An Inexpensive Device for Teaching Public Key Encryption
ERIC Educational Resources Information Center
Pendegraft, Norman
2009-01-01
An inexpensive device to assist in teaching the main ideas of Public Key encryption and its use in class to illustrate the operation of public key encryption is described. It illustrates that there are two keys, and is particularly useful for illustrating that privacy is achieved by using the public key. Initial data from in class use seem to…
An Inexpensive Device for Teaching Public Key Encryption
ERIC Educational Resources Information Center
Pendegraft, Norman
2009-01-01
An inexpensive device to assist in teaching the main ideas of Public Key encryption and its use in class to illustrate the operation of public key encryption is described. It illustrates that there are two keys, and is particularly useful for illustrating that privacy is achieved by using the public key. Initial data from in class use seem to…
Bit-Oriented Quantum Public Key Probabilistic Encryption Schemes
NASA Astrophysics Data System (ADS)
Zheng, Shihui; Gu, Lize; Xiao, Da
2014-01-01
Quantum public-key encryption system provides information confidentiality using quantum mechanics. In this paper, two bit-oriented public key probabilistic encryption schemes are constructed based on a new randomizing method combined with single-qubit rotation. They are strong enough to resist forward search attack and have private key secrecy. Moreover, the ciphertext expansion of the second scheme is low and the number of public key qubits used to encrypt is small under the condition that decryption error is negligible.
Public-key encryption and authentication of quantum information
NASA Astrophysics Data System (ADS)
Liang, Min; Yang, Li
2012-09-01
Public-key cryptosystems for quantum messages are considered from two aspects: public-key encryption and public-key authentication. Firstly, we propose a general construction of quantum public-key encryption scheme, and then construct an information-theoretic secure instance. Then, we propose a quantum public-key authentication scheme, which can protect the integrity of quantum messages. This scheme can both encrypt and authenticate quantum messages. It is information-theoretic secure with regard to encryption, and the success probability of tampering decreases exponentially with the security parameter with regard to authentication. Compared with classical public-key cryptosystems, one private-key in our schemes corresponds to an exponential number of public-keys, and every quantum public-key used by the sender is an unknown quantum state to the sender.
A complete classification of quantum public-key encryption protocols
NASA Astrophysics Data System (ADS)
Wu, Chenmiao; Yang, Li
2015-10-01
We present a classification of quantum public-key encryption protocols. There are six elements in quantum public-key encryption: plaintext, ciphertext, public-key, private-key, encryption algorithm and decryption algorithm. According to the property of each element which is either quantum or classical, the quantum public-key encryption protocols can be divided into 64 kinds. Among 64 kinds of protocols, 8 kinds have already been constructed, 52 kinds can be proved to be impossible to construct and the remaining 4 kinds have not been presented effectively yet. This indicates that the research on quantum public-key encryption protocol should be focus on the existed kinds and the unproposed kinds.
Deducing trapdoor primitives in public key encryption schemes
NASA Astrophysics Data System (ADS)
Pandey, Chandra
2005-03-01
Semantic security of public key encryption schemes is often interchangeable with the art of building trapdoors. In the frame of reference of Random Oracle methodology, the "Key Privacy" and "Anonymity" has often been discussed. However to a certain degree the security of most public key encryption schemes is required to be analyzed with formal proofs using one-way functions. This paper evaluates the design of El Gamal and RSA based schemes and attempts to parallelize the trapdoor primitives used in the computation of the cipher text, thereby magnifying the decryption error δp in the above schemes.
Bit-oriented quantum public-key encryption based on quantum perfect encryption
NASA Astrophysics Data System (ADS)
Wu, Chenmiao; Yang, Li
2016-08-01
A bit-oriented quantum public-key encryption scheme is presented. We use Boolean functions as private-key and randomly changed pairs of quantum state and classical string as public-keys. Following the concept of quantum perfect encryption, we prepare the public-key with Hadamard transformation and Pauli transformation. The quantum part of public-keys is various with different classical strings. In contrast to the typical classical public-key scheme, one private-key in our scheme corresponds to an exponential number of public-keys. We investigate attack to the private-key and prove that the public-key is a totally mixed state. So the adversary cannot acquire any information about private-key from measurement of the public-key. Then, the attack to encryption is analyzed. Since the trace distance between two different ciphertexts is zero, the adversary cannot distinguish between the two ciphertext states and also obtains nothing about plaintext and private-key. Thus, we have the conclusion that the proposed scheme is information-theoretically secure under an attack of the private-key and encryption.
A public key encryption scheme based on idempotent semirings
NASA Astrophysics Data System (ADS)
Durcheva, Mariana; Rachev, Martin
2015-11-01
The problem of solving two sided linear equations in the idempotent semirings R¯m a x and R¯m i n has been proved to be reducible to the problem mean payoff game which is of the NP∩ coNP type. In the present paper, we use the mentioned security results and construct a new public key encryption scheme based on the hardness of the problem of solving two sided linear equations in the idempotent semirings.
Novel Public Key Encryption Technique Based on Multiple Chaotic Systems
NASA Astrophysics Data System (ADS)
Bose, Ranjan
2005-08-01
Public key encryption was first introduced by Diffie and Hellman in 1976. Since then, the Diffie-Hellman key exchange protocol has been used in developing public key systems such as Rivest-Shamir-Adleman and elliptic curve cryptography. Chaotic functions, so far, have been used for symmetric cryptography only. In this Letter we propose, for the first time, a methodology to use multiple chaotic systems and a set of linear functions for key exchange over an insecure channel. To the best of our knowledge, this is the first Letter that reports the use of chaotic systems for public key cryptography. We have shown that the security of the proposed algorithm grows as (NP)m, where N, P, and m are large numbers that can be chosen as the parameters of the cryptosystem.
Novel public key encryption technique based on multiple chaotic systems.
Bose, Ranjan
2005-08-26
Public key encryption was first introduced by Diffie and Hellman in 1976. Since then, the Diffie-Hellman key exchange protocol has been used in developing public key systems such as Rivest-Shamir-Adleman and elliptic curve cryptography. Chaotic functions, so far, have been used for symmetric cryptography only. In this Letter we propose, for the first time, a methodology to use multiple chaotic systems and a set of linear functions for key exchange over an insecure channel. To the best of our knowledge, this is the first Letter that reports the use of chaotic systems for public key cryptography. We have shown that the security of the proposed algorithm grows as (NP)(m), where N, P, and m are large numbers that can be chosen as the parameters of the cryptosystem.
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.
Deterministic quantum-public-key encryption: Forward search attack and randomization
NASA Astrophysics Data System (ADS)
Nikolopoulos, Georgios M.; Ioannou, Lawrence M.
2009-04-01
In the classical setting, public-key encryption requires randomness in order to be secure against a forward search attack, whereby an adversary compares the encryption of a guess of the secret message with the encryption of the actual secret message. We show that this is also true in the information-theoretic setting—where the public keys are quantum systems—by defining and giving an example of a forward search attack for any deterministic quantum-public-key bit-encryption scheme. However, unlike in the classical setting, we show that any such deterministic scheme can be used as a black box to build a randomized bit-encryption scheme that is no longer susceptible to this attack.
Efficient secure-channel free public key encryption with keyword search for EMRs in cloud storage.
Guo, Lifeng; Yau, Wei-Chuen
2015-02-01
Searchable encryption is an important cryptographic primitive that enables privacy-preserving keyword search on encrypted electronic medical records (EMRs) in cloud storage. Efficiency of such searchable encryption in a medical cloud storage system is very crucial as it involves client platforms such as smartphones or tablets that only have constrained computing power and resources. In this paper, we propose an efficient secure-channel free public key encryption with keyword search (SCF-PEKS) scheme that is proven secure in the standard model. We show that our SCF-PEKS scheme is not only secure against chosen keyword and ciphertext attacks (IND-SCF-CKCA), but also secure against keyword guessing attacks (IND-KGA). Furthermore, our proposed scheme is more efficient than other recent SCF-PEKS schemes in the literature.
Symmetries and security of a quantum-public-key encryption based on single-qubit rotations
NASA Astrophysics Data System (ADS)
Seyfarth, U.; Nikolopoulos, G. M.; Alber, G.
2012-02-01
Exploring the symmetries underlying a previously proposed encryption scheme that relies on single-qubit rotations, we derive an improved upper bound on the maximum information that an eavesdropper might extract from all the available copies of the public key. Subsequently, the robustness of the scheme is investigated in the context of attacks that address each public-key qubit independently. The attacks under consideration make use of projective measurements on single qubits and their efficiency is compared to attacks that address many qubits collectively and require complicated quantum operations.
Guo, Rui; Wen, Qiaoyan; Shi, Huixian; Jin, Zhengping; Zhang, Hua
2013-10-01
Telecare Medicine Information Systems (TMIS) promote the traditional medical and healthcare services by information and communication technology. Since the physician and caregiver can monitor the patient's physiological condition remotely in TMIS, the confidentiality of this sensitive data should be protected, which is the key issue in the Health Insurance Portability and Accountability Act. In this paper, we propose an efficient certificateless public key encryption scheme without bilinear pairing for TMIS. Our proposal is proved to be secure in the random oracle model under the hardness assumption of computational Diffie-Hellman problem. Moreover, after modifying the original model of the certificateless encryption, this scheme achieves Girault's trust level 3. Compared with the related protocols, the perform evaluations show that our scheme is more efficient and appropriate to collocate with low power mobile devices for TMIS.
Simultaneous transmission for an encrypted image and a double random-phase encryption key.
Yuan, Sheng; Zhou, Xin; Li, Da-hai; Zhou, Ding-fu
2007-06-20
We propose a method to simultaneously transmit double random-phase encryption key and an encrypted image by making use of the fact that an acceptable decryption result can be obtained when only partial data of the encrypted image have been taken in the decryption process. First, the original image data are encoded as an encrypted image by a double random-phase encryption technique. Second, a double random-phase encryption key is encoded as an encoded key by the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. Then the amplitude of the encrypted image is modulated by the encoded key to form what we call an encoded image. Finally, the encoded image that carries both the encrypted image and the encoded key is delivered to the receiver. Based on such a method, the receiver can have an acceptable result and secure transmission can be guaranteed by the RSA cipher system.
An improved coding technique for image encryption and key management
NASA Astrophysics Data System (ADS)
Wu, Xu; Ma, Jie; Hu, Jiasheng
2005-02-01
An improved chaotic algorithm for image encryption on the basis of conventional chaotic encryption algorithm is proposed. Two keys are presented in our technique. One is called private key, which is fixed and protected in the system. The other is named assistant key, which is public and transferred with the encrypted image together. For different original image, different assistant key should be chosen so that one could get different encrypted key. The updated encryption algorithm not only can resist a known-plaintext attack, but also offers an effective solution for key management. The analyses and the computer simulations show that the security is improved greatly, and can be easily realized with hardware.
Encrypting Digital Camera with Automatic Encryption Key Deletion
NASA Technical Reports Server (NTRS)
Oakley, Ernest C. (Inventor)
2007-01-01
A digital video camera includes an image sensor capable of producing a frame of video data representing an image viewed by the sensor, an image memory for storing video data such as previously recorded frame data in a video frame location of the image memory, a read circuit for fetching the previously recorded frame data, an encryption circuit having an encryption key input connected to receive the previously recorded frame data from the read circuit as an encryption key, an un-encrypted data input connected to receive the frame of video data from the image sensor and an encrypted data output port, and a write circuit for writing a frame of encrypted video data received from the encrypted data output port of the encryption circuit to the memory and overwriting the video frame location storing the previously recorded frame data.
Munisamy, Shyamala Devi; Chokkalingam, Arun
2015-01-01
Cloud computing has pioneered the emerging world by manifesting itself as a service through internet and facilitates third party infrastructure and applications. While customers have no visibility on how their data is stored on service provider's premises, it offers greater benefits in lowering infrastructure costs and delivering more flexibility and simplicity in managing private data. The opportunity to use cloud services on pay-per-use basis provides comfort for private data owners in managing costs and data. With the pervasive usage of internet, the focus has now shifted towards effective data utilization on the cloud without compromising security concerns. In the pursuit of increasing data utilization on public cloud storage, the key is to make effective data access through several fuzzy searching techniques. In this paper, we have discussed the existing fuzzy searching techniques and focused on reducing the searching time on the cloud storage server for effective data utilization. Our proposed Asymmetric Classifier Multikeyword Fuzzy Search method provides classifier search server that creates universal keyword classifier for the multiple keyword request which greatly reduces the searching time by learning the search path pattern for all the keywords in the fuzzy keyword set. The objective of using BTree fuzzy searchable index is to resolve typos and representation inconsistencies and also to facilitate effective data utilization.
Universal Keyword Classifier on Public Key Based Encrypted Multikeyword Fuzzy Search in Public Cloud
Munisamy, Shyamala Devi; Chokkalingam, Arun
2015-01-01
Cloud computing has pioneered the emerging world by manifesting itself as a service through internet and facilitates third party infrastructure and applications. While customers have no visibility on how their data is stored on service provider's premises, it offers greater benefits in lowering infrastructure costs and delivering more flexibility and simplicity in managing private data. The opportunity to use cloud services on pay-per-use basis provides comfort for private data owners in managing costs and data. With the pervasive usage of internet, the focus has now shifted towards effective data utilization on the cloud without compromising security concerns. In the pursuit of increasing data utilization on public cloud storage, the key is to make effective data access through several fuzzy searching techniques. In this paper, we have discussed the existing fuzzy searching techniques and focused on reducing the searching time on the cloud storage server for effective data utilization. Our proposed Asymmetric Classifier Multikeyword Fuzzy Search method provides classifier search server that creates universal keyword classifier for the multiple keyword request which greatly reduces the searching time by learning the search path pattern for all the keywords in the fuzzy keyword set. The objective of using BTree fuzzy searchable index is to resolve typos and representation inconsistencies and also to facilitate effective data utilization. PMID:26380364
Key management for large scale end-to-end encryption
Witzke, E.L.
1994-07-01
Symmetric end-to-end encryption requires separate keys for each pair of communicating confidants. This is a problem of Order N{sup 2}. Other factors, such as multiple sessions per pair of confidants and multiple encryption points in the ISO Reference Model complicate key management by linear factors. Public-key encryption can reduce the number of keys managed to a linear problem which is good for scaleability of key management, but comes with complicating issues and performance penalties. Authenticity is the primary ingredient of key management. If each potential pair of communicating confidants can authenticate data from each other, then any number of public encryption keys of any type can be communicated with requisite integrity. These public encryption keys can be used with the corresponding private keys to exchange symmetric cryptovariables for high data rate privacy protection. The Digital Signature Standard (DSS), which has been adopted by the United States Government, has both public and private components, similar to a public-key cryptosystem. The Digital Signature Algorithm of the DSS is intended for authenticity but not for secrecy. In this paper, the authors will show how the use of the Digital Signature Algorithm combined with both symmetric and asymmetric (public-key) encryption techniques can provide a practical solution to key management scaleability problems, by reducing the key management complexity to a problem of order N, without sacrificing the encryption speed necessary to operate in high performance networks.
NASA Astrophysics Data System (ADS)
Meng, X. F.; Peng, X.; Cai, L. Z.; Li, A. M.; Gao, Z.; Wang, Y. R.
2009-08-01
A hybrid cryptosystem is proposed, in which one image is encrypted to two interferograms with the aid of double random-phase encoding (DRPE) and two-step phase-shifting interferometry (2-PSI), then three pairs of public-private keys are utilized to encode and decode the session keys (geometrical parameters, the second random-phase mask) and interferograms. In the stage of decryption, the ciphered image can be decrypted by wavefront reconstruction, inverse Fresnel diffraction, and real amplitude normalization. This approach can successfully solve the problem of key management and dispatch, resulting in increased security strength. The feasibility of the proposed cryptosystem and its robustness against some types of attack are verified and analyzed by computer simulations.
Method for encryption and transmission of digital keying data
Mniszewski, S.M.; Springer, E.A.; Brenner, D.P.
1988-03-29
A cryptographic method for encrypting, transmitting and decrypting keying data between a master unit and at least one remote unit is described comprising the steps of: storing in the master unit and in the remote unit key encryption keys, generating a first storage address effective to identify a master key encryption key from the key encryption keys; indexing the first storage address by a first predetermined amount to define a second storage address effective to identify a first key encryption key from the key encryption keys; indexing the first storage address by a second predetermined amount to define a third storage address effective to identify a second key encryption key from the key encryption keys; generating a data encryption key in the master unit, using the first key encryption key; encrypting the data encryption key using the second key encryption key to produce an encrypted data encryption key; downloading to the remote unit the encrypted data encryption key together with a designator value for identifying the address of the second key encryption key at the remote unit; and decrypting the encrypted data encryption key at the remote unit to reproduce the data encryption key at the remote unit.
Method for encryption and transmission of digital keying data
Mniszewski, Susan M.; Springer, Edward A.; Brenner, David P.
1988-01-01
A method for the encryption, transmission, and subsequent decryption of digital keying data. The method utilizes the Data Encryption Standard and is implemented by means of a pair of apparatus, each of which is selectable to operate as either a master unit or remote unit. Each unit contains a set of key encryption keys which are indexed by a common indexing system. The master unit operates upon command from the remote unit to generate a data encryption key and encrypt the data encryption key using a preselected key encryption key. The encrypted data encryption key and an index designator are then downloaded to the remote unit, where the data encryption key is decrypted for subsequent use in the encryption and transmission data. Downloading of the encrypted data encryption key enables frequent change of keys without requiring manual entry or storage of keys at the remote unit.
New Security Results on Encrypted Key Exchange
Bresson, Emmanuel; Chevassut, Olivier; Pointcheval, David
2003-12-15
Schemes for encrypted key exchange are designed to provide two entities communicating over a public network, and sharing a (short) password only, with a session key to be used to achieve data integrity and/or message confidentiality. An example of a very efficient and ''elegant'' scheme for encrypted key exchange considered for standardization by the IEEE P1363 Standard working group is AuthA. This scheme was conjectured secure when the symmetric-encryption primitive is instantiated via either a cipher that closely behaves like an ''ideal cipher,'' or a mask generation function that is the product of the message with a hash of the password. While the security of this scheme in the former case has been recently proven, the latter case was still an open problem. For the first time we prove in this paper that this scheme is secure under the assumptions that the hash function closely behaves like a random oracle and that the computational Diffie-Hellman problem is difficult. Furthermore, since Denial-of-Service (DoS) attacks have become a common threat we enhance AuthA with a mechanism to protect against them.
NASA Astrophysics Data System (ADS)
Hassan, Waleed K.; Al-Assam, Hisham
2017-05-01
The main problem associated with using symmetric/ asymmetric keys is how to securely store and exchange the keys between the parties over open networks particularly in the open environment such as cloud computing. Public Key Infrastructure (PKI) have been providing a practical solution for session key exchange for loads of web services. The key limitation of PKI solution is not only the need for a trusted third partly (e.g. certificate authority) but also the absent link between data owner and the encryption keys. The latter is arguably more important where accessing data needs to be linked with identify of the owner. Currently available key exchange protocols depend on using trusted couriers or secure channels, which can be subject to man-in-the-middle attack and various other attacks. This paper proposes a new protocol for Key Exchange using Biometric Identity Based Encryption (KE-BIBE) that enables parties to securely exchange cryptographic keys even an adversary is monitoring the communication channel between the parties. The proposed protocol combines biometrics with IBE in order to provide a secure way to access symmetric keys based on the identity of the users in unsecure environment. In the KE-BIOBE protocol, the message is first encrypted by the data owner using a traditional symmetric key before migrating it to a cloud storage. The symmetric key is then encrypted using public biometrics of the users selected by data owner to decrypt the message based on Fuzzy Identity-Based Encryption. Only the selected users will be able to decrypt the message by providing a fresh sample of their biometric data. The paper argues that the proposed solution eliminates the needs for a key distribution centre in traditional cryptography. It will also give data owner the power of finegrained sharing of encrypted data by control who can access their data.
Encryption key distribution via chaos synchronization.
Keuninckx, Lars; Soriano, Miguel C; Fischer, Ingo; Mirasso, Claudio R; Nguimdo, Romain M; Van der Sande, Guy
2017-02-24
We present a novel encryption scheme, wherein an encryption key is generated by two distant complex nonlinear units, forced into synchronization by a chaotic driver. The concept is sufficiently generic to be implemented on either photonic, optoelectronic or electronic platforms. The method for generating the key bitstream from the chaotic signals is reconfigurable. Although derived from a deterministic process, the obtained bit series fulfill the randomness conditions as defined by the National Institute of Standards test suite. We demonstrate the feasibility of our concept on an electronic delay oscillator circuit and test the robustness against attacks using a state-of-the-art system identification method.
Encryption key distribution via chaos synchronization
Keuninckx, Lars; Soriano, Miguel C.; Fischer, Ingo; Mirasso, Claudio R.; Nguimdo, Romain M.; Van der Sande, Guy
2017-01-01
We present a novel encryption scheme, wherein an encryption key is generated by two distant complex nonlinear units, forced into synchronization by a chaotic driver. The concept is sufficiently generic to be implemented on either photonic, optoelectronic or electronic platforms. The method for generating the key bitstream from the chaotic signals is reconfigurable. Although derived from a deterministic process, the obtained bit series fulfill the randomness conditions as defined by the National Institute of Standards test suite. We demonstrate the feasibility of our concept on an electronic delay oscillator circuit and test the robustness against attacks using a state-of-the-art system identification method. PMID:28233876
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-07
... Software and Other Specified Publicly Available Encryption Software in Object Code AGENCY: Bureau of... available'' mass market encryption object code software with a symmetric key length greater than 64-bits..., because there are no regulatory restrictions on making such software ``publicly available,'' and...
The classification of quantum symmetric-key encryption protocols
NASA Astrophysics Data System (ADS)
Xiang, Chong; Yang, Li; Peng, Yong; Chen, Dongqing
2014-11-01
The classification of quantum symmetric-key encryption protocol is presented. According to five elements of a quantum symmetric-key encryption protocol: plaintext, ciphertext, key, encryption algorithm and decryption algorithm, there are 32 different kinds of them. Among them, 5 kinds of protocols have already been constructed and studied, and 21 kinds of them are proved to be impossible to construct, the last 6 kinds of them are not yet presented effectively. That means the research on quantum symmetric-key encryption protocol only needs to consider with 5 kinds of them nowadays.
