Fast, Parallel and Secure Cryptography Algorithm Using Lorenz's Attractor

NASA Astrophysics Data System (ADS)

Marco, Anderson Gonçalves; Martinez, Alexandre Souto; Bruno, Odemir Martinez

A novel cryptography method based on the Lorenz's attractor chaotic system is presented. The proposed algorithm is secure and fast, making it practical for general use. We introduce the chaotic operation mode, which provides an interaction among the password, message and a chaotic system. It ensures that the algorithm yields a secure codification, even if the nature of the chaotic system is known. The algorithm has been implemented in two versions: one sequential and slow and the other, parallel and fast. Our algorithm assures the integrity of the ciphertext (we know if it has been altered, which is not assured by traditional algorithms) and consequently its authenticity. Numerical experiments are presented, discussed and show the behavior of the method in terms of security and performance. The fast version of the algorithm has a performance comparable to AES, a popular cryptography program used commercially nowadays, but it is more secure, which makes it immediately suitable for general purpose cryptography applications. An internet page has been set up, which enables the readers to test the algorithm and also to try to break into the cipher.

Practical device-independent quantum cryptography via entropy accumulation.

PubMed

Arnon-Friedman, Rotem; Dupuis, Frédéric; Fawzi, Omar; Renner, Renato; Vidick, Thomas

2018-01-31

Device-independent cryptography goes beyond conventional quantum cryptography by providing security that holds independently of the quality of the underlying physical devices. Device-independent protocols are based on the quantum phenomena of non-locality and the violation of Bell inequalities. This high level of security could so far only be established under conditions which are not achievable experimentally. Here we present a property of entropy, termed "entropy accumulation", which asserts that the total amount of entropy of a large system is the sum of its parts. We use this property to prove the security of cryptographic protocols, including device-independent quantum key distribution, while achieving essentially optimal parameters. Recent experimental progress, which enabled loophole-free Bell tests, suggests that the achieved parameters are technologically accessible. Our work hence provides the theoretical groundwork for experimental demonstrations of device-independent cryptography.

Insecurity of position-based quantum-cryptography protocols against entanglement attacks

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

Lau, Hoi-Kwan; Lo, Hoi-Kwong

2011-01-15

Recently, position-based quantum cryptography has been claimed to be unconditionally secure. On the contrary, here we show that the existing proposals for position-based quantum cryptography are, in fact, insecure if entanglement is shared among two adversaries. Specifically, we demonstrate how the adversaries can incorporate ideas of quantum teleportation and quantum secret sharing to compromise the security with certainty. The common flaw to all current protocols is that the Pauli operators always map a codeword to a codeword (up to an irrelevant overall phase). We propose a modified scheme lacking this property in which the same cheating strategy used to underminemore » the previous protocols can succeed with a rate of at most 85%. We prove the modified protocol is secure when the shared quantum resource between the adversaries is a two- or three-level system.« less

Quantum cryptography with entangled photons

PubMed

Jennewein; Simon; Weihs; Weinfurter; Zeilinger

2000-05-15

By realizing a quantum cryptography system based on polarization entangled photon pairs we establish highly secure keys, because a single photon source is approximated and the inherent randomness of quantum measurements is exploited. We implement a novel key distribution scheme using Wigner's inequality to test the security of the quantum channel, and, alternatively, realize a variant of the BB84 protocol. Our system has two completely independent users separated by 360 m, and generates raw keys at rates of 400-800 bits/s with bit error rates around 3%.

Single photon quantum cryptography.

PubMed

Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, André; Poizat, Jean-Philippe; Grangier, Philippe

2002-10-28

We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses.

Geospatial cryptography: enabling researchers to access private, spatially referenced, human subjects data for cancer control and prevention.

PubMed

Jacquez, Geoffrey M; Essex, Aleksander; Curtis, Andrew; Kohler, Betsy; Sherman, Recinda; Emam, Khaled El; Shi, Chen; Kaufmann, Andy; Beale, Linda; Cusick, Thomas; Goldberg, Daniel; Goovaerts, Pierre

2017-07-01

As the volume, accuracy and precision of digital geographic information have increased, concerns regarding individual privacy and confidentiality have come to the forefront. Not only do these challenge a basic tenet underlying the advancement of science by posing substantial obstacles to the sharing of data to validate research results, but they are obstacles to conducting certain research projects in the first place. Geospatial cryptography involves the specification, design, implementation and application of cryptographic techniques to address privacy, confidentiality and security concerns for geographically referenced data. This article defines geospatial cryptography and demonstrates its application in cancer control and surveillance. Four use cases are considered: (1) national-level de-duplication among state or province-based cancer registries; (2) sharing of confidential data across cancer registries to support case aggregation across administrative geographies; (3) secure data linkage; and (4) cancer cluster investigation and surveillance. A secure multi-party system for geospatial cryptography is developed. Solutions under geospatial cryptography are presented and computation time is calculated. As services provided by cancer registries to the research community, de-duplication, case aggregation across administrative geographies and secure data linkage are often time-consuming and in some instances precluded by confidentiality and security concerns. Geospatial cryptography provides secure solutions that hold significant promise for addressing these concerns and for accelerating the pace of research with human subjects data residing in our nation's cancer registries. Pursuit of the research directions posed herein conceivably would lead to a geospatially encrypted geographic information system (GEGIS) designed specifically to promote the sharing and spatial analysis of confidential data. Geospatial cryptography holds substantial promise for accelerating the pace of research with spatially referenced human subjects data.

Securing resource constraints embedded devices using elliptic curve cryptography

NASA Astrophysics Data System (ADS)

Tam, Tony; Alfasi, Mohamed; Mozumdar, Mohammad

2014-06-01

The use of smart embedded device has been growing rapidly in recent time because of miniaturization of sensors and platforms. Securing data from these embedded devices is now become one of the core challenges both in industry and research community. Being embedded, these devices have tight constraints on resources such as power, computation, memory, etc. Hence it is very difficult to implement traditional Public Key Cryptography (PKC) into these resource constrained embedded devices. Moreover, most of the public key security protocols requires both public and private key to be generated together. In contrast with this, Identity Based Encryption (IBE), a public key cryptography protocol, allows a public key to be generated from an arbitrary string and the corresponding private key to be generated later on demand. While IBE has been actively studied and widely applied in cryptography research, conventional IBE primitives are also computationally demanding and cannot be efficiently implemented on embedded system. Simplified version of the identity based encryption has proven its competence in being robust and also satisfies tight budget of the embedded platform. In this paper, we describe the choice of several parameters for implementing lightweight IBE in resource constrained embedded sensor nodes. Our implementation of IBE is built using elliptic curve cryptography (ECC).

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

Jason L. Wright; Milos Manic

Finding and identifying cryptography is a growing concern in the malware analysis community. In this paper, artificial neural networks are used to classify functional blocks from a disassembled program as being either cryptography related or not. The resulting system, referred to as NNLC (Neural Net for Locating Cryptography) is presented and results of applying this system to various libraries are described.

Report on Pairing-based Cryptography.

PubMed

Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

2015-01-01

This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed.

Report on Pairing-based Cryptography

PubMed Central

Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

2015-01-01

This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST’s position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed. PMID:26958435

Physical Cryptography: A New Approach to Key Generation and Direct Encryption

DTIC Science & Technology

2009-11-18

has been  further studied theoretically and P a g e  | 4    experimentally to only a limited extent. The second is quantum cryptography [3] based on...Std Z39-18 P a g e  | 2    Abstract: The security of key generation and direct encryption in quantum and physical cryptography have been...investigated. It is found that similar to the situation of conventional mathematics based cryptography , fundamental and meaningful security levels for either

Decoy state method for quantum cryptography based on phase coding into faint laser pulses

NASA Astrophysics Data System (ADS)

Kulik, S. P.; Molotkov, S. N.

2017-12-01

We discuss the photon number splitting attack (PNS) in systems of quantum cryptography with phase coding. It is shown that this attack, as well as the structural equations for the PNS attack for phase encoding, differs physically from the analogous attack applied to the polarization coding. As far as we know, in practice, in all works to date processing of experimental data has been done for phase coding, but using formulas for polarization coding. This can lead to inadequate results for the length of the secret key. These calculations are important for the correct interpretation of the results, especially if it concerns the criterion of secrecy in quantum cryptography.

Post-quantum cryptography.

PubMed

Bernstein, Daniel J; Lange, Tanja

2017-09-13

Cryptography is essential for the security of online communication, cars and implanted medical devices. However, many commonly used cryptosystems will be completely broken once large quantum computers exist. Post-quantum cryptography is cryptography under the assumption that the attacker has a large quantum computer; post-quantum cryptosystems strive to remain secure even in this scenario. This relatively young research area has seen some successes in identifying mathematical operations for which quantum algorithms offer little advantage in speed, and then building cryptographic systems around those. The central challenge in post-quantum cryptography is to meet demands for cryptographic usability and flexibility without sacrificing confidence.

Post-quantum cryptography

NASA Astrophysics Data System (ADS)

Bernstein, Daniel J.; Lange, Tanja

2017-09-01

Cryptography is essential for the security of online communication, cars and implanted medical devices. However, many commonly used cryptosystems will be completely broken once large quantum computers exist. Post-quantum cryptography is cryptography under the assumption that the attacker has a large quantum computer; post-quantum cryptosystems strive to remain secure even in this scenario. This relatively young research area has seen some successes in identifying mathematical operations for which quantum algorithms offer little advantage in speed, and then building cryptographic systems around those. The central challenge in post-quantum cryptography is to meet demands for cryptographic usability and flexibility without sacrificing confidence.

File Cryptography with AES and RSA for Mobile Based on Android

NASA Astrophysics Data System (ADS)

laia, Yonata; Nababan, Marlince; Sihombing, Oloan; Aisyah, Siti; Sitanggang, Delima; Parsaoran, Saut; Zendato, Niskarto

2018-04-01

The users of mobile based on android were increasing currently even now mobile was almost the same computer one of which could be used to be done by every users mobile was save the individual important data.Saving the data on mobile was very risk because become hackers’ target. That was the reason of researchers want to add cryptography which the combination between Advance Encryption System (AES) dan Ron Rivest, Adi Shamir dan Len Adleman (RSA). The result of the second method above could do cryptography data on mobile. With different encryption time where the file size; 25.44 KB, encryption time 4 second, 200 KB, 5 second, 600 KB 7 second, 2.29 MB, 10 second. Where decryption 25.44 KB, encryption 2 second, 200 KB, 1.5 second, 600 KB 2.5 second, 2.29 MB, 2.7 second.

All-optical cryptography of M-QAM formats by using two-dimensional spectrally sliced keys.

PubMed

Abbade, Marcelo L F; Cvijetic, Milorad; Messani, Carlos A; Alves, Cleiton J; Tenenbaum, Stefan

2015-05-10

There has been an increased interest in enhancing the security of optical communications systems and networks. All-optical cryptography methods have been considered as an alternative to electronic data encryption. In this paper we propose and verify the use of a novel all-optical scheme based on cryptographic keys applied on the spectral signal for encryption of the M-QAM modulated data with bit rates of up to 200 gigabits per second.

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.

Cryptographic robustness of practical quantum cryptography: BB84 key distribution protocol

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

Molotkov, S. N.

2008-07-15

In real fiber-optic quantum cryptography systems, the avalanche photodiodes are not perfect, the source of quantum states is not a single-photon one, and the communication channel is lossy. For these reasons, key distribution is impossible under certain conditions for the system parameters. A simple analysis is performed to find relations between the parameters of real cryptography systems and the length of the quantum channel that guarantee secure quantum key distribution when the eavesdropper's capabilities are limited only by fundamental laws of quantum mechanics while the devices employed by the legitimate users are based on current technologies. Critical values are determinedmore » for the rate of secure real-time key generation that can be reached under the current technology level. Calculations show that the upper bound on channel length can be as high as 300 km for imperfect photodetectors (avalanche photodiodes) with present-day quantum efficiency ({eta} {approx} 20%) and dark count probability (p{sub dark} {approx} 10{sup -7})« less

Cryptographic robustness of practical quantum cryptography: BB84 key distribution protocol

NASA Astrophysics Data System (ADS)

Molotkov, S. N.

2008-07-01

In real fiber-optic quantum cryptography systems, the avalanche photodiodes are not perfect, the source of quantum states is not a single-photon one, and the communication channel is lossy. For these reasons, key distribution is impossible under certain conditions for the system parameters. A simple analysis is performed to find relations between the parameters of real cryptography systems and the length of the quantum channel that guarantee secure quantum key distribution when the eavesdropper’s capabilities are limited only by fundamental laws of quantum mechanics while the devices employed by the legitimate users are based on current technologies. Critical values are determined for the rate of secure real-time key generation that can be reached under the current technology level. Calculations show that the upper bound on channel length can be as high as 300 km for imperfect photodetectors (avalanche photodiodes) with present-day quantum efficiency (η ≈ 20%) and dark count probability ( p dark ˜ 10-7).

An application of different dioids in public key cryptography

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

Durcheva, Mariana I., E-mail: mdurcheva66@gmail.com

2014-11-18

Dioids provide a natural framework for analyzing a broad class of discrete event dynamical systems such as the design and analysis of bus and railway timetables, scheduling of high-throughput industrial processes, solution of combinatorial optimization problems, the analysis and improvement of flow systems in communication networks. They have appeared in several branches of mathematics such as functional analysis, optimization, stochastic systems and dynamic programming, tropical geometry, fuzzy logic. In this paper we show how to involve dioids in public key cryptography. The main goal is to create key – exchange protocols based on dioids. Additionally the digital signature scheme ismore » presented.« less

Report of the Public Cryptography Study Group.

ERIC Educational Resources Information Center

American Council on Education, Washington, DC.

Concerns of the National Security Agency (NSA) that information contained in some articles about cryptography in learned and professional journals and in monographs might be inimical to the national security are addressed. The Public Cryptography Study Group, with one dissenting opinion, recommends that a voluntary system of prior review of…

Image encryption using fingerprint as key based on phase retrieval algorithm and public key cryptography

NASA Astrophysics Data System (ADS)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2015-09-01

In this paper, a novel image encryption system with fingerprint used as a secret key is proposed based on the phase retrieval algorithm and RSA public key algorithm. In the system, the encryption keys include the fingerprint and the public key of RSA algorithm, while the decryption keys are the fingerprint and the private key of RSA algorithm. If the users share the fingerprint, then the system will meet the basic agreement of asymmetric cryptography. The system is also applicable for the information authentication. The fingerprint as secret key is used in both the encryption and decryption processes so that the receiver can identify the authenticity of the ciphertext by using the fingerprint in decryption process. Finally, the simulation results show the validity of the encryption scheme and the high robustness against attacks based on the phase retrieval technique.

Quantum cryptography: Theoretical protocols for quantum key distribution and tests of selected commercial QKD systems in commercial fiber networks

NASA Astrophysics Data System (ADS)

Jacak, Monika; Jacak, Janusz; Jóźwiak, Piotr; Jóźwiak, Ireneusz

2016-06-01

The overview of the current status of quantum cryptography is given in regard to quantum key distribution (QKD) protocols, implemented both on nonentangled and entangled flying qubits. Two commercial R&D platforms of QKD systems are described (the Clavis II platform by idQuantique implemented on nonentangled photons and the EPR S405 Quelle platform by AIT based on entangled photons) and tested for feasibility of their usage in commercial TELECOM fiber metropolitan networks. The comparison of systems efficiency, stability and resistivity against noise and hacker attacks is given with some suggestion toward system improvement, along with assessment of two models of QKD.

Tomographic quantum cryptography

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

Liang, Yeong Cherng; Kaszlikowski, Dagomir; Englert, Berthold-Georg

2003-08-01

We present a protocol for quantum cryptography in which the data obtained for mismatched bases are used in full for the purpose of quantum state tomography. Eavesdropping on the quantum channel is seriously impeded by requiring that the outcome of the tomography is consistent with unbiased noise in the channel. We study the incoherent eavesdropping attacks that are still permissible and establish under which conditions a secure cryptographic key can be generated. The whole analysis is carried out for channels that transmit quantum systems of any finite dimension.

On the complexity of search for keys in quantum cryptography

NASA Astrophysics Data System (ADS)

Molotkov, S. N.

2016-03-01

The trace distance is used as a security criterion in proofs of security of keys in quantum cryptography. Some authors doubted that this criterion can be reduced to criteria used in classical cryptography. The following question has been answered in this work. Let a quantum cryptography system provide an ɛ-secure key such that ½‖ρ XE - ρ U ⊗ ρ E ‖1 < ɛ, which will be repeatedly used in classical encryption algorithms. To what extent does the ɛ-secure key reduce the number of search steps (guesswork) as compared to the use of ideal keys? A direct relation has been demonstrated between the complexity of the complete consideration of keys, which is one of the main security criteria in classical systems, and the trace distance used in quantum cryptography. Bounds for the minimum and maximum numbers of search steps for the determination of the actual key have been presented.

Java-based cryptosystem for PACS and tele-imaging

NASA Astrophysics Data System (ADS)

Tjandra, Donny; Wong, Stephen T. C.; Yu, Yuan-Pin

1998-07-01

Traditional PACS systems are based on two-tier client server architectures, and require the use of costly, high-end client workstations for image viewing. Consequently, PACS systems using the two-tier architecture do not scale well as data increases in size and complexity. Furthermore, use of dedicated viewing workstations incurs costs in deployment and maintenance. To address these issues, the use of digital library technologies, such as the World Wide Web, Java, and CORBA, is being explored to distribute PACS data to serve a broader range of healthcare providers in an economic and efficient manner. Integration of PACS systems with digital library technologies allows access to medical information through open networks such as the Internet. However, use of open networks to transmit medical data introduces problems with maintaining privacy and integrity of patient information. Cryptography and digital timestamping is used to protect sensitive information from unauthorized access or tampering. A major concern when using cryptography and digital timestamping is the performance degradation associated with the mathematical calculations needed to encrypt/decrypt an image dataset, or to calculate the hash value of an image. The performance issue is compounded by the extra layer associated with the CORBA middleware, and the use of programming languages interpreted at the client side, such as Java. This paper study the extent to which Java-based cryptography and digital timestamping affects performance in a PACS system integrated with digital library technologies.

Cognitive approaches for patterns analysis and security applications

NASA Astrophysics Data System (ADS)

Ogiela, Marek R.; Ogiela, Lidia

2017-08-01

In this paper will be presented new opportunities for developing innovative solutions for semantic pattern classification and visual cryptography, which will base on cognitive and bio-inspired approaches. Such techniques can be used for evaluation of the meaning of analyzed patterns or encrypted information, and allow to involve such meaning into the classification task or encryption process. It also allows using some crypto-biometric solutions to extend personalized cryptography methodologies based on visual pattern analysis. In particular application of cognitive information systems for semantic analysis of different patterns will be presented, and also a novel application of such systems for visual secret sharing will be described. Visual shares for divided information can be created based on threshold procedure, which may be dependent on personal abilities to recognize some image details visible on divided images.

Information verification cryptosystem using one-time keys based on double random phase encoding and public-key cryptography

NASA Astrophysics Data System (ADS)

Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing

2016-08-01

A novel image encryption system based on double random phase encoding (DRPE) and RSA public-key algorithm is proposed. The main characteristic of the system is that each encryption process produces a new decryption key (even for the same plaintext), thus the encryption system conforms to the feature of the one-time pad (OTP) cryptography. The other characteristic of the system is the use of fingerprint key. Only with the rightful authorization will the true decryption be obtained, otherwise the decryption will result in noisy images. So the proposed system can be used to determine whether the ciphertext is falsified by attackers. In addition, the system conforms to the basic agreement of asymmetric cryptosystem (ACS) due to the combination with the RSA public-key algorithm. The simulation results show that the encryption scheme has high robustness against the existing attacks.

Error-correcting pairs for a public-key cryptosystem

NASA Astrophysics Data System (ADS)

Pellikaan, Ruud; Márquez-Corbella, Irene

2017-06-01

Code-based Cryptography (CBC) is a powerful and promising alternative for quantum resistant cryptography. Indeed, together with lattice-based cryptography, multivariate cryptography and hash-based cryptography are the principal available techniques for post-quantum cryptography. CBC was first introduced by McEliece where he designed one of the most efficient Public-Key encryption schemes with exceptionally strong security guarantees and other desirable properties that still resist to attacks based on Quantum Fourier Transform and Amplitude Amplification. The original proposal, which remains unbroken, was based on binary Goppa codes. Later, several families of codes have been proposed in order to reduce the key size. Some of these alternatives have already been broken. One of the main requirements of a code-based cryptosystem is having high performance t-bounded decoding algorithms which is achieved in the case the code has a t-error-correcting pair (ECP). Indeed, those McEliece schemes that use GRS codes, BCH, Goppa and algebraic geometry codes are in fact using an error-correcting pair as a secret key. That is, the security of these Public-Key Cryptosystems is not only based on the inherent intractability of bounded distance decoding but also on the assumption that it is difficult to retrieve efficiently an error-correcting pair. In this paper, the class of codes with a t-ECP is proposed for the McEliece cryptosystem. Moreover, we study the hardness of distinguishing arbitrary codes from those having a t-error correcting pair.

Halftone visual cryptography.

PubMed

Zhou, Zhi; Arce, Gonzalo R; Di Crescenzo, Giovanni

2006-08-01

Visual cryptography encodes a secret binary image (SI) into n shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the n shares, however, have no visual meaning and hinder the objectives of visual cryptography. Extended visual cryptography [1] was proposed recently to construct meaningful binary images as shares using hypergraph colourings, but the visual quality is poor. In this paper, a novel technique named halftone visual cryptography is proposed to achieve visual cryptography via halftoning. Based on the blue-noise dithering principles, the proposed method utilizes the void and cluster algorithm [2] to encode a secret binary image into n halftone shares (images) carrying significant visual information. The simulation shows that the visual quality of the obtained halftone shares are observably better than that attained by any available visual cryptography method known to date.

Counterfactual attack on counterfactual quantum key distribution

NASA Astrophysics Data System (ADS)

Zhang, Sheng; Wnang, Jian; Tang, Chao Jing

2012-05-01

It is interesting that counterfactual quantum cryptography protocols allow two remotely separated parties to share a secret key without transmitting any signal particles. Generally, these protocols, expected to provide security advantages, base their security on a translated no-cloning theorem. Therefore, they potentially exhibit unconditional security in theory. In this letter, we propose a new Trojan horse attack, by which an eavesdropper Eve can gain full information about the key without being noticed, to real implementations of a counterfactual quantum cryptography system. Most importantly, the presented attack is available even if the system has negligible imperfections. Therefore, it shows that the present realization of counterfactual quantum key distribution is vulnerable.

Quantum Cryptography for Secure Communications to Low-Earth Orbit Satellites

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

Hughes, R.J.; Buttler, W.T.; Kwiat, P.G.

1999-06-03

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. The security of these transmissions is based on the inviolability of the laws of quantum mechanics. An adversary can neither successfully tap the quantum transmissions, nor evade detection. Key material is built up using the transmission of a single-photon per bit. We have developed an experimental quantum cryptography system based on the transmissionmore » of non-orthogonal single-photon polarization states to generate shared key material over line-of-sight optical links. Our results provide strong evidence that cryptographic key material could be generated on demand between a ground station and a satellite (or between two satellites), allowing a satellite to be securely re-keyed on in orbit.« less

Security Issues on the Internet.

ERIC Educational Resources Information Center

Bar-Ilan, Judit

1996-01-01

Discusses some basic notions of modern cryptography: public key systems and digital signatures. Describes how theoretical modern cryptography can help solve security problems on the Internet. (Author/JKP)

INVITED PAPER: Low power cryptography

NASA Astrophysics Data System (ADS)

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

2005-01-01

Today more and more sensitive data is stored digitally. Bank accounts, medical records and personal emails are some categories that data must keep secure. The science of cryptography tries to encounter the lack of security. Data confidentiality, authentication, non-reputation and data integrity are some of the main parts of cryptography. The evolution of cryptography drove in very complex cryptographic models which they could not be implemented before some years. The use of systems with increasing complexity, which usually are more secure, has as result low throughput rate and more energy consumption. However the evolution of cipher has no practical impact, if it has only theoretical background. Every encryption algorithm should exploit as much as possible the conditions of the specific system without omitting the physical, area and timing limitations. This fact requires new ways in design architectures for secure and reliable crypto systems. A main issue in the design of crypto systems is the reduction of power consumption, especially for portable systems as smart cards.

Free-space quantum cryptography with quantum and telecom communication channels

NASA Astrophysics Data System (ADS)

Toyoshima, Morio; Takayama, Yoshihisa; Klaus, Werner; Kunimori, Hiroo; Fujiwara, Mikio; Sasaki, Masahide

2008-07-01

Quantum cryptography is a new technique that uses the laws of physics to transmit information securely. In such systems, the vehicle to transfer quantum information is a single photon. However, the transmission distance is limited by the absorption of photons in an optical fiber in which the maximum demonstrated range is about 100 km. Free-space quantum cryptography between a ground station and a satellite is a way of sending the quantum information further distances than that with optical fibers since there is no birefringence effect in the atmosphere. At the National Institute of Information and Communications Technology (NICT), the laser communication demonstration between the NICT optical ground station and a low earth orbit satellite was successfully conducted in 2006. For such space communication links, free-space quantum cryptography is considered to be an important application in the future. We have developed a prototype system for free-space quantum cryptography using a weak coherent light and a telecom communication channel. The preliminary results are presented.

Securing information display by use of visual cryptography.

PubMed

Yamamoto, Hirotsugu; Hayasaki, Yoshio; Nishida, Nobuo

2003-09-01

We propose a secure display technique based on visual cryptography. The proposed technique ensures the security of visual information. The display employs a decoding mask based on visual cryptography. Without the decoding mask, the displayed information cannot be viewed. The viewing zone is limited by the decoding mask so that only one person can view the information. We have developed a set of encryption codes to maintain the designed viewing zone and have demonstrated a display that provides a limited viewing zone.

Security and Privacy Assurance Research (SPAR) Pilot Final Report

DTIC Science & Technology

2015-11-30

for a single querier interacting with a single encrypted database. In order to deploy the technology, the underlying cryptography must support multiple...underlying cryptography . A full SPAR system should be evaluated too including the software itself. Software should be checked for consistency with...ESPADA included cryptography libraries (e.g., gnutls, nettle, and openssl). Consider a hypothetical scenario in which a vulnerability is discovered in

A New QKD Protocol Based upon Authentication by EPR Entanglement State

NASA Astrophysics Data System (ADS)

Abushgra, Abdulbast A.

Cryptographic world has faced multiple challenges that are included in encoding and decoding transmitting information into a secure communication channel. Quantum cryptography may be another generation of the cryptography world, which is based on the law of physics. After decades of using the classical cryptography, there is an essential need to move a step forward through the most trusted systems, especially enormous amount of data flows through billions of communicating channels (e.g. The internet), and keeping this transmitting information away from eavesdropping is obligatory. Moreover, quantum cryptography has proved its standing against many weaknesses in the classical cryptography. One of these weaknesses is the ability to copy any type of information using a passive attack without an interruption, which is impossible in the quantum system. Theoretically, several quantum observables are utilized to diagnose an action of one particle. These observables are included in measuring mass, movement, speed, etc. The polarization of one photon occurs normally and randomly in the space. Any interruption that happens during sending of a light will cause a deconstruction of the light polarization. Therefore, particles' movement in a three-dimensional space is supported by Non-Cloning theory that makes eavesdroppers unable to interrupt a communication system. In case an eavesdropper tried to interrupt a photon, the photon will be destroyed after passing the photon into a quantum detector or any measurement device. In the last decades, many Quantum Key Distribution (QKD) protocols have been created to initiate a secret key during encoding and decoding transmitted data operations. Some of these protocols were proven un-secure based on the quantum attacks that were released early. Even though the power of physics is still active and the Non-Cloning theory is unbroken, some QKD protocols failed during the security measurements. The main reason of the failure is based on the inability to provide the authentication between the end users during the quantum and classical channels. The proposed QKD protocol was designed to utilize some advantages of quantum physics as well as solid functions that are used in the classical cryptography. The authentication is a requirement during different communication channels, where both legitimate parties must confirm their identities before starting to submit data (plain-text). Moreover, the protocol uses most needed scenarios to finish the communication without leaking important data. These scenarios have been approved in existing QKD protocols either by classical or quantum systems. The matrix techniques also are used as a part of the preparation of the authentication key, where the end users communicate by an EPR (related to Einstein, Podolsky, and Rosen theory in 1935 ) channel. The EPR channel will be supported by an entanglement of particles. If the EPR communication succeeded, transferring the converted plain-text is required. Finally, both end users will have an authenticated secret key, and the submission will be done without any interruption.

Conventional Cryptography.

ERIC Educational Resources Information Center

Wright, Marie A.

1993-01-01

Cryptography is the science that renders data unintelligible to prevent its unauthorized disclosure or modification. Presents an application of matrices used in linear transformations to illustrate a cryptographic system. An example is provided. (17 references) (MDH)

Applying elliptic curve cryptography to a chaotic synchronisation system: neural-network-based approach

NASA Astrophysics Data System (ADS)

Hsiao, Feng-Hsiag

2017-10-01

In order to obtain double encryption via elliptic curve cryptography (ECC) and chaotic synchronisation, this study presents a design methodology for neural-network (NN)-based secure communications in multiple time-delay chaotic systems. ECC is an asymmetric encryption and its strength is based on the difficulty of solving the elliptic curve discrete logarithm problem which is a much harder problem than factoring integers. Because it is much harder, we can get away with fewer bits to provide the same level of security. To enhance the strength of the cryptosystem, we conduct double encryption that combines chaotic synchronisation with ECC. According to the improved genetic algorithm, a fuzzy controller is synthesised to realise the exponential synchronisation and achieves optimal H∞ performance by minimising the disturbances attenuation level. Finally, a numerical example with simulations is given to demonstrate the effectiveness of the proposed approach.

Using Mathematics to Make Computing on Encrypted Data Secure and Practical

DTIC Science & Technology

2015-12-01

LLL) lattice basis reduction algorithm, G-Lattice, Cryptography , Security, Gentry-Szydlo Algorithm, Ring-LWE 16. SECURITY CLASSIFICATION OF: 17...with symmetry be further developed, in order to quantify the security of lattice-based cryptography , including especially the security of homomorphic...the Gentry-Szydlo algorithm, and the ideas should be applicable to a range of questions in cryptography . The new algorithm of Lenstra and Silverberg

Public Key Cryptography.

ERIC Educational Resources Information Center

Tapson, Frank

1996-01-01

Describes public key cryptography, also known as RSA, which is a system using two keys, one used to put a message into cipher and another used to decipher the message. Presents examples using small prime numbers. (MKR)

Generalized logistic map and its application in chaos based cryptography

NASA Astrophysics Data System (ADS)

Lawnik, M.

2017-12-01

The logistic map is commonly used in, for example, chaos based cryptography. However, its properties do not render a safe construction of encryption algorithms. Thus, the scope of the paper is a proposal of generalization of the logistic map by means of a wellrecognized family of chaotic maps. In the next step, an analysis of Lyapunov exponent and the distribution of the iterative variable are studied. The obtained results confirm that the analyzed model can safely and effectively replace a classic logistic map for applications involving chaotic cryptography.

Quantum and classical noise in practical quantum-cryptography systems based on polarization-entangled photons

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

Castelletto, S.; Degiovanni, I.P.; Rastello, M.L.

2003-02-01

Quantum-cryptography key distribution (QCKD) experiments have been recently reported using polarization-entangled photons. However, in any practical realization, quantum systems suffer from either unwanted or induced interactions with the environment and the quantum measurement system, showing up as quantum and, ultimately, statistical noise. In this paper, we investigate how an ideal polarization entanglement in spontaneous parametric down-conversion (SPDC) suffers quantum noise in its practical implementation as a secure quantum system, yielding errors in the transmitted bit sequence. Since all SPDC-based QCKD schemes rely on the measurement of coincidence to assert the bit transmission between the two parties, we bundle up themore » overall quantum and statistical noise in an exhaustive model to calculate the accidental coincidences. This model predicts the quantum-bit error rate and the sifted key and allows comparisons between different security criteria of the hitherto proposed QCKD protocols, resulting in an objective assessment of performances and advantages of different systems.« less

Femtosecond Laser--Pumped Source of Entangled Photons for Quantum Cryptography Applications

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

Pan, D.; Donaldson, W.; Sobolewski, R.

2007-07-31

We present an experimental setup for generation of entangled-photon pairs via spontaneous parametric down-conversion, based on the femtosecond-pulsed laser. Our entangled-photon source utilizes a 76-MHz-repetition-rate, 100-fs-pulse-width, mode-locked, ultrafast femtosecond laser, which can produce, on average, more photon pairs than a cw laser of an equal pump power. The resulting entangled pairs are counted by a pair of high-quantum-efficiency, single-photon, silicon avalanche photodiodes. Our apparatus is intended as an efficient source/receiver system for the quantum communications and quantum cryptography applications.

Research on Quantum Algorithms at the Institute for Quantum Information and Matter

DTIC Science & Technology

2016-05-29

local quantum computation with applications to position-based cryptography , New Journal of Physics, (09 2011): 0. doi: 10.1088/1367-2630/13/9/093036... cryptography , such as the ability to turn private-key encryption into public-key encryption. While ad hoc obfuscators exist, theoretical progress has mainly...to device-independent quantum cryptography , to quantifying entanglement, and to the classification of quantum phases of matter. Exact synthesis

Distinguishability of quantum states and shannon complexity in quantum cryptography

NASA Astrophysics Data System (ADS)

Arbekov, I. M.; Molotkov, S. N.

2017-07-01

The proof of the security of quantum key distribution is a rather complex problem. Security is defined in terms different from the requirements imposed on keys in classical cryptography. In quantum cryptography, the security of keys is expressed in terms of the closeness of the quantum state of an eavesdropper after key distribution to an ideal quantum state that is uncorrelated to the key of legitimate users. A metric of closeness between two quantum states is given by the trace metric. In classical cryptography, the security of keys is understood in terms of, say, the complexity of key search in the presence of side information. In quantum cryptography, side information for the eavesdropper is given by the whole volume of information on keys obtained from both quantum and classical channels. The fact that the mathematical apparatuses used in the proof of key security in classical and quantum cryptography are essentially different leads to misunderstanding and emotional discussions [1]. Therefore, one should be able to answer the question of how different cryptographic robustness criteria are related to each other. In the present study, it is shown that there is a direct relationship between the security criterion in quantum cryptography, which is based on the trace distance determining the distinguishability of quantum states, and the criterion in classical cryptography, which uses guesswork on the determination of a key in the presence of side information.

Constructing Pairing-Friendly Elliptic Curves under Embedding Degree 1 for Securing Critical Infrastructures.

PubMed

Wang, Maocai; Dai, Guangming; Choo, Kim-Kwang Raymond; Jayaraman, Prem Prakash; Ranjan, Rajiv

2016-01-01

Information confidentiality is an essential requirement for cyber security in critical infrastructure. Identity-based cryptography, an increasingly popular branch of cryptography, is widely used to protect the information confidentiality in the critical infrastructure sector due to the ability to directly compute the user's public key based on the user's identity. However, computational requirements complicate the practical application of Identity-based cryptography. In order to improve the efficiency of identity-based cryptography, this paper presents an effective method to construct pairing-friendly elliptic curves with low hamming weight 4 under embedding degree 1. Based on the analysis of the Complex Multiplication(CM) method, the soundness of our method to calculate the characteristic of the finite field is proved. And then, three relative algorithms to construct pairing-friendly elliptic curve are put forward. 10 elliptic curves with low hamming weight 4 under 160 bits are presented to demonstrate the utility of our approach. Finally, the evaluation also indicates that it is more efficient to compute Tate pairing with our curves, than that of Bertoni et al.

Constructing Pairing-Friendly Elliptic Curves under Embedding Degree 1 for Securing Critical Infrastructures

PubMed Central

Dai, Guangming

2016-01-01

Information confidentiality is an essential requirement for cyber security in critical infrastructure. Identity-based cryptography, an increasingly popular branch of cryptography, is widely used to protect the information confidentiality in the critical infrastructure sector due to the ability to directly compute the user’s public key based on the user’s identity. However, computational requirements complicate the practical application of Identity-based cryptography. In order to improve the efficiency of identity-based cryptography, this paper presents an effective method to construct pairing-friendly elliptic curves with low hamming weight 4 under embedding degree 1. Based on the analysis of the Complex Multiplication(CM) method, the soundness of our method to calculate the characteristic of the finite field is proved. And then, three relative algorithms to construct pairing-friendly elliptic curve are put forward. 10 elliptic curves with low hamming weight 4 under 160 bits are presented to demonstrate the utility of our approach. Finally, the evaluation also indicates that it is more efficient to compute Tate pairing with our curves, than that of Bertoni et al. PMID:27564373

Number Theory and Public-Key Cryptography.

ERIC Educational Resources Information Center

Lefton, Phyllis

1991-01-01

Described are activities in the study of techniques used to conceal the meanings of messages and data. Some background information and two BASIC programs that illustrate the algorithms used in a new cryptographic system called "public-key cryptography" are included. (CW)

Shannon: Theory and cryptography

NASA Astrophysics Data System (ADS)

Roefs, H. F. A.

1982-11-01

The ideas of Shannon as a theoretical basis for cryptography are discussed. The notion of mutual information is introduced to provide a deeper understanding of the functioning of cryptographic systems. Shannon's absolute secure cryptosystem and his notion of unicity distance are explained.

RSA cryptography and multi prime RSA cryptography

NASA Astrophysics Data System (ADS)

Sani, Nur Atiqah Abdul; Kamarulhaili, Hailiza

2017-08-01

RSA cryptography is one of the most powerful and popular cryptosystem which is being applied until now. There is one variant of RSA cryptography named Multi Prime RSA (MPRSA) cryptography. MPRSA cryptography is the improved version of RSA cryptography. We only need to modify a few steps in key generation part and apply the Chinese Remainder Theorem (CRT) in the decryption part to get the MPRSA algorithm. The focus of this research is to compare between the standard RSA cryptography and MPRSA cryptography in a few aspects. The research shows that MPRSA cryptography is more efficient than the RSA cryptography. Time complexity using Mathematica software is also conducted and it is proven that MPRSA cryptography has shorter time taken. It also implies the computational time is less than RSA cryptography. Mathematica software version 9.0 and a laptop HP ProBook 4331s are used to check the timing and to implement both algorithms.

Secure method for biometric-based recognition with integrated cryptographic functions.

PubMed

Chiou, Shin-Yan

2013-01-01

Biometric systems refer to biometric technologies which can be used to achieve authentication. Unlike cryptography-based technologies, the ratio for certification in biometric systems needs not to achieve 100% accuracy. However, biometric data can only be directly compared through proximal access to the scanning device and cannot be combined with cryptographic techniques. Moreover, repeated use, improper storage, or transmission leaks may compromise security. Prior studies have attempted to combine cryptography and biometrics, but these methods require the synchronization of internal systems and are vulnerable to power analysis attacks, fault-based cryptanalysis, and replay attacks. This paper presents a new secure cryptographic authentication method using biometric features. The proposed system combines the advantages of biometric identification and cryptographic techniques. By adding a subsystem to existing biometric recognition systems, we can simultaneously achieve the security of cryptographic technology and the error tolerance of biometric recognition. This method can be used for biometric data encryption, signatures, and other types of cryptographic computation. The method offers a high degree of security with protection against power analysis attacks, fault-based cryptanalysis, and replay attacks. Moreover, it can be used to improve the confidentiality of biological data storage and biodata identification processes. Remote biometric authentication can also be safely applied.

Approach to design neural cryptography: a generalized architecture and a heuristic rule.

PubMed

Mu, Nankun; Liao, Xiaofeng; Huang, Tingwen

2013-06-01

Neural cryptography, a type of public key exchange protocol, is widely considered as an effective method for sharing a common secret key between two neural networks on public channels. How to design neural cryptography remains a great challenge. In this paper, in order to provide an approach to solve this challenge, a generalized network architecture and a significant heuristic rule are designed. The proposed generic framework is named as tree state classification machine (TSCM), which extends and unifies the existing structures, i.e., tree parity machine (TPM) and tree committee machine (TCM). Furthermore, we carefully study and find that the heuristic rule can improve the security of TSCM-based neural cryptography. Therefore, TSCM and the heuristic rule can guide us to designing a great deal of effective neural cryptography candidates, in which it is possible to achieve the more secure instances. Significantly, in the light of TSCM and the heuristic rule, we further expound that our designed neural cryptography outperforms TPM (the most secure model at present) on security. Finally, a series of numerical simulation experiments are provided to verify validity and applicability of our results.

Security proof of counterfactual quantum cryptography against general intercept-resend attacks and its vulnerability

NASA Astrophysics Data System (ADS)

Zhang, Sheng; Wang, Jian; Tang, Chao-Jing

2012-06-01

Counterfactual quantum cryptography, recently proposed by Noh, is featured with no transmission of signal particles. This exhibits evident security advantages, such as its immunity to the well-known photon-number-splitting attack. In this paper, the theoretical security of counterfactual quantum cryptography protocol against the general intercept-resend attacks is proved by bounding the information of an eavesdropper Eve more tightly than in Yin's proposal [Phys. Rev. A 82 042335 (2010)]. It is also shown that practical counterfactual quantum cryptography implementations may be vulnerable when equipped with imperfect apparatuses, by proving that a negative key rate can be achieved when Eve launches a time-shift attack based on imperfect detector efficiency.

Combining Cryptography with EEG Biometrics

PubMed Central

Kazanavičius, Egidijus; Woźniak, Marcin

2018-01-01

Cryptographic frameworks depend on key sharing for ensuring security of data. While the keys in cryptographic frameworks must be correctly reproducible and not unequivocally connected to the identity of a user, in biometric frameworks this is different. Joining cryptography techniques with biometrics can solve these issues. We present a biometric authentication method based on the discrete logarithm problem and Bose-Chaudhuri-Hocquenghem (BCH) codes, perform its security analysis, and demonstrate its security characteristics. We evaluate a biometric cryptosystem using our own dataset of electroencephalography (EEG) data collected from 42 subjects. The experimental results show that the described biometric user authentication system is effective, achieving an Equal Error Rate (ERR) of 0.024.

Combining Cryptography with EEG Biometrics.

PubMed

Damaševičius, Robertas; Maskeliūnas, Rytis; Kazanavičius, Egidijus; Woźniak, Marcin

2018-01-01

Cryptographic frameworks depend on key sharing for ensuring security of data. While the keys in cryptographic frameworks must be correctly reproducible and not unequivocally connected to the identity of a user, in biometric frameworks this is different. Joining cryptography techniques with biometrics can solve these issues. We present a biometric authentication method based on the discrete logarithm problem and Bose-Chaudhuri-Hocquenghem (BCH) codes, perform its security analysis, and demonstrate its security characteristics. We evaluate a biometric cryptosystem using our own dataset of electroencephalography (EEG) data collected from 42 subjects. The experimental results show that the described biometric user authentication system is effective, achieving an Equal Error Rate (ERR) of 0.024.

A copyright protection scheme for digital images based on shuffled singular value decomposition and visual cryptography.

PubMed

Devi, B Pushpa; Singh, Kh Manglem; Roy, Sudipta

2016-01-01

This paper proposes a new watermarking algorithm based on the shuffled singular value decomposition and the visual cryptography for copyright protection of digital images. It generates the ownership and identification shares of the image based on visual cryptography. It decomposes the image into low and high frequency sub-bands. The low frequency sub-band is further divided into blocks of same size after shuffling it and then the singular value decomposition is applied to each randomly selected block. Shares are generated by comparing one of the elements in the first column of the left orthogonal matrix with its corresponding element in the right orthogonal matrix of the singular value decomposition of the block of the low frequency sub-band. The experimental results show that the proposed scheme clearly verifies the copyright of the digital images, and is robust to withstand several image processing attacks. Comparison with the other related visual cryptography-based algorithms reveals that the proposed method gives better performance. The proposed method is especially resilient against the rotation attack.

