organizing networks. Existing auto-configuration based addressing protocols require broadcasting probes to all the nodes in the network before assigning a proper address to a new node. This needs further broadcasts to reflect the status of the acquired address in the network. Such methods incur high communication overheads due to repetitive flooding. To address this overhead, a new partially stateful address allocation scheme, namely Hierarchical Auto-configuration Addressing (HAAM) scheme is extended and proposed. Hierarchical addressing basically reduces latency and overhead caused during address configuration. Partially stateful addressing algorithm assigns addresses without the need for flooding and global state awareness, which in turn reduces the communication overhead and space complexity respectively. Nodes are assigned addresses hierarchically to maintain the graph of the network as a spanning tree which helps in effectively avoiding the broadcast storm problem. Proposed algorithm for HAAM handles network splits and merges efficiently in large scale mobile ad hoc networks incurring low communication overheads.

A Novel Piggyback Selection Scheme in IEEE 802.11e HCCA

NASA Astrophysics Data System (ADS)

Lee, Hyun-Jin; Kim, Jae-Hyun

A control frame can be piggybacked onto a data frame to increase channel efficiency in wireless communication. However, if the control frame including global control information is piggybacked, the delay of the data frame from a access point will be increased even though there is only one station with low physical transmission rate. It is similar to the anomaly phenomenon in a network which supports multi-rate transmission. In this letter, we define this phenomenon as “the piggyback problem at low physical transmission rate” and evaluate the effect of this problem with respect to physical transmission rate and normalized traffic load. Then, we propose a delay-based piggyback scheme. Simulations show that the proposed scheme reduces average frame transmission delay and improves channel utilization about 24% and 25%, respectively.

Non-binary LDPC-coded modulation for high-speed optical metro networks with backpropagation

NASA Astrophysics Data System (ADS)

Arabaci, Murat; Djordjevic, Ivan B.; Saunders, Ross; Marcoccia, Roberto M.

2010-01-01

To simultaneously mitigate the linear and nonlinear channel impairments in high-speed optical communications, we propose the use of non-binary low-density-parity-check-coded modulation in combination with a coarse backpropagation method. By employing backpropagation, we reduce the memory in the channel and in return obtain significant reductions in the complexity of the channel equalizer which is exponentially proportional to the channel memory. We then compensate for the remaining channel distortions using forward error correction based on non-binary LDPC codes. We propose non-binary-LDPC-coded modulation scheme because, compared to bit-interleaved binary-LDPC-coded modulation scheme employing turbo equalization, the proposed scheme lowers the computational complexity and latency of the overall system while providing impressively larger coding gains.

Autonomous distributed self-organization for mobile wireless sensor networks.

PubMed

Wen, Chih-Yu; Tang, Hung-Kai

2009-01-01

This paper presents an adaptive combined-metrics-based clustering scheme for mobile wireless sensor networks, which manages the mobile sensors by utilizing the hierarchical network structure and allocates network resources efficiently A local criteria is used to help mobile sensors form a new cluster or join a current cluster. The messages transmitted during hierarchical clustering are applied to choose distributed gateways such that communication for adjacent clusters and distributed topology control can be achieved. In order to balance the load among clusters and govern the topology change, a cluster reformation scheme using localized criterions is implemented. The proposed scheme is simulated and analyzed to abstract the network behaviors in a number of settings. The experimental results show that the proposed algorithm provides efficient network topology management and achieves high scalability in mobile sensor networks.

A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes

PubMed Central

Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian

2017-01-01

In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme. PMID:28072851

Performance Evaluation of High Speed Multicarrier System for Optical Wireless Communication

NASA Astrophysics Data System (ADS)

Mathur, Harshita; Deepa, T.; Bartalwar, Sophiya

2018-04-01

Optical wireless communication (OWC) in the infrared and visible range is quite impressive solution, especially where radio communication face challenges. Visible light communication (VLC) uses visible light over a range of 400 and 800 THz and is a subdivision of OWC technologies. With an increasing demand for use of wireless communications, wireless access via Wi-Fi is facing many challenges especially in terms of capacity, availability, security and efficiency. VLC uses intensity modulation and direct detection (IM/DD) techniques and hence they require the signals to certainly be real valued positive sequences. These constraints pose limitation on digital modulation techniques. These limitations result in spectrum-efficiency or power-efficiency losses. In this paper, we investigate an amplitude shift keying (ASK) based orthogonal frequency division multiplexing (OFDM) signal transmission scheme using LabVIEW for VLC technology.