Key-space analysis of double random phase encryption technique
NASA Astrophysics Data System (ADS)
Monaghan, David S.; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.
2007-09-01
We perform a numerical analysis on the double random phase encryption/decryption technique. The key-space of an encryption technique is the set of possible keys that can be used to encode data using that technique. In the case of a strong encryption scheme, many keys must be tried in any brute-force attack on that technique. Traditionally, designers of optical image encryption systems demonstrate only how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. However, this type of demonstration does not discuss the properties of the key-space nor refute the feasibility of an efficient brute-force attack. To clarify these issues we present a key-space analysis of the technique. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute-force attack.
A Contents Encryption Mechanism Using Reused Key in IPTV
NASA Astrophysics Data System (ADS)
Jeong, Yoon-Su; Kim, Yong-Tae; Cho, Young-Bok; Lee, Ki-Jeong; Park, Gil-Cheol; Lee, Sang-Ho
Recently IPTV is being spotlighted as a new stream service to stably provide video, audio and control signals to subscribers through the application of IP protocol. However, the IPTV system is facing more security threats than the traditional TV. This study proposes a multicasting encryption mechanism for secure transmission of the contents of IPTV by which the content provider encrypts their contents and send the encrypted contents and the key used for encryption of the contents to the user. In order to reduce the time and cost of Head-End, the proposed mechanism encrypts the media contents at the Head-End, embeds the code of the IPTV terminal used at the Head-End in the media contents for user tracking, and performs desynchronization for protection of the media contents from various attacks.
Public Key Infrastructure Study
1994-04-01
whom it was created. This may require that the ORA load the certificate onto a smart card or floppy disk. The ORA has no authority to generate...appropriate directory server and, possibly, sent to the ORA to be loaded onto the user’s disk, smart card or other token. Adding another PCA, adding a new CA...possibly on a smart card , a PCMCIA card or an encrypted diskette. He is also responsible for having his public key certified by a CA. 5-2 To have his
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
Dual key speech encryption algorithm based underdetermined BSS.
Zhao, Huan; He, Shaofang; Chen, Zuo; Zhang, Xixiang
2014-01-01
When the number of the mixed signals is less than that of the source signals, the underdetermined blind source separation (BSS) is a significant difficult problem. Due to the fact that the great amount data of speech communications and real-time communication has been required, we utilize the intractability of the underdetermined BSS problem to present a dual key speech encryption method. The original speech is mixed with dual key signals which consist of random key signals (one-time pad) generated by secret seed and chaotic signals generated from chaotic system. In the decryption process, approximate calculation is used to recover the original speech signals. The proposed algorithm for speech signals encryption can resist traditional attacks against the encryption system, and owing to approximate calculation, decryption becomes faster and more accurate. It is demonstrated that the proposed method has high level of security and can recover the original signals quickly and efficiently yet maintaining excellent audio quality.
Dual Key Speech Encryption Algorithm Based Underdetermined BSS
Zhao, Huan; Chen, Zuo; Zhang, Xixiang
2014-01-01
When the number of the mixed signals is less than that of the source signals, the underdetermined blind source separation (BSS) is a significant difficult problem. Due to the fact that the great amount data of speech communications and real-time communication has been required, we utilize the intractability of the underdetermined BSS problem to present a dual key speech encryption method. The original speech is mixed with dual key signals which consist of random key signals (one-time pad) generated by secret seed and chaotic signals generated from chaotic system. In the decryption process, approximate calculation is used to recover the original speech signals. The proposed algorithm for speech signals encryption can resist traditional attacks against the encryption system, and owing to approximate calculation, decryption becomes faster and more accurate. It is demonstrated that the proposed method has high level of security and can recover the original signals quickly and efficiently yet maintaining excellent audio quality. PMID:24955430
DNA based random key generation and management for OTP encryption.
Zhang, Yunpeng; Liu, Xin; Sun, Manhui
2017-09-01
One-time pad (OTP) is a principle of key generation applied to the stream ciphering method which offers total privacy. The OTP encryption scheme has proved to be unbreakable in theory, but difficult to realize in practical applications. Because OTP encryption specially requires the absolute randomness of the key, its development has suffered from dense constraints. DNA cryptography is a new and promising technology in the field of information security. DNA chromosomes storing capabilities can be used as one-time pad structures with pseudo-random number generation and indexing in order to encrypt the plaintext messages. In this paper, we present a feasible solution to the OTP symmetric key generation and transmission problem with DNA at the molecular level. Through recombinant DNA technology, by using only sender-receiver known restriction enzymes to combine the secure key represented by DNA sequence and the T vector, we generate the DNA bio-hiding secure key and then place the recombinant plasmid in implanted bacteria for secure key transmission. The designed bio experiments and simulation results show that the security of the transmission of the key is further improved and the environmental requirements of key transmission are reduced. Analysis has demonstrated that the proposed DNA-based random key generation and management solutions are marked by high security and usability. Published by Elsevier B.V.
Efficient multiparty quantum key agreement protocol based on commutative encryption
NASA Astrophysics Data System (ADS)
Sun, Zhiwei; Huang, Jiwu; Wang, Ping
2016-05-01
A secure multiparty quantum key agreement protocol using single-qubit states is proposed. The agreement key is computed by performing exclusive-OR operation on all the participants' secret keys. Based on the commutative property of the commutative encryption, the exclusive-OR operation can be performed on the plaintext in the encrypted state without decrypting it. Thus, it not only protects the final shared key, but also reduces the complexity of the computation. The efficiency of the proposed protocol, compared with previous multiparty QKA protocols, is also improved. In the presented protocol, entanglement states, joint measurement and even the unitary operations are not needed, and only rotation operations and single-state measurement are required, which are easier to be realized with current technology.
NASA Astrophysics Data System (ADS)
Bondareva, A. P.; Cheremkhin, P. A.; Evtikhiev, N. N.; Krasnov, V. V.; Molodtsov, D. Yu; Nalegaev, S. S.
2016-08-01
Optical encryption and numerical decryption of series of test images using a set of different encryption keys is carried out using scheme operating with spatially-incoherent illumination based on two LC SLMs. Results of experiments on images optical encryption and numerical decryption are presented. Satisfactory average decryption error over 49 encrypted images equal to 0.20±0.05 is achieved.
Key management and encryption under the bounded storage model.
Draelos, Timothy John; Neumann, William Douglas; Lanzone, Andrew J.; Anderson, William Erik
2005-11-01
There are several engineering obstacles that need to be solved before key management and encryption under the bounded storage model can be realized. One of the critical obstacles hindering its adoption is the construction of a scheme that achieves reliable communication in the event that timing synchronization errors occur. One of the main accomplishments of this project was the development of a new scheme that solves this problem. We show in general that there exist message encoding techniques under the bounded storage model that provide an arbitrarily small probability of transmission error. We compute the maximum capacity of this channel using the unsynchronized key-expansion as side-channel information at the decoder and provide tight lower bounds for a particular class of key-expansion functions that are pseudo-invariant to timing errors. Using our results in combination with Dziembowski et al. [11] encryption scheme we can construct a scheme that solves the timing synchronization error problem. In addition to this work we conducted a detailed case study of current and future storage technologies. We analyzed the cost, capacity, and storage data rate of various technologies, so that precise security parameters can be developed for bounded storage encryption schemes. This will provide an invaluable tool for developing these schemes in practice.
Quantum Public-Key Cryptosystem
NASA Astrophysics Data System (ADS)
Luo, Ming-Xing; Chen, Xiu-Bo; Yun, Deng; Yang, Yi-Xian
2012-03-01
Quantum one-way functions play a fundamental role in cryptography because of its necessity for the secure encryption schemes taking into account the quantum computer. In this paper our purpose is to establish a theoretical framework for a candidate of the quantum one-way functions and quantum trapdoor functions based on one-parameter unitary groups. The dynamics of parameterized unitary groups ensure the one-wayness and quantum undistinguishability in different levels, and the physical feasibility are derived from the simultaneous approximation of its infinitesimal generators. Moreover, these special functions are used to construct new cryptosystems-the quantum public-key cryptosystems for encrypting both the classical and quantum information.
Security enhanced optical encryption system by random phase key and permutation key.
He, Mingzhao; Tan, Qiaofeng; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2009-12-07
Conventional double random phase encoding (DRPE) encrypts plaintext to white noise-like ciphertext which may attract attention of eavesdroppers, and recent research reported that DRPE is vulnerable to various attacks. Here we propose a security enhanced optical encryption system that can hide the existence of secret information by watermarking. The plaintext is encrypted using iterative fractional Fourier transform with random phase key, and ciphertext is randomly permuted with permutation key before watermarking. Cryptanalysis shows that linearity of the security system has been broken and the permutation key prevent the attacker from accessing the ciphertext in various attacks. A series of simulations have shown the effectiveness of this system and the security strength is enhanced for invisibility, nonlinearity and resistance against attacks.
Sarkadi, Tamás; Koppa, Pál
2012-02-20
In the increasing number of system approaches published in the field of optical encryption, the security level of the system is evaluated by qualitative and empirical methods. To quantify the security of the optical system, we propose to use the equivalent of the key length routinely used in algorithmic encryption. We provide a calculation method of the number of independent keys and deduce the binary key length for optical data encryption. We then investigate and optimize the key length of the combined phase- and amplitude-modulated key encryption in the holographic storage environment, which is one of the promising solutions for the security enhancement of single- and double-random phase-encoding encryption and storage systems. We show that a substantial growth of the key length can be achieved by optimized phase and amplitude modulation compared to phase-only encryption. We also provide experimental confirmation of the model results.
Analysis of double random phase encryption from a key-space perspective
NASA Astrophysics Data System (ADS)
Monaghan, David S.; Situ, Guohai; Ryle, James; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.
2007-09-01
The main advantage of the double random phase encryption technique is its physical implementation however to allow us to analyse its behaviour we perform the encryption/decryption numerically. A typically strong encryption scheme will have an extremely large key-space, which will make the probable success of any brute force attack on that algorithm miniscule. Traditionally, designers of optical image encryption systems only demonstrate how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. We analyse this algorithm from a key-space perspective. The key-space of an encryption algorithm can be defined as the set of possible keys that can be used to encode data using that algorithm. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute force attack.
NASA Astrophysics Data System (ADS)
Metwaly, A. F.; Rashad, M. Z.; Omara, F. A.; Megahed, A. A.
2014-06-01
Multicasting refers to the transmission of a message or information from one sender to multiple receivers simultaneously. Although encryption algorithms can be used to secure transmitted messages among group members, still there are many security aspects for designing a secured multicast cryptosystem. The most important aspects of Multicasting are key generation and management. The researchers have proposed several approaches for solving problems of multicast key distribution and management. In this paper, a secure key generation and distribution solution has been proposed for a single host sending to two or more (N) receivers using centralized Quantum Multicast Key Distribution Centre "QMKDC" and classical symmetric encryption. The proposed scheme uses symmetric classical algorithms for encryption and decryption transmitted messages among multicast group members, but the generated keys which are used for authentication, encryption and decryption also play an important role for designing a secured multicast cryptosystem come from QKD protocols. Authentication verified using EPR entangled Photons and controlled-NOT gate. Multiple requests for initialization as well for transmitting sensitive information handled through priority and sensitivity levels. Multiple members' communication is achieved with full or partial support of QMKDC.
Encrypted optical memory system using three-dimensional keys in the Fresnel domain.
Matoba, O; Javidi, B
1999-06-01
An encrypted optical memory system using double random phase codes in the Fresnel domain is proposed. In this system, two random phase codes and their positions form three-dimensional keys for encryption of images and are used as keys to recover the original data. The third dimension is the positions of the codes, which can have as many as three degrees of freedom. Original images encrypted by use of the two phase codes located in the Fresnel domain are stored holographically in a photorefractive material. We demonstrate in preliminary experiments encryption and decryption of optical memory in a LiNbO(3) :Fe photorefractive crystal by use of angular multiplexing.
NASA Astrophysics Data System (ADS)
Zhang, Long; Sun, Hong-Wei; Zhang, Ke-Jia; Jia, Heng-Yue
2017-03-01
In this paper, a new quantum encryption based on the key-controlled chained CNOT operations, which is named KCCC encryption, is proposed. With the KCCC encryption, an improved arbitrated quantum signature (AQS) protocol is presented. Compared with the existing protocols, our protocol can effectively prevent forgery attacks and disavowal attacks. Moreover, only single state is required in the protocol. We hope it is helpful to further research in the design of AQS protocols in future.
Quantum walk public-key cryptographic system
NASA Astrophysics Data System (ADS)
Vlachou, C.; Rodrigues, J.; Mateus, P.; Paunković, N.; Souto, A.
2015-12-01
Quantum Cryptography is a rapidly developing field of research that benefits from the properties of Quantum Mechanics in performing cryptographic tasks. Quantum walks are a powerful model for quantum computation and very promising for quantum information processing. In this paper, we present a quantum public-key cryptographic system based on quantum walks. In particular, in the proposed protocol the public-key is given by a quantum state generated by performing a quantum walk. We show that the protocol is secure and analyze the complexity of public key generation and encryption/decryption procedures.
Encryption Devices for Use in a Conditional Access System
2007-11-02
cipher such as the well-known DES algorithm . Each elementary stream may be individually encrypted and the resulting encrypted streams ...data stream TDS encrypted control word (CW) E.sub.MSK (CW). The encrypted CW is processed in decryptor 236 using multi-session key MSK as the decryption ...the encryption is done using the well-known RSA public key encryption algorithm . As shown in DHCT 333, EMM 315 can only be decrypted by the
Practical and Secure Recovery of Disk Encryption Key Using Smart Cards
NASA Astrophysics Data System (ADS)
Omote, Kazumasa; Kato, Kazuhiko
In key-recovery methods using smart cards, a user can recover the disk encryption key in cooperation with the system administrator, even if the user has lost the smart card including the disk encryption key. However, the disk encryption key is known to the system administrator in advance in most key-recovery methods. Hence user's disk data may be read by the system administrator. Furthermore, if the disk encryption key is not known to the system administrator in advance, it is difficult to achieve a key authentication. In this paper, we propose a scheme which enables to recover the disk encryption key when the user's smart card is lost. In our scheme, the disk encryption key is not preserved anywhere and then the system administrator cannot know the key before key-recovery phase. Only someone who has a user's smart card and knows the user's password can decrypt that user's disk data. Furthermore, we measured the processing time required for user authentication in an experimental environment using a virtual machine monitor. As a result, we found that this processing time is short enough to be practical.
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)
Public/private key certification authority and key distribution. Draft
Long, J.P.; Christensen, M.J.; Sturtevant, A.P.; Johnston, W.E.
1995-09-25
Traditional encryption, which protects messages from prying eyes, has been used for many decades. The present concepts of encryption are built from that heritage. Utilization of modern software-based encryption techniques implies much more than simply converting files to an unreadable form. Ubiquitous use of computers and advances in encryption technology coupled with the use of wide-area networking completely changed the reasons for utilizing encryption technology. The technology demands a new and extensive infrastructure to support these functions. Full understanding of these functions, their utility and value, and the need for an infrastructure, takes extensive exposure to the new paradigm. This paper addresses issues surrounding the establishment and operation of a key management system (i.e., certification authority) that is essential to the successful implementation and wide-spread use of encryption.
Encrypted optical storage with wavelength-key and random phase codes.
Matoba, O; Javidi, B
1999-11-10
An encrypted optical memory system that uses a wavelength code as well as input and Fourier-plane random phase codes is proposed. Original data are illuminated by a coherent light source with a specified wavelength and are then encrypted with two random phase codes before being stored holographically in a photorefractive material. Successful decryption requires the use of a readout beam with the same wavelength as that used in the recording, in addition to the correct phase key in the Fourier plane. The wavelength selectivity of the proposed system is evaluated numerically. We show that the number of available wavelength keys depends on the correlation length of the phase key in the Fourier plane. Preliminary experiments of encryption and decryption of optical memory in a LiNbO(3):Fe photorefractive crystal are demonstrated.
Field test of classical symmetric encryption with continuous variables quantum key distribution.
Jouguet, Paul; Kunz-Jacques, Sébastien; Debuisschert, Thierry; Fossier, Simon; Diamanti, Eleni; Alléaume, Romain; Tualle-Brouri, Rosa; Grangier, Philippe; Leverrier, Anthony; Pache, Philippe; Painchault, Philippe
2012-06-18
We report on the design and performance of a point-to-point classical symmetric encryption link with fast key renewal provided by a Continuous Variable Quantum Key Distribution (CVQKD) system. Our system was operational and able to encrypt point-to-point communications during more than six months, from the end of July 2010 until the beginning of February 2011. This field test was the first demonstration of the reliability of a CVQKD system over a long period of time in a server room environment. This strengthens the potential of CVQKD for information technology security infrastructure deployments.
Chaotic Image Encryption Based on Running-Key Related to Plaintext
Guanghui, Cao; Kai, Hu; Yizhi, Zhang; Jun, Zhou; Xing, Zhang
2014-01-01
In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack. PMID:24711727
Chaotic image encryption based on running-key related to plaintext.
Guanghui, Cao; Kai, Hu; Yizhi, Zhang; Jun, Zhou; Xing, Zhang
2014-01-01
In the field of chaotic image encryption, the algorithm based on correlating key with plaintext has become a new developing direction. However, for this kind of algorithm, some shortcomings in resistance to reconstruction attack, efficient utilization of chaotic resource, and reducing dynamical degradation of digital chaos are found. In order to solve these problems and further enhance the security of encryption algorithm, based on disturbance and feedback mechanism, we present a new image encryption scheme. In the running-key generation stage, by successively disturbing chaotic stream with cipher-text, the relation of running-key to plaintext is established, reconstruction attack is avoided, effective use of chaotic resource is guaranteed, and dynamical degradation of digital chaos is minimized. In the image encryption stage, by introducing random-feedback mechanism, the difficulty of breaking this scheme is increased. Comparing with the-state-of-the-art algorithms, our scheme exhibits good properties such as large key space, long key period, and extreme sensitivity to the initial key and plaintext. Therefore, it can resist brute-force, reconstruction attack, and differential attack.
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.
Hymel, Ross
2013-07-25
The Public Key (PK) FPGA software performs asymmetric authentication using the 163-bit Elliptic Curve Digital Signature Algorithm (ECDSA) on an embedded FPGA platform. A digital signature is created on user-supplied data, and communication with a host system is performed via a Serial Peripheral Interface (SPI) bus. Software includes all components necessary for signing, including custom random number generator for key creation and SHA-256 for data hashing.
Optical image encryption using password key based on phase retrieval algorithm
NASA Astrophysics Data System (ADS)
Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing
2016-04-01
A novel optical image encryption system is proposed using password key based on phase retrieval algorithm (PRA). In the encryption process, a shared image is taken as a symmetric key and the plaintext is encoded into the phase-only mask based on the iterative PRA. The linear relationship between the plaintext and ciphertext is broken using the password key, which can resist the known plaintext attack. The symmetric key and the retrieved phase are imported into the input plane and Fourier plane of 4f system during the decryption, respectively, so as to obtain the plaintext on the CCD. Finally, we analyse the key space of the password key, and the results show that the proposed scheme can resist a brute force attack due to the flexibility of the password key.
Cryptanalysis of a multiparty quantum key agreement protocol based on commutative encryption
NASA Astrophysics Data System (ADS)
Mohajer, Razieh; Eslami, Ziba
2017-08-01
Recently, Sun et al. (Quantum Inf Process 15(5):2101-2111, 2016) proposed an efficient multiparty quantum key agreement protocol based on commutative encryption. The aim of this protocol is to negotiate a secret shared key among multiple parties with high qubit efficiency as well as security against inside and outside attackers. The shared key is the exclusive-OR of all participants' secret keys. This is achieved by applying the rotation operation on encrypted photons. For retrieving the final secret key, only measurement on single states is needed. Sun et al. claimed that assuming no mutual trust between participants, the scheme is secure against participant's attack. In this paper, we show that this is not true. In particular, we demonstrate how a malicious participant in Sun et al.'s protocol can introduce "a" final fake key to target parties of his choice. We further propose an improvement to guard against this attack.
Controlled order rearrangement encryption for quantum key distribution
Deng Fuguo; Long, G.L.
2003-10-01
A technique is devised to perform orthogonal state quantum key distribution. In this scheme, entangled parts of a quantum information carrier are sent from Alice to Bob through two quantum channels. However, before the transmission, the order of the quantum information carrier in one channel is reordered so that Eve cannot steal useful information. At the receiver's end, the order of the quantum information carrier is restored. The order rearrangement operation in both parties is controlled by a prior shared control key which is used repeatedly in a quantum key distribution session.
NASA Astrophysics Data System (ADS)
Cui, Yue; Zhang, Min; Zhan, Yueying; Wang, Danshi; Huang, Shanguo
2016-08-01
A scheme for optical parallel encryption/decryption of quadrature phase shift keying (QPSK) signals is proposed, in which three QPSK signals at 10 Gb/s are encrypted and decrypted simultaneously in the optical domain through nondegenerate four-wave mixing in a highly nonlinear fiber. The results of theoretical analysis and simulations show that the scheme can perform high-speed wiretapping against the encryption of parallel signals and receiver sensitivities of encrypted signal and the decrypted signal are -25.9 and -23.8 dBm, respectively, at the forward error correction threshold. The results are useful for designing high-speed encryption/decryption of advanced modulated signals and thus enhancing the physical layer security of optical networks.
Digital chaos-masked optical encryption scheme enhanced by two-dimensional key space
NASA Astrophysics Data System (ADS)
Liu, Ling; Xiao, Shilin; Zhang, Lu; Bi, Meihua; Zhang, Yunhao; Fang, Jiafei; Hu, Weisheng
2017-09-01
A digital chaos-masked optical encryption scheme is proposed and demonstrated. The transmitted signal is completely masked by interference chaotic noise in both bandwidth and amplitude with analog method via dual-drive Mach-Zehnder modulator (DDMZM), making the encrypted signal analog, noise-like and unrecoverable by post-processing techniques. The decryption process requires precise matches of both the amplitude and phase between the cancellation and interference chaotic noises, which provide a large two-dimensional key space with the help of optical interference cancellation technology. For 10-Gb/s 16-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) signal over the maximum transmission distance of 80 km without dispersion compensation or inline amplifier, the tolerable mismatch ranges of amplitude and phase/delay at the forward error correction (FEC) threshold of 3.8×10-3 are 0.44 dB and 0.08 ns respectively.