Cryptography for a High-Assurance Web-Based Enterprise

DTIC Science & Technology

2013-10-01

2. Other Cryptographic services - Java provides many cryptographic services through the Java Cryptography Architecture (JCA) framework. The...id=2125 [7]. Miller, Sandra Kay, Fiber Optic Networks Vulnerable to Attack, Information Security Magazine, November 15, 2006, [8]. José R.C

Conceptual designs of onboard transceivers for ground-to-satellite quantum cryptography

NASA Astrophysics Data System (ADS)

Toyoshima, Morio; Shoji, Yozo; Takayama, Yoshihisa; Kunimori, Hiroo; Takeoka, Masahiro; Fujiwara, Mikio; Sasaki, Masahide

2009-05-01

A free-space quantum key distribution system is being developed by the National Institute of Information and Communications Technology (NICT) in Koganei, Japan. Quantum cryptography is a new technique for transmitting information where the security is guaranteed by the laws of physics. In such systems, a single photon is used for the quantum information. However, since the transmission distance in optical fibers is limited by the absorption of photons by the fiber, the maximum demonstrated range has been limited to about 100 km. Free-space quantum cryptography between an optical ground station and a satellite is a possible solution to extend the distance for a quantum network beyond the limits of optical fibers. At NICT, a laser communication demonstration between the NICT optical ground station and a low earth orbit satellite was successfully conducted in 2006. The use of free-space quantum key distribution for such space communication links is considered an important future application. This paper presents conceptual designs for the onboard transceivers for satellite quantum cryptography

Efficient multiuser quantum cryptography network based on entanglement.

PubMed

Xue, Peng; Wang, Kunkun; Wang, Xiaoping

2017-04-04

We present an efficient quantum key distribution protocol with a certain entangled state to solve a special cryptographic task. Also, we provide a proof of security of this protocol by generalizing the proof of modified of Lo-Chau scheme. Based on this two-user scheme, a quantum cryptography network protocol is proposed without any quantum memory.

Efficient multiuser quantum cryptography network based on entanglement

PubMed Central

Xue, Peng; Wang, Kunkun; Wang, Xiaoping

2017-01-01

We present an efficient quantum key distribution protocol with a certain entangled state to solve a special cryptographic task. Also, we provide a proof of security of this protocol by generalizing the proof of modified of Lo-Chau scheme. Based on this two-user scheme, a quantum cryptography network protocol is proposed without any quantum memory. PMID:28374854

Efficient multiuser quantum cryptography network based on entanglement

NASA Astrophysics Data System (ADS)

Xue, Peng; Wang, Kunkun; Wang, Xiaoping

2017-04-01

We present an efficient quantum key distribution protocol with a certain entangled state to solve a special cryptographic task. Also, we provide a proof of security of this protocol by generalizing the proof of modified of Lo-Chau scheme. Based on this two-user scheme, a quantum cryptography network protocol is proposed without any quantum memory.

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.

Optimal eavesdropping in cryptography with three-dimensional quantum states.

PubMed

Bruss, D; Macchiavello, C

2002-03-25

We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.

De Finetti representation theorem for infinite-dimensional quantum systems and applications to quantum cryptography.

PubMed

Renner, R; Cirac, J I

2009-03-20

We show that the quantum de Finetti theorem holds for states on infinite-dimensional systems, provided they satisfy certain experimentally verifiable conditions. This result can be applied to prove the security of quantum key distribution based on weak coherent states or other continuous variable states against general attacks.

Quantum key management

DOEpatents

Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

2016-11-29

Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

A secure RFID mutual authentication protocol for healthcare environments using elliptic curve cryptography.

PubMed

Jin, Chunhua; Xu, Chunxiang; Zhang, Xiaojun; Zhao, Jining

2015-03-01

Radio Frequency Identification(RFID) is an automatic identification technology, which can be widely used in healthcare environments to locate and track staff, equipment and patients. However, potential security and privacy problems in RFID system remain a challenge. In this paper, we design a mutual authentication protocol for RFID based on elliptic curve cryptography(ECC). We use pre-computing method within tag's communication, so that our protocol can get better efficiency. In terms of security, our protocol can achieve confidentiality, unforgeability, mutual authentication, tag's anonymity, availability and forward security. Our protocol also can overcome the weakness in the existing protocols. Therefore, our protocol is suitable for healthcare environments.

Enhancing Undergraduate Mathematics Curriculum via Coding Theory and Cryptography

ERIC Educational Resources Information Center

Aydin, Nuh

2009-01-01

The theory of error-correcting codes and cryptography are two relatively recent applications of mathematics to information and communication systems. The mathematical tools used in these fields generally come from algebra, elementary number theory, and combinatorics, including concepts from computational complexity. It is possible to introduce the…

Encrypted Objects and Decryption Processes: Problem-Solving with Functions in a Learning Environment Based on Cryptography

ERIC Educational Resources Information Center

White, Tobin

2009-01-01

This paper introduces an applied problem-solving task, set in the context of cryptography and embedded in a network of computer-based tools. This designed learning environment engaged students in a series of collaborative problem-solving activities intended to introduce the topic of functions through a set of linked representations. In a…

Secure Method for Biometric-Based Recognition with Integrated Cryptographic Functions

PubMed Central

Chiou, Shin-Yan

2013-01-01

Biometric systems refer to biometric technologies which can be used to achieve authentication. Unlike cryptography-based technologies, the ratio for certification in biometric systems needs not to achieve 100% accuracy. However, biometric data can only be directly compared through proximal access to the scanning device and cannot be combined with cryptographic techniques. Moreover, repeated use, improper storage, or transmission leaks may compromise security. Prior studies have attempted to combine cryptography and biometrics, but these methods require the synchronization of internal systems and are vulnerable to power analysis attacks, fault-based cryptanalysis, and replay attacks. This paper presents a new secure cryptographic authentication method using biometric features. The proposed system combines the advantages of biometric identification and cryptographic techniques. By adding a subsystem to existing biometric recognition systems, we can simultaneously achieve the security of cryptographic technology and the error tolerance of biometric recognition. This method can be used for biometric data encryption, signatures, and other types of cryptographic computation. The method offers a high degree of security with protection against power analysis attacks, fault-based cryptanalysis, and replay attacks. Moreover, it can be used to improve the confidentiality of biological data storage and biodata identification processes. Remote biometric authentication can also be safely applied. PMID:23762851

Electronic Voting Protocol Using Identity-Based Cryptography.

PubMed

Gallegos-Garcia, Gina; Tapia-Recillas, Horacio

2015-01-01

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps.

Electronic Voting Protocol Using Identity-Based Cryptography

PubMed Central

Gallegos-Garcia, Gina; Tapia-Recillas, Horacio

2015-01-01

Electronic voting protocols proposed to date meet their properties based on Public Key Cryptography (PKC), which offers high flexibility through key agreement protocols and authentication mechanisms. However, when PKC is used, it is necessary to implement Certification Authority (CA) to provide certificates which bind public keys to entities and enable verification of such public key bindings. Consequently, the components of the protocol increase notably. An alternative is to use Identity-Based Encryption (IBE). With this kind of cryptography, it is possible to have all the benefits offered by PKC, without neither the need of certificates nor all the core components of a Public Key Infrastructure (PKI). Considering the aforementioned, in this paper we propose an electronic voting protocol, which meets the privacy and robustness properties by using bilinear maps. PMID:26090515

Optical colour image watermarking based on phase-truncated linear canonical transform and image decomposition

NASA Astrophysics Data System (ADS)

Su, Yonggang; Tang, Chen; Li, Biyuan; Lei, Zhenkun

2018-05-01

This paper presents a novel optical colour image watermarking scheme based on phase-truncated linear canonical transform (PT-LCT) and image decomposition (ID). In this proposed scheme, a PT-LCT-based asymmetric cryptography is designed to encode the colour watermark into a noise-like pattern, and an ID-based multilevel embedding method is constructed to embed the encoded colour watermark into a colour host image. The PT-LCT-based asymmetric cryptography, which can be optically implemented by double random phase encoding with a quadratic phase system, can provide a higher security to resist various common cryptographic attacks. And the ID-based multilevel embedding method, which can be digitally implemented by a computer, can make the information of the colour watermark disperse better in the colour host image. The proposed colour image watermarking scheme possesses high security and can achieve a higher robustness while preserving the watermark’s invisibility. The good performance of the proposed scheme has been demonstrated by extensive experiments and comparison with other relevant schemes.

Quantum cryptography using single-particle entanglement

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

Lee, Jae-Weon; Lee, Eok Kyun; Chung, Yong Wook

2003-07-01

A quantum cryptography scheme based on entanglement between a single-particle state and a vacuum state is proposed. The scheme utilizes linear optics devices to detect the superposition of the vacuum and single-particle states. Existence of an eavesdropper can be detected by using a variant of Bell's inequality.

Secure message authentication system for node to node network

NASA Astrophysics Data System (ADS)

Sindhu, R.; Vanitha, M. M.; Norman, J.

2017-10-01

The Message verification remains some of the best actual methods for prevent the illegal and dis honored communication after presence progressed to WSNs (Wireless Sensor Networks). Intend for this purpose, several message verification systems must stand established, created on both symmetric key cryptography otherwise public key cryptosystems. Best of them will have some limits for great computational then statement above in count of deficiency of climb ability then flexibility in node settlement occurrence. In a polynomial based system was newly presented for these problems. Though, this system then situations delay will must the dimness of integral limitation firm in the point of polynomial: once the amount of message transferred remains the greater than the limitation then the opponent will completely improve the polynomial approaches. This paper suggests using ECC (Elliptic Curve Cryptography). Though using the node verification the technique in this paper permits some nodes to transfer a limitless amount of messages lacking misery in the limit problem. This system will have the message cause secrecy. Equally theoretic study then model effects show our planned system will be effective than the polynomial based method in positions of calculation then statement above in privacy points though message basis privacy.

Analysis of the width-w non-adjacent form in conjunction with hyperelliptic curve cryptography and with lattices☆

PubMed Central

Krenn, Daniel

2013-01-01

In this work the number of occurrences of a fixed non-zero digit in the width-w non-adjacent forms of all elements of a lattice in some region (e.g. a ball) is analysed. As bases, expanding endomorphisms with eigenvalues of the same absolute value are allowed. Applications of the main result are on numeral systems with an algebraic integer as base. Those come from efficient scalar multiplication methods (Frobenius-and-add methods) in hyperelliptic curves cryptography, and the result is needed for analysing the running time of such algorithms. The counting result itself is an asymptotic formula, where its main term coincides with the full block length analysis. In its second order term a periodic fluctuation is exhibited. The proof follows Delange’s method. PMID:23805020

Analysis of the width-[Formula: see text] non-adjacent form in conjunction with hyperelliptic curve cryptography and with lattices.

PubMed

Krenn, Daniel

2013-06-17

In this work the number of occurrences of a fixed non-zero digit in the width-[Formula: see text] non-adjacent forms of all elements of a lattice in some region (e.g. a ball) is analysed. As bases, expanding endomorphisms with eigenvalues of the same absolute value are allowed. Applications of the main result are on numeral systems with an algebraic integer as base. Those come from efficient scalar multiplication methods (Frobenius-and-add methods) in hyperelliptic curves cryptography, and the result is needed for analysing the running time of such algorithms. The counting result itself is an asymptotic formula, where its main term coincides with the full block length analysis. In its second order term a periodic fluctuation is exhibited. The proof follows Delange's method.

Practical Quantum Cryptography for Secure Free-Space Communications

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

Buttler, W.T.; Hughes, R.J.; Kwiat, P.G.

1999-02-01

Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. The security of these transmissions is based on the inviolability of the laws of quantum mechanics and information-theoretically secure post-processing methods. An adversary can neither successfully tap the quantum transmissions, nor evade detection, owing to Heisenberg's uncertainty principle. In this paper we describe the theory of quantum cryptography, and the most recent results from our experimental free-space system with which we have demonstrated for the first time the feasibility of quantum key generation overmore » a point-to-point outdoor atmospheric path in daylight. We achieved a transmission distance of 0.5 km, which was limited only by the length of the test range. Our results provide strong evidence that cryptographic key material could be generated on demand between a ground station and a satellite (or between two satellites), allowing a satellite to be securely re-keyed on orbit. We present a feasibility analysis of surface-to-satellite quantum key generation.« less

FREE-SPACE QUANTUM CRYPTOGRAPHY IN DAYLIGHT

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

Hughes, R.J.; Buttler, W.T.

2000-01-01

Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. The security of these transmissions is based on the inviolability of the laws of quantum mechanics and information-theoretically secure post-processing methods. An adversary can neither successfully tap the quantum transmissions, nor evade detection, owing to Heisenberg's uncertainty principle. In this paper we describe the theory of quantum cryptography, and the most recent results from our experimental free-space system with which we have demonstrated for the first time the feasibility of quantum key generation overmore » a point-to-point outdoor atmospheric path in daylight. We achieved a transmission distance of 0.5 km, which was limited only by the length of the test range. Our results provide strong evidence that cryptographic key material could be generated on demand between a ground station and a satellite (or between two satellites), allowing a satellite to be securely re-keyed on orbit. We present a feasibility analysis of surface-to-satellite quantum key generation.« less

Development of the polarization tracking scheme for free-space quantum cryptography

NASA Astrophysics Data System (ADS)

Toyoshima, Morio; Takayama, Yoshihisa; Kunimori, Hiroo; Takeoka, Masahiro; Fujiwara, Mikio; Sasaki, Masahide

2008-04-01

Quantum cryptography is a new technique for transmitting quantum information. The information is securely transmitted due to the laws of physics. In such systems, the vehicle that transfers quantum information is a single photon. The problem with using photons is that the transmission distance is limited by the absorption of the photons by the optical fiber along which they pass. The maximum demonstrated range so far is approximately 100 km. Using free-space quantum cryptography between a ground station and a satellite is a possible way of sending quantum information farther than is possible with optical fibers. This is because there is no birefringence effect in the atmosphere. However, there is a complication in that the directions of the polarization basis between the transmitter and the receiver must coincide with each other. This polarization changes because the mobile terminals for free-space transmission continuously change their attitudes. If the transmission protocol is based on polarization, it is necessary to compensate for the change in attitude between the mobile terminals. We are developing a scheme to track the polarization basis between the transceivers. The preliminary result is presented.

Multivariate Cryptography Based on Clipped Hopfield Neural Network.

PubMed

Wang, Jia; Cheng, Lee-Ming; Su, Tong

2018-02-01

Designing secure and efficient multivariate public key cryptosystems [multivariate cryptography (MVC)] to strengthen the security of RSA and ECC in conventional and quantum computational environment continues to be a challenging research in recent years. In this paper, we will describe multivariate public key cryptosystems based on extended Clipped Hopfield Neural Network (CHNN) and implement it using the MVC (CHNN-MVC) framework operated in space. The Diffie-Hellman key exchange algorithm is extended into the matrix field, which illustrates the feasibility of its new applications in both classic and postquantum cryptography. The efficiency and security of our proposed new public key cryptosystem CHNN-MVC are simulated and found to be NP-hard. The proposed algorithm will strengthen multivariate public key cryptosystems and allows hardware realization practicality.

Quantum cryptography for secure free-space communications

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

Hughes, R.J.; Buttler, W.T.; Kwiat, P.G.

1999-03-01

The secure distribution of the secret random bit sequences known as key material, is an essential precursor to their use for the encryption and decryption of confidential communications. Quantum cryptography is a new technique for secure key distribution with single-photon transmissions: Heisenberg`s uncertainty principle ensures that an adversary can neither successfully tap the key transmissions, nor evade detection (eavesdropping raises the key error rate above a threshold value). The authors have developed experimental quantum cryptography systems based on the transmission of non-orthogonal photon polarization states to generate shared key material over line-of-sight optical links. Key material is built up usingmore » the transmission of a single-photon per bit of an initial secret random sequence. A quantum-mechanically random subset of this sequence is identified, becoming the key material after a data reconciliation stage with the sender. The authors have developed and tested a free-space quantum key distribution (QKD) system over an outdoor optical path of {approximately}1 km at Los Alamos National Laboratory under nighttime conditions. Results show that free-space QKD can provide secure real-time key distribution between parties who have a need to communicate secretly. Finally, they examine the feasibility of surface to satellite QKD.« less

Secure communications using quantum cryptography

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

Hughes, R.J.; Buttler, W.T.; Kwiat, P.G.

1997-08-01

The secure distribution of the secret random bit sequences known as {open_quotes}key{close_quotes} material, is an essential precursor to their use for the encryption and decryption of confidential communications. Quantum cryptography is an emerging technology for secure key distribution with single-photon transmissions, nor evade detection (eavesdropping raises the key error rate above a threshold value). We have developed experimental quantum cryptography systems based on the transmission of non-orthogonal single-photon states to generate shared key material over multi-kilometer optical fiber paths and over line-of-sight links. In both cases, key material is built up using the transmission of a single-photon per bit ofmore » an initial secret random sequence. A quantum-mechanically random subset of this sequence is identified, becoming the key material after a data reconciliation stage with the sender. In our optical fiber experiment we have performed quantum key distribution over 24-km of underground optical fiber using single-photon interference states, demonstrating that secure, real-time key generation over {open_quotes}open{close_quotes} multi-km node-to-node optical fiber communications links is possible. We have also constructed a quantum key distribution system for free-space, line-of-sight transmission using single-photon polarization states, which is currently undergoing laboratory testing. 7 figs.« less

Classical command of quantum systems.

PubMed

Reichardt, Ben W; Unger, Falk; Vazirani, Umesh

2013-04-25

Quantum computation and cryptography both involve scenarios in which a user interacts with an imperfectly modelled or 'untrusted' system. It is therefore of fundamental and practical interest to devise tests that reveal whether the system is behaving as instructed. In 1969, Clauser, Horne, Shimony and Holt proposed an experimental test that can be passed by a quantum-mechanical system but not by a system restricted to classical physics. Here we extend this test to enable the characterization of a large quantum system. We describe a scheme that can be used to determine the initial state and to classically command the system to evolve according to desired dynamics. The bipartite system is treated as two black boxes, with no assumptions about their inner workings except that they obey quantum physics. The scheme works even if the system is explicitly designed to undermine it; any misbehaviour is detected. Among its applications, our scheme makes it possible to test whether a claimed quantum computer is truly quantum. It also advances towards a goal of quantum cryptography: namely, the use of 'untrusted' devices to establish a shared random key, with security based on the validity of quantum physics.

One-time pad, complexity of verification of keys, and practical security of quantum cryptography

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

Molotkov, S. N., E-mail: sergei.molotkov@gmail.com

2016-11-15

A direct relation between the complexity of the complete verification of keys, which is one of the main criteria of security in classical systems, and a trace distance used in quantum cryptography is demonstrated. Bounds for the minimum and maximum numbers of verification steps required to determine the actual key are obtained.

On the passive probing of fiber optic quantum communication channels

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

Korol'kov, A. V., E-mail: sergei.kulik@gmail.co; Katamadze, K. G.; Kulik, S. P.

2010-04-15

Avalanche photodetectors based on InGaAs:P are the most sensitive and only detectors operating in the telecommunication wavelength range 1.30-1.55 {mu}m in the fiber optic quantum cryptography systems that can operate in the single photon count mode. In contrast to the widely used silicon photodetectors for wavelengths up to 1 {mu}m operating in a waiting mode, these detectors always operate in a gated mode. The production of an electron-hole pair in the process of the absorption of a photon and the subsequent appearance of an avalanche of carriers can be accompanied by the inverse processes of the recombination and emission ofmore » photons. Such a backward emission can present a potential serious problem for the stability of fiber optic quantum cryptography systems against passive probing. The results of analyzing the detection of backscattered radiation are reported. The probability of such an emission has been estimated.« less

Optical hiding with visual cryptography

NASA Astrophysics Data System (ADS)

Shi, Yishi; Yang, Xiubo

2017-11-01

We propose an optical hiding method based on visual cryptography. In the hiding process, we convert the secret information into a set of fabricated phase-keys, which are completely independent of each other, intensity-detected-proof and image-covered, leading to the high security. During the extraction process, the covered phase-keys are illuminated with laser beams and then incoherently superimposed to extract the hidden information directly by human vision, without complicated optical implementations and any additional computation, resulting in the convenience of extraction. Also, the phase-keys are manufactured as the diffractive optical elements that are robust to the attacks, such as the blocking and the phase-noise. Optical experiments verify that the high security, the easy extraction and the strong robustness are all obtainable in the visual-cryptography-based optical hiding.

Authenticity techniques for PACS images and records

NASA Astrophysics Data System (ADS)

Wong, Stephen T. C.; Abundo, Marco; Huang, H. K.

1995-05-01

Along with the digital radiology environment supported by picture archiving and communication systems (PACS) comes a new problem: How to establish trust in multimedia medical data that exist only in the easily altered memory of a computer. Trust is characterized in terms of integrity and privacy of digital data. Two major self-enforcing techniques can be used to assure the authenticity of electronic images and text -- key-based cryptography and digital time stamping. Key-based cryptography associates the content of an image with the originator using one or two distinct keys and prevents alteration of the document by anyone other than the originator. A digital time stamping algorithm generates a characteristic `digital fingerprint' for the original document using a mathematical hash function, and checks that it has not been modified. This paper discusses these cryptographic algorithms and their appropriateness for a PACS environment. It also presents experimental results of cryptographic algorithms on several imaging modalities.

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.

Quantum cryptography using entangled photons in energy-time bell states

PubMed

Tittel; Brendel; Zbinden; Gisin

2000-05-15

We present a setup for quantum cryptography based on photon pairs in energy-time Bell states and show its feasibility in a laboratory experiment. Our scheme combines the advantages of using photon pairs instead of faint laser pulses and the possibility to preserve energy-time entanglement over long distances. Moreover, using four-dimensional energy-time states, no fast random change of bases is required in our setup: Nature itself decides whether to measure in the energy or in the time base, thus rendering eavesdropper attacks based on "photon number splitting" less efficient.

On a simple attack, limiting the range transmission of secret keys in a system of quantum cryptography based on coding in a sub-carrier frequency

NASA Astrophysics Data System (ADS)

Klimov, A. N.; Kulik, S. P.; Molotkov, S. N.; Potapova, T. A.

2017-03-01

In the paper by Gleim et al (2016 Opt. Express 24 2619), it was declared that the system of quantum cryptography, exploiting quantum key distribution (QKD) protocol BB84 with the additional reference state and encoding in a sub-carrier, is able to distribute secret keys at a distance of 210 km. The following shows that a simple attack realized with a beam splitter results in a loss of privacy of the keys over substantially smaller distances. It turns out that the actual length of the secret key transmission for the QKD system encoding in the sub-carrier frequency is ten times less than that declared in Gleim et al (2016 Opt. Express 24 2619). Therefore it is impossible to safely use the keys when distributed at a larger length of the communication channel than shown below. The maximum communication distance does not exceed 22 km, even in the most optimistic scenario.

No information flow using statistical fluctuations and quantum cryptography

NASA Astrophysics Data System (ADS)

Larsson, Jan-Åke

2004-04-01

The communication protocol of Home and Whitaker [

One-Time Pad as a nonlinear dynamical system

NASA Astrophysics Data System (ADS)

Nagaraj, Nithin

2012-11-01

The One-Time Pad (OTP) is the only known unbreakable cipher, proved mathematically by Shannon in 1949. In spite of several practical drawbacks of using the OTP, it continues to be used in quantum cryptography, DNA cryptography and even in classical cryptography when the highest form of security is desired (other popular algorithms like RSA, ECC, AES are not even proven to be computationally secure). In this work, we prove that the OTP encryption and decryption is equivalent to finding the initial condition on a pair of binary maps (Bernoulli shift). The binary map belongs to a family of 1D nonlinear chaotic and ergodic dynamical systems known as Generalized Luröth Series (GLS). Having established these interesting connections, we construct other perfect secrecy systems on the GLS that are equivalent to the One-Time Pad, generalizing for larger alphabets. We further show that OTP encryption is related to Randomized Arithmetic Coding - a scheme for joint compression and encryption.

Quantum cryptography with 3-state systems.

PubMed

Bechmann-Pasquinucci, H; Peres, A

2000-10-09

We consider quantum cryptographic schemes where the carriers of information are 3-state particles. One protocol uses four mutually unbiased bases and appears to provide better security than obtainable with 2-state carriers. Another possible method allows quantum states to belong to more than one basis. Security is not better, but many curious features arise.

Elliptic Curve Cryptography-Based Authentication with Identity Protection for Smart Grids

PubMed Central

Zhang, Liping; Tang, Shanyu; Luo, He

2016-01-01

In a smart grid, the power service provider enables the expected power generation amount to be measured according to current power consumption, thus stabilizing the power system. However, the data transmitted over smart grids are not protected, and then suffer from several types of security threats and attacks. Thus, a robust and efficient authentication protocol should be provided to strength the security of smart grid networks. As the Supervisory Control and Data Acquisition system provides the security protection between the control center and substations in most smart grid environments, we focus on how to secure the communications between the substations and smart appliances. Existing security approaches fail to address the performance-security balance. In this study, we suggest a mitigation authentication protocol based on Elliptic Curve Cryptography with privacy protection by using a tamper-resistant device at the smart appliance side to achieve a delicate balance between performance and security of smart grids. The proposed protocol provides some attractive features such as identity protection, mutual authentication and key agreement. Finally, we demonstrate the completeness of the proposed protocol using the Gong-Needham- Yahalom logic. PMID:27007951

Elliptic Curve Cryptography-Based Authentication with Identity Protection for Smart Grids.

PubMed

Zhang, Liping; Tang, Shanyu; Luo, He

2016-01-01

In a smart grid, the power service provider enables the expected power generation amount to be measured according to current power consumption, thus stabilizing the power system. However, the data transmitted over smart grids are not protected, and then suffer from several types of security threats and attacks. Thus, a robust and efficient authentication protocol should be provided to strength the security of smart grid networks. As the Supervisory Control and Data Acquisition system provides the security protection between the control center and substations in most smart grid environments, we focus on how to secure the communications between the substations and smart appliances. Existing security approaches fail to address the performance-security balance. In this study, we suggest a mitigation authentication protocol based on Elliptic Curve Cryptography with privacy protection by using a tamper-resistant device at the smart appliance side to achieve a delicate balance between performance and security of smart grids. The proposed protocol provides some attractive features such as identity protection, mutual authentication and key agreement. Finally, we demonstrate the completeness of the proposed protocol using the Gong-Needham-Yahalom logic.

MURI Center for Photonic Quantum Information Systems

DTIC Science & Technology

2009-10-16

conversion; solid- state quantum gates based on quantum dots in semiconductors and on NV centers in diamond; quantum memories using optical storage...of our high-speed quantum cryptography systems, and also by continuing to work on quantum information encoding into transverse spatial modes. 14...make use of cavity QED effects for quantum information processing, the quantum dot needs to be addressed coherently . We have probed the QD-cavity

Secure quantum key distribution using continuous variables of single photons.

PubMed

Zhang, Lijian; Silberhorn, Christine; Walmsley, Ian A

2008-03-21

We analyze the distribution of secure keys using quantum cryptography based on the continuous variable degree of freedom of entangled photon pairs. We derive the information capacity of a scheme based on the spatial entanglement of photons from a realistic source, and show that the standard measures of security known for quadrature-based continuous variable quantum cryptography (CV-QKD) are inadequate. A specific simple eavesdropping attack is analyzed to illuminate how secret information may be distilled well beyond the bounds of the usual CV-QKD measures.

Chocolate Key Cryptography

ERIC Educational Resources Information Center

Bachman, Dale J.; Brown, Ezra A.; Norton, Anderson H.

2010-01-01

Cryptography is the science of hidden or secret writing. More generally, cryptography refers to the science of safeguarding information. Cryptography allows people to use a public medium such as the Internet to transmit private information securely, thus enabling a whole range of conveniences, from online shopping to personally printed movie…

Quantum cryptography: a view from classical cryptography

NASA Astrophysics Data System (ADS)

Buchmann, Johannes; Braun, Johannes; Demirel, Denise; Geihs, Matthias

2017-06-01

Much of digital data requires long-term protection of confidentiality, for example, medical health records. Cryptography provides such protection. However, currently used cryptographic techniques such as Diffe-Hellman key exchange may not provide long-term security. Such techniques rely on certain computational assumptions, such as the hardness of the discrete logarithm problem that may turn out to be incorrect. On the other hand, quantum cryptography---in particular quantum random number generation and quantum key distribution---offers information theoretic protection. In this paper, we explore the challenge of providing long-term confidentiality and we argue that a combination of quantum cryptography and classical cryptography can provide such protection.

Understanding security failures of two authentication and key agreement schemes for telecare medicine information systems.

PubMed

Mishra, Dheerendra

2015-03-01

Smart card based authentication and key agreement schemes for telecare medicine information systems (TMIS) enable doctors, nurses, patients and health visitors to use smart cards for secure login to medical information systems. In recent years, several authentication and key agreement schemes have been proposed to present secure and efficient solution for TMIS. Most of the existing authentication schemes for TMIS have either higher computation overhead or are vulnerable to attacks. To reduce the computational overhead and enhance the security, Lee recently proposed an authentication and key agreement scheme using chaotic maps for TMIS. Xu et al. also proposed a password based authentication and key agreement scheme for TMIS using elliptic curve cryptography. Both the schemes provide better efficiency from the conventional public key cryptography based schemes. These schemes are important as they present an efficient solution for TMIS. We analyze the security of both Lee's scheme and Xu et al.'s schemes. Unfortunately, we identify that both the schemes are vulnerable to denial of service attack. To understand the security failures of these cryptographic schemes which are the key of patching existing schemes and designing future schemes, we demonstrate the security loopholes of Lee's scheme and Xu et al.'s scheme in this paper.

Device independence for two-party cryptography and position verification with memoryless devices

NASA Astrophysics Data System (ADS)

Ribeiro, Jérémy; Thinh, Le Phuc; Kaniewski, Jedrzej; Helsen, Jonas; Wehner, Stephanie

2018-06-01

Quantum communication has demonstrated its usefulness for quantum cryptography far beyond quantum key distribution. One domain is two-party cryptography, whose goal is to allow two parties who may not trust each other to solve joint tasks. Another interesting application is position-based cryptography whose goal is to use the geographical location of an entity as its only identifying credential. Unfortunately, security of these protocols is not possible against an all powerful adversary. However, if we impose some realistic physical constraints on the adversary, there exist protocols for which security can be proven, but these so far relied on the knowledge of the quantum operations performed during the protocols. In this work we improve the device-independent security proofs of Kaniewski and Wehner [New J. Phys. 18, 055004 (2016), 10.1088/1367-2630/18/5/055004] for two-party cryptography (with memoryless devices) and we add a security proof for device-independent position verification (also memoryless devices) under different physical constraints on the adversary. We assess the quality of the devices by observing a Bell violation, and, as for Kaniewski and Wehner [New J. Phys. 18, 055004 (2016), 10.1088/1367-2630/18/5/055004], security can be attained for any violation of the Clauser-Holt-Shimony-Horne inequality.

A Secure Mobile-Based Authentication System for e-Banking

NASA Astrophysics Data System (ADS)

Rifà-Pous, Helena

Financial information is extremely sensitive. Hence, electronic banking must provide a robust system to authenticate its customers and let them access their data remotely. On the other hand, such system must be usable, affordable, and portable. We propose a challenge-response based one-time password (OTP) scheme that uses symmetric cryptography in combination with a hardware security module. The proposed protocol safeguards passwords from keyloggers and phishing attacks. Besides, this solution provides convenient mobility for users who want to bank online anytime and anywhere, not just from their own trusted computers.

DNA Cryptography and Deep Learning using Genetic Algorithm with NW algorithm for Key Generation.

PubMed

Kalsi, Shruti; Kaur, Harleen; Chang, Victor

2017-12-05

Cryptography is not only a science of applying complex mathematics and logic to design strong methods to hide data called as encryption, but also to retrieve the original data back, called decryption. The purpose of cryptography is to transmit a message between a sender and receiver such that an eavesdropper is unable to comprehend it. To accomplish this, not only we need a strong algorithm, but a strong key and a strong concept for encryption and decryption process. We have introduced a concept of DNA Deep Learning Cryptography which is defined as a technique of concealing data in terms of DNA sequence and deep learning. In the cryptographic technique, each alphabet of a letter is converted into a different combination of the four bases, namely; Adenine (A), Cytosine (C), Guanine (G) and Thymine (T), which make up the human deoxyribonucleic acid (DNA). Actual implementations with the DNA don't exceed laboratory level and are expensive. To bring DNA computing on a digital level, easy and effective algorithms are proposed in this paper. In proposed work we have introduced firstly, a method and its implementation for key generation based on the theory of natural selection using Genetic Algorithm with Needleman-Wunsch (NW) algorithm and Secondly, a method for implementation of encryption and decryption based on DNA computing using biological operations Transcription, Translation, DNA Sequencing and Deep Learning.

Cryptography for Big Data Security

DTIC Science & Technology

2015-07-13

Cryptography for Big Data Security Book Chapter for Big Data: Storage, Sharing, and Security (3S) Distribution A: Public Release Ariel Hamlin1 Nabil...Email: arkady@ll.mit.edu ii Contents 1 Cryptography for Big Data Security 1 1.1 Introduction...48 Chapter 1 Cryptography for Big Data Security 1.1 Introduction With the amount

Analysis of entropy extraction efficiencies in random number generation systems

NASA Astrophysics Data System (ADS)

Wang, Chao; Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Han, Zheng-Fu

2016-05-01

Random numbers (RNs) have applications in many areas: lottery games, gambling, computer simulation, and, most importantly, cryptography [N. Gisin et al., Rev. Mod. Phys. 74 (2002) 145]. In cryptography theory, the theoretical security of the system calls for high quality RNs. Therefore, developing methods for producing unpredictable RNs with adequate speed is an attractive topic. Early on, despite the lack of theoretical support, pseudo RNs generated by algorithmic methods performed well and satisfied reasonable statistical requirements. However, as implemented, those pseudorandom sequences were completely determined by mathematical formulas and initial seeds, which cannot introduce extra entropy or information. In these cases, “random” bits are generated that are not at all random. Physical random number generators (RNGs), which, in contrast to algorithmic methods, are based on unpredictable physical random phenomena, have attracted considerable research interest. However, the way that we extract random bits from those physical entropy sources has a large influence on the efficiency and performance of the system. In this manuscript, we will review and discuss several randomness extraction schemes that are based on radiation or photon arrival times. We analyze the robustness, post-processing requirements and, in particular, the extraction efficiency of those methods to aid in the construction of efficient, compact and robust physical RNG systems.

No information flow using statistical fluctuations and quantum cryptography

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

Larsson, Jan-Aake

2004-04-01

The communication protocol of Home and Whitaker [Phys. Rev. A 67, 022306 (2003)] is examined in some detail, and found to work equally well using a separable state. The protocol is in fact completely classical, based on postselection of suitable experimental runs. The quantum-cryptography protocol proposed in the same publication is also examined, and this protocol uses entanglement, a strictly quantum property of the system. An individual eavesdropping attack on each qubit pair would be detected by the security test proposed in the mentioned paper. However, the key is provided by groups of qubits, and there exists a coherent attack,more » internal to these groups, that will go unnoticed in that security test. A modified test is proposed here that will ensure security, even against such a coherent attack.« less

A Novel Image Steganography Technique for Secured Online Transaction Using DWT and Visual Cryptography

NASA Astrophysics Data System (ADS)

Anitha Devi, M. D.; ShivaKumar, K. B.

2017-08-01

Online payment eco system is the main target especially for cyber frauds. Therefore end to end encryption is very much needed in order to maintain the integrity of secret information related to transactions carried online. With access to payment related sensitive information, which enables lot of money transactions every day, the payment infrastructure is a major target for hackers. The proposed system highlights, an ideal approach for secure online transaction for fund transfer with a unique combination of visual cryptography and Haar based discrete wavelet transform steganography technique. This combination of data hiding technique reduces the amount of information shared between consumer and online merchant needed for successful online transaction along with providing enhanced security to customer’s account details and thereby increasing customer’s confidence preventing “Identity theft” and “Phishing”. To evaluate the effectiveness of proposed algorithm Root mean square error, Peak signal to noise ratio have been used as evaluation parameters

Quantum cryptography and applications in the optical fiber network

NASA Astrophysics Data System (ADS)

Luo, Yuhui

2005-09-01

Quantum cryptography, as part of quantum information and communications, can provide absolute security for information transmission because it is established on the fundamental laws of quantum theory, such as the principle of uncertainty, No-cloning theorem and quantum entanglement. In this thesis research, a novel scheme to implement quantum key distribution based on multiphoton entanglement with a new protocol is proposed. Its advantages are: a larger information capacity can be obtained with a longer transmission distance and the detection of multiple photons is easier than that of a single photon. The security and attacks pertaining to such a system are also studied. Next, a quantum key distribution over wavelength division multiplexed (WDM) optical fiber networks is realized. Quantum key distribution in networks is a long-standing problem for practical applications. Here we combine quantum cryptography and WDM to solve this problem because WDM technology is universally deployed in the current and next generation fiber networks. The ultimate target is to deploy quantum key distribution over commercial networks. The problems arising from the networks are also studied in this part. Then quantum key distribution in multi-access networks using wavelength routing technology is investigated in this research. For the first time, quantum cryptography for multiple individually targeted users has been successfully implemented in sharp contrast to that using the indiscriminating broadcasting structure. It overcomes the shortcoming that every user in the network can acquire the quantum key signals intended to be exchanged between only two users. Furthermore, a more efficient scheme of quantum key distribution is adopted, hence resulting in a higher key rate. Lastly, a quantum random number generator based on quantum optics has been experimentally demonstrated. This device is a key component for quantum key distribution as it can create truly random numbers, which is an essential requirement to perform quantum key distribution. This new generator is composed of a single optical fiber coupler with fiber pigtails, which can be easily used in optical fiber communications.

Cryptography and the Internet: lessons and challenges

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

McCurley, K.S.

1996-12-31

The popularization of the Internet has brought fundamental changes to the world, because it allows a universal method of communication between computers. This carries enormous benefits with it, but also raises many security considerations. Cryptography is a fundamental technology used to provide security of computer networks, and there is currently a widespread engineering effort to incorporate cryptography into various aspects of the Internet. The system-level engineering required to provide security services for the Internet carries some important lessons for researchers whose study is focused on narrowly defined problems. It also offers challenges to the cryptographic research community by raising newmore » questions not adequately addressed by the existing body of knowledge. This paper attempts to summarize some of these lessons and challenges for the cryptographic research community.« less

Protecting Information

NASA Astrophysics Data System (ADS)

Loepp, Susan; Wootters, William K.

2006-09-01

For many everyday transmissions, it is essential to protect digital information from noise or eavesdropping. This undergraduate introduction to error correction and cryptography is unique in devoting several chapters to quantum cryptography and quantum computing, thus providing a context in which ideas from mathematics and physics meet. By covering such topics as Shor's quantum factoring algorithm, this text informs the reader about current thinking in quantum information theory and encourages an appreciation of the connections between mathematics and science.Of particular interest are the potential impacts of quantum physics:(i) a quantum computer, if built, could crack our currently used public-key cryptosystems; and (ii) quantum cryptography promises to provide an alternative to these cryptosystems, basing its security on the laws of nature rather than on computational complexity. No prior knowledge of quantum mechanics is assumed, but students should have a basic knowledge of complex numbers, vectors, and matrices. Accessible to readers familiar with matrix algebra, vector spaces and complex numbers First undergraduate text to cover cryptography, error-correction, and quantum computation together Features exercises designed to enhance understanding, including a number of computational problems, available from www.cambridge.org/9780521534765

Novel optical scanning cryptography using Fresnel telescope imaging.

PubMed

Yan, Aimin; Sun, Jianfeng; Hu, Zhijuan; Zhang, Jingtao; Liu, Liren

2015-07-13

We propose a new method called modified optical scanning cryptography using Fresnel telescope imaging technique for encryption and decryption of remote objects. An image or object can be optically encrypted on the fly by Fresnel telescope scanning system together with an encryption key. For image decryption, the encrypted signals are received and processed with an optical coherent heterodyne detection system. The proposed method has strong performance through use of secure Fresnel telescope scanning with orthogonal polarized beams and efficient all-optical information processing. The validity of the proposed method is demonstrated by numerical simulations and experimental results.

Provably secure and high-rate quantum key distribution with time-bin qudits

DOE PAGES

Islam, Nurul T.; Lim, Charles Ci Wen; Cahall, Clinton; ...

2017-11-24

The security of conventional cryptography systems is threatened in the forthcoming era of quantum computers. Quantum key distribution (QKD) features fundamentally proven security and offers a promising option for quantum-proof cryptography solution. Although prototype QKD systems over optical fiber have been demonstrated over the years, the key generation rates remain several orders of magnitude lower than current classical communication systems. In an effort toward a commercially viable QKD system with improved key generation rates, we developed a discrete-variable QKD system based on time-bin quantum photonic states that can generate provably secure cryptographic keys at megabit-per-second rates over metropolitan distances. Wemore » use high-dimensional quantum states that transmit more than one secret bit per received photon, alleviating detector saturation effects in the superconducting nanowire single-photon detectors used in our system that feature very high detection efficiency (of more than 70%) and low timing jitter (of less than 40 ps). Our system is constructed using commercial off-the-shelf components, and the adopted protocol can be readily extended to free-space quantum channels. In conclusion, the security analysis adopted to distill the keys ensures that the demonstrated protocol is robust against coherent attacks, finite-size effects, and a broad class of experimental imperfections identified in our system.« less

Provably secure and high-rate quantum key distribution with time-bin qudits

PubMed Central

Islam, Nurul T.; Lim, Charles Ci Wen; Cahall, Clinton; Kim, Jungsang; Gauthier, Daniel J.

2017-01-01

The security of conventional cryptography systems is threatened in the forthcoming era of quantum computers. Quantum key distribution (QKD) features fundamentally proven security and offers a promising option for quantum-proof cryptography solution. Although prototype QKD systems over optical fiber have been demonstrated over the years, the key generation rates remain several orders of magnitude lower than current classical communication systems. In an effort toward a commercially viable QKD system with improved key generation rates, we developed a discrete-variable QKD system based on time-bin quantum photonic states that can generate provably secure cryptographic keys at megabit-per-second rates over metropolitan distances. We use high-dimensional quantum states that transmit more than one secret bit per received photon, alleviating detector saturation effects in the superconducting nanowire single-photon detectors used in our system that feature very high detection efficiency (of more than 70%) and low timing jitter (of less than 40 ps). Our system is constructed using commercial off-the-shelf components, and the adopted protocol can be readily extended to free-space quantum channels. The security analysis adopted to distill the keys ensures that the demonstrated protocol is robust against coherent attacks, finite-size effects, and a broad class of experimental imperfections identified in our system. PMID:29202028

Provably secure and high-rate quantum key distribution with time-bin qudits.

PubMed

Islam, Nurul T; Lim, Charles Ci Wen; Cahall, Clinton; Kim, Jungsang; Gauthier, Daniel J

2017-11-01

The security of conventional cryptography systems is threatened in the forthcoming era of quantum computers. Quantum key distribution (QKD) features fundamentally proven security and offers a promising option for quantum-proof cryptography solution. Although prototype QKD systems over optical fiber have been demonstrated over the years, the key generation rates remain several orders of magnitude lower than current classical communication systems. In an effort toward a commercially viable QKD system with improved key generation rates, we developed a discrete-variable QKD system based on time-bin quantum photonic states that can generate provably secure cryptographic keys at megabit-per-second rates over metropolitan distances. We use high-dimensional quantum states that transmit more than one secret bit per received photon, alleviating detector saturation effects in the superconducting nanowire single-photon detectors used in our system that feature very high detection efficiency (of more than 70%) and low timing jitter (of less than 40 ps). Our system is constructed using commercial off-the-shelf components, and the adopted protocol can be readily extended to free-space quantum channels. The security analysis adopted to distill the keys ensures that the demonstrated protocol is robust against coherent attacks, finite-size effects, and a broad class of experimental imperfections identified in our system.