A Peer-Assisted Teaching Scheme to Improve Units with Critically Low Student Satisfaction: Opportunities and Challenges

ERIC Educational Resources Information Center

Carbone, Angela

2014-01-01

This paper outlines a peer-assisted teaching scheme (PATS) which was piloted in the Faculty of Information Technology at Monash University, Australia to address the low student satisfaction with the quality of information and communication technology units. Positive results from the pilot scheme led to a trial of the scheme in other disciplines.…

Channel coding for underwater acoustic single-carrier CDMA communication system

NASA Astrophysics Data System (ADS)

Liu, Lanjun; Zhang, Yonglei; Zhang, Pengcheng; Zhou, Lin; Niu, Jiong

2017-01-01

CDMA is an effective multiple access protocol for underwater acoustic networks, and channel coding can effectively reduce the bit error rate (BER) of the underwater acoustic communication system. For the requirements of underwater acoustic mobile networks based on CDMA, an underwater acoustic single-carrier CDMA communication system (UWA/SCCDMA) based on the direct-sequence spread spectrum is proposed, and its channel coding scheme is studied based on convolution, RA, Turbo and LDPC coding respectively. The implementation steps of the Viterbi algorithm of convolutional coding, BP and minimum sum algorithms of RA coding, Log-MAP and SOVA algorithms of Turbo coding, and sum-product algorithm of LDPC coding are given. An UWA/SCCDMA simulation system based on Matlab is designed. Simulation results show that the UWA/SCCDMA based on RA, Turbo and LDPC coding have good performance such that the communication BER is all less than 10-6 in the underwater acoustic channel with low signal to noise ratio (SNR) from -12 dB to -10dB, which is about 2 orders of magnitude lower than that of the convolutional coding. The system based on Turbo coding with Log-MAP algorithm has the best performance.

Quantum Communication Using Coherent Rejection Sampling.

PubMed

Anshu, Anurag; Devabathini, Vamsi Krishna; Jain, Rahul

2017-09-22

Compression of a message up to the information it carries is key to many tasks involved in classical and quantum information theory. Schumacher [B. Schumacher, Phys. Rev. A 51, 2738 (1995)PLRAAN1050-294710.1103/PhysRevA.51.2738] provided one of the first quantum compression schemes and several more general schemes have been developed ever since [M. Horodecki, J. Oppenheim, and A. Winter, Commun. Math. Phys. 269, 107 (2007); CMPHAY0010-361610.1007/s00220-006-0118-xI. Devetak and J. Yard, Phys. Rev. Lett. 100, 230501 (2008); PRLTAO0031-900710.1103/PhysRevLett.100.230501A. Abeyesinghe, I. Devetak, P. Hayden, and A. Winter, Proc. R. Soc. A 465, 2537 (2009)PRLAAZ1364-502110.1098/rspa.2009.0202]. However, the one-shot characterization of these quantum tasks is still under development, and often lacks a direct connection with analogous classical tasks. Here we show a new technique for the compression of quantum messages with the aid of entanglement. We devise a new tool that we call the convex split lemma, which is a coherent quantum analogue of the widely used rejection sampling procedure in classical communication protocols. As a consequence, we exhibit new explicit protocols with tight communication cost for quantum state merging, quantum state splitting, and quantum state redistribution (up to a certain optimization in the latter case). We also present a port-based teleportation scheme which uses a fewer number of ports in the presence of information about input.

Microwave intersatellite links for communications satellites

NASA Technical Reports Server (NTRS)

Welti, G. R.

1982-01-01

Applications and interface requirements for intersatellite links (ISLs) between commercial communications satellites are reviewed, ranging from ISLs between widely separated satellites to ISLs between clustered satellites. On-board processing architectures for ISLs employing a variety of modulation schemes are described. These schemes include FM remodulation and QPSK regeneration in combination with switching and buffering. The various architectures are compared in terms of complexity, required performance, antenna size, mass, and power.

Emerging Security Mechanisms for Medical Cyber Physical Systems.

PubMed

Kocabas, Ovunc; Soyata, Tolga; Aktas, Mehmet K

2016-01-01

The following decade will witness a surge in remote health-monitoring systems that are based on body-worn monitoring devices. These Medical Cyber Physical Systems (MCPS) will be capable of transmitting the acquired data to a private or public cloud for storage and processing. Machine learning algorithms running in the cloud and processing this data can provide decision support to healthcare professionals. There is no doubt that the security and privacy of the medical data is one of the most important concerns in designing an MCPS. In this paper, we depict the general architecture of an MCPS consisting of four layers: data acquisition, data aggregation, cloud processing, and action. Due to the differences in hardware and communication capabilities of each layer, different encryption schemes must be used to guarantee data privacy within that layer. We survey conventional and emerging encryption schemes based on their ability to provide secure storage, data sharing, and secure computation. Our detailed experimental evaluation of each scheme shows that while the emerging encryption schemes enable exciting new features such as secure sharing and secure computation, they introduce several orders-of-magnitude computational and storage overhead. We conclude our paper by outlining future research directions to improve the usability of the emerging encryption schemes in an MCPS.