NASA Astrophysics Data System (ADS)
Zhou, Nanrun; Zhang, Aidi; Zheng, Fen; Gong, Lihua
2014-10-01
The existing ways to encrypt images based on compressive sensing usually treat the whole measurement matrix as the key, which renders the key too large to distribute and memorize or store. To solve this problem, a new image compression-encryption hybrid algorithm is proposed to realize compression and encryption simultaneously, where the key is easily distributed, stored or memorized. The input image is divided into 4 blocks to compress and encrypt, then the pixels of the two adjacent blocks are exchanged randomly by random matrices. The measurement matrices in compressive sensing are constructed by utilizing the circulant matrices and controlling the original row vectors of the circulant matrices with logistic map. And the random matrices used in random pixel exchanging are bound with the measurement matrices. Simulation results verify the effectiveness, security of the proposed algorithm and the acceptable compression performance.
Quantum Public Key Cryptosystem Based on Bell States
NASA Astrophysics Data System (ADS)
Wu, WanQing; Cai, QingYu; Zhang, HuanGuo; Liang, XiaoYan
2017-08-01
Classical public key cryptosystems (P K C), such as R S A, E I G a m a l, E C C, are no longer secure in quantum algorithms, and quantum cryptography has become a novel research topic. In this paper we present a quantum asymmetrical cryptosystem i.e. quantum public key cryptosystem (Q P K C) based on the Bell states. In particular, in the proposed QPKC the public key are given by the first n particles of Bell states and generalized Pauli operations. The corresponding secret key are the last n particles of Bell states and the inverse of generalized Pauli operations. The proposed QPKC encrypts the message using a public key and decrypts the ciphertext using a private key. By H o l e v o ' s theorem, we proved the security of the secret key and messages during the QPKC.
Channel-Based Key Generation for Encrypted Body-Worn Wireless Sensor Networks.
Van Torre, Patrick
2016-09-08
Body-worn sensor networks are important for rescue-workers, medical and many other applications. Sensitive data are often transmitted over such a network, motivating the need for encryption. Body-worn sensor networks are deployed in conditions where the wireless communication channel varies dramatically due to fading and shadowing, which is considered a disadvantage for communication. Interestingly, these channel variations can be employed to extract a common encryption key at both sides of the link. Legitimate users share a unique physical channel and the variations thereof provide data series on both sides of the link, with highly correlated values. An eavesdropper, however, does not share this physical channel and cannot extract the same information when intercepting the signals. This paper documents a practical wearable communication system implementing channel-based key generation, including an implementation and a measurement campaign comprising indoor as well as outdoor measurements. The results provide insight into the performance of channel-based key generation in realistic practical conditions. Employing a process known as key reconciliation, error free keys are generated in all tested scenarios. The key-generation system is computationally simple and therefore compatible with the low-power micro controllers and low-data rate transmissions commonly used in wireless sensor networks.
Channel-Based Key Generation for Encrypted Body-Worn Wireless Sensor Networks
Van Torre, Patrick
2016-01-01
Body-worn sensor networks are important for rescue-workers, medical and many other applications. Sensitive data are often transmitted over such a network, motivating the need for encryption. Body-worn sensor networks are deployed in conditions where the wireless communication channel varies dramatically due to fading and shadowing, which is considered a disadvantage for communication. Interestingly, these channel variations can be employed to extract a common encryption key at both sides of the link. Legitimate users share a unique physical channel and the variations thereof provide data series on both sides of the link, with highly correlated values. An eavesdropper, however, does not share this physical channel and cannot extract the same information when intercepting the signals. This paper documents a practical wearable communication system implementing channel-based key generation, including an implementation and a measurement campaign comprising indoor as well as outdoor measurements. The results provide insight into the performance of channel-based key generation in realistic practical conditions. Employing a process known as key reconciliation, error free keys are generated in all tested scenarios. The key-generation system is computationally simple and therefore compatible with the low-power micro controllers and low-data rate transmissions commonly used in wireless sensor networks. PMID:27618051
A public-key cryptosystem for quantum message transmission
NASA Astrophysics Data System (ADS)
Yang, Li
2005-01-01
We present a quantum public-key cryptography protocol for quantum message transmission. The private key of this protocol includes three classical matrices: a generator matrix of a Goppa code, an invertible matrix and a permutation matrix. The public key is product of these three matrices. The encryption and decryption algorithms are merely quantum computations related with the transformations between bases of the quantum registers. The security of this protocol is based on the hypothesis that there is no effective algorithm of NP-complete problem.
Analysis of selected methods for the recovery of encrypted WEP key
NASA Astrophysics Data System (ADS)
Wójtowicz, Sebastian; Belka, Radosław
2014-11-01
This paper deals with some of the WEP (Wired Equivalent Privacy) key decryption methods based on aircrack-ng software, which was embedded in Backtrack operating system (Linux distribution). The 64-bit (40-bit) and 128-bit (104- bit) key encrypted with RC4 cipher weakness was shown. Research methods were made in different network environments. In this work we compared different types of keys to check how strong the RC4 stream cipher can be. The 40-bit and 104-bit WEP key has been tested on IEEE 802.11 based wireless LAN using laptop with live-CD Linux operating system. A short analysis of key creation methods was performed to compare the amount of time necessary to decrypt random and nonrandom WEP keys.
High efficient key-insulated attribute based encryption scheme without bilinear pairing operations.
Hong, Hanshu; Sun, Zhixin
2016-01-01
Attribute based encryption (ABE) has been widely applied for secure data protection in various data sharing systems. However, the efficiency of existing ABE schemes is not high enough since running encrypt and decrypt algorithms need frequent bilinear pairing operations, which may occupy too much computing resources on terminal devices. What's more, since different users may share the same attributes in the system, a single user's private key exposure will threaten the security and confidentiality of the whole system. Therefore, to further decrease the computation cost in attribute based cryptosystem as well as provide secure protection when key exposure happens, in this paper, we firstly propose a high efficient key-insulated ABE algorithm without pairings. The key-insulated mechanism guarantees both forward security and backward security when key exposure or user revocation happens. Besides, during the running of algorithms in our scheme, users and attribute authority needn't run any bilinear pairing operations, which will increase the efficiency to a large extent. The high efficiency and security analysis indicate that our scheme is more appropriate for secure protection in data sharing systems.
Comment on the "Quantum Public-Key Cryptosystem"
NASA Astrophysics Data System (ADS)
Zhou, Ri-gui; Li, Wei; Huan, Tian-tian
2015-03-01
In 2012, Luo et al. proposed a new quantum public-key cryptosystems, which can encrypt both the classical and quantum information. (Luo et al. Int. J. Theor. Phys. 51(3), 912-924, 2012). However, it cannot be realized because there are some mistakes in the calculation and design process. This paper points out these failures and proposes an improvement to avoid the loophole.
Physical Cryptography: A New Approach to Key Generation and Direct Encryption
2009-11-18
Std Z39-18 P a g e | 2 Abstract: The security of key generation and direct encryption in quantum and physical cryptography have been...emerging development of classical-noise cryptography [1, 2] and quantum cryptography [3] suggests that a new way of building cryptosystems may be...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
Applications of single-qubit rotations in quantum public-key cryptography
NASA Astrophysics Data System (ADS)
Nikolopoulos, Georgios M.
2008-03-01
We discuss cryptographic applications of single-qubit rotations from the perspective of trapdoor one-way functions and public-key encryption. In particular, we present an asymmetric cryptosystem whose security relies on fundamental principles of quantum physics. A quantum public key is used for the encryption of messages while decryption is possible by means of a classical private key only. The trapdoor one-way function underlying the proposed cryptosystem maps integer numbers to quantum states of a qubit and its inversion can be infeasible by virtue of the Holevo’s theorem.
Chaos-based color pathological image encryption scheme using one-time keys.
Liu, Guoyan; Li, Jie; Liu, Hongjun
2014-02-01
This paper proposes an improved chaos-based color pathological image encryption algorithm, using SHA-2 to generate one-time keys. In order to send different ciphered images to different recipients, the hash value of the plain image and a random number are applied to generate one-time initial conditions for Chebyshev maps, to make the key stream change in every confusion process without changing the common initial values. The permuted image is divided into 256-bit long blocks, the avalanche effect is applied to diffuse the blocks, i.e., each block is XORed with the hash value of the prior block. Simulation results demonstrate that the proposed algorithm is robust against common attacks.
Key rotation multiplexing for multiple-image optical encryption in the Fresnel domain
NASA Astrophysics Data System (ADS)
Yong-Liang, Xiao; Su, Xianyu; Li, Sikun; Liu, Xiaoqing; Zeng, Shuguang
2011-06-01
We introduce a key rotation multiplexing method into the double random phase encoding system for multiple-image optical encryption in the Fresnel domain. Each plaintext is encoded into a stationary-white-noise ciphertext by the same only phase mask located at the input plane, and another only phase mask with a certain rotation angle located at the transform plane. All ciphertexts encoded from different plaintexts are added together to produce a final ciphertext, which serves as a single data source for different plaintexts decryption. Thus, the mask located at transform plane can be utilized to decrypt different plaintexts with a certain rotation angle. Also, we perform computer simulations to investigate how the quantization level of decrypted key and CCD, respectively, affect the decrypted quality and the number of images that can be multiplexed.
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.
KeySlinger and StarSlinger: Secure Key Exchange and Encrypted File Transfer on Smartphones
2011-05-01
being detected . Details of attacks against the exchange protocol itself are described in [2]. They include deleting, modifying, or inserting data...using KeySlinger. It is assumed that signature forgery or file decryption is infeasible without possession of the corresponding RSA private key...signature forgery is infeasible. Potential attacks then are limited to denial of service or spamming. These issues are addressed in Section 6. 3
NASA Astrophysics Data System (ADS)
Weber, Robert E.
2001-11-01
approximately 15 Gigabyte table of IV values can be used to encrypt any packet. On a network only partially infiltrated, bit-wise manipulated packets can spoof their validity using the linear nature of the CSC checksum. Any combination of passive and active attacks can be used to modify commands as they are being sent or login information can be taken for use on another network to access personal accounts. WEP also has a critical flaw outside of the sophisticated attacks that can be used to subvert its security. WEP uses a shared key known by both the client machines and the base stations. For this reason the key can be lost through human security problems. This includes the loss of equipment to theft, employee turnover and general mishandling of key information. In order to implement secure wireless networks it has become clear that a new scheme must be developed which can address the 3 security concerns mentioned earlier and at the same time function on existing hardware and software.
Experiences of Using a Public Key Infrastructure for the Preparation of Examination Papers.
ERIC Educational Resources Information Center
Chadwick, David W.; Tassabehji, Rana; Young, Andrew
2000-01-01
Describes a project at the University of Salford (United Kingdom) that transferred examination papers between participants (lecturers, administrators and external examiners) using secure electronic mail via a managed public key infrastructure that used encryption methods. Discusses resistance to change and technology problems. (Contains 6…
Experiences of Using a Public Key Infrastructure for the Preparation of Examination Papers.
ERIC Educational Resources Information Center
Chadwick, David W.; Tassabehji, Rana; Young, Andrew
2000-01-01
Describes a project at the University of Salford (United Kingdom) that transferred examination papers between participants (lecturers, administrators and external examiners) using secure electronic mail via a managed public key infrastructure that used encryption methods. Discusses resistance to change and technology problems. (Contains 6…
NASA Astrophysics Data System (ADS)
Hennelly, B. M.; Javidi, B.; Sheridan, J. T.
2005-09-01
A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.
NASA Astrophysics Data System (ADS)
Gil, Sang Keun; Jeon, Seok Hee; Jung, Jong Rae
2013-03-01
We propose a new optical symmetric cryptographic system with simultaneous encryption and transmission of binary data and secret key by using dual phase-shifting digital holography. Dual phase-shifting digital holography contains two inner and outer interferometers which are used for encrypting data and a secret key at the same time. The technique using dual phase-shifting digital holographic interferometry is efficient because this scheme has an advantage of interference fringe data acquiring time. Binary information data is encrypted by the secret key by applying phase-shifting digital holographic method, and this secret key is also encrypted by phase-shifting digital holographic method and transmitted. Encrypted digital hologram in our method is Fourier transform hologram and is recorded on CCD with 256 gray-level quantized intensities. These encrypted digital holograms are able to be stored by computer and be transmitted over a communication network. With this encrypted digital hologram, the original binary data are decrypted by the same secret key. Simulation results show that the proposed method can be used for a cipher and security system.
Resource Public Key Infrastructure Extension
2012-01-01
authorization of an Autonomous System to originate a BGP route for a specified address prefix. Second, BBN has been playing a key role on the team...carefully managed local database of RPKI objects. This software complements the software used by registries and ISPs, in their roles as issuers of...a registrar , not as a direct allocator of address space. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED 2 ISP to create a table of
Amplitude-phase retrieval attack free image encryption based on two random masks and interference
NASA Astrophysics Data System (ADS)
Liansheng, Sui; bei, Zhou; Zhanmin, Wang; qindong, Sun
2016-11-01
An amplitude-phase retrieval attack free encryption scheme is proposed by using two random masks, where one is considered as the random image and other as the public key. Initially, the random image is encrypted to two phase-only masks based on interference technique with the help of the public key. These two phase-only masks are real-valued functions and used as the encryption keys. Then, the plain image is encrypted to the ciphertext with the white noise distribution by using the phase-truncated Fourier-transform-based encoding scheme with the previous encryption keys. The encryption process is nonlinear in which no iterative calculation is involved, while the decryption process is linear which can be easily implemented with the 4 f optical system. Moreover, less constraints makes the specific attack unusable. Simulation results are given to verify the feasibility and robustness of the proposed encryption scheme.
NASA Astrophysics Data System (ADS)
Nikulin, Vladimir V.; Hughes, David H.; Malowicki, John; Bedi, Vijit
2015-05-01
Free-space optical communication channels offer secure links with low probability of interception and detection. Despite their point-to-point topology, additional security features may be required in privacy-critical applications. Encryption can be achieved at the physical layer by using quantized values of photons, which makes exploitation of such quantum communication links extremely difficult. One example of such technology is keyed communication in quantum noise, a novel quantum modulation protocol that offers ultra-secure communication with competitive performance characteristics. Its utilization relies on specific coherent measurements to decrypt the signal. The process of measurements is complicated by the inherent and irreducible quantum noise of coherent states. This problem is different from traditional laser communication with coherent detection; therefore continuous efforts are being made to improve the measurement techniques. Quantum-based encryption systems that use the phase of the signal as the information carrier impose aggressive requirements on the accuracy of the measurements when an unauthorized party attempts intercepting the data stream. Therefore, analysis of the secrecy of the data becomes extremely important. In this paper, we present the results of a study that had a goal of assessment of potential vulnerability of the running key. Basic results of the laboratory measurements are combined with simulation studies and statistical analysis that can be used for both conceptual improvement of the encryption approach and for quantitative comparison of secrecy of different quantum communication protocols.
Applied public-key steganography
NASA Astrophysics Data System (ADS)
Guillon, Pierre; Furon, Teddy; Duhamel, Pierre
2002-04-01
We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.
Synchronized chaotic phase masks for encrypting and decrypting images
NASA Astrophysics Data System (ADS)
Rueda, Edgar; Vera, Carlos A.; Rodríguez, Boris; Torroba, Roberto
2008-12-01
This paper presents an alternative to secure exchange of encrypted information through public open channels. Chaotic encryption introduces a security improvement by an efficient masking of the message with a chaotic signal. Message extraction by an authorized end user is done using a synchronization procedure, thus allowing a continuous change of the encrypting and decrypting keys. And optical implementation with a 4f optical encrypting architecture is suggested. Digital simulations, including the effects of missing data, corrupted data and noise addition are shown. These results proof the consistency of the proposal, and demonstrate a practical way to operate with it.
Wang, Dawei; Ren, Pinyi; Cheng, Julian; Du, Qinghe; Wang, Yichen; Sun, Li
2017-05-01
In this paper, we propose a secure transmission scheme to protect the confidential messages in a mixed free space optical-radio frequency (FSO-RF) relay network against malicious eavesdroppers. In the proposed scheme, the physical-layer key generation, encryption method and physical-layer wiretap coding are exploited to protect the FSO and RF links. Specifically, the overall transmission is divided into two time slots. In the first time slot, the transmitter and relay of the FSO link utilize the channel reciprocity of the FSO link to generate key packets. In the second time slot, the confidential messages will be securely transmitted from the transmitter to the receiver assisted by the relay over two phases. In the first phase, the transmitter sends the confidential messages to the relay through the FSO link encrypted by the generated key packets. In the second phase, the relay will forward these confidential messages to the receiver through the RF link protected by the physical-layer wiretap coding. For the proposed scheme, the key generation rate can be obtained. In addition, we analyze the performance of the connection outage probability and the secrecy outage probability, and optimally design the target transmission rate and secrecy rate such that the average secrecy rate is maximized. Numerical results are presented to demonstrate the performance superiority of the proposed scheme in terms of the average secrecy rate.
An Identity-Based (IDB) Broadcast Encryption Scheme with Personalized Messages (BEPM).
Xu, Ke; Liao, Yongjian; Qiao, Li; Liu, Zhangyun; Yang, Xiaowei
2015-01-01
A broadcast encryption scheme with personalized messages (BEPM) is a scheme in which a broadcaster transmits not only encrypted broadcast messages to a subset of recipients but also encrypted personalized messages to each user individually. Several broadcast encryption (BE) schemes allow a broadcaster encrypts a message for a subset S of recipients with public keys and any user in S can decrypt the message with his/her private key. However, these BE schemes can not provide an efficient way to transmit encrypted personalized messages to each user individually. In this paper, we propose a broadcast encryption scheme with a transmission of personalized messages. Besides, the scheme is based on multilinear maps ensure constant ciphertext size and private key size of each user and the scheme can achieve statically security. More realistically, the scheme can be applied to the Conditional Access System (CAS) of pay television (pay-TV) efficiently and safely.
An Identity-Based (IDB) Broadcast Encryption Scheme with Personalized Messages (BEPM)
Xu, Ke; Liao, Yongjian; Qiao, Li
2015-01-01
A broadcast encryption scheme with personalized messages (BEPM) is a scheme in which a broadcaster transmits not only encrypted broadcast messages to a subset of recipients but also encrypted personalized messages to each user individually. Several broadcast encryption (BE) schemes allow a broadcaster encrypts a message for a subset S of recipients with public keys and any user in S can decrypt the message with his/her private key. However, these BE schemes can not provide an efficient way to transmit encrypted personalized messages to each user individually. In this paper, we propose a broadcast encryption scheme with a transmission of personalized messages. Besides, the scheme is based on multilinear maps ensure constant ciphertext size and private key size of each user and the scheme can achieve statically security. More realistically, the scheme can be applied to the Conditional Access System (CAS) of pay television (pay-TV) efficiently and safely. PMID:26629817
Phase retrieval encryption in an enhanced optical interference by key phase constraint.
Shi, Xiaoyan; Chen, Ziyang; Zhao, Daomu; Mao, Haidan; Chen, Linfei
2015-04-10
In this paper, we demonstrate a security system by using optical interference and phase retrieval algorithm (PRA) techniques. The modified PRA is proposed to encode the target image into random phase distribution. Optical and digital methods can be used for decryption. By using this method, silhouette elimination is realized. In addition, due to this simplified system design, the iterative rate is improved and the optical decryption realization is easier. Validity and performance of the proposed system are demonstrated by means of numerical simulations. The system encryption capacity as to both binary and gray images is numerically investigated. Then, the decryption procedure is demonstrated by optical experiment means and the decryption result is given.
Tamaki, Kiyoshi; Kato, Go
2010-02-15
One of the simplest security proofs of quantum key distribution is based on the so-called complementarity scenario, which involves the complementarity control of an actual protocol and a virtual protocol [M. Koashi, e-print arXiv:0704.3661 (2007)]. The existing virtual protocol has a limitation in classical postprocessing, i.e., the syndrome for the error-correction step has to be encrypted. In this paper, we remove this limitation by constructing a quantum circuit for the virtual protocol. Moreover, our circuit with a shield system gives an intuitive proof of why adding noise to the sifted key increases the bit error rate threshold in the general case in which one of the parties does not possess a qubit. Thus, our circuit bridges the simple proof and the use of wider classes of classical postprocessing.
NASA Astrophysics Data System (ADS)
Tamaki, Kiyoshi; Kato, Go
2010-02-01
One of the simplest security proofs of quantum key distribution is based on the so-called complementarity scenario, which involves the complementarity control of an actual protocol and a virtual protocol [M. Koashi, e-print arXiv:0704.3661 (2007)]. The existing virtual protocol has a limitation in classical postprocessing, i.e., the syndrome for the error-correction step has to be encrypted. In this paper, we remove this limitation by constructing a quantum circuit for the virtual protocol. Moreover, our circuit with a shield system gives an intuitive proof of why adding noise to the sifted key increases the bit error rate threshold in the general case in which one of the parties does not possess a qubit. Thus, our circuit bridges the simple proof and the use of wider classes of classical postprocessing.
Information hiding based on double random-phase encoding and public-key cryptography.
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.
NASA Astrophysics Data System (ADS)
Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min
2016-01-01
Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.
Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min
2016-01-29
Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.
Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min
2016-01-01
Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information. PMID:26823196
Quantum Secure Dialogue with Quantum Encryption
NASA Astrophysics Data System (ADS)
Ye, Tian-Yu
2014-09-01
How to solve the information leakage problem has become the research focus of quantum dialogue. In this paper, in order to overcome the information leakage problem in quantum dialogue, a novel approach for sharing the initial quantum state privately between communicators, i.e., quantum encryption sharing, is proposed by utilizing the idea of quantum encryption. The proposed protocol uses EPR pairs as the private quantum key to encrypt and decrypt the traveling photons, which can be repeatedly used after rotation. Due to quantum encryption sharing, the public announcement on the state of the initial quantum state is omitted, thus the information leakage problem is overcome. The information-theoretical efficiency of the proposed protocol is nearly 100%, much higher than previous information leakage resistant quantum dialogue protocols. Moreover, the proposed protocol only needs single-photon measurements and nearly uses single photons as quantum resource so that it is convenient to implement in practice.