Provably secure and high-rate quantum key distribution with time-bin qudits

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

Islam, Nurul T.; Lim, Charles Ci Wen; Cahall, Clinton

The security of conventional cryptography systems is threatened in the forthcoming era of quantum computers. Quantum key distribution (QKD) features fundamentally proven security and offers a promising option for quantum-proof cryptography solution. Although prototype QKD systems over optical fiber have been demonstrated over the years, the key generation rates remain several orders of magnitude lower than current classical communication systems. In an effort toward a commercially viable QKD system with improved key generation rates, we developed a discrete-variable QKD system based on time-bin quantum photonic states that can generate provably secure cryptographic keys at megabit-per-second rates over metropolitan distances. Wemore » use high-dimensional quantum states that transmit more than one secret bit per received photon, alleviating detector saturation effects in the superconducting nanowire single-photon detectors used in our system that feature very high detection efficiency (of more than 70%) and low timing jitter (of less than 40 ps). Our system is constructed using commercial off-the-shelf components, and the adopted protocol can be readily extended to free-space quantum channels. In conclusion, the security analysis adopted to distill the keys ensures that the demonstrated protocol is robust against coherent attacks, finite-size effects, and a broad class of experimental imperfections identified in our system.« less

Research on Electrically Driven Single Photon Emitter by Diamond for Quantum Cryptography

DTIC Science & Technology

2015-03-24

by diamond for quantum cryptography 5a. CONTRACT NUMBER FA2386-14-1-4037 5b. GRANT NUMBE R Grant 14IOA093_144037 5c. PROGRAM ELEMENT...emerged as a highly competitive platform for applications in quantum cryptography , quantum computing, spintronics, and sensing or metrology...15. SUBJECT TERMS Diamond LED, Nitrogen Vacancy Complex, Quantum Computing, Quantum Cryptography , Single Spin Single Photon 16. SECURITY

Secure Information Sharing and Processing (SISAP) Technology

DTIC Science & Technology

2015-08-03

Cryptography   SISAP   relies   heavily   on   commutative   or   cascadeable   cryptography .   This   is  when...commutative   cryptography   can   be   applied.   In   SISAP,   the   content   key  will   be  wrapped  with   the...Commutative   Cryptography ,  and   Private  Disjointness  Testing.  Thesis.  Massachusetts  Institute  of

Implementation of Rivest Shamir Adleman Algorithm (RSA) and Vigenere Cipher In Web Based Information System

NASA Astrophysics Data System (ADS)

Aryanti, Aryanti; Mekongga, Ikhthison

2018-02-01

Data security and confidentiality is one of the most important aspects of information systems at the moment. One attempt to secure data such as by using cryptography. In this study developed a data security system by implementing the cryptography algorithm Rivest, Shamir Adleman (RSA) and Vigenere Cipher. The research was done by combining Rivest, Shamir Adleman (RSA) and Vigenere Cipher cryptographic algorithms to document file either word, excel, and pdf. This application includes the process of encryption and decryption of data, which is created by using PHP software and my SQL. Data encryption is done on the transmit side through RSA cryptographic calculations using the public key, then proceed with Vigenere Cipher algorithm which also uses public key. As for the stage of the decryption side received by using the Vigenere Cipher algorithm still use public key and then the RSA cryptographic algorithm using a private key. Test results show that the system can encrypt files, decrypt files and transmit files. Tests performed on the process of encryption and decryption of files with different file sizes, file size affects the process of encryption and decryption. The larger the file size the longer the process of encryption and decryption.

Quantum Cryptography in Existing Telecommunications Infrastructure

NASA Astrophysics Data System (ADS)

Rogers, Daniel; Bienfang, Joshua; Mink, Alan; Hershman, Barry; Nakassis, Anastase; Tang, Xiao; Ma, Lijun; Su, David; Williams, Carl; Clark, Charles

2006-03-01

Quantum cryptography has shown the potential for ultra-secure communications. However, all systems demonstrated to date operate at speeds that make them impractical for performing continuous one-time-pad encryption of today's broadband communications. By adapting clock and data recovery techniques from modern telecommunications engineering practice, and by designing and implementing expeditious error correction and privacy amplification algorithms, we have demonstrated error-corrected and privacy-amplified key rates up to 1.0 Mbps over a free-space link with a 1.25 Gbps clock. Using new detectors with improved timing resolution, careful wavelength selection and an increased clock speed, we expect to quadruple the transmission rate over a 1.5 km free-space link. We have identified scalable solutions for delivering sustained one-time-pad encryption at 10 Mbps, thus making it possible to integrate quantum cryptography with first-generation Ethernet protocols.

Spectral coherent-state quantum cryptography.

PubMed

Cincotti, Gabriella; Spiekman, Leo; Wada, Naoya; Kitayama, Ken-ichi

2008-11-01

A novel implementation of quantum-noise optical cryptography is proposed, which is based on a simplified architecture that allows long-haul, high-speed transmission in a fiber optical network. By using a single multiport encoder/decoder and 16 phase shifters, this new approach can provide the same confidentiality as other implementations of Yuen's encryption protocol, which use a larger number of phase or polarization coherent states. Data confidentiality and error probability for authorized and unauthorized receivers are carefully analyzed.

Secure satellite communication using multi-photon tolerant quantum communication protocol

NASA Astrophysics Data System (ADS)

Darunkar, Bhagyashri; Punekar, Nikhil; Verma, Pramode K.

2015-09-01

This paper proposes and analyzes the potential of a multi-photon tolerant quantum communication protocol to secure satellite communication. For securing satellite communication, quantum cryptography is the only known unconditionally secure method. A number of recent experiments have shown feasibility of satellite-aided global quantum key distribution (QKD) using different methods such as: Use of entangled photon pairs, decoy state methods, and entanglement swapping. The use of single photon in these methods restricts the distance and speed over which quantum cryptography can be applied. Contemporary quantum cryptography protocols like the BB84 and its variants suffer from the limitation of reaching the distances of only Low Earth Orbit (LEO) at the data rates of few kilobits per second. This makes it impossible to develop a general satellite-based secure global communication network using the existing protocols. The method proposed in this paper allows secure communication at the heights of the Medium Earth Orbit (MEO) and Geosynchronous Earth Orbit (GEO) satellites. The benefits of the proposed method are two-fold: First it enables the realization of a secure global communication network based on satellites and second it provides unconditional security for satellite networks at GEO heights. The multi-photon approach discussed in this paper ameliorates the distance and speed issues associated with quantum cryptography through the use of contemporary laser communication (lasercom) devices. This approach can be seen as a step ahead towards global quantum communication.

Design and Implementation of KSP on the Next Generation Cryptography API

NASA Astrophysics Data System (ADS)

Lina, Zhang

With good seamless connectivity and higher safety, KSP (Key Storage Providers) is the inexorable trend of security requirements and development to take the place of CSP (Cryptographic Service Provider). But the study on KSP has just started in our country, and almost no reports of its implementation can be found. Based on the analysis of function modules and the architecture of Cryptography API (Next Generation (CNG)), this paper discusses the design and implementation of KSP (key storage providers) based on smart card in detail, and an example is also presented to illustrate how to use KSP in Windows Vista.

Deterministic and efficient quantum cryptography based on Bell's theorem

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

Chen Zengbing; Pan Jianwei; Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg

2006-05-15

We propose a double-entanglement-based quantum cryptography protocol that is both efficient and deterministic. The proposal uses photon pairs with entanglement both in polarization and in time degrees of freedom; each measurement in which both of the two communicating parties register a photon can establish one and only one perfect correlation, and thus deterministically create a key bit. Eavesdropping can be detected by violation of local realism. A variation of the protocol shows a higher security, similar to the six-state protocol, under individual attacks. Our scheme allows a robust implementation under the current technology.

Dynamics of neural cryptography

NASA Astrophysics Data System (ADS)

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-05-01

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

Hybrid Cryptosystem Using Tiny Encryption Algorithm and LUC Algorithm

NASA Astrophysics Data System (ADS)

Rachmawati, Dian; Sharif, Amer; Jaysilen; Andri Budiman, Mohammad

2018-01-01

Security becomes a very important issue in data transmission and there are so many methods to make files more secure. One of that method is cryptography. Cryptography is a method to secure file by writing the hidden code to cover the original file. Therefore, if the people do not involve in cryptography, they cannot decrypt the hidden code to read the original file. There are many methods are used in cryptography, one of that method is hybrid cryptosystem. A hybrid cryptosystem is a method that uses a symmetric algorithm to secure the file and use an asymmetric algorithm to secure the symmetric algorithm key. In this research, TEA algorithm is used as symmetric algorithm and LUC algorithm is used as an asymmetric algorithm. The system is tested by encrypting and decrypting the file by using TEA algorithm and using LUC algorithm to encrypt and decrypt the TEA key. The result of this research is by using TEA Algorithm to encrypt the file, the cipher text form is the character from ASCII (American Standard for Information Interchange) table in the form of hexadecimal numbers and the cipher text size increase by sixteen bytes as the plaintext length is increased by eight characters.

Dynamics of neural cryptography.

PubMed

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-05-01

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

Dynamics of neural cryptography

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

Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

2007-05-15

Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently,more » synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.« less

Can Smartphones and Privacy Coexist Assessing Technologies and Regulations Protecting Personal Data on Android and iOS Devices

DTIC Science & Technology

2016-01-01

does not find any critically private information. To What Extent Do Apps Use Cryptography or Transmit Nonessential Private Data? In a third experiment... cryptography and private data. Specifically, we analyzed 50 banking apps on both iOS and Android to understand how well these apps use cryptography . First...RAND’s Engineering and Applied Sciences Department. His research expertise includes applied cryptography and technology policy. Zev Winkelman is a

A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications

DTIC Science & Technology

2001-05-15

is based on a calculated test statistic value, which is a function of the data. If the test statistic value is S and the critical value is t, then...5 Defined in The Handbook of Applied Cryptography ; A. Menezes, P. Van Oorschot and S . Vanstone; CRC Press, 1997. The first 4...3rd ed. Reading: Addison-Wesley, Inc., pp. 61-80. [4] A. J. Menezes, P. C. van Oorschot, and S . A. Vanstone (1997), Handbook of Applied Cryptography

Comment on 'Two-way protocols for quantum cryptography with a nonmaximally entangled qubit pair'

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

Qin Sujuan; Gao Fei; Wen Qiaoyan

2010-09-15

Three protocols of quantum cryptography with a nonmaximally entangled qubit pair [Phys. Rev. A 80, 022323 (2009)] were recently proposed by Shimizu, Tamaki, and Fukasaka. The security of these protocols is based on the quantum-mechanical constraint for a state transformation between nonmaximally entangled states. However, we find that the second protocol is vulnerable under the correlation-elicitation attack. An eavesdropper can obtain the encoded bit M although she has no knowledge about the random bit R.

Calculator Cryptography.

ERIC Educational Resources Information Center

Hall, Matthew

2003-01-01

Uses cryptography to demonstrate the importance of algebra and the use of technology as an effective real application of mathematics. Explains simple encoding and decoding of messages for student learning of modular arithmetic. This elementary encounter with cryptography along with its historical and modern background serves to motivate student…

Threshold quantum cryptography

NASA Astrophysics Data System (ADS)

Tokunaga, Yuuki; Okamoto, Tatsuaki; Imoto, Nobuyuki

2005-01-01

We present the concept of threshold collaborative unitary transformation or threshold quantum cryptography, which is a kind of quantum version of threshold cryptography. Threshold quantum cryptography states that classical shared secrets are distributed to several parties and a subset of them, whose number is greater than a threshold, collaborates to compute a quantum cryptographic function, while keeping each share secretly inside each party. The shared secrets are reusable if no cheating is detected. As a concrete example of this concept, we show a distributed protocol (with threshold) of conjugate coding.

High-rate measurement-device-independent quantum cryptography

NASA Astrophysics Data System (ADS)

Pirandola, Stefano; Ottaviani, Carlo; Spedalieri, Gaetana; Weedbrook, Christian; Braunstein, Samuel L.; Lloyd, Seth; Gehring, Tobias; Jacobsen, Christian S.; Andersen, Ulrik L.

2015-06-01

Quantum cryptography achieves a formidable task—the remote distribution of secret keys by exploiting the fundamental laws of physics. Quantum cryptography is now headed towards solving the practical problem of constructing scalable and secure quantum networks. A significant step in this direction has been the introduction of measurement-device independence, where the secret key between two parties is established by the measurement of an untrusted relay. Unfortunately, although qubit-implemented protocols can reach long distances, their key rates are typically very low, unsuitable for the demands of a metropolitan network. Here we show, theoretically and experimentally, that a solution can come from the use of continuous-variable systems. We design a coherent-state network protocol able to achieve remarkably high key rates at metropolitan distances, in fact three orders of magnitude higher than those currently achieved. Our protocol could be employed to build high-rate quantum networks where devices securely connect to nearby access points or proxy servers.

About approximation of integer factorization problem by the combination fixed-point iteration method and Bayesian rounding for quantum cryptography

NASA Astrophysics Data System (ADS)

Ogorodnikov, Yuri; Khachay, Michael; Pljonkin, Anton

2018-04-01

We describe the possibility of employing the special case of the 3-SAT problem stemming from the well known integer factorization problem for the quantum cryptography. It is known, that for every instance of our 3-SAT setting the given 3-CNF is satisfiable by a unique truth assignment, and the goal is to find this assignment. Since the complexity status of the factorization problem is still undefined, development of approximation algorithms and heuristics adopts interest of numerous researchers. One of promising approaches to construction of approximation techniques is based on real-valued relaxation of the given 3-CNF followed by minimizing of the appropriate differentiable loss function, and subsequent rounding of the fractional minimizer obtained. Actually, algorithms developed this way differ by the rounding scheme applied on their final stage. We propose a new rounding scheme based on Bayesian learning. The article shows that the proposed method can be used to determine the security in quantum key distribution systems. In the quantum distribution the Shannon rules is applied and the factorization problem is paramount when decrypting secret keys.

Microscale optical cryptography using a subdiffraction-limit optical key

NASA Astrophysics Data System (ADS)

Ogura, Yusuke; Aino, Masahiko; Tanida, Jun

2018-04-01

We present microscale optical cryptography using a subdiffraction-limit optical pattern, which is finer than the diffraction-limit size of the decrypting optical system, as a key and a substrate with a reflectance distribution as an encrypted image. Because of the subdiffraction-limit spatial coding, this method enables us to construct a secret image with the diffraction-limit resolution. Simulation and experimental results demonstrate, both qualitatively and quantitatively, that the secret image becomes recognizable when and only when the substrate is illuminated with the designed key pattern.

Public classical communication in quantum cryptography: Error correction, integrity, and authentication

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

Timofeev, A. V.; Pomozov, D. I.; Makkaveev, A. P.

2007-05-15

Quantum cryptography systems combine two communication channels: a quantum and a classical one. (They can be physically implemented in the same fiber-optic link, which is employed as a quantum channel when one-photon states are transmitted and as a classical one when it carries classical data traffic.) Both channels are supposed to be insecure and accessible to an eavesdropper. Error correction in raw keys, interferometer balancing, and other procedures are performed by using the public classical channel. A discussion of the requirements to be met by the classical channel is presented.

DNA-Cryptography-Based Obfuscated Systolic Finite Field Multiplier for Secure Cryptosystem in Smart Grid

NASA Astrophysics Data System (ADS)

Chen, Shaobo; Chen, Pingxiuqi; Shao, Qiliang; Basha Shaik, Nazeem; Xie, Jiafeng

2017-05-01

The elliptic curve cryptography (ECC) provides much stronger security per bits compared to the traditional cryptosystem, and hence it is an ideal role in secure communication in smart grid. On the other side, secure implementation of finite field multiplication over GF(2 m ) is considered as the bottle neck of ECC. In this paper, we present a novel obfuscation strategy for secure implementation of systolic field multiplier for ECC in smart grid. First, for the first time, we propose a novel obfuscation technique to derive a novel obfuscated systolic finite field multiplier for ECC implementation. Then, we employ the DNA cryptography coding strategy to obfuscate the field multiplier further. Finally, we obtain the area-time-power complexity of the proposed field multiplier to confirm the efficiency of the proposed design. The proposed design is highly obfuscated with low overhead, suitable for secure cryptosystem in smart grid.

Optical cryptography topology based on a three-dimensional particle-like distribution and diffractive imaging.

PubMed

Chen, Wen; Chen, Xudong

2011-05-09

In recent years, coherent diffractive imaging has been considered as a promising alternative for information retrieval instead of conventional interference methods. Coherent diffractive imaging using the X-ray light source has opened up a new research perspective for the measurement of non-crystalline and biological specimens, and can achieve unprecedentedly high resolutions. In this paper, we show how a three-dimensional (3D) particle-like distribution and coherent diffractive imaging can be applied for a study of optical cryptography. An optical multiple-random-phase-mask encoding approach is used, and the plaintext is considered as a series of particles distributed in a 3D space. A topology concept is also introduced into the proposed optical cryptosystem. During image decryption, a retrieval algorithm is developed to extract the plaintext from the ciphertexts. In addition, security and advantages of the proposed optical cryptography topology are also analyzed. © 2011 Optical Society of America

A Game Theory Based Solution for Security Challenges in CRNs

NASA Astrophysics Data System (ADS)

Poonam; Nagpal, Chander Kumar

2018-03-01

Cognitive radio networks (CRNs) are being envisioned to drive the next generation Ad hoc wireless networks due to their ability to provide communications resilience in continuously changing environments through the use of dynamic spectrum access. Conventionally CRNs are dependent upon the information gathered by other secondary users to ensure the accuracy of spectrum sensing making them vulnerable to security attacks leading to the need of security mechanisms like cryptography and trust. However, a typical cryptography based solution is not a viable security solution for CRNs owing to their limited resources. Effectiveness of trust based approaches has always been, in question, due to credibility of secondary trust resources. Game theory with its ability to optimize in an environment of conflicting interests can be quite a suitable tool to manage an ad hoc network in the presence of autonomous selfish/malevolent/malicious and attacker nodes. The literature contains several theoretical proposals for augmenting game theory in the ad hoc networks without explicit/detailed implementation. This paper implements a game theory based solution in MATLAB-2015 to secure the CRN environment and compares the obtained results with the traditional approaches of trust and cryptography. The simulation result indicates that as the time progresses the game theory performs much better with higher throughput, lower jitter and better identification of selfish/malicious nodes.

DNA-based cryptographic methods for data hiding in DNA media.

PubMed

Marwan, Samiha; Shawish, Ahmed; Nagaty, Khaled

2016-12-01

Information security can be achieved using cryptography, steganography or a combination of them, where data is firstly encrypted using any of the available cryptography techniques and then hid into any hiding medium. Recently, the famous genomic DNA has been introduced as a hiding medium, known as DNA steganography, due to its notable ability to hide huge data sets with a high level of randomness and hence security. Despite the numerous cryptography techniques, to our knowledge only the vigenere cipher and the DNA-based playfair cipher have been combined with the DNA steganography, which keeps space for investigation of other techniques and coming up with new improvements. This paper presents a comprehensive analysis between the DNA-based playfair, vigenere, RSA and the AES ciphers, each combined with a DNA hiding technique. The conducted analysis reports the performance diversity of each combined technique in terms of security, speed, hiding capacity in addition to both key size and data size. Moreover, this paper proposes a modification of the current combined DNA-based playfair cipher technique, which makes it not only simple and fast but also provides a significantly higher hiding capacity and security. The conducted extensive experimental studies confirm such outstanding performance in comparison with all the discussed combined techniques. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Towards secure quantum key distribution protocol for wireless LANs: a hybrid approach

NASA Astrophysics Data System (ADS)

Naik, R. Lalu; Reddy, P. Chenna

2015-12-01

The primary goals of security such as authentication, confidentiality, integrity and non-repudiation in communication networks can be achieved with secure key distribution. Quantum mechanisms are highly secure means of distributing secret keys as they are unconditionally secure. Quantum key distribution protocols can effectively prevent various attacks in the quantum channel, while classical cryptography is efficient in authentication and verification of secret keys. By combining both quantum cryptography and classical cryptography, security of communications over networks can be leveraged. Hwang, Lee and Li exploited the merits of both cryptographic paradigms for provably secure communications to prevent replay, man-in-the-middle, and passive attacks. In this paper, we propose a new scheme with the combination of quantum cryptography and classical cryptography for 802.11i wireless LANs. Since quantum cryptography is premature in wireless networks, our work is a significant step forward toward securing communications in wireless networks. Our scheme is known as hybrid quantum key distribution protocol. Our analytical results revealed that the proposed scheme is provably secure for wireless networks.

Implementation of Digital Signature Using Aes and Rsa Algorithms as a Security in Disposition System af Letter

NASA Astrophysics Data System (ADS)

Siregar, H.; Junaeti, E.; Hayatno, T.

2017-03-01

Activities correspondence is often used by agencies or companies, so that institutions or companies set up a special division to handle issues related to the letter management. Most of the distribution of letters using electronic media, then the letter should be kept confidential in order to avoid things that are not desirable. Techniques that can be done to meet the security aspect is by using cryptography or by giving a digital signature. The addition of asymmetric and symmetric algorithms, i.e. RSA and AES algorithms, on the digital signature had been done in this study to maintain data security. The RSA algorithm was used during the process of giving digital signature, while the AES algorithm was used during the process of encoding a message that will be sent to the receiver. Based on the research can be concluded that the additions of AES and RSA algorithms on the digital signature meet four objectives of cryptography: Secrecy, Data Integrity, Authentication and Non-repudiation.

Cooperating attackers in neural cryptography.

PubMed

Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

2004-06-01

A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

On protection against a bright-pulse attack in the two-pass quantum cryptography system

NASA Astrophysics Data System (ADS)

Balygin, K. A.; Klimov, A. N.; Korol'kov, A. V.; Kulik, S. P.; Molotkov, S. N.

2016-06-01

The security of keys in quantum cryptography systems, in contrast to mathematical cryptographic algorithms, is guaranteed by fundamental quantum-mechanical laws. However, the cryptographic resistance of such systems, which are distributed physical devices, fundamentally depends on the method of their implementation and particularly on the calibration and control of critical parameters. The most important parameter is the number of photons in quasi-single-photon information states in a communication channel. The sensitivity to a bright-pulse attack has been demonstrated in an explicit form for a number of systems. A method guaranteeing the resistance to such attacks has been proposed and implemented. Furthermore, the relation of physical observables used and obtained at the control of quantum states to the length of final secret keys has been obtained for the first time.

High-chroma visual cryptography using interference color of high-order retarder films

NASA Astrophysics Data System (ADS)

Sugawara, Shiori; Harada, Kenji; Sakai, Daisuke

2015-08-01

Visual cryptography can be used as a method of sharing a secret image through several encrypted images. Conventional visual cryptography can display only monochrome images. We have developed a high-chroma color visual encryption technique using the interference color of high-order retarder films. The encrypted films are composed of a polarizing film and retarder films. The retarder films exhibit interference color when they are sandwiched between two polarizing films. We propose a stacking technique for displaying high-chroma interference color images. A prototype visual cryptography device using high-chroma interference color is developed.

Optical double-image cryptography based on diffractive imaging with a laterally-translated phase grating.

PubMed

Chen, Wen; Chen, Xudong; Sheppard, Colin J R

2011-10-10

In this paper, we propose a method using structured-illumination-based diffractive imaging with a laterally-translated phase grating for optical double-image cryptography. An optical cryptosystem is designed, and multiple random phase-only masks are placed in the optical path. When a phase grating is laterally translated just before the plaintexts, several diffraction intensity patterns (i.e., ciphertexts) can be correspondingly obtained. During image decryption, an iterative retrieval algorithm is developed to extract plaintexts from the ciphertexts. In addition, security and advantages of the proposed method are analyzed. Feasibility and effectiveness of the proposed method are demonstrated by numerical simulation results. © 2011 Optical Society of America

Information hiding based on double random-phase encoding and public-key cryptography.

PubMed

Sheng, Yuan; Xin, Zhou; Alam, Mohammed S; Xi, Lu; Xiao-Feng, Li

2009-03-02

A novel information hiding method based on double random-phase encoding (DRPE) and Rivest-Shamir-Adleman (RSA) public-key cryptosystem is proposed. In the proposed technique, the inherent diffusion property of DRPE is cleverly utilized to make up the diffusion insufficiency of RSA public-key cryptography, while the RSA cryptosystem is utilized for simultaneous transmission of the cipher text and the two phase-masks, which is not possible under the DRPE technique. This technique combines the complementary advantages of the DPRE and RSA encryption techniques and brings security and convenience for efficient information transmission. Extensive numerical simulation results are presented to verify the performance of the proposed technique.

Field test of a practical secure communication network with decoy-state quantum cryptography.

PubMed

Chen, Teng-Yun; Liang, Hao; Liu, Yang; Cai, Wen-Qi; Ju, Lei; Liu, Wei-Yue; Wang, Jian; Yin, Hao; Chen, Kai; Chen, Zeng-Bing; Peng, Cheng-Zhi; Pan, Jian-Wei

2009-04-13

We present a secure network communication system that operated with decoy-state quantum cryptography in a real-world application scenario. The full key exchange and application protocols were performed in real time among three nodes, in which two adjacent nodes were connected by approximate 20 km of commercial telecom optical fiber. The generated quantum keys were immediately employed and demonstrated for communication applications, including unbreakable real-time voice telephone between any two of the three communication nodes, or a broadcast from one node to the other two nodes by using one-time pad encryption.

Counterfactual quantum cryptography.

PubMed

Noh, Tae-Gon

2009-12-04

Quantum cryptography allows one to distribute a secret key between two remote parties using the fundamental principles of quantum mechanics. The well-known established paradigm for the quantum key distribution relies on the actual transmission of signal particle through a quantum channel. In this Letter, we show that the task of a secret key distribution can be accomplished even though a particle carrying secret information is not in fact transmitted through the quantum channel. The proposed protocols can be implemented with current technologies and provide practical security advantages by eliminating the possibility that an eavesdropper can directly access the entire quantum system of each signal particle.

Counterfactual Quantum Cryptography

NASA Astrophysics Data System (ADS)

Noh, Tae-Gon

2009-12-01

Quantum cryptography allows one to distribute a secret key between two remote parties using the fundamental principles of quantum mechanics. The well-known established paradigm for the quantum key distribution relies on the actual transmission of signal particle through a quantum channel. In this Letter, we show that the task of a secret key distribution can be accomplished even though a particle carrying secret information is not in fact transmitted through the quantum channel. The proposed protocols can be implemented with current technologies and provide practical security advantages by eliminating the possibility that an eavesdropper can directly access the entire quantum system of each signal particle.

Disorder generated by interacting neural networks: application to econophysics and cryptography

NASA Astrophysics Data System (ADS)

Kinzel, Wolfgang; Kanter, Ido

2003-10-01

When neural networks are trained on their own output signals they generate disordered time series. In particular, when two neural networks are trained on their mutual output they can synchronize; they relax to a time-dependent state with identical synaptic weights. Two applications of this phenomenon are discussed for (a) econophysics and (b) cryptography. (a) When agents competing in a closed market (minority game) are using neural networks to make their decisions, the total system relaxes to a state of good performance. (b) Two partners communicating over a public channel can find a common secret key.

2D non-separable linear canonical transform (2D-NS-LCT) based cryptography

NASA Astrophysics Data System (ADS)

Zhao, Liang; Muniraj, Inbarasan; Healy, John J.; Malallah, Ra'ed; Cui, Xiao-Guang; Ryle, James P.; Sheridan, John T.

2017-05-01

The 2D non-separable linear canonical transform (2D-NS-LCT) can describe a variety of paraxial optical systems. Digital algorithms to numerically evaluate the 2D-NS-LCTs are not only important in modeling the light field propagations but also of interest in various signal processing based applications, for instance optical encryption. Therefore, in this paper, for the first time, a 2D-NS-LCT based optical Double-random- Phase-Encryption (DRPE) system is proposed which offers encrypting information in multiple degrees of freedom. Compared with the traditional systems, i.e. (i) Fourier transform (FT); (ii) Fresnel transform (FST); (iii) Fractional Fourier transform (FRT); and (iv) Linear Canonical transform (LCT), based DRPE systems, the proposed system is more secure and robust as it encrypts the data with more degrees of freedom with an augmented key-space.

Optical heterodyne accelerometry: passively stabilized, fully balanced velocity interferometer system for any reflector

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

Buttler, William T.; Lamoreaux, Steven K.

2010-08-10

We formalize the physics of an optical heterodyne accelerometer that allows measurement of low and high velocities from material surfaces under high strain. The proposed apparatus incorporates currently common optical velocimetry techniques used in shock physics, with interferometric techniques developed to self-stabilize and passively balance interferometers in quantum cryptography. The result is a robust telecom-fiber-based velocimetry system insensitive to modal and frequency dispersion that should work well in the presence of decoherent scattering processes, such as from ejecta clouds and shocked surfaces.

Image encryption based on nonlinear encryption system and public-key cryptography

NASA Astrophysics Data System (ADS)

Zhao, Tieyu; Ran, Qiwen; Chi, Yingying

2015-03-01

Recently, optical asymmetric cryptosystem (OACS) has became the focus of discussion and concern of researchers. Some researchers pointed out that OACS was not tenable because of misunderstanding the concept of asymmetric cryptosystem (ACS). We propose an improved cryptosystem using RSA public-key algorithm based on existing OACS and the new system conforms to the basic agreement of public key cryptosystem. At the beginning of the encryption process, the system will produce an independent phase matrix and allocate the input image, which also conforms to one-time pad cryptosystem. The simulation results show that the validity of the improved cryptosystem and the high robustness against attack scheme using phase retrieval technique.

Fast and simple high-capacity quantum cryptography with error detection

PubMed Central

Lai, Hong; Luo, Ming-Xing; Pieprzyk, Josef; Zhang, Jun; Pan, Lei; Li, Shudong; Orgun, Mehmet A.

2017-01-01

Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where a symmetric cryptography component consumes the shared key. That is, the security of the symmetric cryptography demands frequent rate of key updates, which leads to a higher consumption of the internal one-time-pad communication bandwidth, since it requires the length of the key to be as long as that of the secret. In order to alleviate these issues, we develop a matrix algorithm for fast and simple high-capacity quantum cryptography. Our scheme can achieve secure private communication with fresh keys generated from Fibonacci- and Lucas- valued orbital angular momentum (OAM) states for the seed to construct recursive Fibonacci and Lucas matrices. Moreover, the proposed matrix algorithm for quantum cryptography can ultimately be simplified to matrix multiplication, which is implemented and optimized in modern computers. Most importantly, considerably information capacity can be improved effectively and efficiently by the recursive property of Fibonacci and Lucas matrices, thereby avoiding the restriction of physical conditions, such as the communication bandwidth. PMID:28406240

Fast and simple high-capacity quantum cryptography with error detection.

PubMed

Lai, Hong; Luo, Ming-Xing; Pieprzyk, Josef; Zhang, Jun; Pan, Lei; Li, Shudong; Orgun, Mehmet A

2017-04-13

Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where a symmetric cryptography component consumes the shared key. That is, the security of the symmetric cryptography demands frequent rate of key updates, which leads to a higher consumption of the internal one-time-pad communication bandwidth, since it requires the length of the key to be as long as that of the secret. In order to alleviate these issues, we develop a matrix algorithm for fast and simple high-capacity quantum cryptography. Our scheme can achieve secure private communication with fresh keys generated from Fibonacci- and Lucas- valued orbital angular momentum (OAM) states for the seed to construct recursive Fibonacci and Lucas matrices. Moreover, the proposed matrix algorithm for quantum cryptography can ultimately be simplified to matrix multiplication, which is implemented and optimized in modern computers. Most importantly, considerably information capacity can be improved effectively and efficiently by the recursive property of Fibonacci and Lucas matrices, thereby avoiding the restriction of physical conditions, such as the communication bandwidth.

Fast and simple high-capacity quantum cryptography with error detection

NASA Astrophysics Data System (ADS)

Lai, Hong; Luo, Ming-Xing; Pieprzyk, Josef; Zhang, Jun; Pan, Lei; Li, Shudong; Orgun, Mehmet A.

2017-04-01

Quantum cryptography is commonly used to generate fresh secure keys with quantum signal transmission for instant use between two parties. However, research shows that the relatively low key generation rate hinders its practical use where a symmetric cryptography component consumes the shared key. That is, the security of the symmetric cryptography demands frequent rate of key updates, which leads to a higher consumption of the internal one-time-pad communication bandwidth, since it requires the length of the key to be as long as that of the secret. In order to alleviate these issues, we develop a matrix algorithm for fast and simple high-capacity quantum cryptography. Our scheme can achieve secure private communication with fresh keys generated from Fibonacci- and Lucas- valued orbital angular momentum (OAM) states for the seed to construct recursive Fibonacci and Lucas matrices. Moreover, the proposed matrix algorithm for quantum cryptography can ultimately be simplified to matrix multiplication, which is implemented and optimized in modern computers. Most importantly, considerably information capacity can be improved effectively and efficiently by the recursive property of Fibonacci and Lucas matrices, thereby avoiding the restriction of physical conditions, such as the communication bandwidth.

Optical asymmetric cryptography based on amplitude reconstruction of elliptically polarized light

NASA Astrophysics Data System (ADS)

Cai, Jianjun; Shen, Xueju; Lei, Ming

2017-11-01

We propose a novel optical asymmetric image encryption method based on amplitude reconstruction of elliptically polarized light, which is free from silhouette problem. The original image is analytically separated into two phase-only masks firstly, and then the two masks are encoded into amplitudes of the orthogonal polarization components of an elliptically polarized light. Finally, the elliptically polarized light propagates through a linear polarizer, and the output intensity distribution is recorded by a CCD camera to obtain the ciphertext. The whole encryption procedure could be implemented by using commonly used optical elements, and it combines diffusion process and confusion process. As a result, the proposed method achieves high robustness against iterative-algorithm-based attacks. Simulation results are presented to prove the validity of the proposed cryptography.

An efficient RFID authentication protocol to enhance patient medication safety using elliptic curve cryptography.

PubMed

Zhang, Zezhong; Qi, Qingqing

2014-05-01

Medication errors are very dangerous even fatal since it could cause serious even fatal harm to patients. In order to reduce medication errors, automated patient medication systems using the Radio Frequency Identification (RFID) technology have been used in many hospitals. The data transmitted in those medication systems is very important and sensitive. In the past decade, many security protocols have been proposed to ensure its secure transition attracted wide attention. Due to providing mutual authentication between the medication server and the tag, the RFID authentication protocol is considered as the most important security protocols in those systems. In this paper, we propose a RFID authentication protocol to enhance patient medication safety using elliptic curve cryptography (ECC). The analysis shows the proposed protocol could overcome security weaknesses in previous protocols and has better performance. Therefore, the proposed protocol is very suitable for automated patient medication systems.

Fourier-based automatic alignment for improved Visual Cryptography schemes.

PubMed

Machizaud, Jacques; Chavel, Pierre; Fournel, Thierry

2011-11-07

In Visual Cryptography, several images, called "shadow images", that separately contain no information, are overlapped to reveal a shared secret message. We develop a method to digitally register one printed shadow image acquired by a camera with a purely digital shadow image, stored in memory. Using Fourier techniques derived from Fourier Optics concepts, the idea is to enhance and exploit the quasi periodicity of the shadow images, composed by a random distribution of black and white patterns on a periodic sampling grid. The advantage is to speed up the security control or the access time to the message, in particular in the cases of a small pixel size or of large numbers of pixels. Furthermore, the interest of visual cryptography can be increased by embedding the initial message in two shadow images that do not have identical mathematical supports, making manual registration impractical. Experimental results demonstrate the successful operation of the method, including the possibility to directly project the result onto the printed shadow image.

Novel single photon sources for new generation of quantum communications

DTIC Science & Technology

2017-06-13

be used as building blocks for quantum cryptography and quantum key distribution There were numerous important achievements for the projects in the...single photon sources that will be used as build- ing blocks for quantum cryptography and quantum key distribution There were numerous im- portant...and enable absolutely secured information transfer between distant nodes – key prerequisite for quantum cryptography . Experiment: the experimental

Nonquadratic Variation of the Blum Blum Shub Pseudorandom Number Generator

DTIC Science & Technology

2016-09-01

maximum 200 words) Cryptography is essential for secure online communications. Many different types of ciphers are implemented in modern-day... cryptography , but they all have one common factor. All ciphers require a source of randomness, which makes them unpre- dictable. One such source of this...Martinsen Second Reader Craig Rasmussen Chair, Department of Applied Mathematics iii THIS PAGE INTENTIONALLY LEFT BLANK iv ABSTRACT Cryptography is

Security analysis of quadratic phase based cryptography

NASA Astrophysics Data System (ADS)

Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Healy, John J.; Sheridan, John T.

2016-09-01

The linear canonical transform (LCT) is essential in modeling a coherent light field propagation through first-order optical systems. Recently, a generic optical system, known as a Quadratic Phase Encoding System (QPES), for encrypting a two-dimensional (2D) image has been reported. It has been reported together with two phase keys the individual LCT parameters serve as keys of the cryptosystem. However, it is important that such the encryption systems also satisfies some dynamic security properties. Therefore, in this work, we examine some cryptographic evaluation methods, such as Avalanche Criterion and Bit Independence, which indicates the degree of security of the cryptographic algorithms on QPES. We compare our simulation results with the conventional Fourier and the Fresnel transform based DRPE systems. The results show that the LCT based DRPE has an excellent avalanche and bit independence characteristics than that of using the conventional Fourier and Fresnel based encryption systems.

Optical asymmetric cryptography based on elliptical polarized light linear truncation and a numerical reconstruction technique.

PubMed

Lin, Chao; Shen, Xueju; Wang, Zhisong; Zhao, Cheng

2014-06-20

We demonstrate a novel optical asymmetric cryptosystem based on the principle of elliptical polarized light linear truncation and a numerical reconstruction technique. The device of an array of linear polarizers is introduced to achieve linear truncation on the spatially resolved elliptical polarization distribution during image encryption. This encoding process can be characterized as confusion-based optical cryptography that involves no Fourier lens and diffusion operation. Based on the Jones matrix formalism, the intensity transmittance for this truncation is deduced to perform elliptical polarized light reconstruction based on two intensity measurements. Use of a quick response code makes the proposed cryptosystem practical, with versatile key sensitivity and fault tolerance. Both simulation and preliminary experimental results that support theoretical analysis are presented. An analysis of the resistance of the proposed method on a known public key attack is also provided.

Quantum cryptography approaching the classical limit.

PubMed

Weedbrook, Christian; Pirandola, Stefano; Lloyd, Seth; Ralph, Timothy C

2010-09-10

We consider the security of continuous-variable quantum cryptography as we approach the classical limit, i.e., when the unknown preparation noise at the sender's station becomes significantly noisy or thermal (even by as much as 10(4) times greater than the variance of the vacuum mode). We show that, provided the channel transmission losses do not exceed 50%, the security of quantum cryptography is not dependent on the channel transmission, and is therefore incredibly robust against significant amounts of excess preparation noise. We extend these results to consider for the first time quantum cryptography at wavelengths considerably longer than optical and find that regions of security still exist all the way down to the microwave.

Laser damage helps the eavesdropper in quantum cryptography.

PubMed

Bugge, Audun Nystad; Sauge, Sebastien; Ghazali, Aina Mardhiyah M; Skaar, Johannes; Lydersen, Lars; Makarov, Vadim

2014-02-21

We propose a class of attacks on quantum key distribution (QKD) systems where an eavesdropper actively engineers new loopholes by using damaging laser illumination to permanently change properties of system components. This can turn a perfect QKD system into a completely insecure system. A proof-of-principle experiment performed on an avalanche photodiode-based detector shows that laser damage can be used to create loopholes. After ∼1  W illumination, the detectors' dark count rate reduces 2-5 times, permanently improving single-photon counting performance. After ∼1.5  W, the detectors switch permanently into the linear photodetection mode and become completely insecure for QKD applications.

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.

An Implementation of RC4+ Algorithm and Zig-zag Algorithm in a Super Encryption Scheme for Text Security

NASA Astrophysics Data System (ADS)

Budiman, M. A.; Amalia; Chayanie, N. I.

2018-03-01

Cryptography is the art and science of using mathematical methods to preserve message security. There are two types of cryptography, namely classical and modern cryptography. Nowadays, most people would rather use modern cryptography than classical cryptography because it is harder to break than the classical one. One of classical algorithm is the Zig-zag algorithm that uses the transposition technique: the original message is unreadable unless the person has the key to decrypt the message. To improve the security, the Zig-zag Cipher is combined with RC4+ Cipher which is one of the symmetric key algorithms in the form of stream cipher. The two algorithms are combined to make a super-encryption. By combining these two algorithms, the message will be harder to break by a cryptanalyst. The result showed that complexity of the combined algorithm is θ(n2 ), while the complexity of Zig-zag Cipher and RC4+ Cipher are θ(n2 ) and θ(n), respectively.

Multiprime Blum-Blum-Shub Pseudorandom Number Generator

DTIC Science & Technology

2016-09-01

Cryptography , National Institute of Standards and Technology Tests 15. NUMBER OF PAGES 83 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18...1: Introduction Cryptography is a part of our daily lives. Many digital communications require secrecy and authentication over open channels such as...security, of which cryptography is an intrinsic part. Encryption is the process of transforming data, in the form of plaintext, into ciphertext using a

Federation for a Secure Enterprise

DTIC Science & Technology

2016-09-10

12 October 2005 e. RFC Internet X.509 Public Key Infrastructure: Certification Path Building, 2005 f. Public Key Cryptography Standard, PKCS #1...v2.2: RSA Cryptography Standard, RSA Laboratories, October 27, 2012 g. PKCS#12 format PKCS #12 v1.0: Personal Information Exchange Syntax Standard, RSA...ClientHello padding extension, 2015-02-17 f. Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS) Versions 1.2 and Earlier

COALA-System for Visual Representation of Cryptography Algorithms

ERIC Educational Resources Information Center

Stanisavljevic, Zarko; Stanisavljevic, Jelena; Vuletic, Pavle; Jovanovic, Zoran

2014-01-01

Educational software systems have an increasingly significant presence in engineering sciences. They aim to improve students' attitudes and knowledge acquisition typically through visual representation and simulation of complex algorithms and mechanisms or hardware systems that are often not available to the educational institutions. This paper…

Full-field implementation of a perfect eavesdropper on a quantum cryptography system.

PubMed

Gerhardt, Ilja; Liu, Qin; Lamas-Linares, Antía; Skaar, Johannes; Kurtsiefer, Christian; Makarov, Vadim

2011-06-14

Quantum key distribution (QKD) allows two remote parties to grow a shared secret key. Its security is founded on the principles of quantum mechanics, but in reality it significantly relies on the physical implementation. Technological imperfections of QKD systems have been previously explored, but no attack on an established QKD connection has been realized so far. Here we show the first full-field implementation of a complete attack on a running QKD connection. An installed eavesdropper obtains the entire 'secret' key, while none of the parameters monitored by the legitimate parties indicate a security breach. This confirms that non-idealities in physical implementations of QKD can be fully practically exploitable, and must be given increased scrutiny if quantum cryptography is to become highly secure.