Hierarchical fractional-step approximations and parallel kinetic Monte Carlo algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arampatzis, Giorgos, E-mail: garab@math.uoc.gr; Katsoulakis, Markos A., E-mail: markos@math.umass.edu; Plechac, Petr, E-mail: plechac@math.udel.edu

2012-10-01

We present a mathematical framework for constructing and analyzing parallel algorithms for lattice kinetic Monte Carlo (KMC) simulations. The resulting algorithms have the capacity to simulate a wide range of spatio-temporal scales in spatially distributed, non-equilibrium physiochemical processes with complex chemistry and transport micro-mechanisms. Rather than focusing on constructing exactly the stochastic trajectories, our approach relies on approximating the evolution of observables, such as density, coverage, correlations and so on. More specifically, we develop a spatial domain decomposition of the Markov operator (generator) that describes the evolution of all observables according to the kinetic Monte Carlo algorithm. This domain decompositionmore » corresponds to a decomposition of the Markov generator into a hierarchy of operators and can be tailored to specific hierarchical parallel architectures such as multi-core processors or clusters of Graphical Processing Units (GPUs). Based on this operator decomposition, we formulate parallel Fractional step kinetic Monte Carlo algorithms by employing the Trotter Theorem and its randomized variants; these schemes, (a) are partially asynchronous on each fractional step time-window, and (b) are characterized by their communication schedule between processors. The proposed mathematical framework allows us to rigorously justify the numerical and statistical consistency of the proposed algorithms, showing the convergence of our approximating schemes to the original serial KMC. The approach also provides a systematic evaluation of different processor communicating schedules. We carry out a detailed benchmarking of the parallel KMC schemes using available exact solutions, for example, in Ising-type systems and we demonstrate the capabilities of the method to simulate complex spatially distributed reactions at very large scales on GPUs. Finally, we discuss work load balancing between processors and propose a re-balancing scheme based on probabilistic mass transport methods.« less

Hybrid Packet-Pheromone-Based Probabilistic Routing for Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Kashkouli Nejad, Keyvan; Shawish, Ahmed; Jiang, Xiaohong; Horiguchi, Susumu

Ad-Hoc networks are collections of mobile nodes communicating using wireless media without any fixed infrastructure. Minimal configuration and quick deployment make Ad-Hoc networks suitable for emergency situations like natural disasters or military conflicts. The current Ad-Hoc networks can only support either high mobility or high transmission rate at a time because they employ static approaches in their routing schemes. However, due to the continuous expansion of the Ad-Hoc network size, node-mobility and transmission rate, the development of new adaptive and dynamic routing schemes has become crucial. In this paper we propose a new routing scheme to support high transmission rates and high node-mobility simultaneously in a big Ad-Hoc network, by combining a new proposed packet-pheromone-based approach with the Hint Based Probabilistic Protocol (HBPP) for congestion avoidance with dynamic path selection in packet forwarding process. Because of using the available feedback information, the proposed algorithm does not introduce any additional overhead. The extensive simulation-based analysis conducted in this paper indicates that the proposed algorithm offers small packet-latency and achieves a significantly higher delivery probability in comparison with the available Hint-Based Probabilistic Protocol (HBPP).

Teleportation of a Toffoli gate among distant solid-state qubits with quantum dots embedded in optical microcavities

PubMed Central

Hu, Shi; Cui, Wen-Xue; Wang, Dong-Yang; Bai, Cheng-Hua; Guo, Qi; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

2015-01-01

Teleportation of unitary operations can be viewed as a quantum remote control. The remote realization of robust multiqubit logic gates among distant long-lived qubit registers is a key challenge for quantum computation and quantum information processing. Here we propose a simple and deterministic scheme for teleportation of a Toffoli gate among three spatially separated electron spin qubits in optical microcavities by using local linear optical operations, an auxiliary electron spin, two circularly-polarized entangled photon pairs, photon measurements, and classical communication. We assess the feasibility of the scheme and show that the scheme can be achieved with high average fidelity under the current technology. The scheme opens promising perspectives for constructing long-distance quantum communication and quantum computation networks with solid-state qubits. PMID:26225781

Teleportation of a Toffoli gate among distant solid-state qubits with quantum dots embedded in optical microcavities.

PubMed

Hu, Shi; Cui, Wen-Xue; Wang, Dong-Yang; Bai, Cheng-Hua; Guo, Qi; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

2015-07-30

Teleportation of unitary operations can be viewed as a quantum remote control. The remote realization of robust multiqubit logic gates among distant long-lived qubit registers is a key challenge for quantum computation and quantum information processing. Here we propose a simple and deterministic scheme for teleportation of a Toffoli gate among three spatially separated electron spin qubits in optical microcavities by using local linear optical operations, an auxiliary electron spin, two circularly-polarized entangled photon pairs, photon measurements, and classical communication. We assess the feasibility of the scheme and show that the scheme can be achieved with high average fidelity under the current technology. The scheme opens promising perspectives for constructing long-distance quantum communication and quantum computation networks with solid-state qubits.