NASA Astrophysics Data System (ADS)
Tickle, Andrew J.; Sun, Jiajing; Gan, Lu; Smith, Jeremy S.
2008-09-01
In this paper, we discuss a Field Programmable Gate Array (FPGA) implementation of steganography for security applications such as anti-theft systems and forensic investigation systems. Our proposed method takes advantage of both conventional encryption/decryption algorithms and fragile image watermarking techniques to provide user-friendly interface. It could potentially be of benefit to financial investment companies, the military and security forces in order to keep certain information hidden within other content with a change so subtle that no one who does not know exactly where or how to look will not be able to obtain the data. In our proposed system, a steganographic message known as plaintext is first encrypted by conventional methods to give an extra layer of security, producing a ciphertext. The steganographic message can be either an image or ASCII text, both of which will be discussed. Then, the cover text or image is modified to contain the ciphertext, yielding a encrypted text or a watermarked image. Details of the circuitry for each stage are given with some of the encryption and randomization circuitry not included in full detail for commercial reasons. Test images before and after watermarking will be shown to demonstrate the validity and effectiveness of the proposed system.
NASA Technical Reports Server (NTRS)
Jackson, Deborah J. (Inventor)
1998-01-01
An analog optical encryption system based on phase scrambling of two-dimensional optical images and holographic transformation for achieving large encryption keys and high encryption speed. An enciphering interface uses a spatial light modulator for converting a digital data stream into a two dimensional optical image. The optical image is further transformed into a hologram with a random phase distribution. The hologram is converted into digital form for transmission over a shared information channel. A respective deciphering interface at a receiver reverses the encrypting process by using a phase conjugate reconstruction of the phase scrambled hologram.
A joint asymmetric watermarking and image encryption scheme
NASA Astrophysics Data System (ADS)
Boato, G.; Conotter, V.; De Natale, F. G. B.; Fontanari, C.
2008-02-01
Here we introduce a novel watermarking paradigm designed to be both asymmetric, i.e., involving a private key for embedding and a public key for detection, and commutative with a suitable encryption scheme, allowing both to cipher watermarked data and to mark encrypted data without interphering with the detection process. In order to demonstrate the effectiveness of the above principles, we present an explicit example where the watermarking part, based on elementary linear algebra, and the encryption part, exploiting a secret random permutation, are integrated in a commutative scheme.
Modular Integer Arithmetic for Public Key Cryptography
NASA Astrophysics Data System (ADS)
Güneysu, Tim; Paar, Christof
This chapter discusses building blocks for implementing popular public key cryptosystems, like RSA, Diffie-Hellman Key Exchange (DHKE) and Elliptic Curve Cryptography (ECC). Therefore, we briefly introduce field-based arithmetic on which most of recently established public key cryptosystems rely. As most popular fields, we give examples for architecture implementing efficient arithmetic operations over prime and binary extension fields for use in cryptographic applications.
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.
Security analysis of public key watermarking schemes
NASA Astrophysics Data System (ADS)
Craver, Scott A.; Katzenbeisser, Stefan
2001-12-01
Traditional watermarking systems require the complete disclosure of the watermarking key in the watermark verification process. In most systems an attacker is able to remove the watermark completely once the key is known, thus subverting the intention of copyright protection. To cope with this problem, public-key watermarking schemes were proposed that allow asymmetric watermark detection. Whereas a public key is used to insert watermarks in digital objects, the marks can be verified with a private key. Knowledge of this private key does not allow piracy. We describe two public-key watermarking schemes which are similar in spirit to zero-knowledge proofs. The key idea of one system is to verify a watermark in a blinded version of the document, where the scrambling is determined by the private key. A probabilistic protocol is constructed that allows public watermark detection with probability of 1/2; by iteration, the verifier can get any degree of certainty that the watermark is present. The second system is based on watermark attacks, using controlled counterfeiting to conceal real watermark data safely amid data useless to an attacker.
Public health governance: views of key stakeholders.
Marks, L; Cave, S; Hunter, D J
2010-01-01
To identify views of key stakeholders on public health governance. Focus groups and interviews. Key national and regional stakeholders in England were invited to participate in focus groups. Three focus groups and four additional interviews were transcribed and a thematic analysis was carried out. Focus groups and interviewees identified points of transition in public health governance including changes in the notion of stewardship, governance across a local public health system and a shift from organizational governance to 'governance of place'. Different governance arrangements and approaches to governance can influence health outcomes through their impact on commissioning strategies, public health practice and performance management regimes. Failure to address these issues will hamper the development of a stewardship role in local organizations and across a local public health system. Copyright 2009 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Multi-Channel Key Agreement Using Encrypted Public Key Exchange (Transcript of Discussion)
NASA Astrophysics Data System (ADS)
Christianson, Bruce
The context for this work is the ubiquitous computing market, where everybody is surrounded by a cloud of little devices that all talk to each other to accomplish various things, and the world we're in is one of talking to strangers.
Wang, Xiaogang; Zhao, Daomu
2012-05-21
A double-image encryption technique that based on an asymmetric algorithm is proposed. In this method, the encryption process is different from the decryption and the encrypting keys are also different from the decrypting keys. In the nonlinear encryption process, the images are encoded into an amplitude cyphertext, and two phase-only masks (POMs) generated based on phase truncation are kept as keys for decryption. By using the classical double random phase encoding (DRPE) system, the primary images can be collected by an intensity detector that located at the output plane. Three random POMs that applied in the asymmetric encryption can be safely applied as public keys. Simulation results are presented to demonstrate the validity and security of the proposed protocol.
Fast WEP-Key Recovery Attack Using Only Encrypted IP Packets
NASA Astrophysics Data System (ADS)
Teramura, Ryoichi; Asakura, Yasuo; Ohigashi, Toshihiro; Kuwakado, Hidenori; Morii, Masakatu
Conventional efficient key recovery attacks against Wired Equivalent Privacy (WEP) require specific initialization vectors or specific packets. Since it takes much time to collect the packets sufficiently, any active attack should be performed. An Intrusion Detection System (IDS), however, will be able to prevent the attack. Since the attack logs are stored at the servers, it is possible to prevent such an attack. This paper proposes an algorithm for recovering a 104-bit WEP key from any IP packets in a realistic environment. This attack needs about 36, 500 packets with a success probability 0.5, and the complexity of our attack is equivalent to about 220 computations of the RC4 key setups. Since our attack is passive, it is difficult for both WEP users and administrators to detect our attack.
Public key infrastructure for DOE security research
Aiken, R.; Foster, I.; Johnston, W.E.
1997-06-01
This document summarizes the Department of Energy`s Second Joint Energy Research/Defence Programs Security Research Workshop. The workshop, built on the results of the first Joint Workshop which reviewed security requirements represented in a range of mission-critical ER and DP applications, discussed commonalties and differences in ER/DP requirements and approaches, and identified an integrated common set of security research priorities. One significant conclusion of the first workshop was that progress in a broad spectrum of DOE-relevant security problems and applications could best be addressed through public-key cryptography based systems, and therefore depended upon the existence of a robust, broadly deployed public-key infrastructure. Hence, public-key infrastructure ({open_quotes}PKI{close_quotes}) was adopted as a primary focus for the second workshop. The Second Joint Workshop covered a range of DOE security research and deployment efforts, as well as summaries of the state of the art in various areas relating to public-key technologies. Key findings were that a broad range of DOE applications can benefit from security architectures and technologies built on a robust, flexible, widely deployed public-key infrastructure; that there exists a collection of specific requirements for missing or undeveloped PKI functionality, together with a preliminary assessment of how these requirements can be met; that, while commercial developments can be expected to provide many relevant security technologies, there are important capabilities that commercial developments will not address, due to the unique scale, performance, diversity, distributed nature, and sensitivity of DOE applications; that DOE should encourage and support research activities intended to increase understanding of security technology requirements, and to develop critical components not forthcoming from other sources in a timely manner.
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)
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)
Locating Encrypted Data Hidden Among Non-Encrypted Data Using Statistical Tools
2007-03-01
Encryption algorithm , or Cipher : The encryption scheme consists of a set of encryption transformations and a set of corresponding decryption ... Algorithms Symmetric Key ciphers can be categorized into two specific types. The types differ based on how the encryption / decryption functions perform...keystream (seed) ([MVV97, pg. 21]). The advantage of a stream cipher is two fold. First, the encryption algorithm can be applied
Quantum fully homomorphic encryption scheme based on universal quantum circuit
NASA Astrophysics Data System (ADS)
Liang, Min
2015-08-01
Fully homomorphic encryption enables arbitrary computation on encrypted data without decrypting the data. Here it is studied in the context of quantum information processing. Based on universal quantum circuit, we present a quantum fully homomorphic encryption (QFHE) scheme, which permits arbitrary quantum transformation on any encrypted data. The QFHE scheme is proved to be perfectly secure. In the scheme, the decryption key is different from the encryption key; however, the encryption key cannot be revealed. Moreover, the evaluation algorithm of the scheme is independent of the encryption key, so it is suitable for delegated quantum computing between two parties.
Compressive optical image encryption.
Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong
2015-05-20
An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume.
Compressive Optical Image Encryption
Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong
2015-01-01
An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume. PMID:25992946
Encrypting personal identifiers.
Meux, E
1994-01-01
STUDY SETTING. A statewide patient discharge database contained only one unique identifier: the social security number (SSN). A method was developed to transform (encrypt) the SSN so that it could be made publicly available, for purposes of linking discharge records, without revealing the SSN itself. The method of encrypting the SSN into a Record Linkage Number (RLN) is described. PRINCIPAL FINDINGS. The same RLN will always result from the same SSN; it is highly improbable that the same RLN would be produced by two different SSNs; the SSN cannot be derived from the RLN, even given access to the encryption program; the encryption method cannot be determined through knowledge of a number of SSN/RLN combinations; and the method can be described, evaluated, and adapted for use by other researchers without compromising confidentiality of the RLNs resulting from the method. PMID:8005792
PEM public key certificate cache server
NASA Astrophysics Data System (ADS)
Cheung, T.
1993-12-01
Privacy Enhanced Mail (PEM) provides privacy enhancement services to users of Internet electronic mail. Confidentiality, authentication, message integrity, and non-repudiation of origin are provided by applying cryptographic measures to messages transferred between end systems by the Message Transfer System. PEM supports both symmetric and asymmetric key distribution. However, the prevalent implementation uses a public key certificate-based strategy, modeled after the X.509 directory authentication framework. This scheme provides an infrastructure compatible with X.509. According to RFC 1422, public key certificates can be stored in directory servers, transmitted via non-secure message exchanges, or distributed via other means. Directory services provide a specialized distributed database for OSI applications. The directory contains information about objects and then provides structured mechanisms for accessing that information. Since directory services are not widely available now, a good approach is to manage certificates in a centralized certificate server. This document describes the detailed design of a centralized certificate cache serve. This server manages a cache of certificates and a cache of Certificate Revocation Lists (CRL's) for PEM applications. PEMapplications contact the server to obtain/store certificates and CRL's. The server software is programmed in C and ELROS. To use this server, ISODE has to be configured and installed properly. The ISODE library 'libisode.a' has to be linked together with this library because ELROS uses the transport layer functions provided by 'libisode.a.' The X.500 DAP library that is included with the ELROS distribution has to be linked in also, since the server uses the DAP library functions to communicate with directory servers.
Continuous QKD and high speed data encryption
NASA Astrophysics Data System (ADS)
Zbinden, Hugo; Walenta, Nino; Guinnard, Olivier; Houlmann, Raphael; Wen, Charles Lim Ci; Korzh, Boris; Lunghi, Tommaso; Gisin, Nicolas; Burg, Andreas; Constantin, Jeremy; Legré, Matthieu; Trinkler, Patrick; Caselunghe, Dario; Kulesza, Natalia; Trolliet, Gregory; Vannel, Fabien; Junod, Pascal; Auberson, Olivier; Graf, Yoan; Curchod, Gilles; Habegger, Gilles; Messerli, Etienne; Portmann, Christopher; Henzen, Luca; Keller, Christoph; Pendl, Christian; Mühlberghuber, Michael; Roth, Christoph; Felber, Norbert; Gürkaynak, Frank; Schöni, Daniel; Muheim, Beat
2013-10-01
We present the results of a Swiss project dedicated to the development of high speed quantum key distribution and data encryption. The QKD engine features fully automated key exchange, hardware key distillation based on finite key security analysis, efficient authentication and wavelength division multiplexing of the quantum and the classical channel and one-time pas encryption. The encryption device allows authenticated symmetric key encryption (e.g AES) at rates of up to 100 Gb/s. A new quantum key can uploaded up to 1000 times second from the QKD engine.
KeyChains: A Decentralized Public-Key Infrastructure
2006-03-02
exposed. This problem is easily solved in KeyChains, taking inspiration from existing techniques: certificate expiration, revocation lists and online...the peer. The peer maintains an access control list indicating what operations (key storage, key retrieval, and peer management) are permitted to a...2002, Norfolk, VA, September 2002. [9] http://www.umiacs.umd.edu/˜mmarsh/ CODEX /. [10] A. Datta, M. Hauswirth, and K. Aberer. Beyond ”web of trust
Low-Power Public Key Cryptography
BEAVER,CHERYL L.; DRAELOS,TIMOTHY J.; HAMILTON,VICTORIA A.; SCHROEPPEL,RICHARD C.; GONZALES,RITA A.; MILLER,RUSSELL D.; THOMAS,EDWARD V.
2000-11-01
This report presents research on public key, digital signature algorithms for cryptographic authentication in low-powered, low-computation environments. We assessed algorithms for suitability based on their signature size, and computation and storage requirements. We evaluated a variety of general purpose and special purpose computing platforms to address issues such as memory, voltage requirements, and special functionality for low-powered applications. In addition, we examined custom design platforms. We found that a custom design offers the most flexibility and can be optimized for specific algorithms. Furthermore, the entire platform can exist on a single Application Specific Integrated Circuit (ASIC) or can be integrated with commercially available components to produce the desired computing platform.
Security Assessment of Two-Wave Encryption
NASA Astrophysics Data System (ADS)
Kitano, Motoki; Okamoto, Atsushi; Sano, Takayuki
2009-03-01
To determine the degree of security in two-wave encryption under practical conditions, we present a novel numerical technique for simulating the recording and readout of two-wave encryption. The calculation results of the retrieval characteristics show that the diffraction efficiency in an incorrect decryption is 10 times as low as that in correct decryption key and that the output data with an incorrect key is a white noise image. We estimate the necessary key correlation to decrypt an encrypted data is 0.2 when the length of an encryption key is 2313. This means that the decoding probability of the encryption key in two-wave encryption is less than 10-6 even if such a short key is used.
Spatial Encryption under Simpler Assumption
NASA Astrophysics Data System (ADS)
Zhou, Muxin; Cao, Zhenfu
Spatial encryption was first proposed by Boneh and Hamburg. They showed that many useful encryption systems can be derived from it. In this paper, we describe two variants of spatial encryption. First we present a scheme that can be proved to be secure under the decisional bilinear Diffie-Hellman assumption, which is much simpler than the BDHE assumption used by Boneh and Hamburg. However, as a compromise, our ciphertext size and private key size are larger. We also discuss some techniques to shrink the private key of this scheme in a real application. Finally, we provide a hybrid construction which allows an optimal tradeoff between efficiency and security.
Private predictive analysis on encrypted medical data.
Bos, Joppe W; Lauter, Kristin; Naehrig, Michael
2014-08-01
Increasingly, confidential medical records are being stored in data centers hosted by hospitals or large companies. As sophisticated algorithms for predictive analysis on medical data continue to be developed, it is likely that, in the future, more and more computation will be done on private patient data. While encryption provides a tool for assuring the privacy of medical information, it limits the functionality for operating on such data. Conventional encryption methods used today provide only very restricted possibilities or none at all to operate on encrypted data without decrypting it first. Homomorphic encryption provides a tool for handling such computations on encrypted data, without decrypting the data, and without even needing the decryption key. In this paper, we discuss possible application scenarios for homomorphic encryption in order to ensure privacy of sensitive medical data. We describe how to privately conduct predictive analysis tasks on encrypted data using homomorphic encryption. As a proof of concept, we present a working implementation of a prediction service running in the cloud (hosted on Microsoft's Windows Azure), which takes as input private encrypted health data, and returns the probability for suffering cardiovascular disease in encrypted form. Since the cloud service uses homomorphic encryption, it makes this prediction while handling only encrypted data, learning nothing about the submitted confidential medical data. Copyright © 2014 Elsevier Inc. All rights reserved.
A Hidden Vector Encryption Scheme with Constant-Size Tokens and Pairing Computations
NASA Astrophysics Data System (ADS)
Park, Jong Hwan; Lee, Dong Hoon
The Hidden Vector Encryption scheme is one of the searchable public key encryption schemes that allow for searching encrypted data. The Hidden Vector Encryption scheme supports conjunctive equality, comparison, and subset queries, as well as arbitrary conjunctive combinations of these queries. In a Hidden Vector Encryption scheme, a receiver generates a token for a vector of searchable components and sends the token to a query server which has the capability to evaluate it on encrypted data. All of the existing Hidden Vector Encryption schemes, which are all pairing-based, require token elements and pairing computations proportional to the number of searchable components in the token. In this paper, we suggest an improved paring-based Hidden Vector Encryption scheme where the token elements and pairing computations are independent of the number of searchable components. Namely, for an arbitrary conjunctive search query, the token is of size O(1) and the query server only needs O(1) pairing computations. The latter improvement in particular might be very attractive to a query server in a larger search system with many users. To achieve our goal, we introduce a novel technique to generate a token, which may be of independent interest.
Holographic memories with encryption-selectable function
NASA Astrophysics Data System (ADS)
Su, Wei-Chia; Lee, Xuan-Hao
2006-03-01
Volume holographic storage has received increasing attention owing to its potential high storage capacity and access rate. In the meanwhile, encrypted holographic memory using random phase encoding technique is attractive for an optical community due to growing demand for protection of information. In this paper, encryption-selectable holographic storage algorithms in LiNbO 3 using angular multiplexing are proposed and demonstrated. Encryption-selectable holographic memory is an advance concept of security storage for content protection. It offers more flexibility to encrypt the data or not optionally during the recording processes. In our system design, the function of encryption and non-encryption storage is switched by a random phase pattern and a uniform phase pattern. Based on a 90-degree geometry, the input patterns including the encryption and non-encryption storage are stored via angular multiplexing with reference plane waves at different incident angles. Image is encrypted optionally by sliding the ground glass into one of the recording waves or removing it away in each exposure. The ground glass is a key for encryption. Besides, it is also an important key available for authorized user to decrypt the encrypted information.
Cryptanalysis of optical encryption: a heuristic approach
NASA Astrophysics Data System (ADS)
Gopinathan, Unnikrishnan; Monaghan, David S.; Naughton, Thomas J.; Sheridan, John T.
2006-10-01
The Fourier plane encryption algorithm is subjected to a heuristic known-plaintext attack. The simulated annealing algorithm is used to estimate the key using a known plaintext-ciphertext pair which decrypts the ciphertext with arbitrarily low error. The strength of the algorithm is tested by using the key to decrypt a different ciphertext encrypted using the same original key. The Fourier plane encryption algorithm is found to be susceptible to a known-plaintext heuristic attack. It is found that phase only encryption, a variation of Fourier plane encoding algorithm, successfully defends against this attack.
Privacy-preserving photo sharing based on a public key infrastructure
NASA Astrophysics Data System (ADS)
Yuan, Lin; McNally, David; Küpçü, Alptekin; Ebrahimi, Touradj
2015-09-01
A significant number of pictures are posted to social media sites or exchanged through instant messaging and cloud-based sharing services. Most social media services offer a range of access control mechanisms to protect users privacy. As it is not in the best interest of many such services if their users restrict access to their shared pictures, most services keep users' photos unprotected which makes them available to all insiders. This paper presents an architecture for a privacy-preserving photo sharing based on an image scrambling scheme and a public key infrastructure. A secure JPEG scrambling is applied to protect regional visual information in photos. Protected images are still compatible with JPEG coding and therefore can be viewed by any one on any device. However, only those who are granted secret keys will be able to descramble the photos and view their original versions. The proposed architecture applies an attribute-based encryption along with conventional public key cryptography, to achieve secure transmission of secret keys and a fine-grained control over who may view shared photos. In addition, we demonstrate the practical feasibility of the proposed photo sharing architecture with a prototype mobile application, ProShare, which is built based on iOS platform.
Optically-induced-potential-based image encryption.
Chen, Bing-Chu; Wang, He-Zhou
2011-11-07
We present a technique of nonlinear image encryption by use of virtual optics. The image to be encrypted is superposed on a random intensity image. And this superposed image propagates through a nonlinear medium and a 4-f system with single phase key. The image is encrypted to a stationary white noise. The decryption process is sensitive to the parameters of the encryption system and the phase key in 4-f system. This sensitivity makes attackers hard to access the phase key. In nonlinear medium, optically-induced potentials, which depend on intensity of optical wave, make the superposition principle frustrated. This nonlinearity based on optically induced potentials highly improves the secrecy level of image encryption. Resistance against attacks based on the phase retrieval technique proves that it has the high secrecy level. This nonlinear image encryption based on optically induced potentials is proposed and demonstrated for the first time.
Quantum computing on encrypted data.
Fisher, K A G; Broadbent, A; Shalm, L K; Yan, Z; Lavoie, J; Prevedel, R; Jennewein, T; Resch, K J
2014-01-01
The ability to perform computations on encrypted data is a powerful tool for protecting privacy. Recently, protocols to achieve this on classical computing systems have been found. Here, we present an efficient solution to the quantum analogue of this problem that enables arbitrary quantum computations to be carried out on encrypted quantum data. We prove that an untrusted server can implement a universal set of quantum gates on encrypted quantum bits (qubits) without learning any information about the inputs, while the client, knowing the decryption key, can easily decrypt the results of the computation. We experimentally demonstrate, using single photons and linear optics, the encryption and decryption scheme on a set of gates sufficient for arbitrary quantum computations. As our protocol requires few extra resources compared with other schemes it can be easily incorporated into the design of future quantum servers. These results will play a key role in enabling the development of secure distributed quantum systems.