Secure self-calibrating quantum random-bit generator

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

Fiorentino, M.; Santori, C.; Spillane, S. M.

2007-03-15

Random-bit generators (RBGs) are key components of a variety of information processing applications ranging from simulations to cryptography. In particular, cryptographic systems require 'strong' RBGs that produce high-entropy bit sequences, but traditional software pseudo-RBGs have very low entropy content and therefore are relatively weak for cryptography. Hardware RBGs yield entropy from chaotic or quantum physical systems and therefore are expected to exhibit high entropy, but in current implementations their exact entropy content is unknown. Here we report a quantum random-bit generator (QRBG) that harvests entropy by measuring single-photon and entangled two-photon polarization states. We introduce and implement a quantum tomographicmore » method to measure a lower bound on the 'min-entropy' of the system, and we employ this value to distill a truly random-bit sequence. This approach is secure: even if an attacker takes control of the source of optical states, a secure random sequence can be distilled.« less

Continuous variable quantum cryptography: beating the 3 dB loss limit.

PubMed

Silberhorn, Ch; Ralph, T C; Lütkenhaus, N; Leuchs, G

2002-10-14

We demonstrate that secure quantum key distribution systems based on continuous variable implementations can operate beyond the apparent 3 dB loss limit that is implied by the beam splitting attack. The loss limit was established for standard minimum uncertainty states such as coherent states. We show that, by an appropriate postselection mechanism, we can enter a region where Eve's knowledge on Alice's key falls behind the information shared between Alice and Bob, even in the presence of substantial losses.

Hybrid ququart-encoded quantum cryptography protected by Kochen-Specker contextuality

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

Cabello, Adan; Department of Physics, Stockholm University, S-10691 Stockholm; D'Ambrosio, Vincenzo

2011-09-15

Quantum cryptographic protocols based on complementarity are not secure against attacks in which complementarity is imitated with classical resources. The Kochen-Specker (KS) theorem provides protection against these attacks, without requiring entanglement or spatially separated composite systems. We analyze the maximum tolerated noise to guarantee the security of a KS-protected cryptographic scheme against these attacks and describe a photonic realization of this scheme using hybrid ququarts defined by the polarization and orbital angular momentum of single photons.

Device-independent two-party cryptography secure against sequential attacks

NASA Astrophysics Data System (ADS)

Kaniewski, Jędrzej; Wehner, Stephanie

2016-05-01

The goal of two-party cryptography is to enable two parties, Alice and Bob, to solve common tasks without the need for mutual trust. Examples of such tasks are private access to a database, and secure identification. Quantum communication enables security for all of these problems in the noisy-storage model by sending more signals than the adversary can store in a certain time frame. Here, we initiate the study of device-independent (DI) protocols for two-party cryptography in the noisy-storage model. Specifically, we present a relatively easy to implement protocol for a cryptographic building block known as weak string erasure and prove its security even if the devices used in the protocol are prepared by the dishonest party. DI two-party cryptography is made challenging by the fact that Alice and Bob do not trust each other, which requires new techniques to establish security. We fully analyse the case of memoryless devices (for which sequential attacks are optimal) and the case of sequential attacks for arbitrary devices. The key ingredient of the proof, which might be of independent interest, is an explicit (and tight) relation between the violation of the Clauser-Horne-Shimony-Holt inequality observed by Alice and Bob and uncertainty generated by Alice against Bob who is forced to measure his system before finding out Alice’s setting (guessing with postmeasurement information). In particular, we show that security is possible for arbitrarily small violation.

Information security system based on virtual-optics imaging methodology and public key infrastructure

NASA Astrophysics Data System (ADS)

Peng, Xiang; Zhang, Peng; Cai, Lilong

In this paper, we present a virtual-optical based information security system model with the aid of public-key-infrastructure (PKI) techniques. The proposed model employs a hybrid architecture in which our previously published encryption algorithm based on virtual-optics imaging methodology (VOIM) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). For an asymmetric system, given an encryption key, it is computationally infeasible to determine the decryption key and vice versa. The whole information security model is run under the framework of PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOIM security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network.

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

AISL-CRYPTO is a library of cryptography functions supporting other AISL software. It provides various crypto functions for Common Lisp, including Digital Signature Algorithm, Data Encryption Standard, Secure Hash Algorithm, and public-key cryptography.

Access Scheme for Controlling Mobile Agents and its Application to Share Medical Information.

PubMed

Liao, Yu-Ting; Chen, Tzer-Shyong; Chen, Tzer-Long; Chung, Yu-Fang; Chen, Yu- Xin; Hwang, Jen-Hung; Wang, Huihui; Wei, Wei

2016-05-01

This study is showing the advantage of mobile agents to conquer heterogeneous system environments and contribute to a virtual integrated sharing system. Mobile agents will collect medical information from each medical institution as a method to achieve the medical purpose of data sharing. Besides, this research also provides an access control and key management mechanism by adopting Public key cryptography and Lagrange interpolation. The safety analysis of the system is based on a network attacker's perspective. The achievement of this study tries to improve the medical quality, prevent wasting medical resources and make medical resources access to appropriate configuration.

The Integrity of Digital Information: Mechanics and Definitional Issues.

ERIC Educational Resources Information Center

Lynch, Clifford A.

1994-01-01

Considers issues regarding the migration of a system of literature into electronic formats. Highlights include integrity in an information distribution system; digest technology; tracings that permit detection of copied digital objects; verifying sources; digital signature technology and cryptography; electronic publishing; and intellectual…

Confidential and Authenticated Communications in a Large Fixed-Wing UAV Swarm

DTIC Science & Technology

2016-12-01

either a UAV or a ground station. Asymmetric cryptography is not an option for swarm communications. It is a potential option for initially keying or...each UAV grows ten bytes for each UAV in the swarm, and a 30% overhead is added on for worst case cryptography . The resulting throughput is...analysis in Section IV, we can predict the burden that cryptography places on the ODroid computer. Given that the average unencrypted message size was

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.

Small Private Key PKS on an Embedded Microprocessor

PubMed Central

Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon

2014-01-01

Multivariate quadratic ( ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012. PMID:24651722

Small private key MQPKS on an embedded microprocessor.

PubMed

Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon

2014-03-19

Multivariate quadratic (MQ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key MQ scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing MQ on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key MQ scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012.

78 FR 14233 - Electronic Retirement Processing

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-05

.... Public/private key (asymmetric) cryptography is a method of creating a unique mark, known as a digital... delivering a broad array of administrative services to multiple agencies. Shared symmetric key cryptography...

Quantum discord as a resource for quantum cryptography.

PubMed

Pirandola, Stefano

2014-11-07

Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper.

Quantum discord as a resource for quantum cryptography

PubMed Central

Pirandola, Stefano

2014-01-01

Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper. PMID:25378231

Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

PubMed

Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

2010-08-16

Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

Quantum cryptography: The power of independence

NASA Astrophysics Data System (ADS)

Ekert, Artur

2018-02-01

Device-independent quantum cryptography promises unprecedented security, but it is regarded as a theorist's dream and an experimentalist's nightmare. A new mathematical tool has now pushed its experimental demonstration much closer to reality.

Efficient and Provable Secure Pairing-Free Security-Mediated Identity-Based Identification Schemes

PubMed Central

Chin, Ji-Jian; Tan, Syh-Yuan; Heng, Swee-Huay; Phan, Raphael C.-W.

2014-01-01

Security-mediated cryptography was first introduced by Boneh et al. in 2001. The main motivation behind security-mediated cryptography was the capability to allow instant revocation of a user's secret key by necessitating the cooperation of a security mediator in any given transaction. Subsequently in 2003, Boneh et al. showed how to convert a RSA-based security-mediated encryption scheme from a traditional public key setting to an identity-based one, where certificates would no longer be required. Following these two pioneering papers, other cryptographic primitives that utilize a security-mediated approach began to surface. However, the security-mediated identity-based identification scheme (SM-IBI) was not introduced until Chin et al. in 2013 with a scheme built on bilinear pairings. In this paper, we improve on the efficiency results for SM-IBI schemes by proposing two schemes that are pairing-free and are based on well-studied complexity assumptions: the RSA and discrete logarithm assumptions. PMID:25207333

Efficient and provable secure pairing-free security-mediated identity-based identification schemes.

PubMed

Chin, Ji-Jian; Tan, Syh-Yuan; Heng, Swee-Huay; Phan, Raphael C-W

2014-01-01

Security-mediated cryptography was first introduced by Boneh et al. in 2001. The main motivation behind security-mediated cryptography was the capability to allow instant revocation of a user's secret key by necessitating the cooperation of a security mediator in any given transaction. Subsequently in 2003, Boneh et al. showed how to convert a RSA-based security-mediated encryption scheme from a traditional public key setting to an identity-based one, where certificates would no longer be required. Following these two pioneering papers, other cryptographic primitives that utilize a security-mediated approach began to surface. However, the security-mediated identity-based identification scheme (SM-IBI) was not introduced until Chin et al. in 2013 with a scheme built on bilinear pairings. In this paper, we improve on the efficiency results for SM-IBI schemes by proposing two schemes that are pairing-free and are based on well-studied complexity assumptions: the RSA and discrete logarithm assumptions.

Quantum key distribution for composite dimensional finite systems

NASA Astrophysics Data System (ADS)

Shalaby, Mohamed; Kamal, Yasser

2017-06-01

The application of quantum mechanics contributes to the field of cryptography with very important advantage as it offers a mechanism for detecting the eavesdropper. The pioneering work of quantum key distribution uses mutually unbiased bases (MUBs) to prepare and measure qubits (or qudits). Weak mutually unbiased bases (WMUBs) have weaker properties than MUBs properties, however, unlike MUBs, a complete set of WMUBs can be constructed for systems with composite dimensions. In this paper, we study the use of weak mutually unbiased bases (WMUBs) in quantum key distribution for composite dimensional finite systems. We prove that the security analysis of using a complete set of WMUBs to prepare and measure the quantum states in the generalized BB84 protocol, gives better results than using the maximum number of MUBs that can be constructed, when they are analyzed against the intercept and resend attack.

5 CFR 850.103 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (asymmetric) cryptography is a method of creating a unique mark, known as a digital signature, on an... cryptography means a method of authentication in which a single key is used to sign and verify an electronic...

New public key cryptosystem based on quaternions

NASA Astrophysics Data System (ADS)

Durcheva, Mariana; Karailiev, Kristian

2017-12-01

Quaternions are not commonly used in cryptography. Nevertheless, the noncommutativity of their multiplication makes them suitable for cryptographic purposes. In this paper we suggest a Diffie-Hellman like cryptosystem based on the the quaternions. Additionally, a computer realization of the protocol is given.

Monitoring of continuous-variable quantum key distribution system in real environment.

PubMed

Liu, Weiqi; Peng, Jinye; Huang, Peng; Huang, Duan; Zeng, Guihua

2017-08-07

How to guarantee the practical security of continuous-variable quantum key distribution (CVQKD) system has been an important issue in the quantum cryptography applications. In contrast to the previous practical security strategies, which focus on the intercept-resend attack or the Gaussian attack, we investigate the practical security strategy based on a general attack, i.e., an arbitrated individual attack or collective attack on the system by Eve in this paper. The low bound of intensity disturbance of the local oscillator signal for eavesdropper successfully concealing herself is obtained, considering all noises can be used by Eve in the practical environment. Furthermore, we obtain an optimal monitoring condition for the practical CVQKD system so that legitimate communicators can monitor the general attack in real-time. As examples, practical security of two special systems, i.e., the Gaussian modulated coherent state CVQKD system and the middle-based CVQKD system, are investigated under the intercept-resend attacks.

Algorithms for Lightweight Key Exchange.

PubMed

Alvarez, Rafael; Caballero-Gil, Cándido; Santonja, Juan; Zamora, Antonio

2017-06-27

Public-key cryptography is too slow for general purpose encryption, with most applications limiting its use as much as possible. Some secure protocols, especially those that enable forward secrecy, make a much heavier use of public-key cryptography, increasing the demand for lightweight cryptosystems that can be implemented in low powered or mobile devices. This performance requirements are even more significant in critical infrastructure and emergency scenarios where peer-to-peer networks are deployed for increased availability and resiliency. We benchmark several public-key key-exchange algorithms, determining those that are better for the requirements of critical infrastructure and emergency applications and propose a security framework based on these algorithms and study its application to decentralized node or sensor networks.

Innovative hyperchaotic encryption algorithm for compressed video

NASA Astrophysics Data System (ADS)

Yuan, Chun; Zhong, Yuzhuo; Yang, Shiqiang

2002-12-01

It is accepted that stream cryptosystem can achieve good real-time performance and flexibility which implements encryption by selecting few parts of the block data and header information of the compressed video stream. Chaotic random number generator, for example Logistics Map, is a comparatively promising substitute, but it is easily attacked by nonlinear dynamic forecasting and geometric information extracting. In this paper, we present a hyperchaotic cryptography scheme to encrypt the compressed video, which integrates Logistics Map with Z(232 - 1) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography, meanwhile, the real-time performance and flexibility of the chaotic sequence cryptography are maintained. It also integrates with the dissymmetrical public-key cryptography and implements encryption and identity authentification on control parameters at initialization phase. In accord with the importance of data in compressed video stream, encryption is performed in layered scheme. In the innovative hyperchaotic cryptography, the value and the updating frequency of control parameters can be changed online to satisfy the requirement of the network quality, processor capability and security requirement. The innovative hyperchaotic cryprography proves robust security by cryptoanalysis, shows good real-time performance and flexible implement capability through the arithmetic evaluating and test.

Quantum technology and cryptology for information security

NASA Astrophysics Data System (ADS)

Naqvi, Syed; Riguidel, Michel

2007-04-01

Cryptology and information security are set to play a more prominent role in the near future. In this regard, quantum communication and cryptography offer new opportunities to tackle ICT security. Quantum Information Processing and Communication (QIPC) is a scientific field where new conceptual foundations and techniques are being developed. They promise to play an important role in the future of information Security. It is therefore essential to have a cross-fertilizing development between quantum technology and cryptology in order to address the security challenges of the emerging quantum era. In this article, we discuss the impact of quantum technology on the current as well as future crypto-techniques. We then analyse the assumptions on which quantum computers may operate. Then we present our vision for the distribution of security attributes using a novel form of trust based on Heisenberg's uncertainty; and, building highly secure quantum networks based on the clear transmission of single photons and/or bundles of photons able to withstand unauthorized reading as a result of secure protocols based on the observations of quantum mechanics. We argue how quantum cryptographic systems need to be developed that can take advantage of the laws of physics to provide long-term security based on solid assumptions. This requires a structured integration effort to deploy quantum technologies within the existing security infrastructure. Finally, we conclude that classical cryptographic techniques need to be redesigned and upgraded in view of the growing threat of cryptanalytic attacks posed by quantum information processing devices leading to the development of post-quantum cryptography.

Counterfactual quantum cryptography network with untrusted relay

NASA Astrophysics Data System (ADS)

Chen, Yuanyuan; Gu, Xuemei; Jiang, Dong; Xie, Ling; Chen, Lijun

2015-07-01

Counterfactual quantum cryptography allows two remote parties to share a secret key even though a physical particle is not in fact transmitted through the quantum channel. In order to extend the scope of counterfactual quantum cryptography, we use an untrusted relay to construct a multi-user network. The implementation issues are discussed to show that the scheme can be realized with current technologies. We also prove the practical security advantages of the scheme by eliminating the probability that an eavesdropper can directly access the signal or an untrusted relay can perform false operations.

Low photon count based digital holography for quadratic phase cryptography.

PubMed

Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Ryle, James P; Healy, John J; Lee, Byung-Geun; Sheridan, John T

2017-07-15

Recently, the vulnerability of the linear canonical transform-based double random phase encryption system to attack has been demonstrated. To alleviate this, we present for the first time, to the best of our knowledge, a method for securing a two-dimensional scene using a quadratic phase encoding system operating in the photon-counted imaging (PCI) regime. Position-phase-shifting digital holography is applied to record the photon-limited encrypted complex samples. The reconstruction of the complex wavefront involves four sparse (undersampled) dataset intensity measurements (interferograms) at two different positions. Computer simulations validate that the photon-limited sparse-encrypted data has adequate information to authenticate the original data set. Finally, security analysis, employing iterative phase retrieval attacks, has been performed.

Exponential H ∞ Synchronization of Chaotic Cryptosystems Using an Improved Genetic Algorithm

PubMed Central

Hsiao, Feng-Hsiag

2015-01-01

This paper presents a systematic design methodology for neural-network- (NN-) based secure communications in multiple time-delay chaotic (MTDC) systems with optimal H ∞ performance and cryptography. On the basis of the Improved Genetic Algorithm (IGA), which is demonstrated to have better performance than that of a traditional GA, a model-based fuzzy controller is then synthesized to stabilize the MTDC systems. A fuzzy controller is synthesized to not only realize the exponential synchronization, but also achieve optimal H ∞ performance by minimizing the disturbance attenuation level. Furthermore, the error of the recovered message is stated by using the n-shift cipher and key. Finally, a numerical example with simulations is given to demonstrate the effectiveness of our approach. PMID:26366432

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2006-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2007-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Color extended visual cryptography using error diffusion.

PubMed

Kang, InKoo; Arce, Gonzalo R; Lee, Heung-Kyu

2011-01-01

Color visual cryptography (VC) encrypts a color secret message into n color halftone image shares. Previous methods in the literature show good results for black and white or gray scale VC schemes, however, they are not sufficient to be applied directly to color shares due to different color structures. Some methods for color visual cryptography are not satisfactory in terms of producing either meaningless shares or meaningful shares with low visual quality, leading to suspicion of encryption. This paper introduces the concept of visual information pixel (VIP) synchronization and error diffusion to attain a color visual cryptography encryption method that produces meaningful color shares with high visual quality. VIP synchronization retains the positions of pixels carrying visual information of original images throughout the color channels and error diffusion generates shares pleasant to human eyes. Comparisons with previous approaches show the superior performance of the new method.

Proposal for founding mistrustful quantum cryptography on coin tossing

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

Kent, Adrian; Hewlett-Packard Laboratories, Filton Road, Stoke Gifford, Bristol BS34 8QZ,

2003-07-01

A significant branch of classical cryptography deals with the problems which arise when mistrustful parties need to generate, process, or exchange information. As Kilian showed a while ago, mistrustful classical cryptography can be founded on a single protocol, oblivious transfer, from which general secure multiparty computations can be built. The scope of mistrustful quantum cryptography is limited by no-go theorems, which rule out, inter alia, unconditionally secure quantum protocols for oblivious transfer or general secure two-party computations. These theorems apply even to protocols which take relativistic signaling constraints into account. The best that can be hoped for, in general, aremore » quantum protocols which are computationally secure against quantum attack. Here a method is described for building a classically certified bit commitment, and hence every other mistrustful cryptographic task, from a secure coin-tossing protocol. No security proof is attempted, but reasons are sketched why these protocols might resist quantum computational attack.« less

Single-photon emitting diode in silicon carbide.

PubMed

Lohrmann, A; Iwamoto, N; Bodrog, Z; Castelletto, S; Ohshima, T; Karle, T J; Gali, A; Prawer, S; McCallum, J C; Johnson, B C

2015-07-23

Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes. The electrically driven emitters display fully polarized output, superior photon statistics (with a count rate of >300 kHz) and stability in both continuous and pulsed modes, all at room temperature. The atomic origin of the single-photon source is proposed. These results provide a foundation for the large scale integration of single-photon sources into a broad range of applications, such as quantum cryptography or linear optics quantum computing.

A secure and efficient authentication and key agreement scheme based on ECC for telecare medicine information systems.

PubMed

Xu, Xin; Zhu, Ping; Wen, Qiaoyan; Jin, Zhengping; Zhang, Hua; He, Lian

2014-01-01

In the field of the Telecare Medicine Information System, recent researches have focused on consummating more convenient and secure healthcare delivery services for patients. In order to protect the sensitive information, various attempts such as access control have been proposed to safeguard patients' privacy in this system. However, these schemes suffered from some certain security defects and had costly consumption, which were not suitable for the telecare medicine information system. In this paper, based on the elliptic curve cryptography, we propose a secure and efficient two-factor mutual authentication and key agreement scheme to reduce the computational cost. Such a scheme enables to provide the patient anonymity by employing the dynamic identity. Compared with other related protocols, the security analysis and performance evaluation show that our scheme overcomes some well-known attacks and has a better performance in the telecare medicine information system.

Study of college library appealing information system: A case of Longyan University

NASA Astrophysics Data System (ADS)

Liao, Jin-Hui

2014-10-01

The complaints from the readers at university libraries mainly focus on the aspects of service attitude, quality of service, reading environment, the management system, etc. Librarians should realize that reader complaints can actually promote the role of the library service and communicate with readers who complain in a friendly manner. In addition, the Longyan University library should establish an internal management system, improve library hardware facilities, improve the quality of librarians and optimize the knowledge structure of librarians, so as to improve the quality of the service for readers and reduce complaints. Based on this point, we have designed an appealing information system in cryptography machine basis, to provide readers online, remote and anonymous complaint functions.

78 FR 43145 - Announcing Approval of Federal Information Processing Standard 186-4, Digital Signature Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... correction of wording and typographical errors, and further aligns the FIPS with Key Cryptography Standard... Cryptography Standard (PKCS) 1. NIST published a Federal Register Notice (77 FR 21538) on April 10, 2012 to...

Security improvement by using a modified coherent state for quantum cryptography

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

Lu, Y.J.; Zhu, Luobei; Ou, Z.Y.

2005-03-01

Weak coherent states as a photon source for quantum cryptography have a limit in secure data rate and transmission distance because of the presence of multiphoton events and loss in transmission line. Two-photon events in a coherent state can be taken out by a two-photon interference scheme. We investigate the security issue of utilizing this modified coherent state in quantum cryptography. A 4-dB improvement in the secure data rate or a nearly twofold increase in transmission distance over the coherent state are found. With a recently proposed and improved encoding strategy, further improvement is possible.

Image size invariant visual cryptography for general access structures subject to display quality constraints.

PubMed

Lee, Kai-Hui; Chiu, Pei-Ling

2013-10-01

Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

Measurement-device-independent quantum key distribution.

PubMed

Lo, Hoi-Kwong; Curty, Marcos; Qi, Bing

2012-03-30

How to remove detector side channel attacks has been a notoriously hard problem in quantum cryptography. Here, we propose a simple solution to this problem--measurement-device-independent quantum key distribution (QKD). It not only removes all detector side channels, but also doubles the secure distance with conventional lasers. Our proposal can be implemented with standard optical components with low detection efficiency and highly lossy channels. In contrast to the previous solution of full device independent QKD, the realization of our idea does not require detectors of near unity detection efficiency in combination with a qubit amplifier (based on teleportation) or a quantum nondemolition measurement of the number of photons in a pulse. Furthermore, its key generation rate is many orders of magnitude higher than that based on full device independent QKD. The results show that long-distance quantum cryptography over say 200 km will remain secure even with seriously flawed detectors.

Optical cryptography with biometrics for multi-depth objects.

PubMed

Yan, Aimin; Wei, Yang; Hu, Zhijuan; Zhang, Jingtao; Tsang, Peter Wai Ming; Poon, Ting-Chung

2017-10-11

We propose an optical cryptosystem for encrypting images of multi-depth objects based on the combination of optical heterodyne technique and fingerprint keys. Optical heterodyning requires two optical beams to be mixed. For encryption, each optical beam is modulated by an optical mask containing either the fingerprint of the person who is sending, or receiving the image. The pair of optical masks are taken as the encryption keys. Subsequently, the two beams are used to scan over a multi-depth 3-D object to obtain an encrypted hologram. During the decryption process, each sectional image of the 3-D object is recovered by convolving its encrypted hologram (through numerical computation) with the encrypted hologram of a pinhole image that is positioned at the same depth as the sectional image. Our proposed method has three major advantages. First, the lost-key situation can be avoided with the use of fingerprints as the encryption keys. Second, the method can be applied to encrypt 3-D images for subsequent decrypted sectional images. Third, since optical heterodyning scanning is employed to encrypt a 3-D object, the optical system is incoherent, resulting in negligible amount of speckle noise upon decryption. To the best of our knowledge, this is the first time optical cryptography of 3-D object images has been demonstrated in an incoherent optical system with biometric keys.

Tight finite-key analysis for quantum cryptography

PubMed Central

Tomamichel, Marco; Lim, Charles Ci Wen; Gisin, Nicolas; Renner, Renato

2012-01-01

Despite enormous theoretical and experimental progress in quantum cryptography, the security of most current implementations of quantum key distribution is still not rigorously established. One significant problem is that the security of the final key strongly depends on the number, M, of signals exchanged between the legitimate parties. Yet, existing security proofs are often only valid asymptotically, for unrealistically large values of M. Another challenge is that most security proofs are very sensitive to small differences between the physical devices used by the protocol and the theoretical model used to describe them. Here we show that these gaps between theory and experiment can be simultaneously overcome by using a recently developed proof technique based on the uncertainty relation for smooth entropies. PMID:22252558

Tight finite-key analysis for quantum cryptography.

PubMed

Tomamichel, Marco; Lim, Charles Ci Wen; Gisin, Nicolas; Renner, Renato

2012-01-17

Despite enormous theoretical and experimental progress in quantum cryptography, the security of most current implementations of quantum key distribution is still not rigorously established. One significant problem is that the security of the final key strongly depends on the number, M, of signals exchanged between the legitimate parties. Yet, existing security proofs are often only valid asymptotically, for unrealistically large values of M. Another challenge is that most security proofs are very sensitive to small differences between the physical devices used by the protocol and the theoretical model used to describe them. Here we show that these gaps between theory and experiment can be simultaneously overcome by using a recently developed proof technique based on the uncertainty relation for smooth entropies.

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

Algorithms for Lightweight Key Exchange †

PubMed Central

Santonja, Juan; Zamora, Antonio

2017-01-01

Public-key cryptography is too slow for general purpose encryption, with most applications limiting its use as much as possible. Some secure protocols, especially those that enable forward secrecy, make a much heavier use of public-key cryptography, increasing the demand for lightweight cryptosystems that can be implemented in low powered or mobile devices. This performance requirements are even more significant in critical infrastructure and emergency scenarios where peer-to-peer networks are deployed for increased availability and resiliency. We benchmark several public-key key-exchange algorithms, determining those that are better for the requirements of critical infrastructure and emergency applications and propose a security framework based on these algorithms and study its application to decentralized node or sensor networks. PMID:28654006

C4I Architecture Supporting Conduct of Defensive and Offensive Joint ASW

DTIC Science & Technology

2008-09-01

David H. Olwell, Ph.D...Switched Network DWTS Digital Wideband Transmission System ECC Elliptic Curve Cryptography ECU End Crypto Unit EEZ Economic Exclusion Zone EHF... relatively short ranges. With a stand alone acoustic sensor system, sensor operators never really know if the area is clear, they only have a

Cryptanalysis on classical cipher based on Indonesian language

NASA Astrophysics Data System (ADS)

Marwati, R.; Yulianti, K.

2018-05-01

Cryptanalysis is a process of breaking a cipher in an illegal decryption. This paper discusses about encryption some classic cryptography, breaking substitution cipher and stream cipher, and increasing its security. Encryption and ciphering based on Indonesian Language text. Microsoft Word and Microsoft Excel were chosen as ciphering and breaking tools.

75 FR 32748 - Availability of Testing and Evaluation Report and Intent To Proceed With the Final Stages of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... authentication of the source and integrity of information stored in the DNS using public key cryptography and a.../DNSSEC_05282010.html . \\7\\ In cryptography, a trust anchor is an authoritative entity represented via a...

Optimizing Security of Cloud Computing within the DoD

DTIC Science & Technology

2010-12-01

information security governance and risk management; application security; cryptography; security architecture and design; operations security; business ...governance and risk management; application security; cryptography; security architecture and design; operations security; business continuity...20 7. Operational Security (OPSEC).........................................................20 8. Business Continuity Planning (BCP) and Disaster

Evolutionary Algorithms for Boolean Functions in Diverse Domains of Cryptography.

PubMed

Picek, Stjepan; Carlet, Claude; Guilley, Sylvain; Miller, Julian F; Jakobovic, Domagoj

2016-01-01

The role of Boolean functions is prominent in several areas including cryptography, sequences, and coding theory. Therefore, various methods for the construction of Boolean functions with desired properties are of direct interest. New motivations on the role of Boolean functions in cryptography with attendant new properties have emerged over the years. There are still many combinations of design criteria left unexplored and in this matter evolutionary computation can play a distinct role. This article concentrates on two scenarios for the use of Boolean functions in cryptography. The first uses Boolean functions as the source of the nonlinearity in filter and combiner generators. Although relatively well explored using evolutionary algorithms, it still presents an interesting goal in terms of the practical sizes of Boolean functions. The second scenario appeared rather recently where the objective is to find Boolean functions that have various orders of the correlation immunity and minimal Hamming weight. In both these scenarios we see that evolutionary algorithms are able to find high-quality solutions where genetic programming performs the best.

The Mathematics of "Star Trek"--An Honors Colloquium

ERIC Educational Resources Information Center

Karls, Michael A.

2011-01-01

After the success of a course on cryptography for a general audience, based on Simon Singh's "The Code Book" [49], I decided to try again and create a mathematics course for a general audience based on "The Physics of Star Trek" by Lawrence Krauss [32]. This article looks at the challenges of designing a physics-based mathematics course "from…

Implementing Diffie-Hellman key exchange using quantum EPR pairs

NASA Astrophysics Data System (ADS)

Mandal, Sayonnha; Parakh, Abhishek

2015-05-01

This paper implements the concepts of perfect forward secrecy and the Diffie-Hellman key exchange using EPR pairs to establish and share a secret key between two non-authenticated parties and transfer messages between them without the risk of compromise. Current implementations of quantum cryptography are based on the BB84 protocol, which is susceptible to siphoning attacks on the multiple photons emitted by practical laser sources. This makes BB84-based quantum cryptography protocol unsuitable for network computing environments. Diffie-Hellman does not require the two parties to be mutually authenticated to each other, yet it can provide a basis for a number of authenticated protocols, most notably the concept of perfect forward secrecy. The work proposed in this paper provides a new direction in utilizing quantum EPR pairs in quantum key exchange. Although, classical cryptography boasts of efficient and robust protocols like the Diffie-Hellman key exchange, in the current times, with the advent of quantum computing they are very much vulnerable to eavesdropping and cryptanalytic attacks. Using quantum cryptographic principles, however, these classical encryption algorithms show more promise and a more robust and secure structure for applications. The unique properties of quantum EPR pairs also, on the other hand, go a long way in removing attacks like eavesdropping by their inherent nature of one particle of the pair losing its state if a measurement occurs on the other. The concept of perfect forward secrecy is revisited in this paper to attribute tighter security to the proposed protocol.

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

Brickell, E.F.; Simmons, G.J.

In the period since 1976, when Diffie and Hellman published the first discussion of two-key cryptography to appear in the open literature, only a handful of two-key cryptoalgorithms have been proposed - two of which are based on the knapsack problem. Consequently there was enormous interest when Shamir announced in early 1982 a cryptanalytic technique that could break many Merkle-Hellman knapsacks. In a rapid sequence of developments, Simmons and Brickell, Adleman, and Lagarias all announced other attacks on knapsack-based cryptosystems that were either computationally much more efficient or else directed at other knapsack schemes such as the Graham-Shamir or iteratedmore » systems. This paper analyzes the common features of knapsack-based cryptosystems and presents all of the cryptanalytic attacks made in 1982 from a unified viewpoint.« less

Sensor Systems Based on FPGAs and Their Applications: A Survey

PubMed Central

de la Piedra, Antonio; Braeken, An; Touhafi, Abdellah

2012-01-01

In this manuscript, we present a survey of designs and implementations of research sensor nodes that rely on FPGAs, either based upon standalone platforms or as a combination of microcontroller and FPGA. Several current challenges in sensor networks are distinguished and linked to the features of modern FPGAs. As it turns out, low-power optimized FPGAs are able to enhance the computation of several types of algorithms in terms of speed and power consumption in comparison to microcontrollers of commercial sensor nodes. We show that architectures based on the combination of microcontrollers and FPGA can play a key role in the future of sensor networks, in fields where processing capabilities such as strong cryptography, self-testing and data compression, among others, are paramount.

The Security Email Based on Smart Card

NASA Astrophysics Data System (ADS)

Lina, Zhang; Jiang, Meng Hai.

Email has become one of the most important communication tools in modern internet society, and its security is an important issue that can't be ignored. The security requirements of Email can be summarized as confidentiality, integrity, authentication and non-repudiation. Recently many researches on IBE (identify based encrypt) have been carried out to solve these security problems. However, because of IBE's fatal flaws and great advantages of PKI (Public Key Infrastructure), PKI is found to be still irreplaceable especially in the applications based on smart card. In this paper, a construction of security Email is presented, then the design of relatively cryptography algorithms and the configuration of certificates are elaborated, and finally the security for the proposed system is discussed.

Temporal steering and security of quantum key distribution with mutually unbiased bases against individual attacks

NASA Astrophysics Data System (ADS)

Bartkiewicz, Karol; Černoch, Antonín; Lemr, Karel; Miranowicz, Adam; Nori, Franco

2016-06-01

Temporal steering, which is a temporal analog of Einstein-Podolsky-Rosen steering, refers to temporal quantum correlations between the initial and final state of a quantum system. Our analysis of temporal steering inequalities in relation to the average quantum bit error rates reveals the interplay between temporal steering and quantum cloning, which guarantees the security of quantum key distribution based on mutually unbiased bases against individual attacks. The key distributions analyzed here include the Bennett-Brassard 1984 protocol and the six-state 1998 protocol by Bruss. Moreover, we define a temporal steerable weight, which enables us to identify a kind of monogamy of temporal correlation that is essential to quantum cryptography and useful for analyzing various scenarios of quantum causality.

Space division multiplexing chip-to-chip quantum key distribution.

PubMed

Bacco, Davide; Ding, Yunhong; Dalgaard, Kjeld; Rottwitt, Karsten; Oxenløwe, Leif Katsuo

2017-09-29

Quantum cryptography is set to become a key technology for future secure communications. However, to get maximum benefit in communication networks, transmission links will need to be shared among several quantum keys for several independent users. Such links will enable switching in quantum network nodes of the quantum keys to their respective destinations. In this paper we present an experimental demonstration of a photonic integrated silicon chip quantum key distribution protocols based on space division multiplexing (SDM), through multicore fiber technology. Parallel and independent quantum keys are obtained, which are useful in crypto-systems and future quantum network.

Cryptographic Research and NSA: Report of the Public Cryptography Study Group.

ERIC Educational Resources Information Center

Davida, George I.

1981-01-01

The Public Cryptography Study Group accepted the claim made by the National Security Agency that some information in some publications concerning cryptology could be inimical to national security, and is allowing the establishment of a voluntary mechanism, on an experimental basis, for NSA to review cryptology manuscripts. (MLW)

Characterization of collective Gaussian attacks and security of coherent-state quantum cryptography.

PubMed

Pirandola, Stefano; Braunstein, Samuel L; Lloyd, Seth

2008-11-14

We provide a simple description of the most general collective Gaussian attack in continuous-variable quantum cryptography. In the scenario of such general attacks, we analyze the asymptotic secret-key rates which are achievable with coherent states, joint measurements of the quadratures and one-way classical communication.

The Design and Evaluation of a Cryptography Teaching Strategy for Software Engineering Students

ERIC Educational Resources Information Center

Dowling, T.

2006-01-01

The present paper describes the design, implementation and evaluation of a cryptography module for final-year software engineering students. The emphasis is on implementation architectures and practical cryptanalysis rather than a standard mathematical approach. The competitive continuous assessment process reflects this approach and rewards…

The Vigenere Cipher with the TI-83

ERIC Educational Resources Information Center

Hamilton, Michael; Yankosky, Bill

2004-01-01

Cryptology, the science of secret writing, is a great way to introduce students to different areas of mathematics such as number theory, linear algebra, probability and statistics. Cryptology consists of two branches: cryptography and cryptanalysis. Cryptography is the science of designing techniques for encrypting and decrypting a message.…

Harry Potter and the Cryptography with Matrices

ERIC Educational Resources Information Center

Chua, Boon Liang

2006-01-01

This article describes Cryptography, defined as the science of encrypting and deciphering messages written in secret codes, it has played a vital role in securing information since ancient times. There are several cryptographic techniques and many make extensive use of mathematics to secure information. The author discusses an activity built…

Cost Comparison Among Provable Data Possession Schemes

DTIC Science & Technology

2016-03-01

possession,” in Proceedings of the 11th International Conference on Ap- plied Cryptography and Network Security. Berlin, Heidelberg: Springer-Verlag, 2013...curves,” in Security and Cryptography (SECRYPT), 2013 International Conference on, July 2013, pp. 1–12. [19] R. S. Kumar and A. Saxena, “Data integrity

Cryptographer

ERIC Educational Resources Information Center

Sullivan, Megan

2005-01-01

For the general public, the field of cryptography has recently become famous as the method used to uncover secrets in Dan Brown's fictional bestseller, The Da Vinci Code. But the science of cryptography has been popular for centuries--secret hieroglyphics discovered in Egypt suggest that code-making dates back almost 4,000 years. In today's…

Steganography and Cryptography Inspired Enhancement of Introductory Programming Courses

ERIC Educational Resources Information Center

Kortsarts, Yana; Kempner, Yulia

2015-01-01

Steganography is the art and science of concealing communication. The goal of steganography is to hide the very existence of information exchange by embedding messages into unsuspicious digital media covers. Cryptography, or secret writing, is the study of the methods of encryption, decryption and their use in communications protocols.…

A Spatiotemporal-Chaos-Based Encryption Having Overall Properties Considerably Better than Advanced Encryption Standard

NASA Astrophysics Data System (ADS)

Wang, Shi-Hong; Ye, Wei-Ping; Lü, Hua-Ping; Kuang, Jin-Yu; Li, Jing-Hua; Luo, Yun-Lun; Hu, Gang

2003-07-01

Spatiotemporal chaos of a two-dimensional one-way coupled map lattice is used for chaotic cryptography. The chaotic outputs of many space units are used for encryption simultaneously. This system shows satisfactory cryptographic properties of high security, fast encryption (decryption) speed, and robustness against noise disturbances in communication channel. The overall features of this spatiotemporal-chaos-based cryptosystem are better than chaotic cryptosystems known so far, and also than currently used conventional cryptosystems, such as the Advanced Encryption Standard (AES). The project supported by National Natural Science Foundation of China under Grant No. 10175010 and the Special Funds for Major State Basic Research Projects under Grant No. G2000077304

A Spatiotemporal-Chaos-Based Cryptosystem Taking Advantage of Both Synchronous and Self-Synchronizing Schemes

NASA Astrophysics Data System (ADS)

Lü, Hua-Ping; Wang, Shi-Hong; Li, Xiao-Wen; Tang, Guo-Ning; Kuang, Jin-Yu; Ye, Wei-Ping; Hu, Gang

2004-06-01

Two-dimensional one-way coupled map lattices are used for cryptography where multiple space units produce chaotic outputs in parallel. One of the outputs plays the role of driving for synchronization of the decryption system while the others perform the function of information encoding. With this separation of functions the receiver can establish a self-checking and self-correction mechanism, and enjoys the advantages of both synchronous and self-synchronizing schemes. A comparison between the present system with the system of advanced encryption standard (AES) is presented in the aspect of channel noise influence. Numerical investigations show that our system is much stronger than AES against channel noise perturbations, and thus can be better used for secure communications with large channel noise.

Fast, efficient error reconciliation for quantum cryptography

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

Buttler, W.T.; Lamoreaux, S.K.; Torgerson, J.R.

2003-05-01

We describe an error-reconciliation protocol, which we call Winnow, based on the exchange of parity and Hamming's 'syndrome' for N-bit subunits of a large dataset. The Winnow protocol was developed in the context of quantum-key distribution and offers significant advantages and net higher efficiency compared to other widely used protocols within the quantum cryptography community. A detailed mathematical analysis of the Winnow protocol is presented in the context of practical implementations of quantum-key distribution; in particular, the information overhead required for secure implementation is one of the most important criteria in the evaluation of a particular error-reconciliation protocol. The increasemore » in efficiency for the Winnow protocol is largely due to the reduction in authenticated public communication required for its implementation.« less

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.

Cryptography: It’s Not Just For Electronic Mail Anymore

DTIC Science & Technology

1993-03-01

David Chaum . Security without identification: Transaction systems to make big brother obsolete. Communications of the ACM, 28(10): 1030-1044, Oc- tober...Jeannette Wing, Maurice Herlihy, Stewart Clamen, David Detlefs, Karen Kietzke, Richard Lerner, and Su-Yuen Ling. The Avalon language: A tutorial

Number theoretical foundations in cryptography

NASA Astrophysics Data System (ADS)

Atan, Kamel Ariffin Mohd

2017-08-01

In recent times the hazards in relationships among entities in different establishments worldwide have generated exciting developments in cryptography. Central to this is the theory of numbers. This area of mathematics provides very rich source of fundamental materials for constructing secret codes. Some number theoretical concepts that have been very actively used in designing crypto systems will be highlighted in this presentation. This paper will begin with introduction to basic number theoretical concepts which for many years have been thought to have no practical applications. This will include several theoretical assertions that were discovered much earlier in the historical development of number theory. This will be followed by discussion on the "hidden" properties of these assertions that were later exploited by designers of cryptosystems in their quest for developing secret codes. This paper also highlights some earlier and existing cryptosystems and the role played by number theoretical concepts in their constructions. The role played by cryptanalysts in detecting weaknesses in the systems developed by cryptographers concludes this presentation.

The Uncertainty Principle in the Presence of Quantum Memory

NASA Astrophysics Data System (ADS)

Renes, Joseph M.; Berta, Mario; Christandl, Matthias; Colbeck, Roger; Renner, Renato

2010-03-01

One consequence of Heisenberg's uncertainty principle is that no observer can predict the outcomes of two incompatible measurements performed on a system to arbitrary precision. However, this implication is invalid if the the observer possesses a quantum memory, a distinct possibility in light of recent technological advances. Entanglement between the system and the memory is responsible for the breakdown of the uncertainty principle, as illustrated by the EPR paradox. In this work we present an improved uncertainty principle which takes this entanglement into account. By quantifying uncertainty using entropy, we show that the sum of the entropies associated with incompatible measurements must exceed a quantity which depends on the degree of incompatibility and the amount of entanglement between system and memory. Apart from its foundational significance, the uncertainty principle motivated the first proposals for quantum cryptography, though the possibility of an eavesdropper having a quantum memory rules out using the original version to argue that these proposals are secure. The uncertainty relation introduced here alleviates this problem and paves the way for its widespread use in quantum cryptography.

An Enhanced Biometric Based Authentication with Key-Agreement Protocol for Multi-Server Architecture Based on Elliptic Curve Cryptography.

PubMed

Reddy, Alavalapati Goutham; Das, Ashok Kumar; Odelu, Vanga; Yoo, Kee-Young

2016-01-01

Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.'s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN) logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.'s protocol and existing similar protocols.

Computer network defense through radial wave functions

NASA Astrophysics Data System (ADS)

Malloy, Ian J.