Multi-stakeholder perspectives of locally commissioned enhanced optometric services

PubMed Central

Baker, H; Harper, R A; Edgar, D F; Lawrenson, J G

2016-01-01

Objectives To explore views of all stakeholders (patients, optometrists, general practitioners (GPs), commissioners and ophthalmologists) regarding the operation of community-based enhanced optometric services. Design Qualitative study using mixed methods (patient satisfaction surveys, semi-structured telephone interviews and optometrist focus groups). Setting A minor eye conditions scheme (MECS) and glaucoma referral refinement scheme (GRRS) provided by accredited community optometrists. Participants 189 patients, 25 community optometrists, 4 glaucoma specialist hospital optometrists (GRRS), 5 ophthalmologists, 6 GPs (MECS), 4 commissioners. Results Overall, 99% (GRRS) and 100% (MECS) patients were satisfied with their optometrists’ examination. The vast majority rated the following as ‘very good’; examination duration, optometrists’ listening skills, explanations of tests and management, patient involvement in decision-making, treating the patient with care and concern. 99% of MECS patients would recommend the service. Manchester optometrists were enthusiastic about GRRS, feeling fortunate to practise in a ‘pro-optometry’ area. No major negatives were reported, although both schemes were limited to patients resident within certain postcode areas, and some inappropriate GP referrals occurred (MECS). Communication with hospitals was praised in GRRS but was variable, depending on hospital (MECS). Training for both schemes was valuable and appropriate but should be ongoing. MECS GPs were very supportive, reporting the scheme would reduce secondary care referral numbers, although some MECS patients were referred back to GPs for medication. Ophthalmologists (MECS and GRRS) expressed very positive views and widely acknowledged that these new care pathways would reduce unnecessary referrals and shorten patient waiting times. Commissioners felt both schemes met or exceeded expectations in terms of quality of care, allowing patients to be seen quicker and more efficiently. Conclusions Locally commissioned schemes can be a positive experience for all involved. With appropriate training, clear referral pathways and good communication, community optometrists can offer high-quality services that are highly acceptable to patients, health professionals and commissioners. PMID:27798000

Images Encryption Method using Steganographic LSB Method, AES and RSA algorithm

NASA Astrophysics Data System (ADS)

Moumen, Abdelkader; Sissaoui, Hocine

2017-03-01

Vulnerability of communication of digital images is an extremely important issue nowadays, particularly when the images are communicated through insecure channels. To improve communication security, many cryptosystems have been presented in the image encryption literature. This paper proposes a novel image encryption technique based on an algorithm that is faster than current methods. The proposed algorithm eliminates the step in which the secrete key is shared during the encryption process. It is formulated based on the symmetric encryption, asymmetric encryption and steganography theories. The image is encrypted using a symmetric algorithm, then, the secret key is encrypted by means of an asymmetrical algorithm and it is hidden in the ciphered image using a least significant bits steganographic scheme. The analysis results show that while enjoying the faster computation, our method performs close to optimal in terms of accuracy.

VideoScheme: A Research, Authoring, and Teaching Tool for Multimedia.

ERIC Educational Resources Information Center

Matthews, James W.; And Others

The availability of digital multimedia technology poses new challenges to researchers, authors, and educators, even as it creates new opportunities for communication. VideoScheme, a prototype video programming environment is described, along with its applications in research, authoring and education. In terms of research, VideoScheme can help…

Long-Range Big Quantum-Data Transmission.

PubMed

Zwerger, M; Pirker, A; Dunjko, V; Briegel, H J; Dür, W

2018-01-19

We introduce an alternative type of quantum repeater for long-range quantum communication with improved scaling with the distance. We show that by employing hashing, a deterministic entanglement distillation protocol with one-way communication, one obtains a scalable scheme that allows one to reach arbitrary distances, with constant overhead in resources per repeater station, and ultrahigh rates. In practical terms, we show that, also with moderate resources of a few hundred qubits at each repeater station, one can reach intercontinental distances. At the same time, a measurement-based implementation allows one to tolerate high loss but also operational and memory errors of the order of several percent per qubit. This opens the way for long-distance communication of big quantum data.

Quantum metropolitan optical network based on wavelength division multiplexing.

PubMed

Ciurana, A; Martínez-Mateo, J; Peev, M; Poppe, A; Walenta, N; Zbinden, H; Martín, V

2014-01-27

Quantum Key Distribution (QKD) is maturing quickly. However, the current approaches to its application in optical networks make it an expensive technology. QKD networks deployed to date are designed as a collection of point-to-point, dedicated QKD links where non-neighboring nodes communicate using the trusted repeater paradigm. We propose a novel optical network model in which QKD systems share the communication infrastructure by wavelength multiplexing their quantum and classical signals. The routing is done using optical components within a metropolitan area which allows for a dynamically any-to-any communication scheme. Moreover, it resembles a commercial telecom network, takes advantage of existing infrastructure and utilizes commercial components, allowing for an easy, cost-effective and reliable deployment.