Quantum computing on encrypted data
NASA Astrophysics Data System (ADS)
Fisher, K. A. G.; Broadbent, A.; Shalm, L. K.; Yan, Z.; Lavoie, J.; Prevedel, R.; Jennewein, T.; Resch, K. J.
2014-01-01
The ability to perform computations on encrypted data is a powerful tool for protecting privacy. Recently, protocols to achieve this on classical computing systems have been found. Here, we present an efficient solution to the quantum analogue of this problem that enables arbitrary quantum computations to be carried out on encrypted quantum data. We prove that an untrusted server can implement a universal set of quantum gates on encrypted quantum bits (qubits) without learning any information about the inputs, while the client, knowing the decryption key, can easily decrypt the results of the computation. We experimentally demonstrate, using single photons and linear optics, the encryption and decryption scheme on a set of gates sufficient for arbitrary quantum computations. As our protocol requires few extra resources compared with other schemes it can be easily incorporated into the design of future quantum servers. These results will play a key role in enabling the development of secure distributed quantum systems.
Proof Checking the RSA (Rivest, Shamir and Adleman) Public Key Encryption Algorithm.
1982-09-01
Fermat’s theorem, number theory , pigeon hole principle. 20. ABSTRACT (Continue an reverse sde it neceeseand Ideify by block nu mbe r) The authors...of integers modulo (p-1)*(q-1). .. Among the lemmas proved mechanically and used in the ma _Aroof are many familia theorems of number theory ...the ring of integers modulo (p-1)*(q-1). Among the lemmas proved mechanically and used in the main proof are many familiar theorems of number theory
Proof Checking the RSA (Rivest, Shamir, and Adleman) Public Key Encryption Algorithm.
1982-09-01
theorem, number theory , pigeon hole principle al20. ABSTRACT (Continue an reverse aide it necessary and Identify by block number) am. We describe the...ring of integers modulo (p-1)*(q-1). Among the lemmas proved mechanically and used in the main proof are many familiar theorems of number theory ...ring of integers modulo (p-1)*(q-1). Among the lemmas proved mechanically and used in the main proof are many familiar theorems of number theory
Multiplexing of encrypted data using fractal masks.
Barrera, John F; Tebaldi, Myrian; Amaya, Dafne; Furlan, Walter D; Monsoriu, Juan A; Bolognini, Néstor; Torroba, Roberto
2012-07-15
In this Letter, we present to the best of our knowledge a new all-optical technique for multiple-image encryption and multiplexing, based on fractal encrypting masks. The optical architecture is a joint transform correlator. The multiplexed encrypted data are stored in a photorefractive crystal. The fractal parameters of the key can be easily tuned to lead to a multiplexing operation without cross talk effects. Experimental results that support the potential of the method are presented.
NASA Astrophysics Data System (ADS)
Bondareva, Alyona P.; Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.
2014-10-01
At present time methods of optical encryption are actively developed. The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution which require application of complex holographic schemes in conjunction with spatially coherent monochromatic illumination. This leads to complex optical schemes and low decryption quality. To eliminate these disadvantages it is possible to implement optical encryption using spatially incoherent monochromatic illumination which requires registration of light intensity distribution only. Encryption is accomplished by means of optical convolution of image of scene to be encrypted and encryption diffractive optical element (DOE) point spread function (PSF) which serves as encryption key. Encryption process is described as follows. Scene is illuminated with spatially-incoherent monochromatic light. In the absence of encryption DOE lens forms image of scene in photosensor plane. DOE serves as encryption element, its PSF - encryption key. Light passing through DOE forms convolution of object image and DOE PSF. Registered by photosensor convolution is encrypted image. Decryption was conducted numerically on computer by means of inverse filtration with regularization. Kinoforms were used as encryption DOE because they have single diffraction order. Two liquid crystal (LC) spatial light modulators (SLM) were used to implement dynamic digital information input and dynamic encryption key change. As input scene amplitude LC SLM HoloEye LC2002 with 800×600 pixels 32×32 μm2 and 256 gray levels was used. To image synthesized encryption kinoforms phase LC SLM HoloEye PLUTO VIS with 1920×1080 pixels 8×8 μm2 and 256 phase levels was used. Set of test images was successfully optically encrypted and then numerically decrypted. Encrypted images contents are hidden. Decrypted images despite quite high noise levels are positively recognizable
Dual encryption scheme of images using polarized light.
Alfalou, A; Brosseau, C
2010-07-01
We propose and analyze a dual encryption/decryption scheme, motivated by recent interest in polarization encoding. Compared to standard optical encryption methods, which are based on phase and amplitude manipulation, this encryption procedure relying on Mueller-Stokes formalism provides large flexibility in the key encryption design. The effectiveness of our algorithm is discussed, thanks to a numerical simulation of the polarization encryption/decryption procedure of a 256 gray-level image. Of additional special interest is the immunity of this encryption algorithm to brute force attacks.
Flexible optical encryption with multiple users and multiple security levels
NASA Astrophysics Data System (ADS)
Nishchal, Naveen K.; Naughton, Thomas J.
2011-02-01
We present a basic optical encryption architecture that admits several cryptography applications based on multiplexing. Users can decrypt different private images from the same encrypted image, a superuser can have a key that decrypts all encrypted images, and multiplexed images can be encrypted with different levels of security. This system is presented in the context of a general framework of optical encryption application development. We illustrate with a real-world three-dimensional scene, captured with digital holography, and encrypted using the fractional Fourier transform, where different users have access to different three-dimensional objects in the scene.
Wang, Yong; Markman, Adam; Quan, Chenggen; Javidi, Bahram
2016-11-01
We present a photon-counting double-random-phase encryption technique that only requires the photon-limited amplitude of the encrypted image for decryption. The double-random-phase encryption is used to encrypt an image, generating a complex image. Photon counting is applied to the amplitude of the encrypted image, generating a sparse noise-like image; however, the phase information is not retained. By not using the phase information, the encryption process is simplified, allowing for intensity detection and also less information to be recorded. Using a phase numerically generated from the correct encryption keys together with the photon-limited amplitude of the encrypted image, we are able to decrypt the image. Moreover, nonlinear correlation algorithms can be used to authenticate the decrypted image. Both amplitude-based and full-phase encryption using the proposed method are investigated. Preliminary computational results and performance evaluation are presented.
Novel Image Encryption based on Quantum Walks
NASA Astrophysics Data System (ADS)
Yang, Yu-Guang; Pan, Qing-Xiang; Sun, Si-Jia; Xu, Peng
2015-01-01
Quantum computation has achieved a tremendous success during the last decades. In this paper, we investigate the potential application of a famous quantum computation model, i.e., quantum walks (QW) in image encryption. It is found that QW can serve as an excellent key generator thanks to its inherent nonlinear chaotic dynamic behavior. Furthermore, we construct a novel QW-based image encryption algorithm. Simulations and performance comparisons show that the proposal is secure enough for image encryption and outperforms prior works. It also opens the door towards introducing quantum computation into image encryption and promotes the convergence between quantum computation and image processing.
Novel Image Encryption based on Quantum Walks
Yang, Yu-Guang; Pan, Qing-Xiang; Sun, Si-Jia; Xu, Peng
2015-01-01
Quantum computation has achieved a tremendous success during the last decades. In this paper, we investigate the potential application of a famous quantum computation model, i.e., quantum walks (QW) in image encryption. It is found that QW can serve as an excellent key generator thanks to its inherent nonlinear chaotic dynamic behavior. Furthermore, we construct a novel QW-based image encryption algorithm. Simulations and performance comparisons show that the proposal is secure enough for image encryption and outperforms prior works. It also opens the door towards introducing quantum computation into image encryption and promotes the convergence between quantum computation and image processing. PMID:25586889
Novel image encryption based on quantum walks.
Yang, Yu-Guang; Pan, Qing-Xiang; Sun, Si-Jia; Xu, Peng
2015-01-14
Quantum computation has achieved a tremendous success during the last decades. In this paper, we investigate the potential application of a famous quantum computation model, i.e., quantum walks (QW) in image encryption. It is found that QW can serve as an excellent key generator thanks to its inherent nonlinear chaotic dynamic behavior. Furthermore, we construct a novel QW-based image encryption algorithm. Simulations and performance comparisons show that the proposal is secure enough for image encryption and outperforms prior works. It also opens the door towards introducing quantum computation into image encryption and promotes the convergence between quantum computation and image processing.
Optical encryption using a joint transform correlator architecture
NASA Astrophysics Data System (ADS)
Nomura, Takanori; Javidi, Bahram
2000-08-01
An optical double random-phase encryption method using a joint transform correlator architecture is proposed. In this method, the joint power spectrum of the image to be encrypted and the key codes is recorded as the encrypted data. Unlike the case with classical double random-phase encryption, the same key code is used to both encrypt and decrypt the data, and the conjugate key is not required. Computer simulations and optical experimental results using a photorefractive-crystal-based processor are presented.
NASA Astrophysics Data System (ADS)
Gunn, Lachlan J.; Chappell, James M.; Allison, Andrew; Abbott, Derek
2014-09-01
While information-theoretic security is often associated with the one-time pad and quantum key distribution, noisy transport media leave room for classical techniques and even covert operation. Transit times across the public internet exhibit a degree of randomness, and cannot be determined noiselessly by an eavesdropper. We demonstrate the use of these measurements for information-theoretically secure communication over the public internet.
Development of a public key infrastructure across multiple enterprises
Sharick, T.M.; Long, J.P.; Desind, B.J.
1997-05-01
Main-stream applications are beginning to incorporate public key cryptography. It can be difficult to deploy this technology without a robust infrastructure to support it. It can also be difficult to deploy a public key infrastructure among multiple enterprises when different applications and standards must be supported. This discussion chronicles the efforts by a team within the US Department of Energy`s Nuclear Weapons Complex to build a public key infrastructure and deploy applications that use it. The emphasis of this talk will be on the lessons learned during this effort and an assessment of the overall impact of this technology.
Encryption Devices for Use in a Conditional Access System
NASA Astrophysics Data System (ADS)
Pinder, Howard G.; Palgon, Michael S.
2002-07-01
A cable television system provides conditional access to services. The cable television system includes a headend from which service 'instances', or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.
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.
Information encryption in phase space.
Liu, Jun; Xu, Xiaobin; Wu, Quanying; Sheridan, John T; Situ, Guohai
2015-03-15
In this Letter, we propose an information encryption technique based on the theory of phase-space optics. We show that encoding the plaintext in phase space provides a higher level of security: first, the key-space is significantly enlarged. Second, it is immune to various known-plaintext (cyphertext) attacks to which the double-random phase encryption (DRPE) is vulnerable. Third, the bilinearity of phase-space distributions offers additional security. Theoretical analysis and numerical calculation results show that the proposed technique has significantly different responses to errors added to the cypheretext and the two phase keys in comparison to the classical DRPE.
Optical image encryption via ptychography.
Shi, Yishi; Li, Tuo; Wang, Yali; Gao, Qiankun; Zhang, Sanguo; Li, Haifei
2013-05-01
Ptychography is combined with optical image encryption for the first time. Due to the nature of ptychography, not only is the interferometric optical setup that is usually adopted not required any more, but also the encryption for a complex-valued image is achievable. Considering that the probes overlapping with each other is the crucial factor in ptychography, their complex-amplitude functions can serve as a kind of secret keys that lead to the enlarged key space and the enhanced system security. Further, since only introducing the probes into the input of common system is required, it is convenient to combine ptychography with many existing optical image encryption systems for varied security applications.
A Public-Key Based Authentication and Key Establishment Protocol Coupled with a Client Puzzle.
ERIC Educational Resources Information Center
Lee, M. C.; Fung, Chun-Kan
2003-01-01
Discusses network denial-of-service attacks which have become a security threat to the Internet community and suggests the need for reliable authentication protocols in client-server applications. Presents a public-key based authentication and key establishment protocol coupled with a client puzzle protocol and validates it through formal logic…
A Public-Key Based Authentication and Key Establishment Protocol Coupled with a Client Puzzle.
ERIC Educational Resources Information Center
Lee, M. C.; Fung, Chun-Kan
2003-01-01
Discusses network denial-of-service attacks which have become a security threat to the Internet community and suggests the need for reliable authentication protocols in client-server applications. Presents a public-key based authentication and key establishment protocol coupled with a client puzzle protocol and validates it through formal logic…
Fuzzy Identities and Attribute-Based Encryption
NASA Astrophysics Data System (ADS)
Sahai, Amit; Waters, Brent
We introduce a new type of Identity-Based Encryption (IBE) scheme that we call Fuzzy Identity-Based Encryption. In fuzzy IBE, we view an identity as a set of descriptive attributes. A fuzzy IBE scheme allows for a private key for an identity,ωù, to decrypt a ciphertext encrypted with an identity, ùω´, if and only if the identities ùω and ùω´are close to each other as measured by the "set overlap" distance metric. A fuzzy IBE scheme can be applied to enable encryption using biometric inputs as identities; the error-tolerance property of a fuzzy IBE scheme is precisely what allows for the use of biometric identities, which inherently will have some noise each time they are sampled. Additionally, we show that fuzzy IBE can be used for a type of application that we term "attribute-based encryption."
Scalable coding of encrypted images.
Zhang, Xinpeng; Feng, Guorui; Ren, Yanli; Qian, Zhenxing
2012-06-01
This paper proposes a novel scheme of scalable coding for encrypted images. In the encryption phase, the original pixel values are masked by a modulo-256 addition with pseudorandom numbers that are derived from a secret key. After decomposing the encrypted data into a downsampled subimage and several data sets with a multiple-resolution construction, an encoder quantizes the subimage and the Hadamard coefficients of each data set to reduce the data amount. Then, the data of quantized subimage and coefficients are regarded as a set of bitstreams. At the receiver side, while a subimage is decrypted to provide the rough information of the original content, the quantized coefficients can be used to reconstruct the detailed content with an iteratively updating procedure. Because of the hierarchical coding mechanism, the principal original content with higher resolution can be reconstructed when more bitstreams are received.
Research on asymmetric searchable encryption
NASA Astrophysics Data System (ADS)
Yu, Zonghua; Wu, Yudong
2017-05-01
Cloud server side to ease the user's local storage pressure at the same time, there are hidden data on the hidden dangers, the user often choose to upload the data in the form of cipher text to the cloud server. However, the classic data encryption and decryption algorithms are not provided search function, affecting the user's efficiency. To this end, an asymmetric searchable encryption scheme is proposed. The scheme can be used for any person can generate a trapdoor, cipher text can be free modified, the key pair generated by the user themselves, encrypt the identity, S-shaped virtual and other five loopholes to improve. The analysis results show that the scheme solves the above five vulnerabilities in the original scheme, so that the information semantics of both parties of communication can be guaranteed.
Dunigan, T.; Cao, C.
1997-08-01
This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.
An Efficient and Provable Secure Revocable Identity-Based Encryption Scheme
Wang, Changji; Li, Yuan; Xia, Xiaonan; Zheng, Kangjia
2014-01-01
Revocation functionality is necessary and crucial to identity-based cryptosystems. Revocable identity-based encryption (RIBE) has attracted a lot of attention in recent years, many RIBE schemes have been proposed in the literature but shown to be either insecure or inefficient. In this paper, we propose a new scalable RIBE scheme with decryption key exposure resilience by combining Lewko and Waters’ identity-based encryption scheme and complete subtree method, and prove our RIBE scheme to be semantically secure using dual system encryption methodology. Compared to existing scalable and semantically secure RIBE schemes, our proposed RIBE scheme is more efficient in term of ciphertext size, public parameters size and decryption cost at price of a little looser security reduction. To the best of our knowledge, this is the first construction of scalable and semantically secure RIBE scheme with constant size public system parameters. PMID:25238418
An efficient and provable secure revocable identity-based encryption scheme.
Wang, Changji; Li, Yuan; Xia, Xiaonan; Zheng, Kangjia
2014-01-01
Revocation functionality is necessary and crucial to identity-based cryptosystems. Revocable identity-based encryption (RIBE) has attracted a lot of attention in recent years, many RIBE schemes have been proposed in the literature but shown to be either insecure or inefficient. In this paper, we propose a new scalable RIBE scheme with decryption key exposure resilience by combining Lewko and Waters' identity-based encryption scheme and complete subtree method, and prove our RIBE scheme to be semantically secure using dual system encryption methodology. Compared to existing scalable and semantically secure RIBE schemes, our proposed RIBE scheme is more efficient in term of ciphertext size, public parameters size and decryption cost at price of a little looser security reduction. To the best of our knowledge, this is the first construction of scalable and semantically secure RIBE scheme with constant size public system parameters.
A hybrid scheme for encryption and watermarking
NASA Astrophysics Data System (ADS)
Xu, Xiaowei; Dexter, Scott D.; Eskicioglu, Ahmet M.
2004-06-01
Encryption and watermarking are complementary lines of defense in protecting multimedia content. Recent watermarking techniques have therefore been developed independent from encryption techniques. In this paper, we present a hybrid image protection scheme to establish a relation between the data encryption key and the watermark. Prepositioned secret sharing allows the reconstruction of different encryption keys by communicating different activating shares for the same prepositioned information. Each activating share is used by the receivers to generate a fresh content decryption key. In the proposed scheme, the activating share is used to carry copyright or usage rights data. The bit stream that represents this data is also embedded in the content as a visual watermark. When the encryption key needs to change, the data source generates a new activating share, and embeds the corresponding watermark into the multimedia stream. Before transmission, the composite stream is encrypted with the key constructed from the new activating share. Each receiver can decrypt the stream after reconstructing the same key, and extract the watermark from the image. Our presentation will include the application of the scheme to a test image, and a discussion on the data hiding capacity, watermark transparency, and robustness to common attacks.
An investigation of DUA caching strategies for public key certificates
Cheung, Terry Ching
1993-11-01
Internet Privacy Enhanced Mail (PEM) provides security services to users of Internet electronic mail. PEM is designed with the intention that it will eventually obtain public key certificates from the X.500 directory service. However, such a capability is not present in most PEM implementations today. While the prevalent PEM implementation uses a public key certificate-based strategy, certificates are mostly distributed via e-mail exchanges, which raises several security and performance issues. In this thesis research, we changed the reference PEM implementation to make use of the X.500 directory service instead of local databases for public key certificate management. The thesis discusses some problems with using the X.500 directory service, explores the relevant issues, and develops an approach to address them. The approach makes use of a memory cache to store public key certificates. We implemented a centralized cache server and addressed the denial-of-service security problem that is present in the server. In designing the cache, we investigated several cache management strategies. One result of our study is that the use of a cache significantly improves performance. Our research also indicates that security incurs extra performance cost. Different cache replacement algorithms do not seem to yield significant performance differences, while delaying dirty-writes to the backing store does improve performance over immediate writes.
Public Expenditures on Children through 2008: Key Facts
ERIC Educational Resources Information Center
Macomber, Jennifer; Isaacs, Julia; Kent, Adam; Vericker, Tracy
2010-01-01
This report provides the key findings on the public spending on children through 2008. They are: (1) Spending on children increased under the American Recovery and Reinvestment Act (ARRA) and other stimulus spending, but not proportionately to other federal spending. As ARRA expires, we project that spending on children will decline, assuming no…
Child protection reports: key issues arising for public health nurses.
Hanafin, Sinead
2013-10-01
Similar to other countries, there have been a number of high-profile reports into past and recent cases of child abuse and neglect in Ireland. The most recent of these have been the Monageer Inquiry, the Ryan Report, the Roscommon Child Care Case and the Report of the Independent Child Death Review Group. An analysis of these reports highlights the critical role played by public health nurses with troubled families. It also makes explicit key issues that consistently emerge as problematic in terms of professional practice. This paper summarises the main findings of the reports as they relate to the public health nursing service and identifies key themes emerging along with recommendations arising. The emerging themes relate to assessment, early intervention, record keeping, communication and interdisciplinary working and the role of public health nursing management.
Optical double-image encryption and authentication by sparse representation.
Mohammed, Emad A; Saadon, H L
2016-12-10
An optical double-image encryption and authentication method by sparse representation is proposed. The information from double-image encryption can be integrated into a sparse representation. Unlike the traditional double-image encryption technique, only sparse (partial) data from the encrypted data is adopted for the authentication process. Simulation results demonstrate that the correct authentication results are achieved even with partial information from the encrypted data. The randomly selected sparse encrypted information will be used as an effective key for a security system. Therefore, the proposed method is feasible, effective, and can provide an additional security layer for optical security systems. In addition, the method also achieved the general requirements of storage and transmission due to a high reduction of the encrypted information.
ID-based encryption scheme with revocation
NASA Astrophysics Data System (ADS)
Othman, Hafizul Azrie; Ismail, Eddie Shahril
2017-04-01
In 2015, Meshram proposed an efficient ID-based cryptographic encryption based on the difficulty of solving discrete logarithm and integer-factoring problems. The scheme was pairing free and claimed to be secure against adaptive chosen plaintext attacks (CPA). Later, Tan et al. proved that the scheme was insecure by presenting a method to recover the secret master key and to obtain prime factorization of modulo n. In this paper, we propose a new pairing-free ID-based encryption scheme with revocation based on Meshram's ID-based encryption scheme, which is also secure against Tan et al.'s attacks.
Digital Image Encryption Scheme Based on Multiple Chaotic Systems
NASA Astrophysics Data System (ADS)
Abd El-Latif, Ahmed A.; Li, Li; Zhang, Tiejun; Wang, Ning; Song, Xianhua; Niu, Xiamu
2012-06-01
Image encryption is a challenging task due to the significant level of sophistication achieved by forgerers and other cybercriminals. Advanced encryption methods for secure transmission, storage, and retrieval of digital images are increasingly needed for a number of military, medical, homeland security, and other applications. In this paper, we introduce a new digital image encryption algorithm. The new algorithm employs multiple chaotic systems and cryptographic primitive operations within the encryption process, which are efficiently implemented on modern processors, and adopts round keys for encryption using a chaotic map. Experiments conducted show that the proposed algorithm possesses robust security features such as fairly uniform distribution, high sensitivity to both keys and plainimages, almost ideal entropy, and the ability to highly de-correlate adjacent pixels in the cipherimages. Furthermore, it has a large key space, which greatly increases its security for image encryption applications.
An application of different dioids in public key cryptography
Durcheva, Mariana I.
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 is presented.