The purpose of this research is to synthesize basic and fundamental findings in quantum computing, as applied to the attack and defense of conventional computer networks. The concept focuses on uses of radio waves as a shield for, and attack against traditional computers. A logic bomb is analogous to a landmine in a computer network, and if one was to implement it as non-trivial mitigation, it will aid computer network defense. As has been seen in kinetic warfare, the use of landmines has been devastating to geopolitical regions in that they are severely difficult for a civilian to avoid triggering given the unknown position of a landmine. Thus, the importance of understanding a logic bomb is relevant and has corollaries to quantum mechanics as well. The research synthesizes quantum logic phase shifts in certain respects using the Dynamic Data Exchange protocol in software written for this work, as well as a C-NOT gate applied to a virtual quantum circuit environment by implementing a Quantum Fourier Transform. The research focus applies the principles of coherence and entanglement from quantum physics, the concept of expert systems in artificial intelligence, principles of prime number based cryptography with trapdoor functions, and modeling radio wave propagation against an event from unknown parameters. This comes as a program relying on the artificial intelligence concept of an expert system in conjunction with trigger events for a trapdoor function relying on infinite recursion, as well as system mechanics for elliptic curve cryptography along orbital angular momenta. Here trapdoor both denotes the form of cipher, as well as the implied relationship to logic bombs.

Science and Technology Resources on the Internet: Computer Security.

ERIC Educational Resources Information Center

Kinkus, Jane F.

2002-01-01

Discusses issues related to computer security, including confidentiality, integrity, and authentication or availability; and presents a selected list of Web sites that cover the basic issues of computer security under subject headings that include ethics, privacy, kids, antivirus, policies, cryptography, operating system security, and biometrics.…

Investigating the Randomness of Numbers

ERIC Educational Resources Information Center

Pendleton, Kenn L.

2009-01-01

The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

Cryptography as a Pedagogical Tool

ERIC Educational Resources Information Center

Kaur, Manmohan

2008-01-01

In order to get undergraduates interested in mathematics, it is necessary to motivate them, give them good reasons to spend time on a subject that requires hard work, and, if possible, involve them in undergraduate research. This article discusses how cryptography can be used for all these purposes. In particular, a special topics course on…

CompGC: Efficient Offline/Online Sem i-honest Two-party Computation

DTIC Science & Technology

2016-04-22

Rivest, and A. T. Sherman, Eds., Plenum Press, New York, USA, pp. 205–210. 13 [9] Goldreich, O. Foundations of Cryptography : Volume 2, Basic...low depth circuits. In FC 2013: 17th International Conference on Financial Cryptography and Data Security (Okinawa, Japan, Apr. 1–5, 2013), A.-R

Quantum-tomographic cryptography with a semiconductor single-photon source

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

Kaszlikowski, D.; Yang, L.J.; Yong, L.S.

2005-09-15

We analyze the security of so-called quantum-tomographic cryptography with the source producing entangled photons via an experimental scheme proposed by Fattal et al. [Phys. Rev. Lett. 92, 37903 (2004)]. We determine the range of the experimental parameters for which the protocol is secure against the most general incoherent attacks.

Elliptic Curve Cryptography with Security System in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Huang, Xu; Sharma, Dharmendra

2010-10-01

The rapid progress of wireless communications and embedded micro-electro-system technologies has made wireless sensor networks (WSN) very popular and even become part of our daily life. WSNs design are generally application driven, namely a particular application's requirements will determine how the network behaves. However, the natures of WSN have attracted increasing attention in recent years due to its linear scalability, a small software footprint, low hardware implementation cost, low bandwidth requirement, and high device performance. It is noted that today's software applications are mainly characterized by their component-based structures which are usually heterogeneous and distributed, including the WSNs. But WSNs typically need to configure themselves automatically and support as hoc routing. Agent technology provides a method for handling increasing software complexity and supporting rapid and accurate decision making. This paper based on our previous works [1, 2], three contributions have made, namely (a) fuzzy controller for dynamic slide window size to improve the performance of running ECC (b) first presented a hidden generation point for protection from man-in-the middle attack and (c) we first investigates multi-agent applying for key exchange together. Security systems have been drawing great attentions as cryptographic algorithms have gained popularity due to the natures that make them suitable for use in constrained environment such as mobile sensor information applications, where computing resources and power availability are limited. Elliptic curve cryptography (ECC) is one of high potential candidates for WSNs, which requires less computational power, communication bandwidth, and memory in comparison with other cryptosystem. For saving pre-computing storages recently there is a trend for the sensor networks that the sensor group leaders rather than sensors communicate to the end database, which highlighted the needs to prevent from the man-in-the middle attack. A designed a hidden generator point that offer a good protection from the man-in-the middle (MinM) attack which becomes one of major worries for the sensor's networks with multiagent system is also discussed.

Quantum cryptography to satellites for global secure key distribution

NASA Astrophysics Data System (ADS)

Rarity, John G.; Gorman, Philip M.; Knight, Paul; Wallace, Kotska; Tapster, Paul R.

2017-11-01

We have designed and built a free space secure key exchange system using weak laser pulses with polarisation modulation by acousto-optic switching. We have used this system to exchange keys over a 1.2km ground range with absolute security. Building from this initial result we analyse the feasibility of exchanging keys to a low earth orbit satellite.

Application of visual cryptography for learning in optics and photonics

NASA Astrophysics Data System (ADS)

Mandal, Avikarsha; Wozniak, Peter; Vauderwange, Oliver; Curticapean, Dan

2016-09-01

In the age data digitalization, important applications of optics and photonics based sensors and technology lie in the field of biometrics and image processing. Protecting user data in a safe and secure way is an essential task in this area. However, traditional cryptographic protocols rely heavily on computer aided computation. Secure protocols which rely only on human interactions are usually simpler to understand. In many scenarios development of such protocols are also important for ease of implementation and deployment. Visual cryptography (VC) is an encryption technique on images (or text) in which decryption is done by human visual system. In this technique, an image is encrypted into number of pieces (known as shares). When the printed shares are physically superimposed together, the image can be decrypted with human vision. Modern digital watermarking technologies can be combined with VC for image copyright protection where the shares can be watermarks (small identification) embedded in the image. Similarly, VC can be used for improving security of biometric authentication. This paper presents about design and implementation of a practical laboratory experiment based on the concept of VC for a course in media engineering. Specifically, our contribution deals with integration of VC in different schemes for applications like digital watermarking and biometric authentication in the field of optics and photonics. We describe theoretical concepts and propose our infrastructure for the experiment. Finally, we will evaluate the learning outcome of the experiment, performed by the students.

Security for decentralized health information systems.

PubMed

Bleumer, G

1994-02-01

Health care information systems must reflect at least two basic characteristics of the health care community: the increasing mobility of patients and the personal liability of everyone giving medical treatment. Open distributed information systems bear the potential to reflect these requirements. But the market for open information systems and operating systems hardly provides secure products today. This 'missing link' is approached by the prototype SECURE Talk that provides secure transmission and archiving of files on top of an existing operating system. Its services may be utilized by existing medical applications. SECURE Talk demonstrates secure communication utilizing only standard hardware. Its message is that cryptography (and in particular asymmetric cryptography) is practical for many medical applications even if implemented in software. All mechanisms are software implemented in order to be executable on standard-hardware. One can investigate more or less decentralized forms of public key management and the performance of many different cryptographic mechanisms. That of, e.g. hybrid encryption and decryption (RSA+DES-PCBC) is about 300 kbit/s. That of signing and verifying is approximately the same using RSA with a DES hash function. The internal speed, without disk accesses etc., is about 1.1 Mbit/s. (Apple Quadra 950 (MC 68040, 33 MHz, RAM: 20 MB, 80 ns. Length of RSA modulus is 512 bit).

Controller–Pilot Data Link Communication Security

PubMed Central

Polishchuk, Tatiana; Wernberg, Max

2018-01-01

The increased utilization of the new types of cockpit communications, including controller–pilot data link communications (CPDLC), puts the airplane at higher risk of hacking or interference than ever before. We review the technological characteristics and properties of the CPDLC and construct the corresponding threat model. Based on the limitations imposed by the system parameters, we propose several solutions for the improved security of the data messaging communication used in air traffic management (ATM). We discuss the applicability of elliptical curve cryptography (ECC), protected aircraft communications addressing and reporting systems (PACARs) and the Host Identity Protocol (HIP) as possible countermeasures to the identified security threats. In addition, we consider identity-defined networking (IDN) as an example of a genuine security solution which implies global changes in the whole air traffic communication system. PMID:29783791

Controller⁻Pilot Data Link Communication Security.

PubMed

Gurtov, Andrei; Polishchuk, Tatiana; Wernberg, Max

2018-05-20

The increased utilization of the new types of cockpit communications, including controller⁻pilot data link communications (CPDLC), puts the airplane at higher risk of hacking or interference than ever before. We review the technological characteristics and properties of the CPDLC and construct the corresponding threat model. Based on the limitations imposed by the system parameters, we propose several solutions for the improved security of the data messaging communication used in air traffic management (ATM). We discuss the applicability of elliptical curve cryptography (ECC), protected aircraft communications addressing and reporting systems (PACARs) and the Host Identity Protocol (HIP) as possible countermeasures to the identified security threats. In addition, we consider identity-defined networking (IDN) as an example of a genuine security solution which implies global changes in the whole air traffic communication system.

An Application-Independent Cryptography Model That Is Easy to Use for All Level Users

ERIC Educational Resources Information Center

Gabrielson, Anthony J.

2013-01-01

Cryptography libraries are inflexible and difficult for developers to integrate with their applications. These difficulties are often encountered by applications, like PGP, which are non-intuitive for end-users and are often used improperly or not at all. This thesis discusses the negative impact of the current prevailing poor usability on…

Chaos and Cryptography: A new dimension in secure communications

NASA Astrophysics Data System (ADS)

Banerjee, Santo; Kurths, J.

2014-06-01

This issue is a collection of contributions on recent developments and achievements of cryptography and communications using chaos. The various contributions report important and promising results such as synchronization of networks and data transmissions; image cipher; optical and TDMA communications, quantum keys etc. Various experiments and applications such as FPGA, smartphone cipher, semiconductor lasers etc, are also included.

Quantum key distribution with an entangled light emitting diode

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

Dzurnak, B.; Stevenson, R. M.; Nilsson, J.

Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurementsmore » also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.« less

Quantum key distribution with an entangled light emitting diode

NASA Astrophysics Data System (ADS)

Dzurnak, B.; Stevenson, R. M.; Nilsson, J.; Dynes, J. F.; Yuan, Z. L.; Skiba-Szymanska, J.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

2015-12-01

Measurements performed on entangled photon pairs shared between two parties can allow unique quantum cryptographic keys to be formed, creating secure links between users. An advantage of using such entangled photon links is that they can be adapted to propagate entanglement to end users of quantum networks with only untrusted nodes. However, demonstrations of quantum key distribution with entangled photons have so far relied on sources optically excited with lasers. Here, we realize a quantum cryptography system based on an electrically driven entangled-light-emitting diode. Measurement bases are passively chosen and we show formation of an error-free quantum key. Our measurements also simultaneously reveal Bell's parameter for the detected light, which exceeds the threshold for quantum entanglement.

Postselection technique for quantum channels with applications to quantum cryptography.

PubMed

Christandl, Matthias; König, Robert; Renner, Renato

2009-01-16

We propose a general method for studying properties of quantum channels acting on an n-partite system, whose action is invariant under permutations of the subsystems. Our main result is that, in order to prove that a certain property holds for an arbitrary input, it is sufficient to consider the case where the input is a particular de Finetti-type state, i.e., a state which consists of n identical and independent copies of an (unknown) state on a single subsystem. Our technique can be applied to the analysis of information-theoretic problems. For example, in quantum cryptography, we get a simple proof for the fact that security of a discrete-variable quantum key distribution protocol against collective attacks implies security of the protocol against the most general attacks. The resulting security bounds are tighter than previously known bounds obtained with help of the exponential de Finetti theorem.

Genetic attack on neural cryptography.

PubMed

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

2006-03-01

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

Relativistic quantum cryptography

NASA Astrophysics Data System (ADS)

Molotkov, S. N.; Nazin, S. S.

2003-07-01

The problem of unconditional security of quantum cryptography (i.e. the security which is guaranteed by the fundamental laws of nature rather than by technical limitations) is one of the central points in quantum information theory. We propose a relativistic quantum cryptosystem and prove its unconditional security against any eavesdropping attempts. Relativistitic causality arguments allow to demonstrate the security of the system in a simple way. Since the proposed protocol does not empoly collective measurements and quantum codes, the cryptosystem can be experimentally realized with the present state-of-art in fiber optics technologies. The proposed cryptosystem employs only the individual measurements and classical codes and, in addition, the key distribution problem allows to postpone the choice of the state encoding scheme until after the states are already received instead of choosing it before sending the states into the communication channel (i.e. to employ a sort of "antedate" coding).

RIPE integrity primitives, part 2 (RACE Integrity Primitives Evaluation)

NASA Astrophysics Data System (ADS)

Denboer, B.; Boly, J. P.; Bosselaers, A.; Brandt, J.; Chaum, D.; Damgaard, I.; Dichtl, M.; Fumy, W.; Vanderham, M.; Jansen, C. J. A.

1993-04-01

A manual intended for those seeking to secure information systems by applying modern cryptography is presented. It represents the successful attainment of goals by RIPE (RACE (Research and development of Advanced Communications technology in Europe) Integrity Primitives Evaluation). The recommended portfolio of integrity primitives, which is the main product of the project, forms the heart of the manual. By integrity, is meant the kinds of security that can be achieved through cryptography, apart from keeping messages secret. Thus included are ways to ensure that stored or communicated data is not illicitly modified, that parties exchanging messages are actually present, and that 'signed' electronic messages can be recognized as authentic by anyone. Of particular concern to the project were the high speed requirements of broadband communication. The project also aimed for completeness in its recommendations. As a result, the portfolio contains primitives, that is building blocks, that can meet most of today's perceived needs for integrity.

RIPE integrity primitives, part 1 (RACE Integrity Primitives Evaluation)

NASA Astrophysics Data System (ADS)

Denboer, B.; Boly, J. P.; Bosselaers, A.; Brandt, J.; Chaum, D.; Damgaard, I.; Dichtl, M.; Fumy, W.; Vanderham, M.; Jansen, C. J. A.

1993-04-01

A manual intended for those seeking to secure information systems by applying modern cryptography is presented. It represents the successful attainment of goals by RIPE (RACE (Research and development of Advanced Communication technology in Europe) Integrity Primitives Evaluation). The recommended portfolio of integrity primitives, which is the main product of the project, forms the heart of the manual. By integrity, is meant the kinds of security that can be achieved through cryptography, apart from keeping messages secret. Thus included are ways to ensure that stored or communicated data is not illicitly modified, that parties exchanging messages are actually present, and that 'signed' electronic messages can be recognized as authentic by anyone. Of particular concern to the project were the high speed requirements of broadband communication. The project also aimed for completeness in its recommendations. As a result, the portfolio contains primitives, that is building blocks, that can meet most of today's perceived needs for integrity.

Genetic attack on neural cryptography

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

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka

2006-03-15

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold formore » the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.« less

Genetic attack on neural cryptography

NASA Astrophysics Data System (ADS)

Ruttor, Andreas; Kinzel, Wolfgang; Naeh, Rivka; Kanter, Ido

2006-03-01

Different scaling properties for the complexity of bidirectional synchronization and unidirectional learning are essential for the security of neural cryptography. Incrementing the synaptic depth of the networks increases the synchronization time only polynomially, but the success of the geometric attack is reduced exponentially and it clearly fails in the limit of infinite synaptic depth. This method is improved by adding a genetic algorithm, which selects the fittest neural networks. The probability of a successful genetic attack is calculated for different model parameters using numerical simulations. The results show that scaling laws observed in the case of other attacks hold for the improved algorithm, too. The number of networks needed for an effective attack grows exponentially with increasing synaptic depth. In addition, finite-size effects caused by Hebbian and anti-Hebbian learning are analyzed. These learning rules converge to the random walk rule if the synaptic depth is small compared to the square root of the system size.

Security enhancement of optical encryption based on biometric array keys

NASA Astrophysics Data System (ADS)

Yan, Aimin; Wei, Yang; Zhang, Jingtao

2018-07-01

A novel optical image encryption method is proposed by using Dammann grating and biometric array keys. Dammann grating is utilized to create a 2D finite uniform-intensity spot array. In encryption, a fingerprint array is used as private encryption keys. An original image can be encrypted by a scanning Fresnel zone plate array. Encrypted signals are processed by an optical coherent heterodyne detection system. Biometric array keys and optical scanning cryptography are integrated with each other to enhance information security greatly. Numerical simulations are performed to demonstrate the feasibility and validity of this method. Analyses on key sensitivity and the resistance against to possible attacks are provided.

Authentication and Encryption Using Modified Elliptic Curve Cryptography with Particle Swarm Optimization and Cuckoo Search Algorithm

NASA Astrophysics Data System (ADS)

Kota, Sujatha; Padmanabhuni, Venkata Nageswara Rao; Budda, Kishor; K, Sruthi

2018-05-01

Elliptic Curve Cryptography (ECC) uses two keys private key and public key and is considered as a public key cryptographic algorithm that is used for both authentication of a person and confidentiality of data. Either one of the keys is used in encryption and other in decryption depending on usage. Private key is used in encryption by the user and public key is used to identify user in the case of authentication. Similarly, the sender encrypts with the private key and the public key is used to decrypt the message in case of confidentiality. Choosing the private key is always an issue in all public key Cryptographic Algorithms such as RSA, ECC. If tiny values are chosen in random the security of the complete algorithm becomes an issue. Since the Public key is computed based on the Private Key, if they are not chosen optimally they generate infinity values. The proposed Modified Elliptic Curve Cryptography uses selection in either of the choices; the first option is by using Particle Swarm Optimization and the second option is by using Cuckoo Search Algorithm for randomly choosing the values. The proposed algorithms are developed and tested using sample database and both are found to be secured and reliable. The test results prove that the private key is chosen optimally not repetitive or tiny and the computations in public key will not reach infinity.

QUANTUM CRYPTOGRAPHY: Single Photons.

PubMed

Benjamin, S

2000-12-22

Quantum cryptography offers the potential of totally secure transfer of information, but as Benjamin discusses in this Perspective, its practical implementation hinges on being able to generate single photons (rather than two or more) at a time. Michler et al. show how this condition can be met in a quantum dot microdisk structure. Single molecules were also recently shown to allow controlled single-photon emission.

Information flow and quantum cryptography using statistical fluctuations

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

Home, D.; Whitaker, M.A.B.

2003-02-01

A procedure is formulated, using the quantum teleportation arrangement, that communicates knowledge of an apparatus setting between the wings of the experiment, using statistical fluctuations in a sequence of measurement results. It requires an entangled state, and transmission of classical information totally unrelated to the apparatus setting actually communicated. Our procedure has conceptual interest, and has applications to quantum cryptography.

Entanglement-based Free Space Quantum Cryptography in Daylight

NASA Astrophysics Data System (ADS)

Gerhardt, Ilja; Peloso, Matthew P.; Ho, Caleb; Lamas-Linares, Antia; Kurtsiefer, Christian

2009-05-01

In quantum key distribution (QKD) two families of protocols are established: One, based on preparing and sending approximations of single photons, the other based on measurements on entangled photon pairs, which allow to establish a secret key using less assumptions on the size of a Hilbert space. The larger optical bandwidth of photon pairs in comparison with light used for the first family makes establishing a free space link challenging. We present a complete entanglement based QKD system following the BBM92 protocol, which generates a secure key continuously 24 hours a day between distant parties. Spectral, spatial and temporal filtering schemes were introduced to a previous setup, suppressing more than 30,B of background. We are able to establish the link during daytime, and have developed an algorithm to start and maintain time synchronization with simple crystal oscillators.

Design of an Elliptic Curve Cryptography processor for RFID tag chips.

PubMed

Liu, Zilong; Liu, Dongsheng; Zou, Xuecheng; Lin, Hui; Cheng, Jian

2014-09-26

Radio Frequency Identification (RFID) is an important technique for wireless sensor networks and the Internet of Things. Recently, considerable research has been performed in the combination of public key cryptography and RFID. In this paper, an efficient architecture of Elliptic Curve Cryptography (ECC) Processor for RFID tag chip is presented. We adopt a new inversion algorithm which requires fewer registers to store variables than the traditional schemes. A new method for coordinate swapping is proposed, which can reduce the complexity of the controller and shorten the time of iterative calculation effectively. A modified circular shift register architecture is presented in this paper, which is an effective way to reduce the area of register files. Clock gating and asynchronous counter are exploited to reduce the power consumption. The simulation and synthesis results show that the time needed for one elliptic curve scalar point multiplication over GF(2163) is 176.7 K clock cycles and the gate area is 13.8 K with UMC 0.13 μm Complementary Metal Oxide Semiconductor (CMOS) technology. Moreover, the low power and low cost consumption make the Elliptic Curve Cryptography Processor (ECP) a prospective candidate for application in the RFID tag chip.

Design of an Elliptic Curve Cryptography Processor for RFID Tag Chips

PubMed Central

Liu, Zilong; Liu, Dongsheng; Zou, Xuecheng; Lin, Hui; Cheng, Jian

2014-01-01

Radio Frequency Identification (RFID) is an important technique for wireless sensor networks and the Internet of Things. Recently, considerable research has been performed in the combination of public key cryptography and RFID. In this paper, an efficient architecture of Elliptic Curve Cryptography (ECC) Processor for RFID tag chip is presented. We adopt a new inversion algorithm which requires fewer registers to store variables than the traditional schemes. A new method for coordinate swapping is proposed, which can reduce the complexity of the controller and shorten the time of iterative calculation effectively. A modified circular shift register architecture is presented in this paper, which is an effective way to reduce the area of register files. Clock gating and asynchronous counter are exploited to reduce the power consumption. The simulation and synthesis results show that the time needed for one elliptic curve scalar point multiplication over GF(2163) is 176.7 K clock cycles and the gate area is 13.8 K with UMC 0.13 μm Complementary Metal Oxide Semiconductor (CMOS) technology. Moreover, the low power and low cost consumption make the Elliptic Curve Cryptography Processor (ECP) a prospective candidate for application in the RFID tag chip. PMID:25264952

Superlinear threshold detectors in quantum cryptography

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

Lydersen, Lars; Maroey, Oystein; Skaar, Johannes

2011-09-15

We introduce the concept of a superlinear threshold detector, a detector that has a higher probability to detect multiple photons if it receives them simultaneously rather than at separate times. Highly superlinear threshold detectors in quantum key distribution systems allow eavesdropping the full secret key without being revealed. Here, we generalize the detector control attack, and analyze how it performs against quantum key distribution systems with moderately superlinear detectors. We quantify the superlinearity in superconducting single-photon detectors based on earlier published data, and gated avalanche photodiode detectors based on our own measurements. The analysis shows that quantum key distribution systemsmore » using detector(s) of either type can be vulnerable to eavesdropping. The avalanche photodiode detector becomes superlinear toward the end of the gate. For systems expecting substantial loss, or for systems not monitoring loss, this would allow eavesdropping using trigger pulses containing less than 120 photons per pulse. Such an attack would be virtually impossible to catch with an optical power meter at the receiver entrance.« less

Efficient and universal quantum key distribution based on chaos and middleware

NASA Astrophysics Data System (ADS)

Jiang, Dong; Chen, Yuanyuan; Gu, Xuemei; Xie, Ling; Chen, Lijun

2017-01-01

Quantum key distribution (QKD) promises unconditionally secure communications, however, the low bit rate of QKD cannot meet the requirements of high-speed applications. Despite the many solutions that have been proposed in recent years, they are neither efficient to generate the secret keys nor compatible with other QKD systems. This paper, based on chaotic cryptography and middleware technology, proposes an efficient and universal QKD protocol that can be directly deployed on top of any existing QKD system without modifying the underlying QKD protocol and optical platform. It initially takes the bit string generated by the QKD system as input, periodically updates the chaotic system, and efficiently outputs the bit sequences. Theoretical analysis and simulation results demonstrate that our protocol can efficiently increase the bit rate of the QKD system as well as securely generate bit sequences with perfect statistical properties. Compared with the existing methods, our protocol is more efficient and universal, it can be rapidly deployed on the QKD system to increase the bit rate when the QKD system becomes the bottleneck of its communication system.

An Enhanced Biometric Based Authentication with Key-Agreement Protocol for Multi-Server Architecture Based on Elliptic Curve Cryptography

PubMed Central

Reddy, Alavalapati Goutham; Das, Ashok Kumar; Odelu, Vanga; Yoo, Kee-Young

2016-01-01

Biometric based authentication protocols for multi-server architectures have gained momentum in recent times due to advancements in wireless technologies and associated constraints. Lu et al. recently proposed a robust biometric based authentication with key agreement protocol for a multi-server environment using smart cards. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful investigation of this paper proves that Lu et al.’s protocol does not provide user anonymity, perfect forward secrecy and is susceptible to server and user impersonation attacks, man-in-middle attacks and clock synchronization problems. In addition, this paper proposes an enhanced biometric based authentication with key-agreement protocol for multi-server architecture based on elliptic curve cryptography using smartcards. We proved that the proposed protocol achieves mutual authentication using Burrows-Abadi-Needham (BAN) logic. The formal security of the proposed protocol is verified using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool to show that our protocol can withstand active and passive attacks. The formal and informal security analyses and performance analysis demonstrates that the proposed protocol is robust and efficient compared to Lu et al.’s protocol and existing similar protocols. PMID:27163786

Efficient Cryptography for the Next Generation Secure Cloud

ERIC Educational Resources Information Center

Kupcu, Alptekin

2010-01-01

Peer-to-peer (P2P) systems, and client-server type storage and computation outsourcing constitute some of the major applications that the next generation cloud schemes will address. Since these applications are just emerging, it is the perfect time to design them with security and privacy in mind. Furthermore, considering the high-churn…

Optimality of Gaussian attacks in continuous-variable quantum cryptography.

PubMed

Navascués, Miguel; Grosshans, Frédéric; Acín, Antonio

2006-11-10

We analyze the asymptotic security of the family of Gaussian modulated quantum key distribution protocols for continuous-variables systems. We prove that the Gaussian unitary attack is optimal for all the considered bounds on the key rate when the first and second momenta of the canonical variables involved are known by the honest parties.

Three-pass protocol scheme for bitmap image security by using vernam cipher algorithm

NASA Astrophysics Data System (ADS)

Rachmawati, D.; Budiman, M. A.; Aulya, L.

2018-02-01

Confidentiality, integrity, and efficiency are the crucial aspects of data security. Among the other digital data, image data is too prone to abuse of operation like duplication, modification, etc. There are some data security techniques, one of them is cryptography. The security of Vernam Cipher cryptography algorithm is very dependent on the key exchange process. If the key is leaked, security of this algorithm will collapse. Therefore, a method that minimizes key leakage during the exchange of messages is required. The method which is used, is known as Three-Pass Protocol. This protocol enables message delivery process without the key exchange. Therefore, the sending messages process can reach the receiver safely without fear of key leakage. The system is built by using Java programming language. The materials which are used for system testing are image in size 200×200 pixel, 300×300 pixel, 500×500 pixel, 800×800 pixel and 1000×1000 pixel. The result of experiments showed that Vernam Cipher algorithm in Three-Pass Protocol scheme could restore the original image.

Remote creation of hybrid entanglement between particle-like and wave-like optical qubits

NASA Astrophysics Data System (ADS)

Morin, Olivier; Huang, Kun; Liu, Jianli; Le Jeannic, Hanna; Fabre, Claude; Laurat, Julien

2014-07-01

The wave-particle duality of light has led to two different encodings for optical quantum information processing. Several approaches have emerged based either on particle-like discrete-variable states (that is, finite-dimensional quantum systems) or on wave-like continuous-variable states (that is, infinite-dimensional systems). Here, we demonstrate the generation of entanglement between optical qubits of these different types, located at distant places and connected by a lossy channel. Such hybrid entanglement, which is a key resource for a variety of recently proposed schemes, including quantum cryptography and computing, enables information to be converted from one Hilbert space to the other via teleportation and therefore the connection of remote quantum processors based upon different encodings. Beyond its fundamental significance for the exploration of entanglement and its possible instantiations, our optical circuit holds promise for implementations of heterogeneous network, where discrete- and continuous-variable operations and techniques can be efficiently combined.

Quantum key distribution using basis encoding of Gaussian-modulated coherent states

NASA Astrophysics Data System (ADS)

Huang, Peng; Huang, Jingzheng; Zhang, Zheshen; Zeng, Guihua

2018-04-01

The continuous-variable quantum key distribution (CVQKD) has been demonstrated to be available in practical secure quantum cryptography. However, its performance is restricted strongly by the channel excess noise and the reconciliation efficiency. In this paper, we present a quantum key distribution (QKD) protocol by encoding the secret keys on the random choices of two measurement bases: the conjugate quadratures X and P . The employed encoding method can dramatically weaken the effects of channel excess noise and reconciliation efficiency on the performance of the QKD protocol. Subsequently, the proposed scheme exhibits the capability to tolerate much higher excess noise and enables us to reach a much longer secure transmission distance even at lower reconciliation efficiency. The proposal can work alternatively to strengthen significantly the performance of the known Gaussian-modulated CVQKD protocol and serve as a multiplier for practical secure quantum cryptography with continuous variables.

Entropy-as-a-Service: Unlocking the Full Potential of Cryptography.

PubMed

Vassilev, Apostol; Staples, Robert

2016-09-01

Securing the Internet requires strong cryptography, which depends on the availability of good entropy for generating unpredictable keys and accurate clocks. Attacks abusing weak keys or old inputs portend challenges for the Internet. EaaS is a novel architecture providing entropy and timestamps from a decentralized root of trust, scaling gracefully across diverse geopolitical locales and remaining trustworthy unless much of the collective is compromised.

Multiphoton entanglement concentration and quantum cryptography.

PubMed

Durkin, Gabriel A; Simon, Christoph; Bouwmeester, Dik

2002-05-06

Multiphoton states from parametric down-conversion can be entangled both in polarization and photon number. Maximal high-dimensional entanglement can be concentrated postselectively from these states via photon counting. This makes them natural candidates for quantum key distribution, where the presence of more than one photon per detection interval has up to now been considered undesirable. We propose a simple multiphoton cryptography protocol for the case of low losses.

Experimental realization of counterfactual quantum cryptography Experimental realization of counterfactual quantum cryptography

NASA Astrophysics Data System (ADS)

Brida, G.; Cavanna, A.; Degiovanni, I. P.; Genovese, M.; Traina, P.

2012-03-01

In counterfactual quantum key distribution (CQKD) information is transferred, in a secure way, between Alice and Bob even when no particle carrying the information is in fact transmitted between them. In this letter we fully implement the scheme for CQKD proposed in [1], demonstrating for the first time that information can be transmitted between two parties without the transmission of a carrier.

Quantum cryptography: Security criteria reexamined

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

Kaszlikowski, Dagomir; Liang, Y.C.; Englert, Berthold-Georg

2004-09-01

We find that the generally accepted security criteria are flawed for a whole class of protocols for quantum cryptography. This is so because a standard assumption of the security analysis, namely that the so-called square-root measurement is optimal for eavesdropping purposes, is not true in general. There are rather large parameter regimes in which the optimal measurement extracts substantially more information than the square-root measurement.

Practical security analysis of continuous-variable quantum key distribution with jitter in clock synchronization

NASA Astrophysics Data System (ADS)

Xie, Cailang; Guo, Ying; Liao, Qin; Zhao, Wei; Huang, Duan; Zhang, Ling; Zeng, Guihua

2018-03-01

How to narrow the gap of security between theory and practice has been a notoriously urgent problem in quantum cryptography. Here, we analyze and provide experimental evidence of the clock jitter effect on the practical continuous-variable quantum key distribution (CV-QKD) system. The clock jitter is a random noise which exists permanently in the clock synchronization in the practical CV-QKD system, it may compromise the system security because of its impact on data sampling and parameters estimation. In particular, the practical security of CV-QKD with different clock jitter against collective attack is analyzed theoretically based on different repetition frequencies, the numerical simulations indicate that the clock jitter has more impact on a high-speed scenario. Furthermore, a simplified experiment is designed to investigate the influence of the clock jitter.

A New Image Encryption Technique Combining Hill Cipher Method, Morse Code and Least Significant Bit Algorithm

NASA Astrophysics Data System (ADS)

Nofriansyah, Dicky; Defit, Sarjon; Nurcahyo, Gunadi W.; Ganefri, G.; Ridwan, R.; Saleh Ahmar, Ansari; Rahim, Robbi

2018-01-01

Cybercrime is one of the most serious threats. Efforts are made to reduce the number of cybercrime is to find new techniques in securing data such as Cryptography, Steganography and Watermarking combination. Cryptography and Steganography is a growing data security science. A combination of Cryptography and Steganography is one effort to improve data integrity. New techniques are used by combining several algorithms, one of which is the incorporation of hill cipher method and Morse code. Morse code is one of the communication codes used in the Scouting field. This code consists of dots and lines. This is a new modern and classic concept to maintain data integrity. The result of the combination of these three methods is expected to generate new algorithms to improve the security of the data, especially images.

Fuzzy Commitment

NASA Astrophysics Data System (ADS)

Juels, Ari

The purpose of this chapter is to introduce fuzzy commitment, one of the earliest and simplest constructions geared toward cryptography over noisy data. The chapter also explores applications of fuzzy commitment to two problems in data security: (1) secure management of biometrics, with a focus on iriscodes, and (2) use of knowledge-based authentication (i.e., personal questions) for password recovery.

Quantum cryptography as a retrodiction problem.

PubMed

Werner, A H; Franz, T; Werner, R F

2009-11-27

We propose a quantum key distribution protocol based on a quantum retrodiction protocol, known as the Mean King problem. The protocol uses a two way quantum channel. We show security against coherent attacks in a transmission-error free scenario, even if Eve is allowed to attack both transmissions. This establishes a connection between retrodiction and key distribution.

Construction of Logarithm Tables for Galois Fields

ERIC Educational Resources Information Center

Torres-Jimenez, Jose; Rangel-Valdez, Nelson; Gonzalez-Hernandez, Ana Loreto; Avila-George, Himer

2011-01-01

A branch of mathematics commonly used in cryptography is Galois Fields GF(p[superscript n]). Two basic operations performed in GF(p[superscript n]) are the addition and the multiplication. While the addition is generally easy to compute, the multiplication requires a special treatment. A well-known method to compute the multiplication is based on…

A PKI Approach for Deploying Modern Secure Distributed E-Learning and M-Learning Environments

ERIC Educational Resources Information Center

Kambourakis, Georgios; Kontoni, Denise-Penelope N.; Rouskas, Angelos; Gritzalis, Stefanos

2007-01-01

While public key cryptography is continuously evolving and its installed base is growing significantly, recent research works examine its potential use in e-learning or m-learning environments. Public key infrastructure (PKI) and attribute certificates (ACs) can provide the appropriate framework to effectively support authentication and…

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

Jason L. Wright

Finding and identifying Cryptography is a growing concern in the malware analysis community. In this paper, a heuristic method for determining the likelihood that a given function contains a cryptographic algorithm is discussed and the results of applying this method in various environments is shown. The algorithm is based on frequency analysis of opcodes that make up each function within a binary.

Counterfactual quantum cryptography based on weak coherent states

NASA Astrophysics Data System (ADS)

Yin, Zhen-Qiang; Li, Hong-Wei; Yao, Yao; Zhang, Chun-Mei; Wang, Shuang; Chen, Wei; Guo, Guang-Can; Han, Zheng-Fu

2012-08-01

In the “counterfactual quantum cryptography” scheme [T.-G. Noh, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.103.230501 103, 230501 (2009)], two legitimate distant peers may share secret-key bits even when the information carriers do not travel in the quantum channel. The security of this protocol with an ideal single-photon source has been proved by Yin [Z.-Q. Yin, H. W. Li, W. Chen, Z. F. Han, and G. C. Guo, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.82.042335 82, 042335 (2010)]. In this paper, we prove the security of the counterfactual-quantum-cryptography scheme based on a commonly used weak-coherent-laser source by considering a general collective attack. The basic assumption of this proof is that the efficiency and dark-counting rate of a single-photon detector are consistent for any n-photon Fock states. Then through randomizing the phases of the encoding weak coherent states, Eve's ancilla will be transformed into a classical mixture. Finally, the lower bound of the secret-key-bit rate and a performance analysis for the practical implementation are both given.

Reservoir computing on the hypersphere

NASA Astrophysics Data System (ADS)

Andrecut, M.

Reservoir Computing (RC) refers to a Recurrent Neural Network (RNNs) framework, frequently used for sequence learning and time series prediction. The RC system consists of a random fixed-weight RNN (the input-hidden reservoir layer) and a classifier (the hidden-output readout layer). Here, we focus on the sequence learning problem, and we explore a different approach to RC. More specifically, we remove the nonlinear neural activation function, and we consider an orthogonal reservoir acting on normalized states on the unit hypersphere. Surprisingly, our numerical results show that the system’s memory capacity exceeds the dimensionality of the reservoir, which is the upper bound for the typical RC approach based on Echo State Networks (ESNs). We also show how the proposed system can be applied to symmetric cryptography problems, and we include a numerical implementation.

Secure quantum key distribution

NASA Astrophysics Data System (ADS)

Lo, Hoi-Kwong; Curty, Marcos; Tamaki, Kiyoshi

2014-08-01

Secure communication is crucial in the Internet Age, and quantum mechanics stands poised to revolutionize cryptography as we know it today. In this Review, we introduce the motivation and the current state of the art of research in quantum cryptography. In particular, we discuss the present security model together with its assumptions, strengths and weaknesses. After briefly introducing recent experimental progress and challenges, we survey the latest developments in quantum hacking and countermeasures against it.

Entropy-as-a-Service: Unlocking the Full Potential of Cryptography

PubMed Central

Vassilev, Apostol; Staples, Robert

2016-01-01

Securing the Internet requires strong cryptography, which depends on the availability of good entropy for generating unpredictable keys and accurate clocks. Attacks abusing weak keys or old inputs portend challenges for the Internet. EaaS is a novel architecture providing entropy and timestamps from a decentralized root of trust, scaling gracefully across diverse geopolitical locales and remaining trustworthy unless much of the collective is compromised. PMID:28003687

Symmetric and asymmetric hybrid cryptosystem based on compressive sensing and computer generated holography

NASA Astrophysics Data System (ADS)

Ma, Lihong; Jin, Weimin

2018-01-01

A novel symmetric and asymmetric hybrid optical cryptosystem is proposed based on compressive sensing combined with computer generated holography. In this method there are six encryption keys, among which two decryption phase masks are different from the two random phase masks used in the encryption process. Therefore, the encryption system has the feature of both symmetric and asymmetric cryptography. On the other hand, because computer generated holography can flexibly digitalize the encrypted information and compressive sensing can significantly reduce data volume, what is more, the final encryption image is real function by phase truncation, the method favors the storage and transmission of the encryption data. The experimental results demonstrate that the proposed encryption scheme boosts the security and has high robustness against noise and occlusion attacks.

Public-channel cryptography based on mutual chaos pass filters.

PubMed

Klein, Einat; Gross, Noam; Kopelowitz, Evi; Rosenbluh, Michael; Khaykovich, Lev; Kinzel, Wolfgang; Kanter, Ido

2006-10-01

We study the mutual coupling of chaotic lasers and observe both experimentally and in numeric simulations that there exists a regime of parameters for which two mutually coupled chaotic lasers establish isochronal synchronization, while a third laser coupled unidirectionally to one of the pair does not synchronize. We then propose a cryptographic scheme, based on the advantage of mutual coupling over unidirectional coupling, where all the parameters of the system are public knowledge. We numerically demonstrate that in such a scheme the two communicating lasers can add a message signal (compressed binary message) to the transmitted coupling signal and recover the message in both directions with high fidelity by using a mutual chaos pass filter procedure. An attacker, however, fails to recover an errorless message even if he amplifies the coupling signal.

A quantum light-emitting diode for the standard telecom window around 1,550 nm.

PubMed

Müller, T; Skiba-Szymanska, J; Krysa, A B; Huwer, J; Felle, M; Anderson, M; Stevenson, R M; Heffernan, J; Ritchie, D A; Shields, A J

2018-02-28

Single photons and entangled photon pairs are a key resource of many quantum secure communication and quantum computation protocols, and non-Poissonian sources emitting in the low-loss wavelength region around 1,550 nm are essential for the development of fibre-based quantum network infrastructure. However, reaching this wavelength window has been challenging for semiconductor-based quantum light sources. Here we show that quantum dot devices based on indium phosphide are capable of electrically injected single photon emission in this wavelength region. Using the biexciton cascade mechanism, they also produce entangled photons with a fidelity of 87 ± 4%, sufficient for the application of one-way error correction protocols. The material system further allows for entangled photon generation up to an operating temperature of 93 K. Our quantum photon source can be directly integrated with existing long distance quantum communication and cryptography systems, and provides a promising material platform for developing future quantum network hardware.

Practical Computer Security through Cryptography

NASA Technical Reports Server (NTRS)

McNab, David; Twetev, David (Technical Monitor)

1998-01-01

The core protocols upon which the Internet was built are insecure. Weak authentication and the lack of low level encryption services introduce vulnerabilities that propagate upwards in the network stack. Using statistics based on CERT/CC Internet security incident reports, the relative likelihood of attacks via these vulnerabilities is analyzed. The primary conclusion is that the standard UNIX BSD-based authentication system is by far the most commonly exploited weakness. Encryption of Sensitive password data and the adoption of cryptographically-based authentication protocols can greatly reduce these vulnerabilities. Basic cryptographic terminology and techniques are presented, with attention focused on the ways in which technology such as encryption and digital signatures can be used to protect against the most commonly exploited vulnerabilities. A survey of contemporary security software demonstrates that tools based on cryptographic techniques, such as Kerberos, ssh, and PGP, are readily available and effectively close many of the most serious security holes. Nine practical recommendations for improving security are described.

Virtual-optical information security system based on public key infrastructure

NASA Astrophysics Data System (ADS)

Peng, Xiang; Zhang, Peng; Cai, Lilong; Niu, Hanben

2005-01-01

A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.

Measurement-device-independent quantum cryptography

DOE PAGES

Xu, Feihu; Curty, Marcos; Qi, Bing; ...

2014-12-18

In theory, quantum key distribution (QKD) provides information-theoretic security based on the laws of physics. Owing to the imperfections of real-life implementations, however, there is a big gap between the theory and practice of QKD, which has been recently exploited by several quantum hacking activities. To fill this gap, a novel approach, called measurement-device-independent QKD (mdiQKD), has been proposed. In addition, it can remove all side-channels from the measurement unit, arguably the most vulnerable part in QKD systems, thus offering a clear avenue toward secure QKD realisations. In this study, we review the latest developments in the framework of mdiQKD,more » together with its assumptions, strengths, and weaknesses.« less

Quantum random bit generation using energy fluctuations in stimulated Raman scattering.

PubMed

Bustard, Philip J; England, Duncan G; Nunn, Josh; Moffatt, Doug; Spanner, Michael; Lausten, Rune; Sussman, Benjamin J

2013-12-02

Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond.

High-visibility two-photon interference at a telecom wavelength using picosecond-regime separated sources

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

Aboussouan, Pierre; Alibart, Olivier; Ostrowsky, Daniel B.

We report on a two-photon interference experiment in a quantum relay configuration using two picosecond regime periodically poled lithium niobate (PPLN) waveguide based sources emitting paired photons at 1550 nm. The results show that the picosecond regime associated with a guided-wave scheme should have important repercussions for quantum relay implementations in real conditions, essential for improving both the working distance and the efficiency of quantum cryptography and networking systems. In contrast to already reported regimes, namely, femtosecond and CW, it allows achieving a 99% net visibility two-photon interference while maintaining a high effective photon pair rate using only standard telecommore » components and detectors.« less

Long-distance continuous-variable quantum key distribution by controlling excess noise

NASA Astrophysics Data System (ADS)

Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua

2016-01-01

Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network.

Long-distance continuous-variable quantum key distribution by controlling excess noise.

PubMed

Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua

2016-01-13

Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network.