Long-Range Big Quantum-Data Transmission

NASA Astrophysics Data System (ADS)

Zwerger, M.; Pirker, A.; Dunjko, V.; Briegel, H. J.; Dür, W.

2018-01-01

We introduce an alternative type of quantum repeater for long-range quantum communication with improved scaling with the distance. We show that by employing hashing, a deterministic entanglement distillation protocol with one-way communication, one obtains a scalable scheme that allows one to reach arbitrary distances, with constant overhead in resources per repeater station, and ultrahigh rates. In practical terms, we show that, also with moderate resources of a few hundred qubits at each repeater station, one can reach intercontinental distances. At the same time, a measurement-based implementation allows one to tolerate high loss but also operational and memory errors of the order of several percent per qubit. This opens the way for long-distance communication of big quantum data.

Aerogel Antennas Communications Study Using Error Vector Magnitude Measurements

NASA Technical Reports Server (NTRS)

Miranda, Felix A.; Mueller, Carl H.; Meador, Mary Ann B.

2014-01-01

This presentation discusses an aerogel antennas communication study using error vector magnitude (EVM) measurements. The study was performed using 2x4 element polyimide (PI) aerogel-based phased arrays designed for operation at 5 GHz as transmit (Tx) and receive (Rx) antennas separated by a line of sight (LOS) distance of 8.5 meters. The results of the EVM measurements demonstrate that polyimide aerogel antennas work appropriately to support digital communication links with typically used modulation schemes such as QPSK and 4 DQPSK. As such, PI aerogel antennas with higher gain, larger bandwidth and lower mass than typically used microwave laminates could be suitable to enable aerospace-to- ground communication links with enough channel capacity to support voice, data and video links from CubeSats, unmanned air vehicles (UAV), and commercial aircraft.

Aerogel Antennas Communications Study Using Error Vector Magnitude Measurements

NASA Technical Reports Server (NTRS)

Miranda, Felix A.; Mueller, Carl H.; Meador, Mary Ann B.

2014-01-01

This paper discusses an aerogel antennas communication study using error vector magnitude (EVM) measurements. The study was performed using 4x2 element polyimide (PI) aerogel-based phased arrays designed for operation at 5 GHz as transmit (Tx) and receive (Rx) antennas separated by a line of sight (LOS) distance of 8.5 meters. The results of the EVM measurements demonstrate that polyimide aerogel antennas work appropriately to support digital communication links with typically used modulation schemes such as QPSK and pi/4 DQPSK. As such, PI aerogel antennas with higher gain, larger bandwidth and lower mass than typically used microwave laminates could be suitable to enable aerospace-to-ground communication links with enough channel capacity to support voice, data and video links from cubesats, unmanned air vehicles (UAV), and commercial aircraft.

Star Tracker Based ATP System Conceptual Design and Pointing Accuracy Estimation

NASA Technical Reports Server (NTRS)

Orfiz, Gerardo G.; Lee, Shinhak

2006-01-01

A star tracker based beaconless (a.k.a. non-cooperative beacon) acquisition, tracking and pointing concept for precisely pointing an optical communication beam is presented as an innovative approach to extend the range of high bandwidth (> 100 Mbps) deep space optical communication links throughout the solar system and to remove the need for a ground based high power laser as a beacon source. The basic approach for executing the ATP functions involves the use of stars as the reference sources from which the attitude knowledge is obtained and combined with high bandwidth gyroscopes for propagating the pointing knowledge to the beam pointing mechanism. Details of the conceptual design are presented including selection of an orthogonal telescope configuration and the introduction of an optical metering scheme to reduce misalignment error. Also, estimates are presented that demonstrate that aiming of the communications beam to the Earth based receive terminal can be achieved with a total system pointing accuracy of better than 850 nanoradians (3 sigma) from anywhere in the solar system.

Average spectral efficiency analysis of FSO links over turbulence channel with adaptive transmissions and aperture averaging

NASA Astrophysics Data System (ADS)

Aarthi, G.; Ramachandra Reddy, G.

2018-03-01

In our paper, the impact of adaptive transmission schemes: (i) optimal rate adaptation (ORA) and (ii) channel inversion with fixed rate (CIFR) on the average spectral efficiency (ASE) are explored for free-space optical (FSO) communications with On-Off Keying (OOK), Polarization shift keying (POLSK), and Coherent optical wireless communication (Coherent OWC) systems under different turbulence regimes. Further to enhance the ASE we have incorporated aperture averaging effects along with the above adaptive schemes. The results indicate that ORA adaptation scheme has the advantage of improving the ASE performance compared with CIFR under moderate and strong turbulence regime. The coherent OWC system with ORA excels the other modulation schemes and could achieve ASE performance of 49.8 bits/s/Hz at the average transmitted optical power of 6 dBm under strong turbulence. By adding aperture averaging effect we could achieve an ASE of 50.5 bits/s/Hz under the same conditions. This makes ORA with Coherent OWC modulation as a favorable candidate for improving the ASE of the FSO communication system.