QR code optical encryption using spatially incoherent illumination
NASA Astrophysics Data System (ADS)
Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.; Starikov, R. S.
2017-02-01
Optical encryption is an actively developing field of science. The majority of encryption techniques use coherent illumination and suffer from speckle noise, which severely limits their applicability. The spatially incoherent encryption technique does not have this drawback, but its effectiveness is dependent on the Fourier spectrum properties of the image to be encrypted. The application of a quick response (QR) code in the capacity of a data container solves this problem, and the embedded error correction code also enables errorless decryption. The optical encryption of digital information in the form of QR codes using spatially incoherent illumination was implemented experimentally. The encryption is based on the optical convolution of the image to be encrypted with the kinoform point spread function, which serves as an encryption key. Two liquid crystal spatial light modulators were used in the experimental setup for the QR code and the kinoform imaging, respectively. The quality of the encryption and decryption was analyzed in relation to the QR code size. Decryption was conducted digitally. The successful decryption of encrypted QR codes of up to 129 × 129 pixels was demonstrated. A comparison with the coherent QR code encryption technique showed that the proposed technique has a signal-to-noise ratio that is at least two times higher.
Design and implementation of encrypted and decrypted file system based on USBKey and hardware code
NASA Astrophysics Data System (ADS)
Wu, Kehe; Zhang, Yakun; Cui, Wenchao; Jiang, Ting
2017-05-01
To protect the privacy of sensitive data, an encrypted and decrypted file system based on USBKey and hardware code is designed and implemented in this paper. This system uses USBKey and hardware code to authenticate a user. We use random key to encrypt file with symmetric encryption algorithm and USBKey to encrypt random key with asymmetric encryption algorithm. At the same time, we use the MD5 algorithm to calculate the hash of file to verify its integrity. Experiment results show that large files can be encrypted and decrypted in a very short time. The system has high efficiency and ensures the security of documents.
EEG based image encryption via quantum walks.
Rawat, N; Shin, Y; Balasingham, I
2016-08-01
An electroencephalogram (EEG) based image encryption combined with Quantum walks (QW) is encoded in Fresnel domain. The computational version of EEG randomizes the original plaintext whereas QW can serve as an excellent key generator due to its inherent nonlinear chaotic dynamic behavior. First, a spatially coherent monochromatic laser beam passes through an SLM, which introduces an arbitrary EEG phase-only mask. The modified beam is collected by a CCD. Further, the intensity is multiply with the QW digitally. EEG shows high sensitivity to system parameters and capable of encrypting and transmitting the data whereas QW has unpredictability, stability and non-periodicity. Only applying the correct keys, the original image can be retrieved successfully. Simulations and comparisons show the proposed method to be secure enough for image encryption and outperforms prior works. The proposed method opens the door towards introducing EEG and quantum computation into image encryption and promotes the convergence between our approach and image processing.
Key-phrase based classification of public health web pages.
Dolamic, Ljiljana; Boyer, Célia
2013-01-01
This paper describes and evaluates the public health web pages classification model based on key phrase extraction and matching. Easily extendible both in terms of new classes as well as the new language this method proves to be a good solution for text classification faced with the total lack of training data. To evaluate the proposed solution we have used a small collection of public health related web pages created by a double blind manual classification. Our experiments have shown that by choosing the adequate threshold value the desired value for either precision or recall can be achieved.
Optical design of cipher block chaining (CBC) encryption mode by using digital holography
NASA Astrophysics Data System (ADS)
Gil, Sang Keun; Jeon, Seok Hee; Jung, Jong Rae; Kim, Nam
2016-03-01
We propose an optical design of cipher block chaining (CBC) encryption by using digital holographic technique, which has higher security than the conventional electronic method because of the analog-type randomized cipher text with 2-D array. In this paper, an optical design of CBC encryption mode is implemented by 2-step quadrature phase-shifting digital holographic encryption technique using orthogonal polarization. A block of plain text is encrypted with the encryption key by applying 2-step phase-shifting digital holography, and it is changed into cipher text blocks which are digital holograms. These ciphered digital holograms with the encrypted information are Fourier transform holograms and are recorded on CCDs with 256 gray levels quantized intensities. The decryption is computed by these encrypted digital holograms of cipher texts, the same encryption key and the previous cipher text. Results of computer simulations are presented to verify that the proposed method shows the feasibility in the high secure CBC encryption system.
A Survey of Research Progress and Development Tendency of Attribute-Based Encryption
Pang, Liaojun; Yang, Jie; Jiang, Zhengtao
2014-01-01
With the development of cryptography, the attribute-based encryption (ABE) draws widespread attention of the researchers in recent years. The ABE scheme, which belongs to the public key encryption mechanism, takes attributes as public key and associates them with the ciphertext or the user's secret key. It is an efficient way to solve open problems in access control scenarios, for example, how to provide data confidentiality and expressive access control at the same time. In this paper, we survey the basic ABE scheme and its two variants: the key-policy ABE (KP-ABE) scheme and the ciphertext-policy ABE (CP-ABE) scheme. We also pay attention to other researches relating to the ABE schemes, including multiauthority, user/attribute revocation, accountability, and proxy reencryption, with an extensive comparison of their functionality and performance. Finally, possible future works and some conclusions are pointed out. PMID:25101313
Report on the Development of the Advanced Encryption Standard (AES).
Nechvatal, J; Barker, E; Bassham, L; Burr, W; Dworkin, M; Foti, J; Roback, E
2001-01-01
In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) Federal information in furtherance of NIST's statutory responsibilities. In 1998, NIST announced the acceptance of 15 candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC™, Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has decided to propose Rijndael as the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report.
Report on the Development of the Advanced Encryption Standard (AES)
Nechvatal, James; Barker, Elaine; Bassham, Lawrence; Burr, William; Dworkin, Morris; Foti, James; Roback, Edward
2001-01-01
In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) Federal information in furtherance of NIST’s statutory responsibilities. In 1998, NIST announced the acceptance of 15 candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC™, Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has decided to propose Rijndael as the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report. PMID:27500035
Multiply-agile encryption in high speed communication networks
Pierson, L.G.; Witzke, E.L.
1997-05-01
Different applications have different security requirements for data privacy, data integrity, and authentication. Encryption is one technique that addresses these requirements. Encryption hardware, designed for use in high-speed communications networks, can satisfy a wide variety of security requirements if that hardware is key-agile, robustness-agile and algorithm-agile. Hence, multiply-agile encryption provides enhanced solutions to the secrecy, interoperability and quality of service issues in high-speed networks. This paper defines these three types of agile encryption. Next, implementation issues are discussed. While single-algorithm, key-agile encryptors exist, robustness-agile and algorithm-agile encryptors are still research topics.
Symmetric quantum fully homomorphic encryption with perfect security
NASA Astrophysics Data System (ADS)
Liang, Min
2013-12-01
Suppose some data have been encrypted, can you compute with the data without decrypting them? This problem has been studied as homomorphic encryption and blind computing. We consider this problem in the context of quantum information processing, and present the definitions of quantum homomorphic encryption (QHE) and quantum fully homomorphic encryption (QFHE). Then, based on quantum one-time pad (QOTP), we construct a symmetric QFHE scheme, where the evaluate algorithm depends on the secret key. This scheme permits any unitary transformation on any -qubit state that has been encrypted. Compared with classical homomorphic encryption, the QFHE scheme has perfect security. Finally, we also construct a QOTP-based symmetric QHE scheme, where the evaluate algorithm is independent of the secret key.
Image encryption under spatially incoherent illumination
NASA Astrophysics Data System (ADS)
Xie, Zhenwei; Zang, Jinliang; Zhang, Yan
2013-06-01
A novel method for image encryption under spatially incoherent illumination is proposed. The LED array is used as the spatially incoherent source. Both the encryption process and decryption process are numerically simulated. Experiments are carried out to demonstrate the basic ideal of the proposed method. The incoherent light is modulated by the spatial light modulator on the input plane as the input image to be encrypted. Then a random phase only mask is used as the key to encode the image, finally a Fourier lens is adopted to image the encrypted image on the output plane. The encrypted intensity distribution is recorded by a CCD. In the numerical simulations, the random phase only mask is generated by a rand function. The incoherent image is composed of many source points, and any two points of these sources are spatially incoherent, but each point is self-spatially coherent. Under this property, the point spread function for the encryption system can be considered as the interference of two beams, one is the spherical beam and the other is the random phase beam. Once the point spread function is given, the system's optical transfer function can be calculated easily. Then the encryption system can be considered as a decryption system, and the output image is the same as the original image. The encrypted image can be calculated with the system's optical transfer function and the output image. The random phase mask, the distance between the random phase mask and the SLM, and the wavelength of the laser can be seen as the keys of the encryption systems. Only when all these parameters are correct, can one get the right decrypted image. The factors which could affect the practical experiment, such as quantization noise and displacement tolerances are also investigated. Compared with the conventional coherent encryption system, the incoherent encryption system proposed in this paper is free of the flaws of the optical elements, the dust particles on the elements, and
A Cryptosystem for Encryption and Decryption of Long Confidential Messages
NASA Astrophysics Data System (ADS)
Giri, Debasis; Barua, Prithayan; Srivastava, P. D.; Jana, Biswapati
In this paper, we propose a cryptosystem which can encrypt and decrypt long (text) messages in efficient manner. The proposed cryptosystem is a combination of symmetric-key and asymmetric-key cryptography, where asymmetric-key cryptography is used to transmit the secret key to an intended receiver and the sender/receiver encrypts/decrypts messages using that secret key. In 2002, Hwang et al. proposed a scheme for encrypting long messages. The main drawback of their scheme is that it requires more computational overhead. Our proposed scheme is more efficient from the computational point of view compared to that of their scheme. Our scheme is a block cipher, long messages are broken into fixed length plaintext blocks for encryption. It supports parallel computation, since encryption/decryption of all the blocks of plaintext/plaintext are independent and thus can be carried out simultaneously. In addition, our scheme retains the same security level as their scheme.
Color encryption scheme based on adapted quantum logistic map
NASA Astrophysics Data System (ADS)
Zaghloul, Alaa; Zhang, Tiejun; Amin, Mohamed; Abd El-Latif, Ahmed A.
2014-04-01
This paper presents a new color image encryption scheme based on quantum chaotic system. In this scheme, a new encryption scheme is accomplished by generating an intermediate chaotic key stream with the help of quantum chaotic logistic map. Then, each pixel is encrypted by the cipher value of the previous pixel and the adapted quantum logistic map. The results show that the proposed scheme has adequate security for the confidentiality of color images.
A quantum approach to homomorphic encryption
Tan, Si-Hui; Kettlewell, Joshua A.; Ouyang, Yingkai; Chen, Lin; Fitzsimons, Joseph F.
2016-01-01
Encryption schemes often derive their power from the properties of the underlying algebra on the symbols used. Inspired by group theoretic tools, we use the centralizer of a subgroup of operations to present a private-key quantum homomorphic encryption scheme that enables a broad class of quantum computation on encrypted data. The quantum data is encoded on bosons of distinct species in distinct spatial modes, and the quantum computations are manipulations of these bosons in a manner independent of their species. A particular instance of our encoding hides up to a constant fraction of the information encrypted. This fraction can be made arbitrarily close to unity with overhead scaling only polynomially in the message length. This highlights the potential of our protocol to hide a non-trivial amount of information, and is suggestive of a large class of encodings that might yield better security. PMID:27658349
Integral transformations applied to image encryption
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Perez, Ronal; Torres, Cesar O.
2017-01-01
In this paper we consider the application of the integral transformations for image encryption through optical systems, a mathematical algorithm under Matlab platform using fractional Fourier transform (FrFT) and Random Phase Mask (RPM) for digital images encryption is implemented. The FrFT can be related to others integral transforms, such as: Fourier transform, Sine and Cosine transforms, Radial Hilbert transform, fractional Sine transform, fractional Cosine transform, fractional Hartley transform, fractional Wavelet transform and Gyrator transform, among other transforms. The encryption scheme is based on the use of the FrFT, the joint transform correlator and two RPMs, which provide security and robustness to the implemented security system. One of the RPMs used during encryption-decryption and the fractional order of the FrFT are the keys to improve security and make the system more resistant against security attacks.
A quantum approach to homomorphic encryption
NASA Astrophysics Data System (ADS)
Tan, Si-Hui; Kettlewell, Joshua A.; Ouyang, Yingkai; Chen, Lin; Fitzsimons, Joseph F.
2016-09-01
Encryption schemes often derive their power from the properties of the underlying algebra on the symbols used. Inspired by group theoretic tools, we use the centralizer of a subgroup of operations to present a private-key quantum homomorphic encryption scheme that enables a broad class of quantum computation on encrypted data. The quantum data is encoded on bosons of distinct species in distinct spatial modes, and the quantum computations are manipulations of these bosons in a manner independent of their species. A particular instance of our encoding hides up to a constant fraction of the information encrypted. This fraction can be made arbitrarily close to unity with overhead scaling only polynomially in the message length. This highlights the potential of our protocol to hide a non-trivial amount of information, and is suggestive of a large class of encodings that might yield better security.
A quantum approach to homomorphic encryption.
Tan, Si-Hui; Kettlewell, Joshua A; Ouyang, Yingkai; Chen, Lin; Fitzsimons, Joseph F
2016-09-23
Encryption schemes often derive their power from the properties of the underlying algebra on the symbols used. Inspired by group theoretic tools, we use the centralizer of a subgroup of operations to present a private-key quantum homomorphic encryption scheme that enables a broad class of quantum computation on encrypted data. The quantum data is encoded on bosons of distinct species in distinct spatial modes, and the quantum computations are manipulations of these bosons in a manner independent of their species. A particular instance of our encoding hides up to a constant fraction of the information encrypted. This fraction can be made arbitrarily close to unity with overhead scaling only polynomially in the message length. This highlights the potential of our protocol to hide a non-trivial amount of information, and is suggestive of a large class of encodings that might yield better security.
The role of decimated sequences in scaling encryption speeds through parallelism
Witzke, E.L.
1995-09-01
Encryption performance, in terms of bits per second encrypted, has not scaled well as network performance has increased. The authors felt that multiple encryption modules operating in parallel would be the cornerstone of scalable encryption. One major problem with parallelizing encryption is ensuring that each encryption module is getting the proper portion of the key sequence at the correct point in the encryption or decryption of the message. Many encryption schemes use linear recurring sequences, which may be generated by a linear feedback shift register. Instead of using a linear feedback shift register, the authors describe a method to generate the linear recurring sequence by using parallel decimated sequences, one per encryption module. Computing decimated sequences can be time consuming, so the authors have also described a way to compute these sequences with logic gates rather than arithmetic operations.
Dynamic video encryption algorithm for H.264/AVC based on a spatiotemporal chaos system.
Xu, Hui; Tong, Xiao-Jun; Zhang, Miao; Wang, Zhu; Li, Ling-Hao
2016-06-01
Video encryption schemes mostly employ the selective encryption method to encrypt parts of important and sensitive video information, aiming to ensure the real-time performance and encryption efficiency. The classic block cipher is not applicable to video encryption due to the high computational overhead. In this paper, we propose the encryption selection control module to encrypt video syntax elements dynamically which is controlled by the chaotic pseudorandom sequence. A novel spatiotemporal chaos system and binarization method is used to generate a key stream for encrypting the chosen syntax elements. The proposed scheme enhances the resistance against attacks through the dynamic encryption process and high-security stream cipher. Experimental results show that the proposed method exhibits high security and high efficiency with little effect on the compression ratio and time cost.
Voltage Identify Based Encryption (VIBE)
2005-03-01
PUBLIC RELEASE; DISTRIBUTION UNLIMITED. 13. ABSTRACT (Maximum 200 Words) Invented by Dr. Dan Boneh and Dr. Matt Franklin in 2001, Identity-Based...20 Introduction Invented by Dr. Dan Boneh and Dr. Matt Franklin in 2001, Identity-Based Encryption or IBE, is a breakthrough in...the effectiveness of the technology developed to implement the Boneh -Franklin IBE. This contract provided for the necessary hardware and software
Attribute-Based Proxy Re-Encryption with Keyword Search
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.
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.
A one-time pad encryption method combining full-phase image encryption and hiding
NASA Astrophysics Data System (ADS)
Li, Jiaosheng; Xiong, Jiaxiang; Zhang, Qinnan; Zhong, Liyun; Zhou, Yunfei; Li, Jun; Lu, Xiaoxu
2017-08-01
A one-time pad encryption method combining full-phase image encryption and hiding is proposed. Firstly, original images are encoded in the phase and encrypted by phase keys loaded on the phase-only liquid crystal spatial light modulator, where the phase keys can be distributed using a quantum key distribution method. Subsequently, a host image is introduced to produce a reference wave, and overlap with an object wave to form an interferogram. Finally, based on phase-shifting interferometry, we can achieve the above encrypted image hiding. Both the simulation and experiment research demonstrate the feasibility of the proposed method, meanwhile the key and the encrypted image can be changed randomly, so the proposed system reveals the high flexibility, anti-attack ability and can be used to implement the one-time pad to achieve absolute secure transmission with the quantum key distribution method. Moreover, system security will be improved due to the fact that encryption information hidden in the host image can be treated as background noise, which does not attract the attention of the attacker.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-19
... From the Federal Register Online via the Government Publishing Office GENERAL SERVICES ADMINISTRATION Public Buildings Service; Key Largo Beacon Annex Site; Key Largo, FL; Transfer of Property..., identified as Key Largo Beacon Annex Site, Key Largo, FL to the U.S. Fish and Wildlife Service, Department of...
2014-02-01
performance overhead. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED 28 Techniques such as watermarking and passive metering are also proposed to...detect IC piracy. In watermarking techniques, a designer embodies his/her signature into the design [13]. During litigation, the designer can reveal...the watermark and claim ownership of the IC/IP. Watermarks are constructed by adding additional states to the finite state machine of the design
Image encryption by redirection and cyclical shift
NASA Astrophysics Data System (ADS)
Grigoryan, Artyom M.; Wiatrek, Bryan A.; Agaian, Sos S.
2015-05-01
In this paper, we present a novel method for encrypting and decrypting large amounts of data such as two-dimensional (2-D) images, both gray-scale and color, without the loss of information, and using private keys of varying lengths. The proposed method is based on the concept of the tensor representation of an image and splitting the 2-D discrete Fourier transform (DFT) by one-dimensional (1-D) DFTs of signals from the tensor representation, or transform. The splitting of the transform is accomplished in a three-dimensional (3-D) space, namely on the 3-D lattice placed on the torus. Each splitting-signal of the image defines the 2-D DFT along the frequency-points located on the spirals on the torus. Spirals have different form and cover the lattice on the torus in a complex form, which makes them very effective when moving data through and between the spirals, and data along the spirals. The encryption consists of several iterative applications of mapping the 3-D torus into several ones of smaller sizes, and rotates then moves the data around the spirals on all tori. The encryption results in the image which is uncorrelated. The decryption algorithm uses the encrypted data, and processes them in inverse order with an identical number of iterations. The proposed method can be extended to encrypt and decrypt documents as well as other types of digital media. Simulation results of the purposed method are presented to show the performance for image encryption.
Three-dimensional information encryption and anticounterfeiting using digital holography.
Shiu, Min-Tzung; Chew, Yang-Kun; Chan, Huang-Tian; Wong, Xin-Yu; Chang, Chi-Ching
2015-01-01
In this work, arbitrary micro phase-step digital holography with optical interferometry and digital image processing is utilized to obtain information about an image of a three-dimensional object and encrypting keys. Then, a computer-generated hologram is used for the purpose of holographic encryption. All information about the keys is required to perform the decryption, comprising the amplitude and phase distribution of the encrypting key, the distance of image reconstruction, zero-order term elimination, and twin-image term suppression. In addition to using identifiable information on different image planes and linear superposition processing hidden within the encrypted information, not only can we convey an important message, but we can also achieve anticounterfeiting. This approach retains the strictness of traditional holographic encryption and the convenience of digital holographic processing without image distortion. Therefore, this method provides better solutions to earlier methods for the security of the transmission of holographic information.
Single-random-phase holographic encryption of images
NASA Astrophysics Data System (ADS)
Tsang, P. W. M.
2017-02-01
In this paper, a method is proposed for encrypting an optical image onto a phase-only hologram, utilizing a single random phase mask as the private encryption key. The encryption process can be divided into 3 stages. First the source image to be encrypted is scaled in size, and pasted onto an arbitrary position in a larger global image. The remaining areas of the global image that are not occupied by the source image could be filled with randomly generated contents. As such, the global image as a whole is very different from the source image, but at the same time the visual quality of the source image is preserved. Second, a digital Fresnel hologram is generated from the new image, and converted into a phase-only hologram based on bi-directional error diffusion. In the final stage, a fixed random phase mask is added to the phase-only hologram as the private encryption key. In the decryption process, the global image together with the source image it contained, can be reconstructed from the phase-only hologram if it is overlaid with the correct decryption key. The proposed method is highly resistant to different forms of Plain-Text-Attacks, which are commonly used to deduce the encryption key in existing holographic encryption process. In addition, both the encryption and the decryption processes are simple and easy to implement.
Shao, Zhuhong; Shu, Huazhong; Wu, Jiasong; Dong, Zhifang; Coatrieux, Gouenou; Coatrieux, Jean Louis
2014-03-10
This paper describes a novel algorithm to encrypt double color images into a single undistinguishable image in quaternion gyrator domain. By using an iterative phase retrieval algorithm, the phase masks used for encryption are obtained. Subsequently, the encrypted image is generated via cascaded quaternion gyrator transforms with different rotation angles. The parameters in quaternion gyrator transforms and phases serve as encryption keys. By knowing these keys, the original color images can be fully restituted. Numerical simulations have demonstrated the validity of the proposed encryption system as well as its robustness against loss of data and additive Gaussian noise.
Quantum Image Encryption Algorithm Based on Quantum Image XOR Operations
NASA Astrophysics Data System (ADS)
Gong, Li-Hua; He, Xiang-Tao; Cheng, Shan; Hua, Tian-Xiang; Zhou, Nan-Run
2016-07-01
A novel encryption algorithm for quantum images based on quantum image XOR operations is designed. The quantum image XOR operations are designed by using the hyper-chaotic sequences generated with the Chen's hyper-chaotic system to control the control-NOT operation, which is used to encode gray-level information. The initial conditions of the Chen's hyper-chaotic system are the keys, which guarantee the security of the proposed quantum image encryption algorithm. Numerical simulations and theoretical analyses demonstrate that the proposed quantum image encryption algorithm has larger key space, higher key sensitivity, stronger resistance of statistical analysis and lower computational complexity than its classical counterparts.