Long-distance continuous-variable quantum key distribution by controlling excess noise

PubMed Central

Huang, Duan; Huang, Peng; Lin, Dakai; Zeng, Guihua

2016-01-01

Quantum cryptography founded on the laws of physics could revolutionize the way in which communication information is protected. Significant progresses in long-distance quantum key distribution based on discrete variables have led to the secure quantum communication in real-world conditions being available. However, the alternative approach implemented with continuous variables has not yet reached the secure distance beyond 100 km. Here, we overcome the previous range limitation by controlling system excess noise and report such a long distance continuous-variable quantum key distribution experiment. Our result paves the road to the large-scale secure quantum communication with continuous variables and serves as a stepping stone in the quest for quantum network. PMID:26758727

Increasing complexity with quantum physics.

PubMed

Anders, Janet; Wiesner, Karoline

2011-09-01

We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task.

Entangled state quantum cryptography: eavesdropping on the ekert protocol

PubMed

Naik; Peterson; White; Berglund; Kwiat

2000-05-15

Using polarization-entangled photons from spontaneous parametric down-conversion, we have implemented Ekert's quantum cryptography protocol. The near-perfect correlations of the photons allow the sharing of a secret key between two parties. The presence of an eavesdropper is continually checked by measuring Bell's inequalities. We investigated several possible eavesdropper strategies, including pseudo-quantum-nondemolition measurements. In all cases, the eavesdropper's presence was readily apparent. We discuss a procedure to increase her detectability.

Nonequivalence of two flavors of oblivious transfer at the quantum level

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

He Guangping; Wang, Z. D.; Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong

2006-04-15

Though all-or-nothing oblivious transfer and one-out-of-two oblivious transfer are equivalent in classical cryptography, we here show that a protocol built upon secure quantum all-or-nothing oblivious transfer cannot satisfy the rigorous definition of quantum one-out-of-two oblivious transfer due to the nature of quantum cryptography. Thus the securities of the two oblivious transfer protocols are not equivalent at the quantum level.

Spatiotemporal chaos in mixed linear-nonlinear two-dimensional coupled logistic map lattice

NASA Astrophysics Data System (ADS)

Zhang, Ying-Qian; He, Yi; Wang, Xing-Yuan

2018-01-01

We investigate a new spatiotemporal dynamics with mixing degrees of nonlinear chaotic maps for spatial coupling connections based on 2DCML. Here, the coupling methods are including with linear neighborhood coupling and the nonlinear chaotic map coupling of lattices, and the former 2DCML system is only a special case in the proposed system. In this paper the criteria such Kolmogorov-Sinai entropy density and universality, bifurcation diagrams, space-amplitude and snapshot pattern diagrams are provided in order to investigate the chaotic behaviors of the proposed system. Furthermore, we also investigate the parameter ranges of the proposed system which holds those features in comparisons with those of the 2DCML system and the MLNCML system. Theoretical analysis and computer simulation indicate that the proposed system contains features such as the higher percentage of lattices in chaotic behaviors for most of parameters, less periodic windows in bifurcation diagrams and the larger range of parameters for chaotic behaviors, which is more suitable for cryptography.

Practicality of quantum information processing

NASA Astrophysics Data System (ADS)

Lau, Hoi-Kwan

Quantum Information Processing (QIP) is expected to bring revolutionary enhancement to various technological areas. However, today's QIP applications are far from being practical. The problem involves both hardware issues, i.e., quantum devices are imperfect, and software issues, i.e., the functionality of some QIP applications is not fully understood. Aiming to improve the practicality of QIP, in my PhD research I have studied various topics in quantum cryptography and ion trap quantum computation. In quantum cryptography, I first studied the security of position-based quantum cryptography (PBQC). I discovered a wrong assumption in the previous literature that the cheaters are not allowed to share entangled resources. I proposed entanglement attacks that could cheat all known PBQC protocols. I also studied the practicality of continuous-variable (CV) quantum secret sharing (QSS). While the security of CV QSS was considered by the literature only in the limit of infinite squeezing, I found that finitely squeezed CV resources could also provide finite secret sharing rate. Our work relaxes the stringent resources requirement of implementing QSS. In ion trap quantum computation, I studied the phase error of quantum information induced by dc Stark effect during ion transportation. I found an optimized ion trajectory for which the phase error is the minimum. I also defined a threshold speed, above which ion transportation would induce significant error. In addition, I proposed a new application for ion trap systems as universal bosonic simulators (UBS). I introduced two architectures, and discussed their respective strength and weakness. I illustrated the implementations of bosonic state initialization, transformation, and measurement by applying radiation fields or by varying the trap potential. When comparing with conducting optical experiments, the ion trap UBS is advantageous in higher state initialization efficiency and higher measurement accuracy. Finally, I proposed a new method to re-cool ion qubits during quantum computation. The idea is to transfer the motional excitation of a qubit to another ion that is prepared in the motional ground state. I showed that my method could be ten times faster than current laser cooling techniques, and thus could improve the speed of ion trap quantum computation.

Quantum cryptography without switching.

PubMed

Weedbrook, Christian; Lance, Andrew M; Bowen, Warwick P; Symul, Thomas; Ralph, Timothy C; Lam, Ping Koy

2004-10-22

We propose a new coherent state quantum key distribution protocol that eliminates the need to randomly switch between measurement bases. This protocol provides significantly higher secret key rates with increased bandwidths than previous schemes that only make single quadrature measurements. It also offers the further advantage of simplicity compared to all previous protocols which, to date, have relied on switching.

Quantum-chaotic cryptography

NASA Astrophysics Data System (ADS)

de Oliveira, G. L.; Ramos, R. V.

2018-03-01

In this work, it is presented an optical scheme for quantum key distribution employing two synchronized optoelectronic oscillators (OEO) working in the chaotic regime. The produced key depends on the chaotic dynamic, and the synchronization between Alice's and Bob's OEOs uses quantum states. An attack on the synchronization signals will disturb the synchronization of the chaotic systems increasing the error rate in the final key.

Experimental realization of a highly secure chaos communication under strong channel noise

NASA Astrophysics Data System (ADS)

Ye, Weiping; Dai, Qionglin; Wang, Shihong; Lu, Huaping; Kuang, Jinyu; Zhao, Zhenfeng; Zhu, Xiangqing; Tang, Guoning; Huang, Ronghuai; Hu, Gang

2004-09-01

A one-way coupled spatiotemporally chaotic map lattice is used to construct cryptosystem. With the combinatorial applications of both chaotic computations and conventional algebraic operations, our system has optimal cryptographic properties much better than the separative applications of known chaotic and conventional methods. We have realized experiments to practice duplex voice secure communications in realistic Wired Public Switched Telephone Network by applying our chaotic system and the system of Advanced Encryption Standard (AES), respectively, for cryptography. Our system can work stably against strong channel noise when AES fails to work.

Experimental quantum secret sharing and third-man quantum cryptography.

PubMed

Chen, Yu-Ao; Zhang, An-Ning; Zhao, Zhi; Zhou, Xiao-Qi; Lu, Chao-Yang; Peng, Cheng-Zhi; Yang, Tao; Pan, Jian-Wei

2005-11-11

Quantum secret sharing (QSS) and third-man quantum cryptography (TQC) are essential for advanced quantum communication; however, the low intensity and fragility of the multiphoton entanglement source in previous experiments have made their realization an extreme experimental challenge. Here, we develop and exploit an ultrastable high intensity source of four-photon entanglement to report an experimental realization of QSS and TQC. The technology developed in our experiment will be important for future multiparty quantum communication.

Quantum Cryptography Based on the Deutsch-Jozsa Algorithm

NASA Astrophysics Data System (ADS)

Nagata, Koji; Nakamura, Tadao; Farouk, Ahmed

2017-09-01

Recently, secure quantum key distribution based on Deutsch's algorithm using the Bell state is reported (Nagata and Nakamura, Int. J. Theor. Phys. doi: 10.1007/s10773-017-3352-4, 2017). Our aim is of extending the result to a multipartite system. In this paper, we propose a highly speedy key distribution protocol. We present sequre quantum key distribution based on a special Deutsch-Jozsa algorithm using Greenberger-Horne-Zeilinger states. Bob has promised to use a function f which is of one of two kinds; either the value of f( x) is constant for all values of x, or else the value of f( x) is balanced, that is, equal to 1 for exactly half of the possible x, and 0 for the other half. Here, we introduce an additional condition to the function when it is balanced. Our quantum key distribution overcomes a classical counterpart by a factor O(2 N ).

Practical implementation of multilevel quantum cryptography

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

Kulik, S. P.; Maslennikov, G. A.; Moreva, E. V.

2006-05-15

The physical principles of a quantum key distribution protocol using four-level optical systems are discussed. Quantum information is encoded into polarization states created by frequency-nondegenerate spontaneous parametric down-conversion in collinear geometry. In the scheme under analysis, the required nonorthogonal states are generated in a single nonlinear crystal. All states in the selected basis are measured deterministically. The results of initial experiments on transformation of the basis polarization states of a four-level optical system are discussed.

Effect of source tampering in the security of quantum cryptography

NASA Astrophysics Data System (ADS)

Sun, Shi-Hai; Xu, Feihu; Jiang, Mu-Sheng; Ma, Xiang-Chun; Lo, Hoi-Kwong; Liang, Lin-Mei

2015-08-01

The security of source has become an increasingly important issue in quantum cryptography. Based on the framework of measurement-device-independent quantum key distribution (MDI-QKD), the source becomes the only region exploitable by a potential eavesdropper (Eve). Phase randomization is a cornerstone assumption in most discrete-variable (DV) quantum communication protocols (e.g., QKD, quantum coin tossing, weak-coherent-state blind quantum computing, and so on), and the violation of such an assumption is thus fatal to the security of those protocols. In this paper, we show a simple quantum hacking strategy, with commercial and homemade pulsed lasers, by Eve that allows her to actively tamper with the source and violate such an assumption, without leaving a trace afterwards. Furthermore, our attack may also be valid for continuous-variable (CV) QKD, which is another main class of QKD protocol, since, excepting the phase random assumption, other parameters (e.g., intensity) could also be changed, which directly determine the security of CV-QKD.

Generalized optical angular momentum sorter and its application to high-dimensional quantum cryptography.

PubMed

Larocque, Hugo; Gagnon-Bischoff, Jérémie; Mortimer, Dominic; Zhang, Yingwen; Bouchard, Frédéric; Upham, Jeremy; Grillo, Vincenzo; Boyd, Robert W; Karimi, Ebrahim

2017-08-21

The orbital angular momentum (OAM) carried by optical beams is a useful quantity for encoding information. This form of encoding has been incorporated into various works ranging from telecommunications to quantum cryptography, most of which require methods that can rapidly process the OAM content of a beam. Among current state-of-the-art schemes that can readily acquire this information are so-called OAM sorters, which consist of devices that spatially separate the OAM components of a beam. Such devices have found numerous applications in optical communications, a field that is in constant demand for additional degrees of freedom, such as polarization and wavelength, into which information can also be encoded. Here, we report the implementation of a device capable of sorting a beam based on its OAM and polarization content, which could be of use in works employing both of these degrees of freedom as information channels. After characterizing our fabricated device, we demonstrate how it can be used for quantum communications via a quantum key distribution protocol.

IBE-Lite: a lightweight identity-based cryptography for body sensor networks.

PubMed

Tan, Chiu C; Wang, Haodong; Zhong, Sheng; Li, Qun

2009-11-01

A body sensor network (BSN) is a network of sensors deployed on a person's body for health care monitoring. Since the sensors collect personal medical data, security and privacy are important components in a BSN. In this paper, we developed IBE-Lite, a lightweight identity-based encryption suitable for sensors in a BSN. We present protocols based on IBE-Lite that balance security and privacy with accessibility and perform evaluation using experiments conducted on commercially available sensors.

Cryptography based on the absorption/emission features of multicolor semiconductor nanocrystal quantum dots.

PubMed

Zhou, Ming; Chang, Shoude; Grover, Chander

2004-06-28

Further to the optical coding based on fluorescent semiconductor quantum dots (QDs), a concept of using mixtures of multiple single-color QDs for creating highly secret cryptograms based on their absorption/emission properties was demonstrated. The key to readout of the optical codes is a group of excitation lights with the predetermined wavelengths programmed in a secret manner. The cryptograms can be printed on the surfaces of different objects such as valuable documents for security purposes.

A user anonymity preserving three-factor authentication scheme for telecare medicine information systems.

PubMed

Tan, Zuowen

2014-03-01

The telecare medicine information system enables the patients gain health monitoring at home and access medical services over internet or mobile networks. In recent years, the schemes based on cryptography have been proposed to address the security and privacy issues in the telecare medicine information systems. However, many schemes are insecure or they have low efficiency. Recently, Awasthi and Srivastava proposed a three-factor authentication scheme for telecare medicine information systems. In this paper, we show that their scheme is vulnerable to the reflection attacks. Furthermore, it fails to provide three-factor security and the user anonymity. We propose a new three-factor authentication scheme for the telecare medicine information systems. Detailed analysis demonstrates that the proposed scheme provides mutual authentication, server not knowing password and freedom of password, biometric update and three-factor security. Moreover, the new scheme provides the user anonymity. As compared with the previous three-factor authentication schemes, the proposed scheme is more secure and practical.

Comment on "Cheating prevention in visual cryptography".

PubMed

Chen, Yu-Chi; Horng, Gwoboa; Tsai, Du-Shiau

2012-07-01

Visual cryptography (VC), proposed by Naor and Shamir, has numerous applications, including visual authentication and identification, steganography, and image encryption. In 2006, Horng showed that cheating is possible in VC, where some participants can deceive the remaining participants by forged transparencies. Since then, designing cheating-prevention visual secret-sharing (CPVSS) schemes has been studied by many researchers. In this paper, we cryptanalyze the Hu-Tzeng CPVSS scheme and show that it is not cheating immune. We also outline an improvement that helps to overcome the problem.

Relativistic quantum cryptography

NASA Astrophysics Data System (ADS)

Kaniewski, Jedrzej

Special relativity states that information cannot travel faster than the speed of light, which means that communication between agents occupying distinct locations incurs some minimal delay. Alternatively, we can see it as temporary communication constraints between distinct agents and such constraints turn out to be useful for cryptographic purposes. In relativistic cryptography we consider protocols in which interactions occur at distinct locations at well-defined times and we investigate why such a setting allows to implement primitives which would not be possible otherwise. (Abstract shortened by UMI.).

Entangled State Quantum Cryptography: Eavesdropping on the Ekert Protocol

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

Naik, D. S.; Peterson, C. G.; White, A. G.

2000-05-15

Using polarization-entangled photons from spontaneous parametric down-conversion, we have implemented Ekert's quantum cryptography protocol. The near-perfect correlations of the photons allow the sharing of a secret key between two parties. The presence of an eavesdropper is continually checked by measuring Bell's inequalities. We investigated several possible eavesdropper strategies, including pseudo-quantum-nondemolition measurements. In all cases, the eavesdropper's presence was readily apparent. We discuss a procedure to increase her detectability. (c) 2000 The American Physical Society.

Attribute-Based Proxy Re-Encryption with Keyword Search

PubMed Central

Shi, Yanfeng; Liu, Jiqiang; Han, Zhen; Zheng, Qingji; Zhang, Rui; Qiu, Shuo

2014-01-01

Keyword search on encrypted data allows one to issue the search token and conduct search operations on encrypted data while still preserving keyword privacy. In the present paper, we consider the keyword search problem further and introduce a novel notion called attribute-based proxy re-encryption with keyword search (), which introduces a promising feature: In addition to supporting keyword search on encrypted data, it enables data owners to delegate the keyword search capability to some other data users complying with the specific access control policy. To be specific, allows (i) the data owner to outsource his encrypted data to the cloud and then ask the cloud to conduct keyword search on outsourced encrypted data with the given search token, and (ii) the data owner to delegate other data users keyword search capability in the fine-grained access control manner through allowing the cloud to re-encrypted stored encrypted data with a re-encrypted data (embedding with some form of access control policy). We formalize the syntax and security definitions for , and propose two concrete constructions for : key-policy and ciphertext-policy . In the nutshell, our constructions can be treated as the integration of technologies in the fields of attribute-based cryptography and proxy re-encryption cryptography. PMID:25549257

Attribute-based proxy re-encryption with keyword search.

PubMed

Shi, Yanfeng; Liu, Jiqiang; Han, Zhen; Zheng, Qingji; Zhang, Rui; Qiu, Shuo

2014-01-01

Keyword search on encrypted data allows one to issue the search token and conduct search operations on encrypted data while still preserving keyword privacy. In the present paper, we consider the keyword search problem further and introduce a novel notion called attribute-based proxy re-encryption with keyword search (ABRKS), which introduces a promising feature: In addition to supporting keyword search on encrypted data, it enables data owners to delegate the keyword search capability to some other data users complying with the specific access control policy. To be specific, ABRKS allows (i) the data owner to outsource his encrypted data to the cloud and then ask the cloud to conduct keyword search on outsourced encrypted data with the given search token, and (ii) the data owner to delegate other data users keyword search capability in the fine-grained access control manner through allowing the cloud to re-encrypted stored encrypted data with a re-encrypted data (embedding with some form of access control policy). We formalize the syntax and security definitions for ABRKS, and propose two concrete constructions for ABRKS: key-policy ABRKS and ciphertext-policy ABRKS. In the nutshell, our constructions can be treated as the integration of technologies in the fields of attribute-based cryptography and proxy re-encryption cryptography.

High-Performance Single-Photon Sources via Spatial Multiplexing

DTIC Science & Technology

2014-01-01

ingredient for tasks such as quantum cryptography , quantum repeater, quantum teleportation, quantum computing, and truly-random number generation. Recently...SECURITY CLASSIFICATION OF: Single photons sources are desired for many potential quantum information applications. One common method to produce...photons sources are desired for many potential quantum information applications. One common method to produce single photons is based on a “heralding

The Analysis of Dimensionality Reduction Techniques in Cryptographic Object Code Classification

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

Jason L. Wright; Milos Manic

2010-05-01

This paper compares the application of three different dimension reduction techniques to the problem of locating cryptography in compiled object code. A simple classi?er is used to compare dimension reduction via sorted covariance, principal component analysis, and correlation-based feature subset selection. The analysis concentrates on the classi?cation accuracy as the number of dimensions is increased.

Secure open cloud in data transmission using reference pattern and identity with enhanced remote privacy checking

NASA Astrophysics Data System (ADS)

Vijay Singh, Ran; Agilandeeswari, L.

2017-11-01

To handle the large amount of client’s data in open cloud lots of security issues need to be address. Client’s privacy should not be known to other group members without data owner’s valid permission. Sometime clients are fended to have accessing with open cloud servers due to some restrictions. To overcome the security issues and these restrictions related to storing, data sharing in an inter domain network and privacy checking, we propose a model in this paper which is based on an identity based cryptography in data transmission and intermediate entity which have client’s reference with identity that will take control handling of data transmission in an open cloud environment and an extended remote privacy checking technique which will work at admin side. On behalf of data owner’s authority this proposed model will give best options to have secure cryptography in data transmission and remote privacy checking either as private or public or instructed. The hardness of Computational Diffie-Hellman assumption algorithm for key exchange makes this proposed model more secure than existing models which are being used for public cloud environment.

MedBlock: Efficient and Secure Medical Data Sharing Via Blockchain.

PubMed

Fan, Kai; Wang, Shangyang; Ren, Yanhui; Li, Hui; Yang, Yintang

2018-06-21

With the development of electronic information technology, electronic medical records (EMRs) have been a common way to store the patients' data in hospitals. They are stored in different hospitals' databases, even for the same patient. Therefore, it is difficult to construct a summarized EMR for one patient from multiple hospital databases due to the security and privacy concerns. Meanwhile, current EMRs systems lack a standard data management and sharing policy, making it difficult for pharmaceutical scientists to develop precise medicines based on data obtained under different policies. To solve the above problems, we proposed a blockchain-based information management system, MedBlock, to handle patients' information. In this scheme, the distributed ledger of MedBlock allows the efficient EMRs access and EMRs retrieval. The improved consensus mechanism achieves consensus of EMRs without large energy consumption and network congestion. In addition, MedBlock also exhibits high information security combining the customized access control protocols and symmetric cryptography. MedBlock can play an important role in the sensitive medical information sharing.

Research in Computer Forensics

DTIC Science & Technology

2002-06-01

systems and how they can aid in the recovery of digital evidence in a forensic analysis. Exposures to hacking techniques and tools in CS3675—Internet...cryptography, access control, authentication, biometrics, actions to be taken during an attack and case studies of hacking and information warfare. 11...chat, surfing, instant messaging and hacking with powerful access control and filter capabilities. The monitor can operates in a Prevention mode to

Wireless, amphibious theory for reinforcement learning

NASA Astrophysics Data System (ADS)

Li, Jinci

2013-10-01

Cryptographers agree that heterogeneous information are an interesting new topic in the field of cryptography, and biologists concur. Given the current status of stochastic epistemologies, security experts clearly desire the construction of flip-flop gates [1, 2, 3]. Mungo, our new system for authenticated algorithms, is the solution to all of these challenges. Though such a hypothesis at first glance seems perverse, it has ample historical precedence.

Source-Device-Independent Ultrafast Quantum Random Number Generation.

PubMed

Marangon, Davide G; Vallone, Giuseppe; Villoresi, Paolo

2017-02-10

Secure random numbers are a fundamental element of many applications in science, statistics, cryptography and more in general in security protocols. We present a method that enables the generation of high-speed unpredictable random numbers from the quadratures of an electromagnetic field without any assumption on the input state. The method allows us to eliminate the numbers that can be predicted due to the presence of classical and quantum side information. In particular, we introduce a procedure to estimate a bound on the conditional min-entropy based on the entropic uncertainty principle for position and momentum observables of infinite dimensional quantum systems. By the above method, we experimentally demonstrated the generation of secure true random bits at a rate greater than 1.7 Gbit/s.

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.

Optimized ECC Implementation for Secure Communication between Heterogeneous IoT Devices.

PubMed

Marin, Leandro; Pawlowski, Marcin Piotr; Jara, Antonio

2015-08-28

The Internet of Things is integrating information systems, places, users and billions of constrained devices into one global network. This network requires secure and private means of communications. The building blocks of the Internet of Things are devices manufactured by various producers and are designed to fulfil different needs. There would be no common hardware platform that could be applied in every scenario. In such a heterogeneous environment, there is a strong need for the optimization of interoperable security. We present optimized elliptic curve Cryptography algorithms that address the security issues in the heterogeneous IoT networks. We have combined cryptographic algorithms for the NXP/Jennic 5148- and MSP430-based IoT devices and used them to created novel key negotiation protocol.

Trojan horse attacks on counterfactual quantum key distribution

NASA Astrophysics Data System (ADS)

Yang, Xiuqing; Wei, Kejin; Ma, Haiqiang; Sun, Shihai; Du, Yungang; Wu, Lingan

2016-04-01

There has been much interest in ;counterfactual quantum cryptography; (T.-G. Noh, 2009 [10]). It seems that the counterfactual quantum key distribution protocol without any photon carrier through the quantum channel provides practical security advantages. However, we show that it is easy to break counterfactual quantum key distribution systems in practical situations. We introduce the two types of Trojan horse attacks that are available for the two-way protocol and become possible for practical counterfactual systems with our eavesdropping schemes.

Analysis of Multiple Data Hiding Combined Coloured Visual Cryptography and LSB

NASA Astrophysics Data System (ADS)

Maulana, Halim; Rahman Syahputra, Edy

2017-12-01

Currently the level of data security becoming a major factor in data transfer. As we know every process of sending data through any medium the risk of that data gets hacked will still be there. Some techniques for securing data such as steganography and cryptography also often used as a solution for securing data. But it does not last long because it has been found out the weaknesses of the algorithm so that the security be assured. So, in need of variety of new algorithms to be able to protect the data so that data security can be guaranteed. In this study tries to combine two visual algorithms that steganography and cryptography. Where in these experiments will try to secure two pieces of data type that is the type of image data and text data where both the data is regarded as a message so to obtain the correct information receiver should get that two types of data.

Design and Development of Layered Security: Future Enhancements and Directions in Transmission

PubMed Central

Shahzad, Aamir; Lee, Malrey; Kim, Suntae; Kim, Kangmin; Choi, Jae-Young; Cho, Younghwa; Lee, Keun-Kwang

2016-01-01

Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA) systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3) design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack. PMID:26751443

Design and Development of Layered Security: Future Enhancements and Directions in Transmission.

PubMed

Shahzad, Aamir; Lee, Malrey; Kim, Suntae; Kim, Kangmin; Choi, Jae-Young; Cho, Younghwa; Lee, Keun-Kwang

2016-01-06

Today, security is a prominent issue when any type of communication is being undertaken. Like traditional networks, supervisory control and data acquisition (SCADA) systems suffer from a number of vulnerabilities. Numerous end-to-end security mechanisms have been proposed for the resolution of SCADA-system security issues, but due to insecure real-time protocol use and the reliance upon open protocols during Internet-based communication, these SCADA systems can still be compromised by security challenges. This study reviews the security challenges and issues that are commonly raised during SCADA/protocol transmissions and proposes a secure distributed-network protocol version 3 (DNP3) design, and the implementation of the security solution using a cryptography mechanism. Due to the insecurities found within SCADA protocols, the new development consists of a DNP3 protocol that has been designed as a part of the SCADA system, and the cryptographically derived security is deployed within the application layer as a part of the DNP3 stack.

Permutation parity machines for neural cryptography.

PubMed

Reyes, Oscar Mauricio; Zimmermann, Karl-Heinz

2010-06-01

Recently, synchronization was proved for permutation parity machines, multilayer feed-forward neural networks proposed as a binary variant of the tree parity machines. This ability was already used in the case of tree parity machines to introduce a key-exchange protocol. In this paper, a protocol based on permutation parity machines is proposed and its performance against common attacks (simple, geometric, majority and genetic) is studied.

Permutation parity machines for neural cryptography

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

Reyes, Oscar Mauricio; Escuela de Ingenieria Electrica, Electronica y Telecomunicaciones, Universidad Industrial de Santander, Bucaramanga; Zimmermann, Karl-Heinz

2010-06-15

Recently, synchronization was proved for permutation parity machines, multilayer feed-forward neural networks proposed as a binary variant of the tree parity machines. This ability was already used in the case of tree parity machines to introduce a key-exchange protocol. In this paper, a protocol based on permutation parity machines is proposed and its performance against common attacks (simple, geometric, majority and genetic) is studied.

Experimental investigation of practical unforgeable quantum money

NASA Astrophysics Data System (ADS)

Bozzio, Mathieu; Orieux, Adeline; Trigo Vidarte, Luis; Zaquine, Isabelle; Kerenidis, Iordanis; Diamanti, Eleni

2018-01-01

Wiesner's unforgeable quantum money scheme is widely celebrated as the first quantum information application. Based on the no-cloning property of quantum mechanics, this scheme allows for the creation of credit cards used in authenticated transactions offering security guarantees impossible to achieve by classical means. However, despite its central role in quantum cryptography, its experimental implementation has remained elusive because of the lack of quantum memories and of practical verification techniques. Here, we experimentally implement a quantum money protocol relying on classical verification that rigorously satisfies the security condition for unforgeability. Our system exploits polarization encoding of weak coherent states of light and operates under conditions that ensure compatibility with state-of-the-art quantum memories. We derive working regimes for our system using a security analysis taking into account all practical imperfections. Our results constitute a major step towards a real-world realization of this milestone protocol.

On the vulnerability of basic quantum key distribution protocols and three protocols stable to attack with 'blinding' of avalanche photodetectors

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

Molotkov, S. N., E-mail: sergei.molotkov@gmail.com

2012-05-15

The fundamental quantum mechanics prohibitions on the measurability of quantum states allow secure key distribution between spatially remote users to be performed. Experimental and commercial implementations of quantum cryptography systems, however, use components that exist at the current technology level, in particular, one-photon avalanche photodetectors. These detectors are subject to the blinding effect. It was shown that all the known basic quantum key distribution protocols and systems based on them are vulnerable to attacks with blinding of photodetectors. In such attacks, an eavesdropper knows all the key transferred, does not produce errors at the reception side, and remains undetected. Threemore » protocols of quantum key distribution stable toward such attacks are suggested. The security of keys and detection of eavesdropping attempts are guaranteed by the internal structure of protocols themselves rather than additional technical improvements.« less

Revealing of photon-number splitting attack on quantum key distribution system by photon-number resolving devices

NASA Astrophysics Data System (ADS)

Gaidash, A. A.; Egorov, V. I.; Gleim, A. V.

2016-08-01

Quantum cryptography allows distributing secure keys between two users so that any performed eavesdropping attempt would be immediately discovered. However, in practice an eavesdropper can obtain key information from multi-photon states when attenuated laser radiation is used as a source of quantum states. In order to prevent actions of an eavesdropper, it is generally suggested to implement special cryptographic protocols, like decoy states or SARG04. In this paper, we describe an alternative method based on monitoring photon number statistics after detection. We provide a useful rule of thumb to estimate approximate order of difference of expected distribution and distribution in case of attack. Formula for calculating a minimum value of total pulses or time-gaps to resolve attack is shown. Also formulas for actual fraction of raw key known to Eve were derived. This method can therefore be used with any system and even combining with mentioned special protocols.

Quantum Information in Non-physics Departments at Liberal Arts Colleges

NASA Astrophysics Data System (ADS)

Westmoreland, Michael

2012-02-01

Quantum information and quantum computing have changed our thinking about the basic concepts of quantum physics. These fields have also introduced exciting new applications of quantum mechanics such as quantum cryptography and non-interactive measurement. It is standard to teach such topics only to advanced physics majors who have completed coursework in quantum mechanics. Recent encounters with teaching quantum cryptography to non-majors and a bout of textbook-writing suggest strategies for teaching this interesting material to those without the standard quantum mechanics background. This talk will share some of those strategies.

Cryptography; An Introductory Bibliography of Books and Periodical Articles.

DTIC Science & Technology

1982-06-05

Martin’s H25 Pr., c1976. D810 Johnson, Brian. The Secret War, N.Y., NY: Methuen, c1978. $2J6 D810 Jones, Reginald Victor. The Wizard War: British...Park Pr., c1976. UB290 Langie, Andre. Cryptography, London, Eng.: Constable & L3 Co., Ltd., c1922. D810 Lawson, Don. The Secret World War II, N.Y., NY...Writing, N.Y., NY: W.W. Norton & Co., c1943. Z6724 Smith, Myron J., Jr. The Secret Wars, Vol. 1: Intelligence, I7 Propaganda and Psychological Warfare

One-way entangled-photon autocompensating quantum cryptography

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

Walton, Zachary D.; Abouraddy, Ayman F.; Sergienko, Alexander V.

2003-06-01

A quantum cryptography implementation is presented that uses entanglement to combine one-way operation with an autocompensating feature that has hitherto only been available in implementations that require the signal to make a round trip between the users. Using the concept of advanced waves, it is shown that this proposed implementation is related to the round-trip implementation in the same way that Ekert's two-particle scheme is related to the original one-particle scheme of Bennett and Brassard. The practical advantages and disadvantages of the proposed implementation are discussed in the context of existing schemes.

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.

High-Rate Strong-Signal Quantum Cryptography

NASA Technical Reports Server (NTRS)

Yuen, Horace P.

1996-01-01

Several quantum cryptosystems utilizing different kinds of nonclassical lights, which can accommodate high intensity fields and high data rate, are described. However, they are all sensitive to loss and both the high rate and the strong-signal character rapidly disappear. A squeezed light homodyne detection scheme is proposed which, with present-day technology, leads to more than two orders of magnitude data rate improvement over other current experimental systems for moderate loss.

Performance Analysis and Optimization of the Winnow Secret Key Reconciliation Protocol

DTIC Science & Technology

2011-06-01

use in a quantum key system can be defined in two ways :  The number of messages passed between Alice and Bob  The...classical and quantum environment. Post- quantum cryptography , which is generally used to describe classical quantum -resilient protocols, includes...composed of a one- way quantum channel and a two - way classical channel. Owing to the physics of the channel, the quantum channel is subject to

PRISMATIC: Unified Hierarchical Probabilistic Verification Tool

DTIC Science & Technology

2011-09-01

security protocols such as for anonymity and quantum cryptography ; and biological reaction pathways. PRISM is currently the leading probabilistic...a whole will only deadlock and fail with a probability ≤ p/2. The assumption allows us to partition the overall system verification problem into two ...run on any port using the standard HTTP protocol. In this way multiple instances of the PRISMATIC web service can respond to different requests when

Meeting the security requirements of electronic medical records in the ERA of high-speed computing.

PubMed

Alanazi, H O; Zaidan, A A; Zaidan, B B; Kiah, M L Mat; Al-Bakri, S H

2015-01-01

This study has two objectives. First, it aims to develop a system with a highly secured approach to transmitting electronic medical records (EMRs), and second, it aims to identify entities that transmit private patient information without permission. The NTRU and the Advanced Encryption Standard (AES) cryptosystems are secured encryption methods. The AES is a tested technology that has already been utilized in several systems to secure sensitive data. The United States government has been using AES since June 2003 to protect sensitive and essential information. Meanwhile, NTRU protects sensitive data against attacks through the use of quantum computers, which can break the RSA cryptosystem and elliptic curve cryptography algorithms. A hybrid of AES and NTRU is developed in this work to improve EMR security. The proposed hybrid cryptography technique is implemented to secure the data transmission process of EMRs. The proposed security solution can provide protection for over 40 years and is resistant to quantum computers. Moreover, the technique provides the necessary evidence required by law to identify disclosure or misuse of patient records. The proposed solution can effectively secure EMR transmission and protect patient rights. It also identifies the source responsible for disclosing confidential patient records. The proposed hybrid technique for securing data managed by institutional websites must be improved in the future.

Successful attack on permutation-parity-machine-based neural cryptography.

PubMed

Seoane, Luís F; Ruttor, Andreas

2012-02-01

An algorithm is presented which implements a probabilistic attack on the key-exchange protocol based on permutation parity machines. Instead of imitating the synchronization of the communicating partners, the strategy consists of a Monte Carlo method to sample the space of possible weights during inner rounds and an analytic approach to convey the extracted information from one outer round to the next one. The results show that the protocol under attack fails to synchronize faster than an eavesdropper using this algorithm.

Symmetric Stream Cipher using Triple Transposition Key Method and Base64 Algorithm for Security Improvement

NASA Astrophysics Data System (ADS)

Nurdiyanto, Heri; Rahim, Robbi; Wulan, Nur

2017-12-01

Symmetric type cryptography algorithm is known many weaknesses in encryption process compared with asymmetric type algorithm, symmetric stream cipher are algorithm that works on XOR process between plaintext and key, to improve the security of symmetric stream cipher algorithm done improvisation by using Triple Transposition Key which developed from Transposition Cipher and also use Base64 algorithm for encryption ending process, and from experiment the ciphertext that produced good enough and very random.

Secret sharing based on quantum Fourier transform

NASA Astrophysics Data System (ADS)

Yang, Wei; Huang, Liusheng; Shi, Runhua; He, Libao

2013-07-01

Secret sharing plays a fundamental role in both secure multi-party computation and modern cryptography. We present a new quantum secret sharing scheme based on quantum Fourier transform. This scheme enjoys the property that each share of a secret is disguised with true randomness, rather than classical pseudorandomness. Moreover, under the only assumption that a top priority for all participants (secret sharers and recovers) is to obtain the right result, our scheme is able to achieve provable security against a computationally unbounded attacker.

A squeezed light source operated under high vacuum

PubMed Central

Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.

2015-01-01

Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments. PMID:26657616

A squeezed light source operated under high vacuum

NASA Astrophysics Data System (ADS)

Wade, Andrew R.; Mansell, Georgia L.; Chua, Sheon S. Y.; Ward, Robert L.; Slagmolen, Bram J. J.; Shaddock, Daniel A.; McClelland, David E.

2015-12-01

Non-classical squeezed states of light are becoming increasingly important to a range of metrology and other quantum optics applications in cryptography, quantum computation and biophysics. Applications such as improving the sensitivity of advanced gravitational wave detectors and the development of space-based metrology and quantum networks will require robust deployable vacuum-compatible sources. To date non-linear photonics devices operated under high vacuum have been simple single pass systems, testing harmonic generation and the production of classically correlated photon pairs for space-based applications. Here we demonstrate the production under high-vacuum conditions of non-classical squeezed light with an observed 8.6 dB of quantum noise reduction down to 10 Hz. Demonstration of a resonant non-linear optical device, for the generation of squeezed light under vacuum, paves the way to fully exploit the advantages of in-vacuum operations, adapting this technology for deployment into new extreme environments.

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.

Security Enhanced User Authentication Protocol for Wireless Sensor Networks Using Elliptic Curves Cryptography

PubMed Central

Choi, Younsung; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Nam, Junghyun; Won, Dongho

2014-01-01

Wireless sensor networks (WSNs) consist of sensors, gateways and users. Sensors are widely distributed to monitor various conditions, such as temperature, sound, speed and pressure but they have limited computational ability and energy. To reduce the resource use of sensors and enhance the security of WSNs, various user authentication protocols have been proposed. In 2011, Yeh et al. first proposed a user authentication protocol based on elliptic curve cryptography (ECC) for WSNs. However, it turned out that Yeh et al.'s protocol does not provide mutual authentication, perfect forward secrecy, and key agreement between the user and sensor. Later in 2013, Shi et al. proposed a new user authentication protocol that improves both security and efficiency of Yeh et al.'s protocol. However, Shi et al.'s improvement introduces other security weaknesses. In this paper, we show that Shi et al.'s improved protocol is vulnerable to session key attack, stolen smart card attack, and sensor energy exhausting attack. In addition, we propose a new, security-enhanced user authentication protocol using ECC for WSNs. PMID:24919012

Security enhanced user authentication protocol for wireless sensor networks using elliptic curves cryptography.

PubMed

Choi, Younsung; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Nam, Junghyun; Won, Dongho

2014-06-10

Wireless sensor networks (WSNs) consist of sensors, gateways and users. Sensors are widely distributed to monitor various conditions, such as temperature, sound, speed and pressure but they have limited computational ability and energy. To reduce the resource use of sensors and enhance the security of WSNs, various user authentication protocols have been proposed. In 2011, Yeh et al. first proposed a user authentication protocol based on elliptic curve cryptography (ECC) for WSNs. However, it turned out that Yeh et al.'s protocol does not provide mutual authentication, perfect forward secrecy, and key agreement between the user and sensor. Later in 2013, Shi et al. proposed a new user authentication protocol that improves both security and efficiency of Yeh et al.'s protocol. However, Shi et al.'s improvement introduces other security weaknesses. In this paper, we show that Shi et al.'s improved protocol is vulnerable to session key attack, stolen smart card attack, and sensor energy exhausting attack. In addition, we propose a new, security-enhanced user authentication protocol using ECC for WSNs.

Super-Encryption Implementation Using Monoalphabetic Algorithm and XOR Algorithm for Data Security

NASA Astrophysics Data System (ADS)

Rachmawati, Dian; Andri Budiman, Mohammad; Aulia, Indra

2018-03-01

The exchange of data that occurs offline and online is very vulnerable to the threat of data theft. In general, cryptography is a science and art to maintain data secrecy. An encryption is a cryptography algorithm in which data is transformed into cipher text, which is something that is unreadable and meaningless so it cannot be read or understood by other parties. In super-encryption, two or more encryption algorithms are combined to make it more secure. In this work, Monoalphabetic algorithm and XOR algorithm are combined to form a super- encryption. Monoalphabetic algorithm works by changing a particular letter into a new letter based on existing keywords while the XOR algorithm works by using logic operation XOR Since Monoalphabetic algorithm is a classical cryptographic algorithm and XOR algorithm is a modern cryptographic algorithm, this scheme is expected to be both easy-to-implement and more secure. The combination of the two algorithms is capable of securing the data and restoring it back to its original form (plaintext), so the data integrity is still ensured.

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

Social Noise: Generating Random Numbers from Twitter Streams

NASA Astrophysics Data System (ADS)

Fernández, Norberto; Quintas, Fernando; Sánchez, Luis; Arias, Jesús

2015-12-01

Due to the multiple applications of random numbers in computer systems (cryptography, online gambling, computer simulation, etc.) it is important to have mechanisms to generate these numbers. True Random Number Generators (TRNGs) are commonly used for this purpose. TRNGs rely on non-deterministic sources to generate randomness. Physical processes (like noise in semiconductors, quantum phenomenon, etc.) play this role in state of the art TRNGs. In this paper, we depart from previous work and explore the possibility of defining social TRNGs using the stream of public messages of the microblogging service Twitter as randomness source. Thus, we define two TRNGs based on Twitter stream information and evaluate them using the National Institute of Standards and Technology (NIST) statistical test suite. The results of the evaluation confirm the feasibility of the proposed approach.

Optimized ECC Implementation for Secure Communication between Heterogeneous IoT Devices

PubMed Central

Marin, Leandro; Piotr Pawlowski, Marcin; Jara, Antonio

2015-01-01

The Internet of Things is integrating information systems, places, users and billions of constrained devices into one global network. This network requires secure and private means of communications. The building blocks of the Internet of Things are devices manufactured by various producers and are designed to fulfil different needs. There would be no common hardware platform that could be applied in every scenario. In such a heterogeneous environment, there is a strong need for the optimization of interoperable security. We present optimized elliptic curve Cryptography algorithms that address the security issues in the heterogeneous IoT networks. We have combined cryptographic algorithms for the NXP/Jennic 5148- and MSP430-based IoT devices and used them to created novel key negotiation protocol. PMID:26343677

Measurement-Device-Independent Quantum Key Distribution over Untrustful Metropolitan Network

NASA Astrophysics Data System (ADS)

Tang, Yan-Lin; Yin, Hua-Lei; Zhao, Qi; Liu, Hui; Sun, Xiang-Xiang; Huang, Ming-Qi; Zhang, Wei-Jun; Chen, Si-Jing; Zhang, Lu; You, Li-Xing; Wang, Zhen; Liu, Yang; Lu, Chao-Yang; Jiang, Xiao; Ma, Xiongfeng; Zhang, Qiang; Chen, Teng-Yun; Pan, Jian-Wei

2016-01-01

Quantum cryptography holds the promise to establish an information-theoretically secure global network. All field tests of metropolitan-scale quantum networks to date are based on trusted relays. The security critically relies on the accountability of the trusted relays, which will break down if the relay is dishonest or compromised. Here, we construct a measurement-device-independent quantum key distribution (MDIQKD) network in a star topology over a 200-square-kilometer metropolitan area, which is secure against untrustful relays and against all detection attacks. In the field test, our system continuously runs through one week with a secure key rate 10 times larger than previous results. Our results demonstrate that the MDIQKD network, combining the best of both worlds—security and practicality, constitutes an appealing solution to secure metropolitan communications.

Scalability, Complexity and Reliability in Quantum Information Processing

DTIC Science & Technology

2007-03-01

finding short lattice vectors . In [2], we showed that the generalization of the standard method --- random coset state preparation followed by fourier...results in cryptography. In [3], we proposed an efficient new cryptosystem based on the quantum intractability of finding short vectors in a lattice...state. We have explored realizations with neutral atoms as well as a more promising scheme employing polar molecules that allows for much stronger

Public-Key Cryptography: A Hardware Implementation and Novel Neural Network-Based Approach

DTIC Science & Technology

1992-09-01

FUNDINGISPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (if applicable ) 8c. ADDRESS (City, State, and ZIP Code) 10...8217....... ......... 4. .. . . iii TABLE OF CONTENTS I. INTRODUCTION ............................. 1 II. MATHEMATICAL BASIS FOR THE DEVELOPMENT OF PUBLIC-KEY...in the spirit of this future that this thesis is presented. It is an in-depth study of the public-key cryptosystem. First, the mathematical basis

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.