Networked iterative learning control design for discrete-time systems with stochastic communication delay in input and output channels

NASA Astrophysics Data System (ADS)

Liu, Jian; Ruan, Xiaoe

2017-07-01

This paper develops two kinds of derivative-type networked iterative learning control (NILC) schemes for repetitive discrete-time systems with stochastic communication delay occurred in input and output channels and modelled as 0-1 Bernoulli-type stochastic variable. In the two schemes, the delayed signal of the current control input is replaced by the synchronous input utilised at the previous iteration, whilst for the delayed signal of the system output the one scheme substitutes it by the synchronous predetermined desired trajectory and the other takes it by the synchronous output at the previous operation, respectively. In virtue of the mathematical expectation, the tracking performance is analysed which exhibits that for both the linear time-invariant and nonlinear affine systems the two kinds of NILCs are convergent under the assumptions that the probabilities of communication delays are adequately constrained and the product of the input-output coupling matrices is full-column rank. Last, two illustrative examples are presented to demonstrate the effectiveness and validity of the proposed NILC schemes.

Unconditional security of entanglement-based continuous-variable quantum secret sharing

NASA Astrophysics Data System (ADS)

Kogias, Ioannis; Xiang, Yu; He, Qiongyi; Adesso, Gerardo

2017-01-01

The need for secrecy and security is essential in communication. Secret sharing is a conventional protocol to distribute a secret message to a group of parties, who cannot access it individually but need to cooperate in order to decode it. While several variants of this protocol have been investigated, including realizations using quantum systems, the security of quantum secret sharing schemes still remains unproven almost two decades after their original conception. Here we establish an unconditional security proof for entanglement-based continuous-variable quantum secret sharing schemes, in the limit of asymptotic keys and for an arbitrary number of players. We tackle the problem by resorting to the recently developed one-sided device-independent approach to quantum key distribution. We demonstrate theoretically the feasibility of our scheme, which can be implemented by Gaussian states and homodyne measurements, with no need for ideal single-photon sources or quantum memories. Our results contribute to validating quantum secret sharing as a viable primitive for quantum technologies.

A Novel Deployment Scheme Based on Three-Dimensional Coverage Model for Wireless Sensor Networks

PubMed Central

Xiao, Fu; Yang, Yang; Wang, Ruchuan; Sun, Lijuan

2014-01-01

Coverage pattern and deployment strategy are directly related to the optimum allocation of limited resources for wireless sensor networks, such as energy of nodes, communication bandwidth, and computing power, and quality improvement is largely determined by these for wireless sensor networks. A three-dimensional coverage pattern and deployment scheme are proposed in this paper. Firstly, by analyzing the regular polyhedron models in three-dimensional scene, a coverage pattern based on cuboids is proposed, and then relationship between coverage and sensor nodes' radius is deduced; also the minimum number of sensor nodes to maintain network area's full coverage is calculated. At last, sensor nodes are deployed according to the coverage pattern after the monitor area is subdivided into finite 3D grid. Experimental results show that, compared with traditional random method, sensor nodes number is reduced effectively while coverage rate of monitor area is ensured using our coverage pattern and deterministic deployment scheme. PMID:25045747

Dynamic Key Management Schemes for Secure Group Access Control Using Hierarchical Clustering in Mobile Ad Hoc Networks

NASA Astrophysics Data System (ADS)

Tsaur, Woei-Jiunn; Pai, Haw-Tyng

2008-11-01

The applications of group computing and communication motivate the requirement to provide group access control in mobile ad hoc networks (MANETs). The operation in MANETs' groups performs a decentralized manner and accommodated membership dynamically. Moreover, due to lack of centralized control, MANETs' groups are inherently insecure and vulnerable to attacks from both within and outside the groups. Such features make access control more challenging in MANETs. Recently, several researchers have proposed group access control mechanisms in MANETs based on a variety of threshold signatures. However, these mechanisms cannot actually satisfy MANETs' dynamic environments. This is because the threshold-based mechanisms cannot be achieved when the number of members is not up to the threshold value. Hence, by combining the efficient elliptic curve cryptosystem, self-certified public key cryptosystem and secure filter technique, we construct dynamic key management schemes based on hierarchical clustering for securing group access control in MANETs. Specifically, the proposed schemes can constantly accomplish secure group access control only by renewing the secure filters of few cluster heads, when a cluster head joins or leaves a cross-cluster. In such a new way, we can find that the proposed group access control scheme can be very effective for securing practical applications in MANETs.

Robust Timing Synchronization for Aviation Communications, and Efficient Modulation and Coding Study for Quantum Communication

NASA Technical Reports Server (NTRS)

Xiong, Fugin

2003-01-01

One half of Professor Xiong's effort will investigate robust timing synchronization schemes for dynamically varying characteristics of aviation communication channels. The other half of his time will focus on efficient modulation and coding study for the emerging quantum communications.