Optimal Symmetric Ternary Quantum Encryption Schemes
NASA Astrophysics Data System (ADS)
Wang, Yu-qi; She, Kun; Huang, Ru-fen; Ouyang, Zhong
2016-11-01
In this paper, we present two definitions of the orthogonality and orthogonal rate of an encryption operator, and we provide a verification process for the former. Then, four improved ternary quantum encryption schemes are constructed. Compared with Scheme 1 (see Section 2.3), these four schemes demonstrate significant improvements in term of calculation and execution efficiency. Especially, under the premise of the orthogonal rate ɛ as secure parameter, Scheme 3 (see Section 4.1) shows the highest level of security among them. Through custom interpolation functions, the ternary secret key source, which is composed of the digits 0, 1 and 2, is constructed. Finally, we discuss the security of both the ternary encryption operator and the secret key source, and both of them show a high level of security and high performance in execution efficiency.
Optical double image encryption employing a pseudo image technique in the Fourier domain
NASA Astrophysics Data System (ADS)
Guo, Changliang; Liu, Shi; Sheridan, John T.
2014-06-01
A novel optical encryption method is proposed involving double image encryption in which one image is introduced as the pseudo image while the other is the original object image. The Double Random Phase Encoding technique is used to encrypt both the pseudo and object images into complex images. A unique binary image is then employed to first generate the random phase key for the object image encryption and then to embed the encrypted object image into the encrypted pseudo image, which acts as host image. Both the second random phase mask used for encoding the pseudo image and the binary image act as encryption keys. If an attacker attempts to crack the random phase key and decrypt the original object image, the pseudo image will be obtained instead. Simulation results and robustness tests are performed which demonstrate the feasibility of the algorithm.
Investigating Encrypted Material
NASA Astrophysics Data System (ADS)
McGrath, Niall; Gladyshev, Pavel; Kechadi, Tahar; Carthy, Joe
When encrypted material is discovered during a digital investigation and the investigator cannot decrypt the material then s/he is faced with the problem of how to determine the evidential value of the material. This research is proposing a methodology of extracting probative value from the encrypted file of a hybrid cryptosystem. The methodology also incorporates a technique for locating the original plaintext file. Since child pornography (KP) images and terrorist related information (TI) are transmitted in encrypted format the digital investigator must ask the question Cui Bono? - who benefits or who is the recipient? By doing this the scope of the digital investigation can be extended to reveal the intended recipient.
Sandia Scalable Encryption Software
Tarman, Thomas D.
1997-08-13
Sandia Scalable Encryption Library (SSEL) Version 1.0 is a library of functions that implement Sandia''s scalable encryption algorithm. This algorithm is used to encrypt Asynchronous Transfer Mode (ATM) data traffic, and is capable of operating on an arbitrary number of bits at a time (which permits scaling via parallel implementations), while being interoperable with differently scaled versions of this algorithm. The routines in this library implement 8 bit and 32 bit versions of a non-linear mixer which is compatible with Sandia''s hardware-based ATM encryptor.
Trust Threshold Based Public Key Management in Mobile Ad Hoc Networks
2016-03-05
public key cryptography Shamir [26] proposed threshold cryptography based on aring of secrets to generate a private key. In threshold yptography , the...compromised, the whole system is compromise [29] . 2.3. ID-based public key cryptography Shamir [30] also proposed the concept of ID-based pub lic key... cryptography (ID-PKC) which generates a public ke based on the ID of the node (e.g., IP or email address and its corresponding private key generated by a
Chaos-Based Simultaneous Compression and Encryption for Hadoop
Zakaria, Nordin
2017-01-01
Data compression and encryption are key components of commonly deployed platforms such as Hadoop. Numerous data compression and encryption tools are presently available on such platforms and the tools are characteristically applied in sequence, i.e., compression followed by encryption or encryption followed by compression. This paper focuses on the open-source Hadoop framework and proposes a data storage method that efficiently couples data compression with encryption. A simultaneous compression and encryption scheme is introduced that addresses an important implementation issue of source coding based on Tent Map and Piece-wise Linear Chaotic Map (PWLM), which is the infinite precision of real numbers that result from their long products. The approach proposed here solves the implementation issue by removing fractional components that are generated by the long products of real numbers. Moreover, it incorporates a stealth key that performs a cyclic shift in PWLM without compromising compression capabilities. In addition, the proposed approach implements a masking pseudorandom keystream that enhances encryption quality. The proposed algorithm demonstrated a congruent fit within the Hadoop framework, providing robust encryption security and compression. PMID:28072850
Chaos-Based Simultaneous Compression and Encryption for Hadoop.
Usama, Muhammad; Zakaria, Nordin
2017-01-01
Data compression and encryption are key components of commonly deployed platforms such as Hadoop. Numerous data compression and encryption tools are presently available on such platforms and the tools are characteristically applied in sequence, i.e., compression followed by encryption or encryption followed by compression. This paper focuses on the open-source Hadoop framework and proposes a data storage method that efficiently couples data compression with encryption. A simultaneous compression and encryption scheme is introduced that addresses an important implementation issue of source coding based on Tent Map and Piece-wise Linear Chaotic Map (PWLM), which is the infinite precision of real numbers that result from their long products. The approach proposed here solves the implementation issue by removing fractional components that are generated by the long products of real numbers. Moreover, it incorporates a stealth key that performs a cyclic shift in PWLM without compromising compression capabilities. In addition, the proposed approach implements a masking pseudorandom keystream that enhances encryption quality. The proposed algorithm demonstrated a congruent fit within the Hadoop framework, providing robust encryption security and compression.
Verifiable Quantum Encryption and its Practical Applications
NASA Astrophysics Data System (ADS)
Shi, Run-hua
2017-04-01
In this paper, we present a novel verifiable quantum encryption scheme, in which a sender encrypts a classical plaintext into a quantum ciphertext, such that only a specified receiver can decrypt the ciphertext and further get the plaintext. This scheme can not only ensure the unconditional security of the plaintext, but can also verify the validness of the plaintext. In addition, we consider its practical applications with key reuse and further present a practical application protocol for secure two-party quantum scalar product.
Verifiable Quantum Encryption and its Practical Applications
NASA Astrophysics Data System (ADS)
Shi, Run-hua
2016-12-01
In this paper, we present a novel verifiable quantum encryption scheme, in which a sender encrypts a classical plaintext into a quantum ciphertext, such that only a specified receiver can decrypt the ciphertext and further get the plaintext. This scheme can not only ensure the unconditional security of the plaintext, but can also verify the validness of the plaintext. In addition, we consider its practical applications with key reuse and further present a practical application protocol for secure two-party quantum scalar product.
A Novel Image Encryption Algorithm Based on DNA Subsequence Operation
Zhang, Qiang; Xue, Xianglian; Wei, Xiaopeng
2012-01-01
We present a novel image encryption algorithm based on DNA subsequence operation. Different from the traditional DNA encryption methods, our algorithm does not use complex biological operation but just uses the idea of DNA subsequence operations (such as elongation operation, truncation operation, deletion operation, etc.) combining with the logistic chaotic map to scramble the location and the value of pixel points from the image. The experimental results and security analysis show that the proposed algorithm is easy to be implemented, can get good encryption effect, has a wide secret key's space, strong sensitivity to secret key, and has the abilities of resisting exhaustive attack and statistic attack. PMID:23093912
Phase retrieval for attacking fractional Fourier transform encryption.
Kong, Dezhao; Shen, Xueju; Cao, Liangcai; Jin, Guofan
2017-04-20
An advanced iterative phase retrieval algorithm is applied to perform a ciphertext-only attack on the fractional Fourier transform-based double random phase encryption system. With the given complex amplitude of ciphertext and definite support of the object image, the original object image can be recovered by estimating the energy of support area in the recovered image. The encryption system can be attacked by analyzing the sensibility of fractional Fourier transform order keys and evaluating the energy of the object image support area. The proposed algorithm can obtain encrypted fractional order and retrieve two random phase keys. Numerical results demonstrate the efficacy of the proposed attacking method.
Images Encryption Method using Steganographic LSB Method, AES and RSA algorithm
NASA Astrophysics Data System (ADS)
Moumen, Abdelkader; Sissaoui, Hocine
2017-03-01
Vulnerability of communication of digital images is an extremely important issue nowadays, particularly when the images are communicated through insecure channels. To improve communication security, many cryptosystems have been presented in the image encryption literature. This paper proposes a novel image encryption technique based on an algorithm that is faster than current methods. The proposed algorithm eliminates the step in which the secrete key is shared during the encryption process. It is formulated based on the symmetric encryption, asymmetric encryption and steganography theories. The image is encrypted using a symmetric algorithm, then, the secret key is encrypted by means of an asymmetrical algorithm and it is hidden in the ciphered image using a least significant bits steganographic scheme. The analysis results show that while enjoying the faster computation, our method performs close to optimal in terms of accuracy.
Image encryption using eight dimensional chaotic cat map
NASA Astrophysics Data System (ADS)
Ganesan, K.; Murali, K.
2014-06-01
In recent years, a large number of discrete chaotic cryptographic algorithms have been proposed. However, most of them encounter some problems such as lack of robustness and security. In this paper, we introduce a new image encryption algorithm based on eight-dimensional (nonlinear) chaotic cat map. Encryption of image is different from that of texts due to some intrinsic features of image such as bulk data capacity and high redundancy, which are generally difficult to handle by traditional methods. In traditional methods the key space is small and the security is weak. The proposed algorithm tries to address these problems and also tries to enhance the encryption speed. In this paper an eight dimensional chaotic cat map is used to encrypt the intensity values of pixels using lookup table method thereby significantly increasing the speed and security of encryption. The proposed algorithm is found to be resistive against chosen/known-plaintext attacks, statistical and differential attacks.
Fully phase encrypted memory using cascaded extended fractional Fourier transform
NASA Astrophysics Data System (ADS)
Nishchal, Naveen K.; Joseph, Joby; Singh, Kehar
2003-11-01
In this paper, we implement a fully phase encrypted memory system using cascaded extended fractional Fourier transform (FRT). We encrypt and decrypt a two-dimensional image obtained from an amplitude image. The fully phase image to be encrypted is fractional Fourier transformed three times and random phase masks are placed in the two intermediate planes. Performing the FRT three times increases the key size, at an added complexity of one more lens. The encrypted image is holographically recorded in a photorefractive crystal and is then decrypted by generating through phase conjugation, conjugate of encrypted image. The decrypted phase image is converted into an amplitude image by using phase contrast technique. A lithium niobate crystal has been used as a phase contrast filter to reconstruct the phase image, alleviating the need of alignment in the Fourier plane, thereby making the system rugged.
A DRM based on renewable broadcast encryption
NASA Astrophysics Data System (ADS)
Ramkumar, Mahalingam; Memon, Nasir
2005-07-01
We propose an architecture for digital rights management based on a renewable, random key pre-distribution (KPD) scheme, HARPS (hashed random preloaded subsets). The proposed architecture caters for broadcast encryption by a trusted authority (TA) and by "parent" devices (devices used by vendors who manufacture compliant devices) for periodic revocation of devices. The KPD also facilitates broadcast encryption by peer devices, which permits peers to distribute content, and efficiently control access to the content encryption secret using subscription secrets. The underlying KPD also caters for broadcast authentication and mutual authentication of any two devices, irrespective of the vendors manufacturing the device, and thus provides a comprehensive solution for securing interactions between devices taking part in a DRM system.
Usage of the hybrid encryption in a cloud instant messages exchange system
NASA Astrophysics Data System (ADS)
Kvyetnyy, Roman N.; Romanyuk, Olexander N.; Titarchuk, Evgenii O.; Gromaszek, Konrad; Mussabekov, Nazarbek
2016-09-01
A new approach for constructing cloud instant messaging represented in this article allows users to encrypt data locally by using Diffie - Hellman key exchange protocol. The described approach allows to construct a cloud service which operates only by users encrypted messages; encryption and decryption takes place locally at the user party using a symmetric AES encryption. A feature of the service is the conferences support without the need for messages reecryption for each participant. In the article it is given an example of the protocol implementation on the ECC and RSA encryption algorithms basis, as well as a comparison of these implementations.
Argumentation Key to Communicating Climate Change to the Public
NASA Astrophysics Data System (ADS)
Bleicher, R. E.; Lambert, J. L.
2012-12-01
Argumentation plays an important role in how we communicate climate change science to the public and is a key component integrated throughout the Next Generation Science Standards. A scientific argument can be described as a disagreement between explanations with data being used to justify each position. Argumentation is social process where two or more individuals construct and critique arguments (Kuhn & Udell, 2003; Nussbaum, 1997). Sampson, Grooms, and Walker's (2011) developed a framework for understanding the components of a scientific argument. The three components start with a claim (a conjecture, conclusion, explanation, or an answer to a research question). This claim must fit the evidence (observations that show trends over time, relationships between variables or difference between groups). The evidence must be justified with reasoning (explains how the evidence supports the explanation and whey it should count as support). In a scientific argument, or debate, the controversy focuses on how data were collected, what data can or should be included, and what inferences can be made based on a set of evidence. Toulmin's model (1969) also includes rebutting or presenting an alternative explanation supported by counter evidence and reasoning of why the alternative is not the appropriate explanation for the question of the problem. The process of scientific argumentation should involve the construction and critique of scientific arguments, one that involves the consideration of alternative hypotheses (Lawson, 2003). Scientific literacy depends as much on the ability to refute and recognize poor scientific arguments as much as it does on the ability to present an effective argument based on good scientific data (Osborne, 2010). Argument is, therefore, a core feature of science. When students learn to construct a sound scientific argument, they demonstrate critical thinking and a mastery of the science being taught. To present a convincing argument in support of
Public engagement with CCS: barriers, key issues and ways forward
NASA Astrophysics Data System (ADS)
Xenias, Dimitrios
2017-04-01
Although Carbon Capture and Storage (CCS) is recognised as a crucial transition technology to a low-carbon world, it has not been popular with the public or some governments (e.g. the UK). Also, despite its use in industrial processes for decades, CCS remains and unfamiliar technology for most publics. It is therefore important to foster top-down and bottom-up acceptance of large scale CCS. In an exploratory round of interviews we canvassed the views of British, Dutch, German and Norwegian experts (N=13) with previous experience in public engagement with CCS. They identified barriers and drivers for CCS deployment and public engagement with CCS. Thematic analysis revealed a small number of recurrent issues, including: (a) lack of political leadership on CCS; (b) lack of public knowledge on relevant technologies and (c) difficulty communicating why CCS is necessary. Emphasis on these barriers varied with the level of experts' engagement with the public. More interestingly, although most experts agreed on the importance of public engagement, their views divided between 'why' engage and 'how' best to do this. In a subsequent expert survey (N=99) interview findings were reinforced: public support was seen as important for CCS roll-out (72%), though lower than political support and funding. The survey also showed that local public was expected to experience most risks, while global public will experience most benefits; whereas local business is seen to benefit more than global. Experts were overwhelmingly positive about CCS - risks outweigh benefits, and are confident that CCS will play a major role in climate change mitigation (along with reduced energy demand and renewables). These findings will be expanded on and triangulated in a follow-up public survey which will benefit those involved with public engagement with CCS.
Encryption and the loss of patient data.
Miller, Amalia R; Tucker, Catherine E
2011-01-01
Fast-paced IT advances have made it increasingly possible and useful for firms to collect data on their customers on an unprecedented scale. One downside of this is that firms can experience negative publicity and financial damage if their data are breached. This is particularly the case in the medical sector, where we find empirical evidence that increased digitization of patient data is associated with more data breaches. The encryption of customer data is often presented as a potential solution, because encryption acts as a disincentive for potential malicious hackers, and can minimize the risk of breached data being put to malicious use. However, encryption both requires careful data management policies to be successful and does not ward off the insider threat. Indeed, we find no empirical evidence of a decrease in publicized instances of data loss associated with the use of encryption. Instead, there are actually increases in the cases of publicized data loss due to internal fraud or loss of computer equipment.
Lin, Chao; Shen, Xueju; Li, Baochen
2014-08-25
We demonstrate that all parameters of optical lightwave can be simultaneously designed as keys in security system. This multi-dimensional property of key can significantly enlarge the key space and further enhance the security level of the system. The single-shot off-axis digital holography with orthogonal polarized reference waves is employed to perform polarization state recording on object wave. Two pieces of polarization holograms are calculated and fabricated to be arranged in reference arms to generate random amplitude and phase distribution respectively. When reconstruction, original information which is represented with QR code can be retrieved using Fresnel diffraction with decryption keys and read out noise-free. Numerical simulation results for this cryptosystem are presented. An analysis on the key sensitivity and fault tolerance properties are also provided.
An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption
NASA Astrophysics Data System (ADS)
Sun, Xiaoqiang; Wang, Ting; Sun, Zhiwei; Wang, Ping; Yu, Jianping; Xie, Weixin
2017-04-01
In 2009, Gentry first introduced an ideal lattices fully homomorphic encryption (FHE) scheme. Later, based on the approximate greatest common divisor problem, learning with errors problem or learning with errors over rings problem, FHE has developed rapidly, along with the low efficiency and computational security. Combined with quantum mechanics, Liang proposed a symmetric quantum somewhat homomorphic encryption (QSHE) scheme based on quantum one-time pad, which is unconditional security. And it was converted to a quantum fully homomorphic encryption scheme, whose evaluation algorithm is based on the secret key. Compared with Liang's QSHE scheme, we propose a more efficient QSHE scheme for classical input states with perfect security, which is used to encrypt the classical message, and the secret key is not required in the evaluation algorithm. Furthermore, an efficient symmetric searchable encryption (SSE) scheme is constructed based on our QSHE scheme. SSE is important in the cloud storage, which allows users to offload search queries to the untrusted cloud. Then the cloud is responsible for returning encrypted files that match search queries (also encrypted), which protects users' privacy.
An Efficient Quantum Somewhat Homomorphic Symmetric Searchable Encryption
NASA Astrophysics Data System (ADS)
Sun, Xiaoqiang; Wang, Ting; Sun, Zhiwei; Wang, Ping; Yu, Jianping; Xie, Weixin
2017-01-01
In 2009, Gentry first introduced an ideal lattices fully homomorphic encryption (FHE) scheme. Later, based on the approximate greatest common divisor problem, learning with errors problem or learning with errors over rings problem, FHE has developed rapidly, along with the low efficiency and computational security. Combined with quantum mechanics, Liang proposed a symmetric quantum somewhat homomorphic encryption (QSHE) scheme based on quantum one-time pad, which is unconditional security. And it was converted to a quantum fully homomorphic encryption scheme, whose evaluation algorithm is based on the secret key. Compared with Liang's QSHE scheme, we propose a more efficient QSHE scheme for classical input states with perfect security, which is used to encrypt the classical message, and the secret key is not required in the evaluation algorithm. Furthermore, an efficient symmetric searchable encryption (SSE) scheme is constructed based on our QSHE scheme. SSE is important in the cloud storage, which allows users to offload search queries to the untrusted cloud. Then the cloud is responsible for returning encrypted files that match search queries (also encrypted), which protects users' privacy.
On the security of a simple three-party key exchange protocol without server's public keys.
Nam, Junghyun; Choo, Kim-Kwang Raymond; Park, Minkyu; Paik, Juryon; Won, Dongho
2014-01-01
Authenticated key exchange protocols are of fundamental importance in securing communications and are now extensively deployed for use in various real-world network applications. In this work, we reveal major previously unpublished security vulnerabilities in the password-based authenticated three-party key exchange protocol according to Lee and Hwang (2010): (1) the Lee-Hwang protocol is susceptible to a man-in-the-middle attack and thus fails to achieve implicit key authentication; (2) the protocol cannot protect clients' passwords against an offline dictionary attack; and (3) the indistinguishability-based security of the protocol can be easily broken even in the presence of a passive adversary. We also propose an improved password-based authenticated three-party key exchange protocol that addresses the security vulnerabilities identified in the Lee-Hwang protocol.
NASA Astrophysics Data System (ADS)
Bellare, Mihir; Ristenpart, Thomas; Rogaway, Phillip; Stegers, Till
Format-preserving encryption (FPE) encrypts a plaintext of some specified format into a ciphertext of identical format—for example, encrypting a valid credit-card number into a valid credit-card number. The problem has been known for some time, but it has lacked a fully general and rigorous treatment. We provide one, starting off by formally defining FPE and security goals for it. We investigate the natural approach for achieving FPE on complex domains, the “rank-then-encipher” approach, and explore what it can and cannot do. We describe two flavors of unbalanced Feistel networks that can be used for achieving FPE, and we prove new security results for each. We revisit the cycle-walking approach for enciphering on a non-sparse subset of an encipherable domain, showing that the timing information that may be divulged by cycle walking is not a damaging thing to leak.
An Image Encryption Algorithm Utilizing Julia Sets and Hilbert Curves
Sun, Yuanyuan; Chen, Lina; Xu, Rudan; Kong, Ruiqing
2014-01-01
Image encryption is an important and effective technique to protect image security. In this paper, a novel image encryption algorithm combining Julia sets and Hilbert curves is proposed. The algorithm utilizes Julia sets’ parameters to generate a random sequence as the initial keys and gets the final encryption keys by scrambling the initial keys through the Hilbert curve. The final cipher image is obtained by modulo arithmetic and diffuse operation. In this method, it needs only a few parameters for the key generation, which greatly reduces the storage space. Moreover, because of the Julia sets’ properties, such as infiniteness and chaotic characteristics, the keys have high sensitivity even to a tiny perturbation. The experimental results indicate that the algorithm has large key space, good statistical property, high sensitivity for the keys, and effective resistance to the chosen-plaintext attack. PMID:24404181
An image encryption algorithm utilizing julia sets and hilbert curves.