Towards Trustable Digital Evidence with PKIDEV: PKI Based Digital Evidence Verification Model

NASA Astrophysics Data System (ADS)

Uzunay, Yusuf; Incebacak, Davut; Bicakci, Kemal

How to Capture and Preserve Digital Evidence Securely? For the investigation and prosecution of criminal activities that involve computers, digital evidence collected in the crime scene has a vital importance. On one side, it is a very challenging task for forensics professionals to collect them without any loss or damage. On the other, there is the second problem of providing the integrity and authenticity in order to achieve legal acceptance in a court of law. By conceiving digital evidence simply as one instance of digital data, it is evident that modern cryptography offers elegant solutions for this second problem. However, to our knowledge, there is not any previous work proposing a systematic model having a holistic view to address all the related security problems in this particular case of digital evidence verification. In this paper, we present PKIDEV (Public Key Infrastructure based Digital Evidence Verification model) as an integrated solution to provide security for the process of capturing and preserving digital evidence. PKIDEV employs, inter alia, cryptographic techniques like digital signatures and secure time-stamping as well as latest technologies such as GPS and EDGE. In our study, we also identify the problems public-key cryptography brings when it is applied to the verification of digital evidence.

Device-independent security of quantum cryptography against collective attacks.

PubMed

Acín, Antonio; Brunner, Nicolas; Gisin, Nicolas; Massar, Serge; Pironio, Stefano; Scarani, Valerio

2007-06-08

We present the optimal collective attack on a quantum key distribution protocol in the "device-independent" security scenario, where no assumptions are made about the way the quantum key distribution devices work or on what quantum system they operate. Our main result is a tight bound on the Holevo information between one of the authorized parties and the eavesdropper, as a function of the amount of violation of a Bell-type inequality.

One-way entangled-photon autocompensating quantum cryptography

NASA Astrophysics Data System (ADS)

Walton, Zachary D.; Abouraddy, Ayman F.; Sergienko, Alexander V.; Saleh, Bahaa E.; Teich, Malvin C.

2003-06-01

A quantum cryptography implementation is presented that uses entanglement to combine one-way operation with an autocompensating feature that has hitherto only been available in implementations that require the signal to make a round trip between the users. Using the concept of advanced waves, it is shown that this proposed implementation is related to the round-trip implementation in the same way that Ekert’s two-particle scheme is related to the original one-particle scheme of Bennett and Brassard. The practical advantages and disadvantages of the proposed implementation are discussed in the context of existing schemes.

Secure information display with limited viewing zone by use of multi-color visual cryptography.

PubMed

Yamamoto, Hirotsugu; Hayasaki, Yoshio; Nishida, Nobuo

2004-04-05

We propose a display technique that ensures security of visual information by use of visual cryptography. A displayed image appears as a completely random pattern unless viewed through a decoding mask. The display has a limited viewing zone with the decoding mask. We have developed a multi-color encryption code set. Eight colors are represented in combinations of a displayed image composed of red, green, blue, and black subpixels and a decoding mask composed of transparent and opaque subpixels. Furthermore, we have demonstrated secure information display by use of an LCD panel.

Reduced randomness in quantum cryptography with sequences of qubits encoded in the same basis

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

Lamoureux, L.-P.; Cerf, N. J.; Bechmann-Pasquinucci, H.

2006-03-15

We consider the cloning of sequences of qubits prepared in the states used in the BB84 or six-state quantum cryptography protocol, and show that the single-qubit fidelity is unaffected even if entire sequences of qubits are prepared in the same basis. This result is only valid provided that the sequences are much shorter than the total key. It is of great importance for practical quantum cryptosystems because it reduces the need for high-speed random number generation without impairing on the security against finite-size cloning attacks.

Analysis of limiting information characteristics of quantum-cryptography protocols

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

Sych, D V; Grishanin, Boris A; Zadkov, Viktor N

2005-01-31

The problem of increasing the critical error rate of quantum-cryptography protocols by varying a set of letters in a quantum alphabet for space of a fixed dimensionality is studied. Quantum alphabets forming regular polyhedra on the Bloch sphere and the continual alphabet equally including all the quantum states are considered. It is shown that, in the absence of basis reconciliation, a protocol with the tetrahedral alphabet has the highest critical error rate among the protocols considered, while after the basis reconciliation, a protocol with the continual alphabet possesses the highest critical error rate. (quantum optics and quantum computation)

Entanglement witnessing and quantum cryptography with nonideal ferromagnetic detectors

NASA Astrophysics Data System (ADS)

Kłobus, Waldemar; Grudka, Andrzej; Baumgartner, Andreas; Tomaszewski, Damian; Schönenberger, Christian; Martinek, Jan

2014-03-01

We investigate theoretically the use of nonideal ferromagnetic contacts as a means to detect quantum entanglement of electron spins in transport experiments. We use a designated entanglement witness and find a minimal spin polarization of η >1/√3 ≈58% required to demonstrate spin entanglement. This is significantly less stringent than the ubiquitous tests of Bell's inequality with η >1/√24 >≈84%. In addition, we discuss the impact of decoherence and noise on entanglement detection and apply the presented framework to a simple quantum cryptography protocol. Our results are directly applicable to a large variety of experiments.

Methods for reliability evaluation of trust and reputation systems

NASA Astrophysics Data System (ADS)

Janiszewski, Marek B.

2016-09-01

Trust and reputation systems are a systematic approach to build security on the basis of observations of node's behaviour. Exchange of node's opinions about other nodes is very useful to indicate nodes which act selfishly or maliciously. The idea behind trust and reputation systems gets significance because of the fact that conventional security measures (based on cryptography) are often not sufficient. Trust and reputation systems can be used in various types of networks such as WSN, MANET, P2P and also in e-commerce applications. Trust and reputation systems give not only benefits but also could be a thread itself. Many attacks aim at trust and reputation systems exist, but such attacks still have not gain enough attention of research teams. Moreover, joint effects of many of known attacks have been determined as a very interesting field of research. Lack of an acknowledged methodology of evaluation of trust and reputation systems is a serious problem. This paper aims at presenting various approaches of evaluation such systems. This work also contains a description of generalization of many trust and reputation systems which can be used to evaluate reliability of such systems in the context of preventing various attacks.

SHAMROCK: A Synthesizable High Assurance Cryptography and Key Management Coprocessor

DTIC Science & Technology

2016-11-01

and excluding devices from a communicating group as they become trusted, or untrusted. An example of using rekeying to dynamically adjust group...algorithms, such as the Elliptic Curve Digital Signature Algorithm (ECDSA), work by computing a cryptographic hash of a message using, for example , the...material is based upon work supported by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract No. FA8721- 05-C

Deficiencies of the cryptography based on multiple-parameter fractional Fourier transform.

PubMed

Ran, Qiwen; Zhang, Haiying; Zhang, Jin; Tan, Liying; Ma, Jing

2009-06-01

Methods of image encryption based on fractional Fourier transform have an incipient flaw in security. We show that the schemes have the deficiency that one group of encryption keys has many groups of keys to decrypt the encrypted image correctly for several reasons. In some schemes, many factors result in the deficiencies, such as the encryption scheme based on multiple-parameter fractional Fourier transform [Opt. Lett.33, 581 (2008)]. A modified method is proposed to avoid all the deficiencies. Security and reliability are greatly improved without increasing the complexity of the encryption process. (c) 2009 Optical Society of America.

Git as an Encrypted Distributed Version Control System

DTIC Science & Technology

2015-03-01

options. The algorithm uses AES- 256 counter mode with an IV derived from SHA -1-HMAC hash (this is nearly identical to the GCM mode discussed earlier...built into the internal structure of Git. Every file in a Git repository is check summed with a SHA -1 hash, a one-way function with arbitrarily long...implementation. Git-encrypt calls OpenSSL cryptography library command line functions. The default cipher used is AES- 256 - Electronic Code Book (ECB), which is

Spectroscopy of Single AlInAs Quantum Dots

NASA Astrophysics Data System (ADS)

Derebezov, I. A.; Gaisler, A. V.; Gaisler, V. A.; Dmitriev, D. V.; Toropov, A. I.; Kozhukhov, A. S.; Shcheglov, D. V.; Latyshev, A. V.; Aseev, A. L.

2018-03-01

A system of quantum dots based on Al x In1- x As/Al y Ga1- y As solid solutions is investigated. The use of Al x In1- x As wide-gap solid solutions as the basis of quantum dots substantially extends the spectral emission range to the short-wavelength region, including the wavelength region near 770 nm, which is of interest for the development of aerospace systems of quantum cryptography. The optical characteristics of Al x In1- x As single quantum dots grown by the Stranski-Krastanov mechanism were studied by cryogenic microphotoluminescence. The statistics of the emission of single quantum dot excitons was studied using a Hanbury Brown-Twiss interferometer. The pair photon correlation function indicates the sub-Poissonian nature of the emission statistics, which directly confirms the possibility of developing single-photon emitters based on Al x In1- x As quantum dots. The fine structure of quantum dot exciton states was investigated at wavelengths near 770 nm. The splitting of the exciton states is found to be similar to the natural width of exciton lines, which is of great interest for the development of entangled photon pair emitters based on Al x In1- x As quantum dots.

Quantum cryptography with a predetermined key, using continuous-variable Einstein-Podolsky-Rosen correlations

NASA Astrophysics Data System (ADS)

Reid, M. D.

2000-12-01

Correlations of the type discussed by EPR in their original 1935 paradox for continuous variables exist for the quadrature phase amplitudes of two spatially separated fields. These correlations were first experimentally reported in 1992. We propose to use such EPR beams in quantum cryptography, to transmit with high efficiency messages in such a way that the receiver and sender may later determine whether eavesdropping has occurred. The merit of the new proposal is in the possibility of transmitting a reasonably secure yet predetermined key. This would allow relay of a cryptographic key over long distances in the presence of lossy channels.

Practical limitation for continuous-variable quantum cryptography using coherent States.

PubMed

Namiki, Ryo; Hirano, Takuya

2004-03-19

In this Letter, first, we investigate the security of a continuous-variable quantum cryptographic scheme with a postselection process against individual beam splitting attack. It is shown that the scheme can be secure in the presence of the transmission loss owing to the postselection. Second, we provide a loss limit for continuous-variable quantum cryptography using coherent states taking into account excess Gaussian noise on quadrature distribution. Since the excess noise is reduced by the loss mechanism, a realistic intercept-resend attack which makes a Gaussian mixture of coherent states gives a loss limit in the presence of any excess Gaussian noise.

Truly random number generation: an example

NASA Astrophysics Data System (ADS)

Frauchiger, Daniela; Renner, Renato

2013-10-01

Randomness is crucial for a variety of applications, ranging from gambling to computer simulations, and from cryptography to statistics. However, many of the currently used methods for generating randomness do not meet the criteria that are necessary for these applications to work properly and safely. A common problem is that a sequence of numbers may look random but nevertheless not be truly random. In fact, the sequence may pass all standard statistical tests and yet be perfectly predictable. This renders it useless for many applications. For example, in cryptography, the predictability of a "andomly" chosen password is obviously undesirable. Here, we review a recently developed approach to generating true | and hence unpredictable | randomness.

Threshold Things That Think: Authorisation for Resharing

NASA Astrophysics Data System (ADS)

Peeters, Roel; Kohlweiss, Markulf; Preneel, Bart

As we are evolving towards ubiquitous computing, users carry an increasing number of mobile devices with sensitive information. The security of this information can be protected using threshold cryptography, in which secret computations are shared between multiple devices. Threshold cryptography can be made more robust by resharing protocols, which allow recovery from partial compromises. This paper introduces user-friendly and secure protocols for the authorisation of resharing protocols. We present both automatic and manual protocols, utilising a group manual authentication protocol to add a new device. We analyse the security of these protocols: our analysis considers permanent and temporary compromises, denial of service attacks and manual authentications errors of the user.

Transverse-mode beam splitter of a light beam and its application to quantum cryptography

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

Sasada, Hiroyuki; Okamoto, Megumi

2003-07-01

We have theoretically and experimentally studied how a Mach-Zehnder interferometer with an additional mirror transforms a light beam composed of the second lowest transverse modes, HG{sub 10}, HG{sub 01}, LG{sub 01}, and LG{sub 0-1} (HG denotes Hermite-Gaussian mode; LG denotes Laguerre-Gaussian mode). In certain conditions, the interferometer divides the incident beam into the HG{sub 10} and HG{sub 01} components as a transverse-mode beam splitter. We propose a practical device involving the two interferometers for quantum cryptography, in which a photon carries two bits corresponding to the polarization and the transverse mode.

Learning Perfectly Secure Cryptography to Protect Communications with Adversarial Neural Cryptography

PubMed Central

2018-01-01

Researches in Artificial Intelligence (AI) have achieved many important breakthroughs, especially in recent years. In some cases, AI learns alone from scratch and performs human tasks faster and better than humans. With the recent advances in AI, it is natural to wonder whether Artificial Neural Networks will be used to successfully create or break cryptographic algorithms. Bibliographic review shows the main approach to this problem have been addressed throughout complex Neural Networks, but without understanding or proving the security of the generated model. This paper presents an analysis of the security of cryptographic algorithms generated by a new technique called Adversarial Neural Cryptography (ANC). Using the proposed network, we show limitations and directions to improve the current approach of ANC. Training the proposed Artificial Neural Network with the improved model of ANC, we show that artificially intelligent agents can learn the unbreakable One-Time Pad (OTP) algorithm, without human knowledge, to communicate securely through an insecure communication channel. This paper shows in which conditions an AI agent can learn a secure encryption scheme. However, it also shows that, without a stronger adversary, it is more likely to obtain an insecure one. PMID:29695066

Learning Perfectly Secure Cryptography to Protect Communications with Adversarial Neural Cryptography.

PubMed

Coutinho, Murilo; de Oliveira Albuquerque, Robson; Borges, Fábio; García Villalba, Luis Javier; Kim, Tai-Hoon

2018-04-24

Researches in Artificial Intelligence (AI) have achieved many important breakthroughs, especially in recent years. In some cases, AI learns alone from scratch and performs human tasks faster and better than humans. With the recent advances in AI, it is natural to wonder whether Artificial Neural Networks will be used to successfully create or break cryptographic algorithms. Bibliographic review shows the main approach to this problem have been addressed throughout complex Neural Networks, but without understanding or proving the security of the generated model. This paper presents an analysis of the security of cryptographic algorithms generated by a new technique called Adversarial Neural Cryptography (ANC). Using the proposed network, we show limitations and directions to improve the current approach of ANC. Training the proposed Artificial Neural Network with the improved model of ANC, we show that artificially intelligent agents can learn the unbreakable One-Time Pad (OTP) algorithm, without human knowledge, to communicate securely through an insecure communication channel. This paper shows in which conditions an AI agent can learn a secure encryption scheme. However, it also shows that, without a stronger adversary, it is more likely to obtain an insecure one.

Multi-heuristic dynamic task allocation using genetic algorithms in a heterogeneous distributed system

PubMed Central

Page, Andrew J.; Keane, Thomas M.; Naughton, Thomas J.

2010-01-01

We present a multi-heuristic evolutionary task allocation algorithm to dynamically map tasks to processors in a heterogeneous distributed system. It utilizes a genetic algorithm, combined with eight common heuristics, in an effort to minimize the total execution time. It operates on batches of unmapped tasks and can preemptively remap tasks to processors. The algorithm has been implemented on a Java distributed system and evaluated with a set of six problems from the areas of bioinformatics, biomedical engineering, computer science and cryptography. Experiments using up to 150 heterogeneous processors show that the algorithm achieves better efficiency than other state-of-the-art heuristic algorithms. PMID:20862190

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

The smooth entropy formalism for von Neumann algebras

NASA Astrophysics Data System (ADS)

Berta, Mario; Furrer, Fabian; Scholz, Volkher B.

2016-01-01

We discuss information-theoretic concepts on infinite-dimensional quantum systems. In particular, we lift the smooth entropy formalism as introduced by Renner and collaborators for finite-dimensional systems to von Neumann algebras. For the smooth conditional min- and max-entropy, we recover similar characterizing properties and information-theoretic operational interpretations as in the finite-dimensional case. We generalize the entropic uncertainty relation with quantum side information of Tomamichel and Renner and discuss applications to quantum cryptography. In particular, we prove the possibility to perform privacy amplification and classical data compression with quantum side information modeled by a von Neumann algebra.

Experimental quantum cryptography with qutrits

NASA Astrophysics Data System (ADS)

Gröblacher, Simon; Jennewein, Thomas; Vaziri, Alipasha; Weihs, Gregor; Zeilinger, Anton

2006-05-01

We produce two identical keys using, for the first time, entangled trinary quantum systems (qutrits) for quantum key distribution. The advantage of qutrits over the normally used binary quantum systems is an increased coding density and a higher security margin. The qutrits are encoded into the orbital angular momentum of photons, namely Laguerre Gaussian modes with azimuthal index l + 1, 0 and -1, respectively. The orbital angular momentum is controlled with phase holograms. In an Ekert-type protocol the violation of a three-dimensional Bell inequality verifies the security of the generated keys. A key is obtained with a qutrit error rate of approximately 10%.

The smooth entropy formalism for von Neumann algebras

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

Berta, Mario, E-mail: berta@caltech.edu; Furrer, Fabian, E-mail: furrer@eve.phys.s.u-tokyo.ac.jp; Scholz, Volkher B., E-mail: scholz@phys.ethz.ch

2016-01-15

We discuss information-theoretic concepts on infinite-dimensional quantum systems. In particular, we lift the smooth entropy formalism as introduced by Renner and collaborators for finite-dimensional systems to von Neumann algebras. For the smooth conditional min- and max-entropy, we recover similar characterizing properties and information-theoretic operational interpretations as in the finite-dimensional case. We generalize the entropic uncertainty relation with quantum side information of Tomamichel and Renner and discuss applications to quantum cryptography. In particular, we prove the possibility to perform privacy amplification and classical data compression with quantum side information modeled by a von Neumann algebra.

Language time series analysis

NASA Astrophysics Data System (ADS)

Kosmidis, Kosmas; Kalampokis, Alkiviadis; Argyrakis, Panos

2006-10-01

We use the detrended fluctuation analysis (DFA) and the Grassberger-Proccacia analysis (GP) methods in order to study language characteristics. Despite that we construct our signals using only word lengths or word frequencies, excluding in this way huge amount of information from language, the application of GP analysis indicates that linguistic signals may be considered as the manifestation of a complex system of high dimensionality, different from random signals or systems of low dimensionality such as the Earth climate. The DFA method is additionally able to distinguish a natural language signal from a computer code signal. This last result may be useful in the field of cryptography.

Chaos in quantum steering in high-dimensional systems

NASA Astrophysics Data System (ADS)

He, Guang Ping

2018-04-01

Quantum steering means that in some bipartite quantum systems the local measurements on one side can determine the state of the other side. Here we show that in high-dimensional systems there exists a specific entangled state which can display a kind of chaos effect when being adopted for steering. That is, a subtle difference in the measurement results on one side can steer the other side into completely orthogonal states. Moreover, by expanding the result to infinite-dimensional systems, we find two sets of states for which, contrary to common belief, even though their density matrices approach being identical, the steering between them is impossible. This property makes them very useful for quantum cryptography.

Multi-image encryption based on synchronization of chaotic lasers and iris authentication

NASA Astrophysics Data System (ADS)

Banerjee, Santo; Mukhopadhyay, Sumona; Rondoni, Lamberto

2012-07-01

A new technique of transmitting encrypted combinations of gray scaled and chromatic images using chaotic lasers derived from Maxwell-Bloch's equations has been proposed. This novel scheme utilizes the general method of solution of a set of linear equations to transmit similar sized heterogeneous images which are a combination of monochrome and chromatic images. The chaos encrypted gray scaled images are concatenated along the three color planes resulting in color images. These are then transmitted over a secure channel along with a cover image which is an iris scan. The entire cryptology is augmented with an iris-based authentication scheme. The secret messages are retrieved once the authentication is successful. The objective of our work is briefly outlined as (a) the biometric information is the iris which is encrypted before transmission, (b) the iris is used for personal identification and verifying for message integrity, (c) the information is transmitted securely which are colored images resulting from a combination of gray images, (d) each of the images transmitted are encrypted through chaos based cryptography, (e) these encrypted multiple images are then coupled with the iris through linear combination of images before being communicated over the network. The several layers of encryption together with the ergodicity and randomness of chaos render enough confusion and diffusion properties which guarantee a fool-proof approach in achieving secure communication as demonstrated by exhaustive statistical methods. The result is vital from the perspective of opening a fundamental new dimension in multiplexing and simultaneous transmission of several monochromatic and chromatic images along with biometry based authentication and cryptography.

Error-free holographic frames encryption with CA pixel-permutation encoding algorithm

NASA Astrophysics Data System (ADS)

Li, Xiaowei; Xiao, Dan; Wang, Qiong-Hua

2018-01-01

The security of video data is necessary in network security transmission hence cryptography is technique to make video data secure and unreadable to unauthorized users. In this paper, we propose a holographic frames encryption technique based on the cellular automata (CA) pixel-permutation encoding algorithm. The concise pixel-permutation algorithm is used to address the drawbacks of the traditional CA encoding methods. The effectiveness of the proposed video encoding method is demonstrated by simulation examples.

Lightweight and scalable secure communication in VANET

NASA Astrophysics Data System (ADS)

Zhu, Xiaoling; Lu, Yang; Zhu, Xiaojuan; Qiu, Shuwei

2015-05-01

To avoid a message to be tempered and forged in vehicular ad hoc network (VANET), the digital signature method is adopted by IEEE1609.2. However, the costs of the method are excessively high for large-scale networks. The paper efficiently copes with the issue with a secure communication framework by introducing some lightweight cryptography primitives. In our framework, point-to-point and broadcast communications for vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) are studied, mainly based on symmetric cryptography. A new issue incurred is symmetric key management. Thus, we develop key distribution and agreement protocols for two-party key and group key under different environments, whether a road side unit (RSU) is deployed or not. The analysis shows that our protocols provide confidentiality, authentication, perfect forward secrecy, forward secrecy and backward secrecy. The proposed group key agreement protocol especially solves the key leak problem caused by members joining or leaving in existing key agreement protocols. Due to aggregated signature and substitution of XOR for point addition, the average computation and communication costs do not significantly increase with the increase in the number of vehicles; hence, our framework provides good scalability.

Self-stabilized narrow-bandwidth and high-fidelity entangled photons generated from cold atoms

NASA Astrophysics Data System (ADS)

Yu, Y. C.; Ding, D. S.; Dong, M. X.; Shi, S.; Zhang, W.; Shi, B. S.

2018-04-01

Entangled photon pairs are critically important in fundamental quantum mechanics research as well as in many areas within the field of quantum information, such as quantum communication, quantum computation, and quantum cryptography. Previous demonstrations of entangled photons based on atomic ensembles were achieved by using a reference laser to stabilize the phase of two spontaneous four-wave mixing paths. Here, we demonstrate a convenient and efficient scheme to generate polarization-entangled photons with a narrow bandwidth of 57.2 ±1.6 MHz and a high-fidelity of 96.3 ±0.8 % by using a phase self-stabilized multiplexing system formed by two beam displacers and two half-wave plates where the relative phase between the different signal paths can be eliminated completely. It is possible to stabilize an entangled photon pair for a long time with this system and produce all four Bell states, making this a vital step forward in the field of quantum information.

Experimental Eavesdropping Based on Optimal Quantum Cloning

NASA Astrophysics Data System (ADS)

Bartkiewicz, Karol; Lemr, Karel; Černoch, Antonín; Soubusta, Jan; Miranowicz, Adam

2013-04-01

The security of quantum cryptography is guaranteed by the no-cloning theorem, which implies that an eavesdropper copying transmitted qubits in unknown states causes their disturbance. Nevertheless, in real cryptographic systems some level of disturbance has to be allowed to cover, e.g., transmission losses. An eavesdropper can attack such systems by replacing a noisy channel by a better one and by performing approximate cloning of transmitted qubits which disturb them but below the noise level assumed by legitimate users. We experimentally demonstrate such symmetric individual eavesdropping on the quantum key distribution protocols of Bennett and Brassard (BB84) and the trine-state spherical code of Renes (R04) with two-level probes prepared using a recently developed photonic multifunctional quantum cloner [Lemr et al., Phys. Rev. A 85, 050307(R) (2012)PLRAAN1050-2947]. We demonstrated that our optimal cloning device with high-success rate makes the eavesdropping possible by hiding it in usual transmission losses. We believe that this experiment can stimulate the quest for other operational applications of quantum cloning.

Practical cryptographic strategies in the post-quantum era

NASA Astrophysics Data System (ADS)

Kabanov, I. S.; Yunusov, R. R.; Kurochkin, Y. V.; Fedorov, A. K.

2018-02-01

Quantum key distribution technologies promise information-theoretic security and are currently being deployed in com-mercial applications. We review new frontiers in information security technologies in communications and distributed storage applications with the use of classical, quantum, hybrid classical-quantum, and post-quantum cryptography. We analyze the cur-rent state-of-the-art, critical characteristics, development trends, and limitations of these techniques for application in enterprise information protection systems. An approach concerning the selection of practical encryption technologies for enterprises with branched communication networks is discussed.

Computing border bases using mutant strategies

NASA Astrophysics Data System (ADS)

Ullah, E.; Abbas Khan, S.

2014-01-01

Border bases, a generalization of Gröbner bases, have actively been addressed during recent years due to their applicability to industrial problems. In cryptography and coding theory a useful application of border based is to solve zero-dimensional systems of polynomial equations over finite fields, which motivates us for developing optimizations of the algorithms that compute border bases. In 2006, Kehrein and Kreuzer formulated the Border Basis Algorithm (BBA), an algorithm which allows the computation of border bases that relate to a degree compatible term ordering. In 2007, J. Ding et al. introduced mutant strategies bases on finding special lower degree polynomials in the ideal. The mutant strategies aim to distinguish special lower degree polynomials (mutants) from the other polynomials and give them priority in the process of generating new polynomials in the ideal. In this paper we develop hybrid algorithms that use the ideas of J. Ding et al. involving the concept of mutants to optimize the Border Basis Algorithm for solving systems of polynomial equations over finite fields. In particular, we recall a version of the Border Basis Algorithm which is actually called the Improved Border Basis Algorithm and propose two hybrid algorithms, called MBBA and IMBBA. The new mutants variants provide us space efficiency as well as time efficiency. The efficiency of these newly developed hybrid algorithms is discussed using standard cryptographic examples.

Cryptographie quantique à variables continues

NASA Astrophysics Data System (ADS)

Bencheikh, K.; Jankovic, A.; Symul, T.; Levenson, J. A.

2002-06-01

Nous avons élaboré un protocole de cryptographie quantique qui permet de générer et de distribuer une clé secrète aléatoire. Le protocole repose sur l'utilisation de paires de champs électromagnétiques dont les quadratures présentent des corrélations quantiques de type Einstein-Podolsky-Rosen. Les fluctuations quantiques instantanése constituent les bits aléatoires de la clé secrète, et la dégradation irréversible des corrélations quantiques des quadratures causée par une tierce personne permet de la détecter et de garantir la sécurité d'échange.

Quantum cryptography using coherent states: Randomized encryption and key generation

NASA Astrophysics Data System (ADS)

Corndorf, Eric

With the advent of the global optical-telecommunications infrastructure, an increasing number of individuals, companies, and agencies communicate information with one another over public networks or physically-insecure private networks. While the majority of the traffic flowing through these networks requires little or no assurance of secrecy, the same cannot be said for certain communications between banks, between government agencies, within the military, and between corporations. In these arenas, the need to specify some level of secrecy in communications is a high priority. While the current approaches to securing sensitive information (namely the public-key-cryptography infrastructure and deterministic private-key ciphers like AES and 3DES) seem to be cryptographically strong based on empirical evidence, there exist no mathematical proofs of secrecy for any widely deployed cryptosystem. As an example, the ubiquitous public-key cryptosystems infer all of their secrecy from the assumption that factoring of the product of two large primes is necessarily time consuming---something which has not, and perhaps cannot, be proven. Since the 1980s, the possibility of using quantum-mechanical features of light as a physical mechanism for satisfying particular cryptographic objectives has been explored. This research has been fueled by the hopes that cryptosystems based on quantum systems may provide provable levels of secrecy which are at least as valid as quantum mechanics itself. Unfortunately, the most widely considered quantum-cryptographic protocols (BB84 and the Ekert protocol) have serious implementation problems. Specifically, they require quantum-mechanical states which are not readily available, and they rely on unproven relations between intrusion-level detection and the information available to an attacker. As a result, the secrecy level provided by these experimental implementations is entirely unspecified. In an effort to provably satisfy the cryptographic objectives of key generation and direct data-encryption, a new quantum cryptographic principle is demonstrated wherein keyed coherent-state signal sets are employed. Taking advantage of the fundamental and irreducible quantum-measurement noise of coherent states, these schemes do not require the users to measure the influence of an attacker. Experimental key-generation and data encryption schemes based on these techniques, which are compatible with today's WDM fiber-optic telecommunications infrastructure, are implemented and analyzed.

Pseudo-random generator based on Chinese Remainder Theorem

NASA Astrophysics Data System (ADS)

Bajard, Jean Claude; Hördegen, Heinrich

2009-08-01

Pseudo-Random Generators (PRG) are fundamental in cryptography. Their use occurs at different level in cipher protocols. They need to verify some properties for being qualified as robust. The NIST proposes some criteria and a tests suite which gives informations on the behavior of the PRG. In this work, we present a PRG constructed from the conversion between further residue systems of representation of the elements of GF(2)[X]. In this approach, we use some pairs of co-prime polynomials of degree k and a state vector of 2k bits. The algebraic properties are broken by using different independent pairs during the process. Since this method is reversible, we also can use it as a symmetric crypto-system. We evaluate the cost of a such system, taking into account that some operations are commonly implemented on crypto-processors. We give the results of the different NIST Tests and we explain this choice compare to others found in the literature. We describe the behavior of this PRG and explain how the different rounds are chained for ensuring a fine secure randomness.

A no-key-exchange secure image sharing scheme based on Shamir's three-pass cryptography protocol and the multiple-parameter fractional Fourier transform.

PubMed

Lang, Jun

2012-01-30

In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.

Experimental realization of an entanglement access network and secure multi-party computation

NASA Astrophysics Data System (ADS)

Chang, X.-Y.; Deng, D.-L.; Yuan, X.-X.; Hou, P.-Y.; Huang, Y.-Y.; Duan, L.-M.

2016-07-01

To construct a quantum network with many end users, it is critical to have a cost-efficient way to distribute entanglement over different network ends. We demonstrate an entanglement access network, where the expensive resource, the entangled photon source at the telecom wavelength and the core communication channel, is shared by many end users. Using this cost-efficient entanglement access network, we report experimental demonstration of a secure multiparty computation protocol, the privacy-preserving secure sum problem, based on the network quantum cryptography.

Experimental realization of an entanglement access network and secure multi-party computation

NASA Astrophysics Data System (ADS)

Chang, Xiuying; Deng, Donglin; Yuan, Xinxing; Hou, Panyu; Huang, Yuanyuan; Duan, Luming; Department of Physics, University of Michigan Collaboration; CenterQuantum Information in Tsinghua University Team

2017-04-01

To construct a quantum network with many end users, it is critical to have a cost-efficient way to distribute entanglement over different network ends. We demonstrate an entanglement access network, where the expensive resource, the entangled photon source at the telecom wavelength and the core communication channel, is shared by many end users. Using this cost-efficient entanglement access network, we report experimental demonstration of a secure multiparty computation protocol, the privacy-preserving secure sum problem, based on the network quantum cryptography.

The Role of Frame Force in Quantum Detection

DTIC Science & Technology

2007-01-01

42040) 10. C. H. Bennett, Quantum cryptography using any two nonorthogonal states, Phys. Rev. Lett. 68 (1992), no. 21, 3121–3124. MR 1 163 546 11. S ...SUBTITLE The Role of Frame Force in Quantum Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d. PROJECT...equivalent to a quantum detection problem from quantum mechanics. To this end we first reformulate Problem 1.2 in terms of orthonormal bases instead of 1

Generation and confirmation of a (100 x 100)-dimensional entangled quantum system.

PubMed

Krenn, Mario; Huber, Marcus; Fickler, Robert; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

2014-04-29

Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing. Here we present the creation of a (100 × 100)-dimensional entangled quantum system, using spatial modes of photons. For its verification we develop a novel nonlinear criterion which infers entanglement dimensionality of a global state by using only information about its subspace correlations. This allows very practical experimental implementation as well as highly efficient extraction of entanglement dimensionality information. Applications in quantum cryptography and other protocols are very promising.

New Directions in Online Fraud

NASA Astrophysics Data System (ADS)

Mohatar, Oscar Delgado; Sierra Cámara, José M.

2007-12-01

The security of a system can be seen as a chain of protection methods, and the global level is just as strong as its weakest link. From this point of view, cryptography is no more than other link in the chain. And most of the times, it is probably the strongest link, but there are many others weak links which decrease the security level until unacceptable level for carrying out electronic commerce. In last term, exclusively technical protection methods seem not be able to completely resolve the situation. The focus should be changed towards trying to increase the resistance of the system, instead of its invulnerability that, in any case, can not be completely achieved in general purpose operating systems.

Generation and confirmation of a (100 × 100)-dimensional entangled quantum system

PubMed Central

Krenn, Mario; Huber, Marcus; Fickler, Robert; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

2014-01-01

Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing. Here we present the creation of a (100 × 100)-dimensional entangled quantum system, using spatial modes of photons. For its verification we develop a novel nonlinear criterion which infers entanglement dimensionality of a global state by using only information about its subspace correlations. This allows very practical experimental implementation as well as highly efficient extraction of entanglement dimensionality information. Applications in quantum cryptography and other protocols are very promising. PMID:24706902

Genomics-Based Security Protocols: From Plaintext to Cipherprotein

NASA Technical Reports Server (NTRS)

Shaw, Harry; Hussein, Sayed; Helgert, Hermann

2011-01-01

The evolving nature of the internet will require continual advances in authentication and confidentiality protocols. Nature provides some clues as to how this can be accomplished in a distributed manner through molecular biology. Cryptography and molecular biology share certain aspects and operations that allow for a set of unified principles to be applied to problems in either venue. A concept for developing security protocols that can be instantiated at the genomics level is presented. A DNA (Deoxyribonucleic acid) inspired hash code system is presented that utilizes concepts from molecular biology. It is a keyed-Hash Message Authentication Code (HMAC) capable of being used in secure mobile Ad hoc networks. It is targeted for applications without an available public key infrastructure. Mechanics of creating the HMAC are presented as well as a prototype HMAC protocol architecture. Security concepts related to the implementation differences between electronic domain security and genomics domain security are discussed.

Quantum random number generation

DOE PAGES

Ma, Xiongfeng; Yuan, Xiao; Cao, Zhu; ...

2016-06-28

Quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness -- coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at a highmore » speed by properly modeling the devices. The second category is self-testing QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semi-self-testing QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.« less

Quantum key distribution session with 16-dimensional photonic states.

PubMed

Etcheverry, S; Cañas, G; Gómez, E S; Nogueira, W A T; Saavedra, C; Xavier, G B; Lima, G

2013-01-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD.

Quantum key distribution session with 16-dimensional photonic states

NASA Astrophysics Data System (ADS)

Etcheverry, S.; Cañas, G.; Gómez, E. S.; Nogueira, W. A. T.; Saavedra, C.; Xavier, G. B.; Lima, G.

2013-07-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD.

[Secure e-mail between physicians--aspect of a telemedicine platform for the health care system].

PubMed

Goetz, C F

2001-10-01

Ever since the Roland-Berger-Study in 1997, the concept of a "telematics platform" for health care describes the combination of all technical and organizational components and services for the online transmission of patient data. This platform works on an interoperable collection of standards for addressing, security and content-description. In this context the security for application and transport data is based on data protection as well as medical non-disclosure rules. The methods of cryptography can provide security services for data transmitted realizing addressed, direct and indirect privacy. The first German health professional card, the electronic physicians' ID, provides central tools for such applications. First functionally simple pilot projects will prove the effectiveness of chosen methods in this year, even if not all identified construction sites in health care telematics have yet been lead towards a finalized solution.

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

Ma, Xiongfeng; Yuan, Xiao; Cao, Zhu

Quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness -- coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at a highmore » speed by properly modeling the devices. The second category is self-testing QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semi-self-testing QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.« less

Quantum key distribution session with 16-dimensional photonic states

PubMed Central

Etcheverry, S.; Cañas, G.; Gómez, E. S.; Nogueira, W. A. T.; Saavedra, C.; Xavier, G. B.; Lima, G.

2013-01-01

The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote parties, that can be used to extract a secret key. QKD with D-dimensional quantum channels provides security advantages that grow with increasing D. However, the vast majority of QKD implementations has been restricted to two dimensions. Here we demonstrate the feasibility of using higher dimensions for real-world quantum cryptography by performing, for the first time, a fully automated QKD session based on the BB84 protocol with 16-dimensional quantum states. Information is encoded in the single-photon transverse momentum and the required states are dynamically generated with programmable spatial light modulators. Our setup paves the way for future developments in the field of experimental high-dimensional QKD. PMID:23897033

Home and Clinical Cardiovascular Care Center (H4C): a Framework for Integrating Body Sensor Networks and QTRU Cryptography System.

PubMed

Zakerolhosseini, Ali; Sokouti, Massoud; Pezeshkian, Massoud

2013-01-01

Quick responds to heart attack patients before arriving to hospital is a very important factor. In this paper, a combined model of Body Sensor Network and Personal Digital Access using QTRU cipher algorithm in Wifi networks is presented to efficiently overcome these life threatening attacks. The algorithm for optimizing the routing paths between sensor nodes and an algorithm for reducing the power consumption are also applied for achieving the best performance by this model. This system is consumes low power and has encrypting and decrypting processes. It also has an efficient routing path in a fast manner.

Home and Clinical Cardiovascular Care Center (H4C): a Framework for Integrating Body Sensor Networks and QTRU Cryptography System

PubMed Central

Zakerolhosseini, Ali; Sokouti, Massoud; Pezeshkian, Massoud

2013-01-01

Quick responds to heart attack patients before arriving to hospital is a very important factor. In this paper, a combined model of Body Sensor Network and Personal Digital Access using QTRU cipher algorithm in Wifi networks is presented to efficiently overcome these life threatening attacks. The algorithm for optimizing the routing paths between sensor nodes and an algorithm for reducing the power consumption are also applied for achieving the best performance by this model. This system is consumes low power and has encrypting and decrypting processes. It also has an efficient routing path in a fast manner. PMID:24252988

Experimental Measurement-Device-Independent Entanglement Detection

NASA Astrophysics Data System (ADS)

Nawareg, Mohamed; Muhammad, Sadiq; Amselem, Elias; Bourennane, Mohamed

2015-02-01

Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.

Experimental Measurement-Device-Independent Entanglement Detection

PubMed Central

Nawareg, Mohamed; Muhammad, Sadiq; Amselem, Elias; Bourennane, Mohamed

2015-01-01

Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols. PMID:25649664

An Improved and Secure Biometric Authentication Scheme for Telecare Medicine Information Systems Based on Elliptic Curve Cryptography.

PubMed

Chaudhry, Shehzad Ashraf; Mahmood, Khalid; Naqvi, Husnain; Khan, Muhammad Khurram

2015-11-01

Telecare medicine information system (TMIS) offers the patients convenient and expedite healthcare services remotely anywhere. Patient security and privacy has emerged as key issues during remote access because of underlying open architecture. An authentication scheme can verify patient's as well as TMIS server's legitimacy during remote healthcare services. To achieve security and privacy a number of authentication schemes have been proposed. Very recently Lu et al. (J. Med. Syst. 39(3):1-8, 2015) proposed a biometric based three factor authentication scheme for TMIS to confiscate the vulnerabilities of Arshad et al.'s (J. Med. Syst. 38(12):136, 2014) scheme. Further, they emphasized the robustness of their scheme against several attacks. However, in this paper we establish that Lu et al.'s scheme is vulnerable to numerous attacks including (1) Patient anonymity violation attack, (2) Patient impersonation attack, and (3) TMIS server impersonation attack. Furthermore, their scheme does not provide patient untraceability. We then, propose an improvement of Lu et al.'s scheme. We have analyzed the security of improved scheme using popular automated tool ProVerif. The proposed scheme while retaining the plusses of Lu et al.'s scheme is also robust against known attacks.

Finger-Vein Image Enhancement Using a Fuzzy-Based Fusion Method with Gabor and Retinex Filtering

PubMed Central

Shin, Kwang Yong; Park, Young Ho; Nguyen, Dat Tien; Park, Kang Ryoung

2014-01-01

Because of the advantages of finger-vein recognition systems such as live detection and usage as bio-cryptography systems, they can be used to authenticate individual people. However, images of finger-vein patterns are typically unclear because of light scattering by the skin, optical blurring, and motion blurring, which can degrade the performance of finger-vein recognition systems. In response to these issues, a new enhancement method for finger-vein images is proposed. Our method is novel compared with previous approaches in four respects. First, the local and global features of the vein lines of an input image are amplified using Gabor filters in four directions and Retinex filtering, respectively. Second, the means and standard deviations in the local windows of the images produced after Gabor and Retinex filtering are used as inputs for the fuzzy rule and fuzzy membership function, respectively. Third, the optimal weights required to combine the two Gabor and Retinex filtered images are determined using a defuzzification method. Fourth, the use of a fuzzy-based method means that image enhancement does not require additional training data to determine the optimal weights. Experimental results using two finger-vein databases showed that the proposed method enhanced the accuracy of finger-vein recognition compared with previous methods. PMID:24549251

PKI-based secure mobile access to electronic health services and data.

PubMed

Kambourakis, G; Maglogiannis, I; Rouskas, A

2005-01-01

Recent research works examine the potential employment of public-key cryptography schemes in e-health environments. In such systems, where a Public Key Infrastructure (PKI) is established beforehand, Attribute Certificates (ACs) and public key enabled protocols like TLS, can provide the appropriate mechanisms to effectively support authentication, authorization and confidentiality services. In other words, mutual trust and secure communications between all the stakeholders, namely physicians, patients and e-health service providers, can be successfully established and maintained. Furthermore, as the recently introduced mobile devices with access to computer-based patient record systems are expanding, the need of physicians and nurses to interact increasingly with such systems arises. Considering public key infrastructure requirements for mobile online health networks, this paper discusses the potential use of Attribute Certificates (ACs) in an anticipated trust model. Typical trust interactions among doctors, patients and e-health providers are presented, indicating that resourceful security mechanisms and trust control can be obtained and implemented. The application of attribute certificates to support medical mobile service provision along with the utilization of the de-facto TLS protocol to offer competent confidentiality and authorization services is also presented and evaluated through experimentation, using both the 802.11 WLAN and General Packet Radio Service (GPRS) networks.

Modeling, Simulation and Analysis of Public Key Infrastructure

NASA Technical Reports Server (NTRS)

Liu, Yuan-Kwei; Tuey, Richard; Ma, Paul (Technical Monitor)

1998-01-01

Security is an essential part of network communication. The advances in cryptography have provided solutions to many of the network security requirements. Public Key Infrastructure (PKI) is the foundation of the cryptography applications. The main objective of this research is to design a model to simulate a reliable, scalable, manageable, and high-performance public key infrastructure. We build a model to simulate the NASA public key infrastructure by using SimProcess and MatLab Software. The simulation is from top level all the way down to the computation needed for encryption, decryption, digital signature, and secure web server. The application of secure web server could be utilized in wireless communications. The results of the simulation are analyzed and confirmed by using queueing theory.

A new method for generating an invariant iris private key based on the fuzzy vault system.