Secure and Efficient Key Coordination Algorithm for Line Topology Network Maintenance for Use in Maritime Wireless Sensor Networks.

PubMed

Elgenaidi, Walid; Newe, Thomas; O'Connell, Eoin; Toal, Daniel; Dooly, Gerard

2016-12-21

There has been a significant increase in the proliferation and implementation of Wireless Sensor Networks (WSNs) in different disciplines, including the monitoring of maritime environments, healthcare systems, and industrial sectors. It has now become critical to address the security issues of data communication while considering sensor node constraints. There are many proposed schemes, including the scheme being proposed in this paper, to ensure that there is a high level of security in WSNs. This paper presents a symmetric security scheme for a maritime coastal environment monitoring WSN. The scheme provides security for travelling packets via individually encrypted links between authenticated neighbors, thus avoiding a reiteration of a global rekeying process. Furthermore, this scheme proposes a dynamic update key based on a trusted node configuration, called a leader node, which works as a trusted third party. The technique has been implemented in real time on a Waspmote test bed sensor platform and the results from both field testing and indoor bench testing environments are discussed in this paper.

Secure and Efficient Key Coordination Algorithm for Line Topology Network Maintenance for Use in Maritime Wireless Sensor Networks

PubMed Central

Elgenaidi, Walid; Newe, Thomas; O’Connell, Eoin; Toal, Daniel; Dooly, Gerard

2016-01-01

There has been a significant increase in the proliferation and implementation of Wireless Sensor Networks (WSNs) in different disciplines, including the monitoring of maritime environments, healthcare systems, and industrial sectors. It has now become critical to address the security issues of data communication while considering sensor node constraints. There are many proposed schemes, including the scheme being proposed in this paper, to ensure that there is a high level of security in WSNs. This paper presents a symmetric security scheme for a maritime coastal environment monitoring WSN. The scheme provides security for travelling packets via individually encrypted links between authenticated neighbors, thus avoiding a reiteration of a global rekeying process. Furthermore, this scheme proposes a dynamic update key based on a trusted node configuration, called a leader node, which works as a trusted third party. The technique has been implemented in real time on a Waspmote test bed sensor platform and the results from both field testing and indoor bench testing environments are discussed in this paper. PMID:28009834

A comprehensive study of sampling-based optimum signal detection in concentration-encoded molecular communication.

PubMed

Mahfuz, Mohammad U; Makrakis, Dimitrios; Mouftah, Hussein T

2014-09-01

In this paper, a comprehensive analysis of the sampling-based optimum signal detection in ideal (i.e., free) diffusion-based concentration-encoded molecular communication (CEMC) system has been presented. A generalized amplitude-shift keying (ASK)-based CEMC system has been considered in diffusion-based noise and intersymbol interference (ISI) conditions. Information is encoded by modulating the amplitude of the transmission rate of information molecules at the TN. The critical issues involved in the sampling-based receiver thus developed are addressed in detail, and its performance in terms of the number of samples per symbol, communication range, and transmission data rate is evaluated. ISI produced by the residual molecules deteriorates the performance of the CEMC system significantly, which further deteriorates when the communication range and/or the transmission data rate increase(s). In addition, the performance of the optimum receiver depends on the receiver's ability to compute the ISI accurately, thus providing a trade-off between receiver complexity and achievable bit error rate (BER). Exact and approximate detection performances have been derived. Finally, it is found that the sampling-based signal detection scheme thus developed can be applied to both binary and multilevel (M-ary) ASK-based CEMC systems, although M-ary systems suffer more from higher BER.

A Code Division Multiple Access Communication System for the Low Frequency Band.

DTIC Science & Technology

1983-04-01

frequency channels spread-spectrum communication / complex sequences, orthogonal codes impulsive noise 20. ABSTRACT (Continue an reverse side It...their transmissions with signature sequences. Our LF/CDMA scheme is different in that each user’s signature sequence set consists of M orthogonal ...signature sequences. Our LF/CDMA scheme is different in that each user’s signature sequence set consists of M orthogonal sequences and thus log 2 M

Self-Encoded Spread Spectrum Modulation for Robust Anti-Jamming Communication

DTIC Science & Technology

2009-06-30

experience in both theoretical and experimental aspects of RF and optical communications, multi-user CDMA systems, transmitter precoding and code...the performance of DS - and FH-SESS modulation in the presence of worst-case jamming, develop innovative SESS schemes that further exploit time and...Determine BER and AJ performance of the feedback and iterative detectors in DS -SESS under pulsed-noise and multi-tone jamming • Task 2: Develop a scheme

High security chaotic multiple access scheme for visible light communication systems with advanced encryption standard interleaving

NASA Astrophysics Data System (ADS)

Qiu, Junchao; Zhang, Lin; Li, Diyang; Liu, Xingcheng

2016-06-01

Chaotic sequences can be applied to realize multiple user access and improve the system security for a visible light communication (VLC) system. However, since the map patterns of chaotic sequences are usually well known, eavesdroppers can possibly derive the key parameters of chaotic sequences and subsequently retrieve the information. We design an advanced encryption standard (AES) interleaving aided multiple user access scheme to enhance the security of a chaotic code division multiple access-based visible light communication (C-CDMA-VLC) system. We propose to spread the information with chaotic sequences, and then the spread information is interleaved by an AES algorithm and transmitted over VLC channels. Since the computation complexity of performing inverse operations to deinterleave the information is high, the eavesdroppers in a high speed VLC system cannot retrieve the information in real time; thus, the system security will be enhanced. Moreover, we build a mathematical model for the AES-aided VLC system and derive the theoretical information leakage to analyze the system security. The simulations are performed over VLC channels, and the results demonstrate the effectiveness and high security of our presented AES interleaving aided chaotic CDMA-VLC system.

Performance analysis of optimal power allocation in wireless cooperative communication systems

NASA Astrophysics Data System (ADS)

Babikir Adam, Edriss E.; Samb, Doudou; Yu, Li

2013-03-01

Cooperative communication has been recently proposed in wireless communication systems for exploring the inherent spatial diversity in relay channels.The Amplify-and-Forward (AF) cooperation protocols with multiple relays have not been sufficiently investigated even if it has a low complexity in term of implementation. We consider in this work a cooperative diversity system in which a source transmits some information to a destination with the help of multiple relay nodes with AF protocols and investigate the optimality of allocating powers both at the source and the relays system by optimizing the symbol error rate (SER) performance in an efficient way. Firstly we derive a closedform SER formulation for MPSK signal using the concept of moment generating function and some statistical approximations in high signal to noise ratio (SNR) for the system under studied. We then find a tight corresponding lower bound which converges to the same limit as the theoretical upper bound and develop an optimal power allocation (OPA) technique with mean channel gains to minimize the SER. Simulation results show that our scheme outperforms the equal power allocation (EPA) scheme and is tight to the theoretical approximation based on the SER upper bound in high SNR for different number of relays.

Relative position coordinated control for spacecraft formation flying with communication delays

NASA Astrophysics Data System (ADS)

Ran, Dechao; Chen, Xiaoqian; Misra, Arun K.; Xiao, Bing

2017-08-01

This study addresses a relative position coordinated control problem for spacecraft formation flying subject to directed communication topology. Two different kinds of communication delay cases, including time-varying delays and arbitrarily bounded delays are investigated. Using the backstepping control technique, two virtual velocity control inputs are firstly designed to achieve coordinated position tracking for the kinematic subsystem. Furthermore, a hyperbolic tangent function is introduced to guarantee the boundedness of the virtual controller. Then, a finite-time control algorithm is designed for the dynamic subsystem. It can guarantee that the virtual velocity can be followed by the real velocity after finite time. It is theoretically proved that the proposed control scheme can asymptotically stabilize the closed-loop system. Numerical simulations are further presented that not only highlight closed-loop performance benefiting from the proposed control scheme, but also illustrate its superiority in comparison with conventional formation control schemes.

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks.

PubMed

Saleh, Mohammed A; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks.

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks

PubMed Central

Saleh, Mohammed A.; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks. PMID:26065015

(a,k)-Anonymous Scheme for Privacy-Preserving Data Collection in IoT-based Healthcare Services Systems.

PubMed

Li, Hongtao; Guo, Feng; Zhang, Wenyin; Wang, Jie; Xing, Jinsheng

2018-02-14

The widely use of IoT technologies in healthcare services has pushed forward medical intelligence level of services. However, it also brings potential privacy threat to the data collection. In healthcare services system, health and medical data that contains privacy information are often transmitted among networks, and such privacy information should be protected. Therefore, there is a need for privacy-preserving data collection (PPDC) scheme to protect clients (patients) data. We adopt (a,k)-anonymity model as privacy pretection scheme for data collection, and propose a novel anonymity-based PPDC method for healthcare services in this paper. The threat model is analyzed in the client-server-to-user (CS2U) model. On client-side, we utilize (a,k)-anonymity notion to generate anonymous tuples which can resist possible attack, and adopt a bottom-up clustering method to create clusters that satisfy a base privacy level of (a 1 ,k 1 )-anonymity. On server-side, we reduce the communication cost through generalization technology, and compress (a 1 ,k 1 )-anonymous data through an UPGMA-based cluster combination method to make the data meet the deeper level of privacy (a 2 ,k 2 )-anonymity (a 1  ≥ a 2 , k 2  ≥ k 1 ). Theoretical analysis and experimental results prove that our scheme is effective in privacy-preserving and data quality.