PubMed

Lee, Youn Joo; Park, Kang Ryoung; Lee, Sung Joo; Bae, Kwanghyuk; Kim, Jaihie

2008-10-01

Cryptographic systems have been widely used in many information security applications. One main challenge that these systems have faced has been how to protect private keys from attackers. Recently, biometric cryptosystems have been introduced as a reliable way of concealing private keys by using biometric data. A fuzzy vault refers to a biometric cryptosystem that can be used to effectively protect private keys and to release them only when legitimate users enter their biometric data. In biometric systems, a critical problem is storing biometric templates in a database. However, fuzzy vault systems do not need to directly store these templates since they are combined with private keys by using cryptography. Previous fuzzy vault systems were designed by using fingerprint, face, and so on. However, there has been no attempt to implement a fuzzy vault system that used an iris. In biometric applications, it is widely known that an iris can discriminate between persons better than other biometric modalities. In this paper, we propose a reliable fuzzy vault system based on local iris features. We extracted multiple iris features from multiple local regions in a given iris image, and the exact values of the unordered set were then produced using the clustering method. To align the iris templates with the new input iris data, a shift-matching technique was applied. Experimental results showed that 128-bit private keys were securely and robustly generated by using any given iris data without requiring prealignment.

Cryptographic framework for document-objects resulting from multiparty collaborative transactions.

PubMed

Goh, A

2000-01-01

Multiparty transactional frameworks--i.e. Electronic Data Interchange (EDI) or Health Level (HL) 7--often result in composite documents which can be accurately modelled using hyperlinked document-objects. The structural complexity arising from multiauthor involvement and transaction-specific sequencing would be poorly handled by conventional digital signature schemes based on a single evaluation of a one-way hash function and asymmetric cryptography. In this paper we outline the generation of structure-specific authentication hash-trees for the the authentication of transactional document-objects, followed by asymmetric signature generation on the hash-tree value. Server-side multi-client signature verification would probably constitute the single most compute-intensive task, hence the motivation for our usage of the Rabin signature protocol which results in significantly reduced verification workloads compared to the more commonly applied Rivest-Shamir-Adleman (RSA) protocol. Data privacy is handled via symmetric encryption of message traffic using session-specific keys obtained through key-negotiation mechanisms based on discrete-logarithm cryptography. Individual client-to-server channels can be secured using a double key-pair variation of Diffie-Hellman (DH) key negotiation, usage of which also enables bidirectional node authentication. The reciprocal server-to-client multicast channel is secured through Burmester-Desmedt (BD) key-negotiation which enjoys significant advantages over the usual multiparty extensions to the DH protocol. The implementation of hash-tree signatures and bi/multidirectional key negotiation results in a comprehensive cryptographic framework for multiparty document-objects satisfying both authentication and data privacy requirements.

PREFACE: Quantum Information, Communication, Computation and Cryptography

NASA Astrophysics Data System (ADS)

Benatti, F.; Fannes, M.; Floreanini, R.; Petritis, D.

2007-07-01

The application of quantum mechanics to information related fields such as communication, computation and cryptography is a fast growing line of research that has been witnessing an outburst of theoretical and experimental results, with possible practical applications. On the one hand, quantum cryptography with its impact on secrecy of transmission is having its first important actual implementations; on the other hand, the recent advances in quantum optics, ion trapping, BEC manipulation, spin and quantum dot technologies allow us to put to direct test a great deal of theoretical ideas and results. These achievements have stimulated a reborn interest in various aspects of quantum mechanics, creating a unique interplay between physics, both theoretical and experimental, mathematics, information theory and computer science. In view of all these developments, it appeared timely to organize a meeting where graduate students and young researchers could be exposed to the fundamentals of the theory, while senior experts could exchange their latest results. The activity was structured as a school followed by a workshop, and took place at The Abdus Salam International Center for Theoretical Physics (ICTP) and The International School for Advanced Studies (SISSA) in Trieste, Italy, from 12-23 June 2006. The meeting was part of the activity of the Joint European Master Curriculum Development Programme in Quantum Information, Communication, Cryptography and Computation, involving the Universities of Cergy-Pontoise (France), Chania (Greece), Leuven (Belgium), Rennes1 (France) and Trieste (Italy). This special issue of Journal of Physics A: Mathematical and Theoretical collects 22 contributions from well known experts who took part in the workshop. They summarize the present day status of the research in the manifold aspects of quantum information. The issue is opened by two review articles, the first by G Adesso and F Illuminati discussing entanglement in continuous variable systems, the second by T Prosen, discussing chaos and complexity in quantum systems. Both topics have theoretical as well as experimental relevance and are likely to witness a fast growing development in the near future. The remaining contributions present more specific and very recent results. They involve the study of the structure of quantum states and their estimation (B Baumgartner et al, C King et al, S Olivares et al, D Petz et al and W van Dam et al), of entanglement generation and its quantification (G Brida et al, F Ciccarello et al, G Costantini et al, O Romero-Isart et al, D Rossini et al, A Serafini et al and D Vitali et al), of randomness related effects on entanglement behaviour (I Akhalwaya et al, O Dahlsten et al and L Viola et al), and of abstract and applied aspects of quantum computation and communication (K Audenart, G M D'Ariano et al, N Datta et al, L C Kwek et al and M Nathanson et al). We would like to express our gratitude to the European Commission, the Abdus Salam ICTP, SISSA and Eurotech SpA (Amaro, Udine, Italy) for financial and/or logistic support. Special thanks also go to the workshop secretary Marina De Comelli, and the secretaries of the Department of Theoretical Physics, University of Trieste, Sabrina Gaspardis and Rosita Glavina for their precious help and assistance.

Photon-number-splitting versus cloning attacks in practical implementations of the Bennett-Brassard 1984 protocol for quantum cryptography

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

Niederberger, Armand; Scarani, Valerio; Gisin, Nicolas

2005-04-01

In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Luetkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob's detection efficiency, Eve gains a larger amount of information using another attack based on a 2{yields}3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2{yields}3more » cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve's better strategy uses 2{yields}3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.« less

Bit-level plane image encryption based on coupled map lattice with time-varying delay

NASA Astrophysics Data System (ADS)

Lv, Xiupin; Liao, Xiaofeng; Yang, Bo

2018-04-01

Most of the existing image encryption algorithms had two basic properties: confusion and diffusion in a pixel-level plane based on various chaotic systems. Actually, permutation in a pixel-level plane could not change the statistical characteristics of an image, and many of the existing color image encryption schemes utilized the same method to encrypt R, G and B components, which means that the three color components of a color image are processed three times independently. Additionally, dynamical performance of a single chaotic system degrades greatly with finite precisions in computer simulations. In this paper, a novel coupled map lattice with time-varying delay therefore is applied in color images bit-level plane encryption to solve the above issues. Spatiotemporal chaotic system with both much longer period in digitalization and much excellent performances in cryptography is recommended. Time-varying delay embedded in coupled map lattice enhances dynamical behaviors of the system. Bit-level plane image encryption algorithm has greatly reduced the statistical characteristics of an image through the scrambling processing. The R, G and B components cross and mix with one another, which reduces the correlation among the three components. Finally, simulations are carried out and all the experimental results illustrate that the proposed image encryption algorithm is highly secure, and at the same time, also demonstrates superior performance.

Access control based on attribute certificates for medical intranet applications.

PubMed

Mavridis, I; Georgiadis, C; Pangalos, G; Khair, M

2001-01-01

Clinical information systems frequently use intranet and Internet technologies. However these technologies have emphasized sharing and not security, despite the sensitive and private nature of much health information. Digital certificates (electronic documents which recognize an entity or its attributes) can be used to control access in clinical intranet applications. To outline the need for access control in distributed clinical database systems, to describe the use of digital certificates and security policies, and to propose the architecture for a system using digital certificates, cryptography and security policy to control access to clinical intranet applications. We have previously developed a security policy, DIMEDAC (Distributed Medical Database Access Control), which is compatible with emerging public key and privilege management infrastructure. In our implementation approach we propose the use of digital certificates, to be used in conjunction with DIMEDAC. Our proposed access control system consists of two phases: the ways users gain their security credentials; and how these credentials are used to access medical data. Three types of digital certificates are used: identity certificates for authentication; attribute certificates for authorization; and access-rule certificates for propagation of access control policy. Once a user is identified and authenticated, subsequent access decisions are based on a combination of identity and attribute certificates, with access-rule certificates providing the policy framework. Access control in clinical intranet applications can be successfully and securely managed through the use of digital certificates and the DIMEDAC security policy.

A survey of noninteractive zero knowledge proof system and its applications.

PubMed

Wu, Huixin; Wang, Feng

2014-01-01

Zero knowledge proof system which has received extensive attention since it was proposed is an important branch of cryptography and computational complexity theory. Thereinto, noninteractive zero knowledge proof system contains only one message sent by the prover to the verifier. It is widely used in the construction of various types of cryptographic protocols and cryptographic algorithms because of its good privacy, authentication, and lower interactive complexity. This paper reviews and analyzes the basic principles of noninteractive zero knowledge proof system, and summarizes the research progress achieved by noninteractive zero knowledge proof system on the following aspects: the definition and related models of noninteractive zero knowledge proof system, noninteractive zero knowledge proof system of NP problems, noninteractive statistical and perfect zero knowledge, the connection between noninteractive zero knowledge proof system, interactive zero knowledge proof system, and zap, and the specific applications of noninteractive zero knowledge proof system. This paper also points out the future research directions.

Quantum correlations in multipartite quantum systems

NASA Astrophysics Data System (ADS)

Jafarizadeh, M. A.; Heshmati, A.; Karimi, N.; Yahyavi, M.

2018-03-01

Quantum entanglement is the most famous type of quantum correlation between elements of a quantum system that has a basic role in quantum communication protocols like quantum cryptography, teleportation and Bell inequality detection. However, it has already been shown that various applications in quantum information theory do not require entanglement. Quantum discord as a new kind of quantum correlations beyond entanglement, is the most popular candidate for general quantum correlations. In this paper, first we find the entanglement witness in a particular multipartite quantum system which consists of a N-partite system in 2 n -dimensional space. Then we give an exact analytical formula for the quantum discord of this system. At the end of the paper, we investigate the additivity relation of the quantum correlation and show that this relation is satisfied for a N-partite system with 2 n -dimensional space.

Applying transpose matrix on advanced encryption standard (AES) for database content

NASA Astrophysics Data System (ADS)

Manurung, E. B. P.; Sitompul, O. S.; Suherman

2018-03-01

Advanced Encryption Standard (AES) is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) and has been adopted by the U.S. government and is now used worldwide. This paper reports the impact of transpose matrix integration to AES. Transpose matrix implementation on AES is aimed at first stage of chypertext modifications for text based database security so that the confidentiality improves. The matrix is also able to increase the avalanche effect of the cryptography algorithm 4% in average.

Experimental realization of an entanglement access network and secure multi-party computation

PubMed Central

Chang, X.-Y.; Deng, D.-L.; Yuan, X.-X.; Hou, P.-Y.; Huang, Y.-Y.; Duan, L.-M.

2016-01-01

To construct a quantum network with many end users, it is critical to have a cost-efficient way to distribute entanglement over different network ends. We demonstrate an entanglement access network, where the expensive resource, the entangled photon source at the telecom wavelength and the core communication channel, is shared by many end users. Using this cost-efficient entanglement access network, we report experimental demonstration of a secure multiparty computation protocol, the privacy-preserving secure sum problem, based on the network quantum cryptography. PMID:27404561

Present and future free-space quantum key distribution

NASA Astrophysics Data System (ADS)

Nordholt, Jane E.; Hughes, Richard J.; Morgan, George L.; Peterson, C. Glen; Wipf, Christopher C.

2002-04-01

Free-space quantum key distribution (QKD), more popularly know as quantum cryptography, uses single-photon free-space optical communications to distribute the secret keys required for secure communications. At Los Alamos National Laboratory we have demonstrated a fully automated system that is capable of operations at any time of day over a horizontal range of several kilometers. This has proven the technology is capable of operation from a spacecraft to the ground, opening up the possibility of QKD between any group of users anywhere on Earth. This system, the prototyping of a new system for use on a spacecraft, and the techniques required for world-wide quantum key distribution will be described. The operational parameters and performance of a system designed to operate between low earth orbit (LEO) and the ground will also be discussed.

Visual cryptography for face privacy

NASA Astrophysics Data System (ADS)

Ross, Arun; Othman, Asem A.

2010-04-01

We discuss the problem of preserving the privacy of a digital face image stored in a central database. In the proposed scheme, a private face image is dithered into two host face images such that it can be revealed only when both host images are simultaneously available; at the same time, the individual host images do not reveal the identity of the original image. In order to accomplish this, we appeal to the field of Visual Cryptography. Experimental results confirm the following: (a) the possibility of hiding a private face image in two unrelated host face images; (b) the successful matching of face images that are reconstructed by superimposing the host images; and (c) the inability of the host images, known as sheets, to reveal the identity of the secret face image.

Cheating prevention in visual cryptography.

PubMed

Hu, Chih-Ming; Tzeng, Wen-Guey

2007-01-01

Visual cryptography (VC) is a method of encrypting a secret image into shares such that stacking a sufficient number of shares reveals the secret image. Shares are usually presented in transparencies. Each participant holds a transparency. Most of the previous research work on VC focuses on improving two parameters: pixel expansion and contrast. In this paper, we studied the cheating problem in VC and extended VC. We considered the attacks of malicious adversaries who may deviate from the scheme in any way. We presented three cheating methods and applied them on attacking existent VC or extended VC schemes. We improved one cheat-preventing scheme. We proposed a generic method that converts a VCS to another VCS that has the property of cheating prevention. The overhead of the conversion is near optimal in both contrast degression and pixel expansion.

Step to improve neural cryptography against flipping attacks.

PubMed

Zhou, Jiantao; Xu, Qinzhen; Pei, Wenjiang; He, Zhenya; Szu, Harold

2004-12-01

Synchronization of neural networks by mutual learning has been demonstrated to be possible for constructing key exchange protocol over public channel. However, the neural cryptography schemes presented so far are not the securest under regular flipping attack (RFA) and are completely insecure under majority flipping attack (MFA). We propose a scheme by splitting the mutual information and the training process to improve the security of neural cryptosystem against flipping attacks. Both analytical and simulation results show that the success probability of RFA on the proposed scheme can be decreased to the level of brute force attack (BFA) and the success probability of MFA still decays exponentially with the weights' level L. The synchronization time of the parties also remains polynomial with L. Moreover, we analyze the security under an advanced flipping attack.

Iris Cryptography for Security Purpose

NASA Astrophysics Data System (ADS)

Ajith, Srighakollapu; Balaji Ganesh Kumar, M.; Latha, S.; Samiappan, Dhanalakshmi; Muthu, P.

2018-04-01

In today's world, the security became the major issue to every human being. A major issue is hacking as hackers are everywhere, as the technology was developed still there are many issues where the technology fails to meet the security. Engineers, scientists were discovering the new products for security purpose as biometrics sensors like face recognition, pattern recognition, gesture recognition, voice authentication etcetera. But these devices fail to reach the expected results. In this work, we are going to present an approach to generate a unique secure key using the iris template. Here the iris templates are processed using the well-defined processing techniques. Using the encryption and decryption process they are stored, traversed and utilized. As of the work, we can conclude that the iris cryptography gives us the expected results for securing the data from eavesdroppers.

Using Compilers to Enhance Cryptographic Product Development

NASA Astrophysics Data System (ADS)

Bangerter, E.; Barbosa, M.; Bernstein, D.; Damgård, I.; Page, D.; Pagter, J. I.; Sadeghi, A.-R.; Sovio, S.

Developing high-quality software is hard in the general case, and it is significantly more challenging in the case of cryptographic software. A high degree of new skill and understanding must be learnt and applied without error to avoid vulnerability and inefficiency. This is often beyond the financial, manpower or intellectual resources avail-able. In this paper we present the motivation for the European funded CACE (Computer Aided Cryptography Engineering) project The main objective of CACE is to provide engineers (with limited or no expertise in cryptography) with a toolbox that allows them to generate robust and efficient implementations of cryptographic primitives. We also present some preliminary results already obtained in the early stages of this project, and discuss the relevance of the project as perceived by stakeholders in the mobile device arena.

Access and accounting schemes of wireless broadband

NASA Astrophysics Data System (ADS)

Zhang, Jian; Huang, Benxiong; Wang, Yan; Yu, Xing

2004-04-01

In this paper, two wireless broadband access and accounting schemes were introduced. There are some differences in the client and the access router module between them. In one scheme, Secure Shell (SSH) protocol is used in the access system. The SSH server makes the authentication based on private key cryptography. The advantage of this scheme is the security of the user's information, and we have sophisticated access control. In the other scheme, Secure Sockets Layer (SSL) protocol is used the access system. It uses the technology of public privacy key. Nowadays, web browser generally combines HTTP and SSL protocol and we use the SSL protocol to implement the encryption of the data between the clients and the access route. The schemes are same in the radius sever part. Remote Authentication Dial in User Service (RADIUS), as a security protocol in the form of Client/Sever, is becoming an authentication/accounting protocol for standard access to the Internet. It will be explained in a flow chart. In our scheme, the access router serves as the client to the radius server.

Hybrid cryptosystem for image file using elgamal and double playfair cipher algorithm

NASA Astrophysics Data System (ADS)

Hardi, S. M.; Tarigan, J. T.; Safrina, N.

2018-03-01

In this paper, we present an implementation of an image file encryption using hybrid cryptography. We chose ElGamal algorithm to perform asymmetric encryption and Double Playfair for the symmetric encryption. Our objective is to show that these algorithms are capable to encrypt an image file with an acceptable running time and encrypted file size while maintaining the level of security. The application was built using C# programming language and ran as a stand alone desktop application under Windows Operating System. Our test shows that the system is capable to encrypt an image with a resolution of 500×500 to a size of 976 kilobytes with an acceptable running time.

Partially Key Distribution with Public Key Cryptosystem Based on Error Control Codes

NASA Astrophysics Data System (ADS)

Tavallaei, Saeed Ebadi; Falahati, Abolfazl

Due to the low level of security in public key cryptosystems based on number theory, fundamental difficulties such as "key escrow" in Public Key Infrastructure (PKI) and a secure channel in ID-based cryptography, a new key distribution cryptosystem based on Error Control Codes (ECC) is proposed . This idea is done by some modification on McEliece cryptosystem. The security of ECC cryptosystem obtains from the NP-Completeness of block codes decoding. The capability of generating public keys with variable lengths which is suitable for different applications will be provided by using ECC. It seems that usage of these cryptosystems because of decreasing in the security of cryptosystems based on number theory and increasing the lengths of their keys would be unavoidable in future.

High-performance compression and double cryptography based on compressive ghost imaging with the fast Fourier transform

NASA Astrophysics Data System (ADS)

Leihong, Zhang; Zilan, Pan; Luying, Wu; Xiuhua, Ma

2016-11-01

To solve the problem that large images can hardly be retrieved for stringent hardware restrictions and the security level is low, a method based on compressive ghost imaging (CGI) with Fast Fourier Transform (FFT) is proposed, named FFT-CGI. Initially, the information is encrypted by the sender with FFT, and the FFT-coded image is encrypted by the system of CGI with a secret key. Then the receiver decrypts the image with the aid of compressive sensing (CS) and FFT. Simulation results are given to verify the feasibility, security, and compression of the proposed encryption scheme. The experiment suggests the method can improve the quality of large images compared with conventional ghost imaging and achieve the imaging for large-sized images, further the amount of data transmitted largely reduced because of the combination of compressive sensing and FFT, and improve the security level of ghost images through ciphertext-only attack (COA), chosen-plaintext attack (CPA), and noise attack. This technique can be immediately applied to encryption and data storage with the advantages of high security, fast transmission, and high quality of reconstructed information.

Cut-and-paste restoration of entanglement transmission

NASA Astrophysics Data System (ADS)

Cuevas, Álvaro; Mari, Andrea; De Pasquale, Antonella; Orieux, Adeline; Massaro, Marcello; Sciarrino, Fabio; Mataloni, Paolo; Giovannetti, Vittorio

2017-07-01

The distribution of entangled quantum systems among two or more nodes of a network is a key task at the basis of quantum communication, quantum computation, and quantum cryptography. Unfortunately, the transmission lines used in this procedure can introduce so many perturbations and so much noise in the transmitted signal that they prevent the possibility of restoring quantum correlations in the received messages either by means of encoding optimization or by exploiting local operations and classical communication. In this work we present a procedure which allows one to improve the performance of some of these channels. The mechanism underpinning this result is a protocol which we dub cut and paste, as it consists in extracting and reshuffling the subcomponents of these communication lines, which finally succeed in correcting each other. The proof of this counterintuitive phenomenon, while improving our theoretical understanding of quantum entanglement, also has a direct application in the realization of quantum information networks based on imperfect and highly noisy communication lines. A quantum optics experiment, based on the transmission of single-photon polarization states, is also presented which provides a proof-of-principle test of the proposed protocol.

Advanced active quenching circuit for ultra-fast quantum cryptography.

PubMed

Stipčević, Mario; Christensen, Bradley G; Kwiat, Paul G; Gauthier, Daniel J

2017-09-04

Commercial photon-counting modules based on actively quenched solid-state avalanche photodiode sensors are used in a wide variety of applications. Manufacturers characterize their detectors by specifying a small set of parameters, such as detection efficiency, dead time, dark counts rate, afterpulsing probability and single-photon arrival-time resolution (jitter). However, they usually do not specify the range of conditions over which these parameters are constant or present a sufficient description of the characterization process. In this work, we perform a few novel tests on two commercial detectors and identify an additional set of imperfections that must be specified to sufficiently characterize their behavior. These include rate-dependence of the dead time and jitter, detection delay shift, and "twilighting". We find that these additional non-ideal behaviors can lead to unexpected effects or strong deterioration of the performance of a system using these devices. We explain their origin by an in-depth analysis of the active quenching process. To mitigate the effects of these imperfections, a custom-built detection system is designed using a novel active quenching circuit. Its performance is compared against two commercial detectors in a fast quantum key distribution system with hyper-entangled photons and a random number generator.

Photons protect privacy

NASA Astrophysics Data System (ADS)

Graham-Rowe, Duncan

2008-02-01

The idea of using quantum optics to protect the transmission of sensitive data is becoming a commercial reality and starting to be deployed. Duncan Graham-Rowe takes a look at recent progress in quantum cryptography.

Stability assessment of QKD procedures in commercial quantum cryptography systems versus quality of dark channel

NASA Astrophysics Data System (ADS)

Jacak, Monika; Melniczuk, Damian; Jacak, Janusz; Jóźwiak, Ireneusz; Gruber, Jacek; Jóźwiak, Piotr

2015-02-01

In order to assess the susceptibility of the quantum key distribution (QKD) systems to the hacking attack including simultaneous and frequent system self-decalibrations, we analyze the stability of the QKD transmission organized in two commercially available systems. The first one employs non-entangled photons as flying qubits in the dark quantum channel for communication whereas the second one utilizes the entangled photon pairs to secretly share the cryptographic key. Applying standard methods of the statistical data analysis to the characteristic indicators of the quality of the QKD communication (the raw key exchange rate [RKER] and the quantum bit error rate [QBER]), we have estimated the pace of the self-decalibration of both systems and the repeatability rate in the case of controlled worsening of the dark channel quality.

On the efficiency of the image encryption and decryption by using logistic-sine chaotic system and logistic-tent chaotic system

NASA Astrophysics Data System (ADS)

Chiun, Lee Chia; Mandangan, Arif; Daud, Muhamad Azlan; Hussin, Che Haziqah Che

2017-04-01

We may secure the content of text, audio, image and video during their transmission from one party to another party via an open channel such as the internet by using cryptograph. Logistic-Sine System (LSS) is a combination on two 1D chaotic maps which are Logistic Map and Sine Map. By applying the LSS into cryptography, the image encryption and decryption can be performed. This study is focusing on the performance test of the image encryption and decryption processes by using the LSS. For comparison purpose, we compare the performance of the encryption and decryption by using two different chaotic systems, which are the LSS and Logistic-Tent System (LTS). The result shows that system with LSS is less efficient than LTS in term of encryption time but both systems have similar efficiency in term of decryption time.

Robust PRNG based on homogeneously distributed chaotic dynamics

NASA Astrophysics Data System (ADS)

Garasym, Oleg; Lozi, René; Taralova, Ina

2016-02-01

This paper is devoted to the design of new chaotic Pseudo Random Number Generator (CPRNG). Exploring several topologies of network of 1-D coupled chaotic mapping, we focus first on two dimensional networks. Two topologically coupled maps are studied: TTL rc non-alternate, and TTL SC alternate. The primary idea of the novel maps has been based on an original coupling of the tent and logistic maps to achieve excellent random properties and homogeneous /uniform/ density in the phase plane, thus guaranteeing maximum security when used for chaos base cryptography. In this aim two new nonlinear CPRNG: MTTL 2 sc and NTTL 2 are proposed. The maps successfully passed numerous statistical, graphical and numerical tests, due to proposed ring coupling and injection mechanisms.

Subcarrier Wave Quantum Key Distribution in Telecommunication Network with Bitrate 800 kbit/s

NASA Astrophysics Data System (ADS)

Gleim, A. V.; Nazarov, Yu. V.; Egorov, V. I.; Smirnov, S. V.; Bannik, O. I.; Chistyakov, V. V.; Kynev, S. M.; Anisimov, A. A.; Kozlov, S. A.; Vasiliev, V. N.

2015-09-01

In the course of work on creating the first quantum communication network in Russia we demonstrated quantum key distribution in metropolitan optical network infrastructure. A single-pass subcarrier wave quantum cryptography scheme was used in the experiments. BB84 protocol with strong reference was chosen for performing key distribution. The registered sifted key rate in an optical cable with 1.5 dB loss was 800 Kbit/s. Signal visibility exceeded 98%, and quantum bit error rate value was 1%. The achieved result is a record for this type of systems.

Bell's Theorem, Entaglement, Quantum Teleportation and All That

ScienceCinema

Leggett, Anthony

2018-04-19

One of the most surprising aspects of quantum mechanics is that under certain circumstances it does not allow individual physical systems, even when isolated, to possess properties in their own right. This feature, first clearly appreciated by John Bell in 1964, has in the last three decades been tested experimentally and found (in most people's opinion) to be spectacularly confirmed. More recently it has been realized that it permits various operations which are classically impossible, such as "teleportation" and secure-in-principle cryptography. This talk is a very basic introduction to the subject, which requires only elementary quantum mechanics.

From Greeks to Today: Cipher Trees and Computer Cryptography.

ERIC Educational Resources Information Center

Grady, M. Tim; Brumbaugh, Doug

1988-01-01

Explores the use of computers for teaching mathematical models of transposition ciphers. Illustrates the ideas, includes activities and extensions, provides a mathematical model and includes computer programs to implement these topics. (MVL)

China demonstrates intercontinental quantum key distribution

NASA Astrophysics Data System (ADS)

Johnston, Hamish

2017-11-01

A quantum cryptography key has been shared between Beijing and Vienna using a satellite - allowing the presidents of the Chinese Academy of Sciences and Austrian Academy of Sciences to communicate via a secure video link.

Tripartite counterfactual quantum cryptography

NASA Astrophysics Data System (ADS)

Salih, Hatim

2014-07-01

We show how two distrustful parties, "Bob" and "Charlie," can share a secret key with the help of a mutually trusted "Alice" counterfactually; that is, with no information-carrying particles traveling between any of the three.

Coherent-pulse implementations of quantum cryptography protocols resistant to photon-number-splitting attacks

NASA Astrophysics Data System (ADS)

Acín, Antonio; Gisin, Nicolas; Scarani, Valerio

2004-01-01

We propose a class of quantum cryptography protocols that are robust against photon-number-splitting attacks (PNS) in a weak coherent-pulse implementation. We give a quite exhaustive analysis of several eavesdropping attacks on these schemes. The honest parties (Alice and Bob) use present-day technology, in particular an attenuated laser as an approximation of a single-photon source. The idea of the protocols is to exploit the nonorthogonality of quantum states to decrease the information accessible to Eve due to the multiphoton pulses produced by the imperfect source. The distance at which the key distribution becomes insecure due to the PNS attack is significantly increased compared to the existing schemes. We also show that strong-pulse implementations, where a strong pulse is included as a reference, allow for key distribution robust against photon-number-splitting attacks.

Statistical complexity measure of pseudorandom bit generators

NASA Astrophysics Data System (ADS)

González, C. M.; Larrondo, H. A.; Rosso, O. A.

2005-08-01

Pseudorandom number generators (PRNG) are extensively used in Monte Carlo simulations, gambling machines and cryptography as substitutes of ideal random number generators (RNG). Each application imposes different statistical requirements to PRNGs. As L’Ecuyer clearly states “the main goal for Monte Carlo methods is to reproduce the statistical properties on which these methods are based whereas for gambling machines and cryptology, observing the sequence of output values for some time should provide no practical advantage for predicting the forthcoming numbers better than by just guessing at random”. In accordance with different applications several statistical test suites have been developed to analyze the sequences generated by PRNGs. In a recent paper a new statistical complexity measure [Phys. Lett. A 311 (2003) 126] has been defined. Here we propose this measure, as a randomness quantifier of a PRNGs. The test is applied to three very well known and widely tested PRNGs available in the literature. All of them are based on mathematical algorithms. Another PRNGs based on Lorenz 3D chaotic dynamical system is also analyzed. PRNGs based on chaos may be considered as a model for physical noise sources and important new results are recently reported. All the design steps of this PRNG are described, and each stage increase the PRNG randomness using different strategies. It is shown that the MPR statistical complexity measure is capable to quantify this randomness improvement. The PRNG based on the chaotic 3D Lorenz dynamical system is also evaluated using traditional digital signal processing tools for comparison.

Robust ECC-based authenticated key agreement scheme with privacy protection for Telecare medicine information systems.

PubMed

Zhang, Liping; Zhu, Shaohui

2015-05-01

To protect the transmission of the sensitive medical data, a secure and efficient authenticated key agreement scheme should be deployed when the healthcare delivery session is established via Telecare Medicine Information Systems (TMIS) over the unsecure public network. Recently, Islam and Khan proposed an authenticated key agreement scheme using elliptic curve cryptography for TMIS. They claimed that their proposed scheme is provably secure against various attacks in random oracle model and enjoys some good properties such as user anonymity. In this paper, however, we point out that any legal but malicious patient can reveal other user's identity. Consequently, their scheme suffers from server spoofing attack and off-line password guessing attack. Moreover, if the malicious patient performs the same time of the registration as other users, she can further launch the impersonation attack, man-in-the-middle attack, modification attack, replay attack, and strong replay attack successfully. To eliminate these weaknesses, we propose an improved ECC-based authenticated key agreement scheme. Security analysis demonstrates that the proposed scheme can resist various attacks and enables the patient to enjoy the remote healthcare services with privacy protection. Through the performance evaluation, we show that the proposed scheme achieves a desired balance between security and performance in comparisons with other related schemes.

Nonclassical light sources for silicon photonics

NASA Astrophysics Data System (ADS)

Bajoni, Daniele; Galli, Matteo

2017-09-01

Quantum photonics has recently attracted a lot of attention for its disruptive potential in emerging technologies like quantum cryptography, quantum communication and quantum computing. Driven by the impressive development in nanofabrication technologies and nanoscale engineering, silicon photonics has rapidly become the platform of choice for on-chip integration of high performing photonic devices, now extending their functionalities towards quantum-based applications. Focusing on quantum Information Technology (qIT) as a key application area, we review recent progress in integrated silicon-based sources of nonclassical states of light. We assess the state of the art in this growing field and highlight the challenges that need to be overcome to make quantum photonics a reliable and widespread technology.

Elliptic net and its cryptographic application

NASA Astrophysics Data System (ADS)

Muslim, Norliana; Said, Mohamad Rushdan Md

2017-11-01

Elliptic net is a generalization of elliptic divisibility sequence and in cryptography field, most cryptographic pairings that are based on elliptic curve such as Tate pairing can be improved by applying elliptic nets algorithm. The elliptic net is constructed by using n dimensional array of values in rational number satisfying nonlinear recurrence relations that arise from elliptic divisibility sequences. The two main properties hold in the recurrence relations are for all positive integers m>n, hm +nhm -n=hm +1hm -1hn2-hn +1hn -1hm2 and hn divides hm whenever n divides m. In this research, we discuss elliptic divisibility sequence associated with elliptic nets based on cryptographic perspective and its possible research direction.

Measurement-device-independent entanglement-based quantum key distribution

NASA Astrophysics Data System (ADS)

Yang, Xiuqing; Wei, Kejin; Ma, Haiqiang; Sun, Shihai; Liu, Hongwei; Yin, Zhenqiang; Li, Zuohan; Lian, Shibin; Du, Yungang; Wu, Lingan

2016-05-01

We present a quantum key distribution protocol in a model in which the legitimate users gather statistics as in the measurement-device-independent entanglement witness to certify the sources and the measurement devices. We show that the task of measurement-device-independent quantum communication can be accomplished based on monogamy of entanglement, and it is fairly loss tolerate including source and detector flaws. We derive a tight bound for collective attacks on the Holevo information between the authorized parties and the eavesdropper. Then with this bound, the final secret key rate with the source flaws can be obtained. The results show that long-distance quantum cryptography over 144 km can be made secure using only standard threshold detectors.

Optical digital chaos cryptography

NASA Astrophysics Data System (ADS)

Arenas-Pingarrón, Álvaro; González-Marcos, Ana P.; Rivas-Moscoso, José M.; Martín-Pereda, José A.

2007-10-01

In this work we present a new way to mask the data in a one-user communication system when direct sequence - code division multiple access (DS-CDMA) techniques are used. The code is generated by a digital chaotic generator, originally proposed by us and previously reported for a chaos cryptographic system. It is demonstrated that if the user's data signal is encoded with a bipolar phase-shift keying (BPSK) technique, usual in DS-CDMA, it can be easily recovered from a time-frequency domain representation. To avoid this situation, a new system is presented in which a previous dispersive stage is applied to the data signal. A time-frequency domain analysis is performed, and the devices required at the transmitter and receiver end, both user-independent, are presented for the optical domain.

Hacking commercial quantum cryptography systems by tailored bright illumination

NASA Astrophysics Data System (ADS)

Lydersen, Lars; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim

2010-10-01

The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built from off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.

Privacy Protection for Telecare Medicine Information Systems Using a Chaotic Map-Based Three-Factor Authenticated Key Agreement Scheme.

PubMed

Zhang, Liping; Zhu, Shaohui; Tang, Shanyu

2017-03-01

Telecare medicine information systems (TMIS) provide flexible and convenient e-health care. However, the medical records transmitted in TMIS are exposed to unsecured public networks, so TMIS are more vulnerable to various types of security threats and attacks. To provide privacy protection for TMIS, a secure and efficient authenticated key agreement scheme is urgently needed to protect the sensitive medical data. Recently, Mishra et al. proposed a biometrics-based authenticated key agreement scheme for TMIS by using hash function and nonce, they claimed that their scheme could eliminate the security weaknesses of Yan et al.'s scheme and provide dynamic identity protection and user anonymity. In this paper, however, we demonstrate that Mishra et al.'s scheme suffers from replay attacks, man-in-the-middle attacks and fails to provide perfect forward secrecy. To overcome the weaknesses of Mishra et al.'s scheme, we then propose a three-factor authenticated key agreement scheme to enable the patient to enjoy the remote healthcare services via TMIS with privacy protection. The chaotic map-based cryptography is employed in the proposed scheme to achieve a delicate balance of security and performance. Security analysis demonstrates that the proposed scheme resists various attacks and provides several attractive security properties. Performance evaluation shows that the proposed scheme increases efficiency in comparison with other related schemes.

Observable measure of quantum coherence in finite dimensional systems.

PubMed

Girolami, Davide

2014-10-24

Quantum coherence is the key resource for quantum technology, with applications in quantum optics, information processing, metrology, and cryptography. Yet, there is no universally efficient method for quantifying coherence either in theoretical or in experimental practice. I introduce a framework for measuring quantum coherence in finite dimensional systems. I define a theoretical measure which satisfies the reliability criteria established in the context of quantum resource theories. Then, I present an experimental scheme implementable with current technology which evaluates the quantum coherence of an unknown state of a d-dimensional system by performing two programmable measurements on an ancillary qubit, in place of the O(d2) direct measurements required by full state reconstruction. The result yields a benchmark for monitoring quantum effects in complex systems, e.g., certifying nonclassicality in quantum protocols and probing the quantum behavior of biological complexes.

Control of entanglement dynamics in a system of three coupled quantum oscillators.

PubMed

Gonzalez-Henao, J C; Pugliese, E; Euzzor, S; Meucci, R; Roversi, J A; Arecchi, F T

2017-08-30

Dynamical control of entanglement and its connection with the classical concept of instability is an intriguing matter which deserves accurate investigation for its important role in information processing, cryptography and quantum computing. Here we consider a tripartite quantum system made of three coupled quantum parametric oscillators in equilibrium with a common heat bath. The introduced parametrization consists of a pulse train with adjustable amplitude and duty cycle representing a more general case for the perturbation. From the experimental observation of the instability in the classical system we are able to predict the parameter values for which the entangled states exist. A different amount of entanglement and different onset times emerge when comparing two and three quantum oscillators. The system and the parametrization considered here open new perspectives for manipulating quantum features at high temperatures.

Light for the quantum. Entangled photons and their applications: a very personal perspective

NASA Astrophysics Data System (ADS)

Zeilinger, Anton

2017-07-01

The quantum physics of light is a most fascinating field. Here I present a very personal viewpoint, focusing on my own path to quantum entanglement and then on to applications. I have been fascinated by quantum physics ever since I heard about it for the first time in school. The theory struck me immediately for two reasons: (1) its immense mathematical beauty, and (2) the unparalleled precision to which its predictions have been verified again and again. Particularly fascinating for me were the predictions of quantum mechanics for individual particles, individual quantum systems. Surprisingly, the experimental realization of many of these fundamental phenomena has led to novel ideas for applications. Starting from my early experiments with neutrons, I later became interested in quantum entanglement, initially focusing on multi-particle entanglement like GHZ states. This work opened the experimental possibility to do quantum teleportation and quantum hyper-dense coding. The latter became the first entanglement-based quantum experiment breaking a classical limitation. One of the most fascinating phenomena is entanglement swapping, the teleportation of an entangled state. This phenomenon is fundamentally interesting because it can entangle two pairs of particles which do not share any common past. Surprisingly, it also became an important ingredient in a number of applications, including quantum repeaters which will connect future quantum computers with each other. Another application is entanglement-based quantum cryptography where I present some recent long-distance experiments. Entanglement swapping has also been applied in very recent so-called loophole-free tests of Bell’s theorem. Within the physics community such loophole-free experiments are perceived as providing nearly definitive proof that local realism is untenable. While, out of principle, local realism can never be excluded entirely, the 2015 achievements narrow down the remaining possibilities for local realistic explanations of the quantum phenomenon of entanglement in a significant way. These experiments may go down in the history books of science. Future experiments will address particularly the freedom-of-choice loophole using cosmic sources of randomness. Such experiments confirm that unconditionally secure quantum cryptography is possible, since quantum cryptography based on Bell’s theorem can provide unconditional security. The fact that the experiments were loophole-free proves that an eavesdropper cannot avoid detection in an experiment that correctly follows the protocol. I finally discuss some recent experiments with single- and entangled-photon states in higher dimensions. Such experiments realized quantum entanglement between two photons, each with quantum numbers beyond 10 000 and also simultaneous entanglement of two photons where each carries more than 100 dimensions. Thus they offer the possibility of quantum communication with more than one bit or qubit per photon. The paper concludes discussing Einstein’s contributions and viewpoints of quantum mechanics. Even if some of his positions are not supported by recent experiments, he has to be given credit for the fact that his analysis of fundamental issues gave rise to developments which led to a new information technology. Finally, I reflect on some of the lessons learned by the fact that nature cannot be local, that objective randomness exists and about the emergence of a classical world. It is suggestive that information plays a fundamental role also in the foundations of quantum physics.

Low-power cryptographic coprocessor for autonomous wireless sensor networks

NASA Astrophysics Data System (ADS)

Olszyna, Jakub; Winiecki, Wiesław

2013-10-01

The concept of autonomous wireless sensor networks involves energy harvesting, as well as effective management of system resources. Public-key cryptography (PKC) offers the advantage of elegant key agreement schemes with which a secret key can be securely established over unsecure channels. In addition to solving the key management problem, the other major application of PKC is digital signatures, with which non-repudiation of messages exchanges can be achieved. The motivation for studying low-power and area efficient modular arithmetic algorithms comes from enabling public-key security for low-power devices that can perform under constrained environment like autonomous wireless sensor networks. This paper presents a cryptographic coprocessor tailored to the autonomous wireless sensor networks constraints. Such hardware circuit is aimed to support the implementation of different public-key cryptosystems based on modular arithmetic in GF(p) and GF(2m). Key components of the coprocessor are described as GEZEL models and can be easily transformed to VHDL and implemented in hardware.

An Enhanced Secure Identity-Based Certificateless Public Key Authentication Scheme for Vehicular Sensor Networks.

PubMed

Li, Congcong; Zhang, Xi; Wang, Haiping; Li, Dongfeng

2018-01-11

Vehicular sensor networks have been widely applied in intelligent traffic systems in recent years. Because of the specificity of vehicular sensor networks, they require an enhanced, secure and efficient authentication scheme. Existing authentication protocols are vulnerable to some problems, such as a high computational overhead with certificate distribution and revocation, strong reliance on tamper-proof devices, limited scalability when building many secure channels, and an inability to detect hardware tampering attacks. In this paper, an improved authentication scheme using certificateless public key cryptography is proposed to address these problems. A security analysis of our scheme shows that our protocol provides an enhanced secure anonymous authentication, which is resilient against major security threats. Furthermore, the proposed scheme reduces the incidence of node compromise and replication attacks. The scheme also provides a malicious-node detection and warning mechanism, which can quickly identify compromised static nodes and immediately alert the administrative department. With performance evaluations, the scheme can obtain better trade-offs between security and efficiency than the well-known available schemes.

High-fidelity transmission of polarization encoded qubits from an entangled source over 100 km of fiber.

PubMed

Hübel, Hannes; Vanner, Michael R; Lederer, Thomas; Blauensteiner, Bibiane; Lorünser, Thomas; Poppe, Andreas; Zeilinger, Anton

2007-06-11

We demonstrate non-degenerate down-conversion at 810 and 1550 nm for long-distance fiber based quantum communication using polarization entangled photon pairs. Measurements of the two-photon visibility, without dark count subtraction, have shown that the quantum correlations (raw visibility 89%) allow secure quantum cryptography after 100 km of non-zero dispersion shifted fiber using commercially available single photon detectors. In addition, quantum state tomography has revealed little degradation of state negativity, decreasing from 0.99 at the source to 0.93 after 100 km, indicating minimal loss in fidelity during the transmission.

Eavesdropping on counterfactual quantum key distribution with finite resources

NASA Astrophysics Data System (ADS)

Liu, Xingtong; Zhang, Bo; Wang, Jian; Tang, Chaojing; Zhao, Jingjing; Zhang, Sheng

2014-08-01

A striking scheme called "counterfactual quantum cryptography" gives a conceptually new approach to accomplish the task of key distribution. It allows two legitimate parties to share a secret even though a particle carrying secret information is not, in fact, transmitted through the quantum channel. Since an eavesdropper cannot directly access the entire quantum system of each signal particle, the protocol seems to provide practical security advantages. However, here we propose an eavesdropping method which works on the scheme in a finite key scenario. We show that, for practical systems only generating a finite number of keys, the eavesdropping can obtain all of the secret information without being detected. We also present a improved protocol as a countermeasure against this attack.