Sun, Yuanyuan; Chen, Lina; Xu, Rudan; Kong, Ruiqing
2014-01-01
Image encryption is an important and effective technique to protect image security. In this paper, a novel image encryption algorithm combining Julia sets and Hilbert curves is proposed. The algorithm utilizes Julia sets' parameters to generate a random sequence as the initial keys and gets the final encryption keys by scrambling the initial keys through the Hilbert curve. The final cipher image is obtained by modulo arithmetic and diffuse operation. In this method, it needs only a few parameters for the key generation, which greatly reduces the storage space. Moreover, because of the Julia sets' properties, such as infiniteness and chaotic characteristics, the keys have high sensitivity even to a tiny perturbation. The experimental results indicate that the algorithm has large key space, good statistical property, high sensitivity for the keys, and effective resistance to the chosen-plaintext attack.
NASA Astrophysics Data System (ADS)
Seshu, Ch.
Quantum Key Distribution (QKD) uses Quantum Mechanics to guarantee secure communication. It enables two parties to produce a shared random bit string known only to them, which can be used as a key to encrypt and decrypt messages.
Secure key storage and distribution
Agrawal, Punit
2015-06-02
This disclosure describes a distributed, fault-tolerant security system that enables the secure storage and distribution of private keys. In one implementation, the security system includes a plurality of computing resources that independently store private keys provided by publishers and encrypted using a single security system public key. To protect against malicious activity, the security system private key necessary to decrypt the publication private keys is not stored at any of the computing resources. Rather portions, or shares of the security system private key are stored at each of the computing resources within the security system and multiple security systems must communicate and share partial decryptions in order to decrypt the stored private key.
NASA Technical Reports Server (NTRS)
Bishop, Matt
1988-01-01
The organization of some tools to help improve passwork security at a UNIX-based site is described along with how to install and use them. These tools and their associated library enable a site to force users to pick reasonably safe passwords (safe being site configurable) and to enable site management to try to crack existing passworks. The library contains various versions of a very fast implementation of the Data Encryption Standard and of the one-way encryption functions used to encryp the password.
A DNA-Inspired Encryption Methodology for Secure, Mobile Ad Hoc Networks
NASA Technical Reports Server (NTRS)
Shaw, Harry
2012-01-01
Users are pushing for greater physical mobility with their network and Internet access. Mobile ad hoc networks (MANET) can provide an efficient mobile network architecture, but security is a key concern. A figure summarizes differences in the state of network security for MANET and fixed networks. MANETs require the ability to distinguish trusted peers, and tolerate the ingress/egress of nodes on an unscheduled basis. Because the networks by their very nature are mobile and self-organizing, use of a Public Key Infra structure (PKI), X.509 certificates, RSA, and nonce ex changes becomes problematic if the ideal of MANET is to be achieved. Molecular biology models such as DNA evolution can provide a basis for a proprietary security architecture that achieves high degrees of diffusion and confusion, and resistance to cryptanalysis. A proprietary encryption mechanism was developed that uses the principles of DNA replication and steganography (hidden word cryptography) for confidentiality and authentication. The foundation of the approach includes organization of coded words and messages using base pairs organized into genes, an expandable genome consisting of DNA-based chromosome keys, and a DNA-based message encoding, replication, and evolution and fitness. In evolutionary computing, a fitness algorithm determines whether candidate solutions, in this case encrypted messages, are sufficiently encrypted to be transmitted. The technology provides a mechanism for confidential electronic traffic over a MANET without a PKI for authenticating users.
Key Performance Indicators of Public Universities Based on Quality Assessment Criteria in Thailand
ERIC Educational Resources Information Center
Sukboonyasatit, Kritsana; Thanapaisarn, Chaiwit; Manmar, Lampang
2011-01-01
The research objective was to develop public universities' key performance indicators. Qualitative research and interviews were employed with each public university's senior executive and quality assessors. The sample group was selected by the office of the public sector development commission and Thailand's public universities can be separated…
Image encryption techniques based on the fractional Fourier transform
NASA Astrophysics Data System (ADS)
Hennelly, B. M.; Sheridan, J. T.
2003-11-01
The fractional Fourier transform, (FRT), is a generalisation of the Fourier transform which allows domains of mixed spatial frequency and spatial information to be examined. A number of method have recently been proposed in the literature for the encryption of two dimensional information using optical systems based on the FRT. Typically, these methods require random phase screen keys to decrypt the data, which must be stored at the receiver and must be carefully aligned with the received encrypted data. We have proposed a new technique based on a random shifting or Jigsaw transformation. This method does not require the use of phase keys. The image is encrypted by juxtaposition of sections of the image in various FRT domains. The new method has been compared numerically with existing methods and shows comparable or superior robustness to blind decryption. An optical implementation is also proposed and the sensitivity of the various encryption keys to blind decryption is quantified. We also present a second image encryption technique, which is based on a recently proposed method of optical phase retrieval using the optical FRT and one of its discrete counterparts. Numerical simulations of the new algorithm indicates that the sensitivity of the keys is much greater than any of the techniques currently available. In fact the sensitivity appears to be so high that optical implementation, based on existing optical signal processing technology, may be impossible. However, the technique has been shown to be a powerful method of 2-D image data encryption.
Writing for Professional Publication. Keys to Academic and Business Success.
ERIC Educational Resources Information Center
Henson, Kenneth T.
This book provides practical help for people writing for publication, especially for those writing for professional journals or university presses. Chapters cover the following topics: (1) reasons for writing; (2) finding topics; (3) getting started; (4) writing style; (5) organizing articles; (6) using journals, libraries, surveys, and action…
Quantum Image Encryption Algorithm Based on Image Correlation Decomposition
NASA Astrophysics Data System (ADS)
Hua, Tianxiang; Chen, Jiamin; Pei, Dongju; Zhang, Wenquan; Zhou, Nanrun
2015-02-01
A novel quantum gray-level image encryption and decryption algorithm based on image correlation decomposition is proposed. The correlation among image pixels is established by utilizing the superposition and measurement principle of quantum states. And a whole quantum image is divided into a series of sub-images. These sub-images are stored into a complete binary tree array constructed previously and then randomly performed by one of the operations of quantum random-phase gate, quantum revolving gate and Hadamard transform. The encrypted image can be obtained by superimposing the resulting sub-images with the superposition principle of quantum states. For the encryption algorithm, the keys are the parameters of random phase gate, rotation angle, binary sequence and orthonormal basis states. The security and the computational complexity of the proposed algorithm are analyzed. The proposed encryption algorithm can resist brute force attack due to its very large key space and has lower computational complexity than its classical counterparts.
An Asymmetric Image Encryption Based on Phase Truncated Hybrid Transform
NASA Astrophysics Data System (ADS)
Khurana, Mehak; Singh, Hukum
2017-09-01
To enhance the security of the system and to protect it from the attacker, this paper proposes a new asymmetric cryptosystem based on hybrid approach of Phase Truncated Fourier and Discrete Cosine Transform (PTFDCT) which adds non linearity by including cube and cube root operation in the encryption and decryption path respectively. In this cryptosystem random phase masks are used as encryption keys and phase masks generated after the cube operation in encryption process are reserved as decryption keys and cube root operation is required to decrypt image in decryption process. The cube and cube root operation introduced in the encryption and decryption path makes system resistant against standard attacks. The robustness of the proposed cryptosystem has been analysed and verified on the basis of various parameters by simulating on MATLAB 7.9.0 (R2008a). The experimental results are provided to highlight the effectiveness and suitability of the proposed cryptosystem and prove the system is secure.
Optical encryption using photon-counting polarimetric imaging.
Maluenda, David; Carnicer, Artur; Martínez-Herrero, Rosario; Juvells, Ignasi; Javidi, Bahram
2015-01-26
We present a polarimetric-based optical encoder for image encryption and verification. A system for generating random polarized vector keys based on a Mach-Zehnder configuration combined with translucent liquid crystal displays in each path of the interferometer is developed. Polarization information of the encrypted signal is retrieved by taking advantage of the information provided by the Stokes parameters. Moreover, photon-counting model is used in the encryption process which provides data sparseness and nonlinear transformation to enhance security. An authorized user with access to the polarization keys and the optical design variables can retrieve and validate the photon-counting plain-text. Optical experimental results demonstrate the feasibility of the encryption method.
Attribute-Based Encryption with Partially Hidden Ciphertext Policies
NASA Astrophysics Data System (ADS)
Nishide, Takashi; Yoneyama, Kazuki; Ohta, Kazuo
We propose attribute-based encryption schemes where encryptor-specified policies (called ciphertext policies) are hidden. By using our schemes, an encryptor can encrypt data with a hidden access control policy. A decryptor obtains her secret key associated with her attributes from a trusted authority in advance and if the attributes associated with the decryptor's secret key do not satisfy the access control policy associated with the encrypted data, the decryptor cannot decrypt the data or guess even what access control policy was specified by the encryptor. We prove security of our construction based on the Decisional Bilinear Diffie-Hellman assumption and the Decision Linear assumption. In our security notion, even the legitimate decryptor cannot obtain the information about the access control policy associated with the encrypted data more than the fact that she can decrypt the data.
Photonic encryption using all optical logic.
Blansett, Ethan L.; Schroeppel, Richard Crabtree; Tang, Jason D.; Robertson, Perry J.; Vawter, Gregory Allen; Tarman, Thomas David; Pierson, Lyndon George
2003-12-01
With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines two classes of all optical logic (SEED, gain competition) and how each discrete logic element can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of the SEED and gain competition devices in an optical circuit were modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model of the SEED or gain competition device takes certain parameters (reflectance, intensity, input response), and models the optical ripple and time delay characteristics. These 'black box' models are interconnected and cascaded in an
NASA Astrophysics Data System (ADS)
Liu, Yuexin; Metzner, John J.; Guo, Ruyan; Yu, Francis T. S.
2005-09-01
An efficient and secure algorithm for random phase mask generation used in optical data encryption and transmission system is proposed, based on Diffie-Hellman public key distribution. Thus-generated random mask has higher security due to the fact that it is never exposed to the vulnerable transmitting channels. The effectiveness to retrieve the original image and its robustness against blind manipulation have been demonstrated by our numerical results. In addition, this algorithm can be easily extended to multicast networking system and refresh of this shared random key is also very simple to implement.
Cryptanalysis of Chatterjee-Sarkar Hierarchical Identity-Based Encryption Scheme at PKC 06
NASA Astrophysics Data System (ADS)
Park, Jong Hwan; Lee, Dong Hoon
In 2006, Chatterjee and Sarkar proposed a hierarchical identity-based encryption (HIBE) scheme which can support an unbounded number of identity levels. This property is particularly useful in providing forward secrecy by embedding time components within hierarchical identities. In this paper we show that their scheme does not provide the claimed property. Our analysis shows that if the number of identity levels becomes larger than the value of a fixed public parameter, an unintended receiver can reconstruct a new valid ciphertext and decrypt the ciphertext using his or her own private key. The analysis is similarly applied to a multi-receiver identity-based encryption scheme presented as an application of Chatterjee and Sarkar's HIBE scheme.
DOE and Public Involvement A Key to Successful Clean Up
Sarten, S.
2008-07-01
The combination of two vital elements in the Oak Ridge, TN area are the Department of Energy and the education of the public, at any age, of the necessary work that is and has been going on this region of the country since the setting aside of land during the World War II era. A wide variety of interested citizens from surrounding counties make up a group of individuals that bring different elements of education and involvement to form a committee of whose interest is the Department of Energy's handling of contaminated material. The effort of one of the committees on this board has given the public a resource of material to develop a better understanding of the history and stewardship efforts taking place at the Oak Ridge Reservation. (authors)
Chaos based encryption system for encrypting electroencephalogram signals.
Lin, Chin-Feng; Shih, Shun-Han; Zhu, Jin-De
2014-05-01
In the paper, we use the Microsoft Visual Studio Development Kit and C# programming language to implement a chaos-based electroencephalogram (EEG) encryption system involving three encryption levels. A chaos logic map, initial value, and bifurcation parameter for the map were used to generate Level I chaos-based EEG encryption bit streams. Two encryption-level parameters were added to these elements to generate Level II chaos-based EEG encryption bit streams. An additional chaotic map and chaotic address index assignment process was used to implement the Level III chaos-based EEG encryption system. Eight 16-channel EEG Vue signals were tested using the encryption system. The encryption was the most rapid and robust in the Level III system. The test yielded superior encryption results, and when the correct deciphering parameter was applied, the EEG signals were completely recovered. However, an input parameter error (e.g., a 0.00001 % initial point error) causes chaotic encryption bit streams, preventing the recovery of 16-channel EEG Vue signals.
A Literature Review on Image Encryption Techniques
NASA Astrophysics Data System (ADS)
Khan, Majid; Shah, Tariq
2014-12-01
Image encryption plays a paramount part to guarantee classified transmission and capacity of image over web. Then again, a real-time image encryption confronts a more noteworthy test because of vast measure of information included. This paper exhibits an audit on image encryption in spatial, frequency and hybrid domains with both full encryption and selective encryption strategy.
Fresnel domain double-phase encoding encryption of color image via ptychography
NASA Astrophysics Data System (ADS)
Qiao, Liang; Wang, Yali; Li, Tuo; Shi, Yishi
2015-10-01
In this paper, color image encryption combined with ptychography has been investigated. Ptychographic imaging possesses a remarkable advantage of simple optics architecture and complex amplitude of object can be reconstructed just by a series of diffraction intensity patterns via aperture movement. Traditional technique of three primary color synthesis is applied for encrypting color image. In order to reduce physical limitations, the encryption's algorithm is based on Fresnel transformation domain. It is illustrated that the proposed optical encryption scheme has well ability to recover the encrypted color plaintext and advances in security enhancement thanks to introducing ptychography, since light probe as key factor enlarges the key space. Finally, the encryption's immunity to noise and reconstruction impact from lateral offset of probe has been investigated.
Bouslimi, D; Bellafqira, R; Coatrieux, G
2016-08-01
In this paper, we propose a new scheme of data hiding of encrypted images for the purpose of verifying the reliability of an image into both encrypted and spatial domains. This scheme couples the Quantization Index Modulation (QIM) and the Paillier cryptosystem. It relies on the insertion into the image, before its encryption, of a predefined watermark, a "pre-watermark". Message insertion (resp. extraction) is conducted into (resp. from) the encrypted image using a modified version of QIM. It is the impact of this insertion process onto the "pre-watermark" that gives access to the message in the spatial domain, i.e. after the image has been decrypted. With our scheme, encryption/decryption processes are completely independent from message embedding/extraction. One does not need to know the encryption/decryption key for hiding a message into the encrypted image. Experiments conducted on ultrasound medical images show that the image distortion is very low while offering a high capacity that can support different watermarking based security objectives.
Quantum asymmetric cryptography with symmetric keys
NASA Astrophysics Data System (ADS)
Gao, Fei; Wen, Qiaoyan; Qin, Sujuan; Zhu, Fuchen
2009-12-01
Based on quantum encryption, we present a new idea for quantum public-key cryptography (QPKC) and construct a whole theoretical framework of a QPKC system. We show that the quantum-mechanical nature renders it feasible and reasonable to use symmetric keys in such a scheme, which is quite different from that in conventional public-key cryptography. The security of our scheme is analyzed and some features are discussed. Furthermore, the state-estimation attack to a prior QPKC scheme is demonstrated.
Sustainability as the key to prioritize investments in public infrastructures
Pardo-Bosch, Francesc; Aguado, Antonio
2016-09-15
Infrastructure construction, one of the biggest driving forces of the economy nowadays, requires a huge analysis and clear transparency to decide what projects have to be executed with the few resources available. With the aim to provide the public administrations a tool with which they can make their decisions easier, the Sustainability Index of Infrastructure Projects (SIIP) has been defined, with a multi-criteria decision system called MIVES, in order to classify non-uniform investments. This index evaluates, in two inseparable stages, the contribution to the sustainable development of each infrastructure project, analyzing its social, environmental and economic impact. The result of the SIIP allows to decide the order with which projects will be prioritized. The case of study developed proves the adaptability and utility of this tool for the ordinary budget management.
Composite Trust-Based Public Key Management in Mobile Ad Hoc Networks
2013-01-01
private key generation. Li et al. [12] used Sattam’s certificate-less public key cryptography to eliminate the key escrow problem and employed...based on unanimous agreement by all intermediate nodes that pass the recommendation are used as indirect evidence while new direct evidence cannot be
A novel cellular automata based technique for visual multimedia content encryption
NASA Astrophysics Data System (ADS)
Chatzichristofis, Savvas A.; Mitzias, Dimitris A.; Sirakoulis, Georgios Ch.; Boutalis, Yiannis S.
2010-11-01
This paper proposes a new method for visual multimedia content encryption using Cellular Automata (CA). The encryption scheme is based on the application of an attribute of the CLF XOR filter, according to which the original content of a cellular neighborhood can be reconstructed following a predetermined number of repeated applications of the filter. The encryption is achieved using a key image of the same dimensions as the image being encrypted. This technique is accompanied by the one-time pad (OTP) encryption method, rendering the proposed method reasonably powerful, given the very large number of resultant potential security keys. The method presented here makes encryption possible in cases where there is more than one image with the use of just one key image. A further significant characteristic of the proposed method is that it demonstrates how techniques from the field of image retrieval can be used in the field of image encryption. The proposed method is further strengthened by the fact that the resulting encrypted image for a given key image is different each time. The encryption result depends on the structure of an artificial image produced by the superposition of four 1-D CA time-space diagrams as well as from a CA random number generator. A semi-blind source separation algorithm is used to decrypt the encrypted image. The result of the decryption is a lossless representation of the encrypted image. Simulation results demonstrate the effectiveness of the proposed encryption method. The proposed method is implemented in C# and is available online through the img(Rummager) application.
Wikipedia: a key tool for global public health promotion.
Heilman, James M; Kemmann, Eckhard; Bonert, Michael; Chatterjee, Anwesh; Ragar, Brent; Beards, Graham M; Iberri, David J; Harvey, Matthew; Thomas, Brendan; Stomp, Wouter; Martone, Michael F; Lodge, Daniel J; Vondracek, Andrea; de Wolff, Jacob F; Liber, Casimir; Grover, Samir C; Vickers, Tim J; Meskó, Bertalan; Laurent, Michaël R
2011-01-31
The Internet has become an important health information resource for patients and the general public. Wikipedia, a collaboratively written Web-based encyclopedia, has become the dominant online reference work. It is usually among the top results of search engine queries, including when medical information is sought. Since April 2004, editors have formed a group called WikiProject Medicine to coordinate and discuss the English-language Wikipedia's medical content. This paper, written by members of the WikiProject Medicine, discusses the intricacies, strengths, and weaknesses of Wikipedia as a source of health information and compares it with other medical wikis. Medical professionals, their societies, patient groups, and institutions can help improve Wikipedia's health-related entries. Several examples of partnerships already show that there is enthusiasm to strengthen Wikipedia's biomedical content. Given its unique global reach, we believe its possibilities for use as a tool for worldwide health promotion are underestimated. We invite the medical community to join in editing Wikipedia, with the goal of providing people with free access to reliable, understandable, and up-to-date health information.
Wikipedia: A Key Tool for Global Public Health Promotion
Heilman, James M; Kemmann, Eckhard; Bonert, Michael; Chatterjee, Anwesh; Ragar, Brent; Beards, Graham M; Iberri, David J; Harvey, Matthew; Thomas, Brendan; Stomp, Wouter; Martone, Michael F; Lodge, Daniel J; Vondracek, Andrea; de Wolff, Jacob F; Liber, Casimir; Grover, Samir C; Vickers, Tim J; Meskó, Bertalan
2011-01-01
The Internet has become an important health information resource for patients and the general public. Wikipedia, a collaboratively written Web-based encyclopedia, has become the dominant online reference work. It is usually among the top results of search engine queries, including when medical information is sought. Since April 2004, editors have formed a group called WikiProject Medicine to coordinate and discuss the English-language Wikipedia’s medical content. This paper, written by members of the WikiProject Medicine, discusses the intricacies, strengths, and weaknesses of Wikipedia as a source of health information and compares it with other medical wikis. Medical professionals, their societies, patient groups, and institutions can help improve Wikipedia’s health-related entries. Several examples of partnerships already show that there is enthusiasm to strengthen Wikipedia’s biomedical content. Given its unique global reach, we believe its possibilities for use as a tool for worldwide health promotion are underestimated. We invite the medical community to join in editing Wikipedia, with the goal of providing people with free access to reliable, understandable, and up-to-date health information. PMID:21282098
Algorithms for Lightweight Key Exchange.
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.
A New Color Image Encryption Scheme Using CML and a Fractional-Order Chaotic System
Wu, Xiangjun; Li, Yang; Kurths, Jürgen
2015-01-01
The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML) and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks. PMID:25826602
A new color image encryption scheme using CML and a fractional-order chaotic system.
Wu, Xiangjun; Li, Yang; Kurths, Jürgen
2015-01-01
The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML) and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks.
Chaotic Order Preserving Encryption for Efficient and Secure Queries on Databases
NASA Astrophysics Data System (ADS)
Lee, Seungmin; Park, Tae-Jun; Lee, Donghyeok; Nam, Taekyong; Kim, Sehun
The need for data encryption that protects sensitive data in a database has increased rapidly. However, encrypted data can no longer be efficiently queried because nearly all of the data should be decrypted. Several order-preserving encryption schemes that enable indexes to be built over encrypted data have been suggested to solve this problem. They allow any comparison operation to be directly applied to encrypted data. However, one of the main disadvantages of these schemes is that they expose sensitive data to inference attacks with order information, especially when the data are used together with unencrypted columns in the database. In this study, a new order-preserving encryption scheme that provides secure queries by hiding the order is introduced. Moreover, it provides efficient queries because any user who has the encryption key knows the order. The proposed scheme is designed to be efficient and secure in such an environment. Thus, it is possible to encrypt only sensitive data while leaving other data unencrypted. The encryption is not only robust against order exposure, but also shows high performance for any query over encrypted data. In addition, the proposed scheme provides strong updates without assumptions of the distribution of plaintext. This allows it to be integrated easily with the existing database system.
Fractional Fourier Transform Applied to Digital Images Encryption
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Torres, Cesar O.; Mattos, Lorenzo
2008-04-01
In the present paper a digital algorithm was developed to make phase encryption of digital indexed images to color using the fractional Fourier transform (the images in RGB are converted to indexed before to encrypt). The indexed images are represented by a matrix of M×N pixels (where M defines the height and N is the Width of the image) and a color map (it's a matrix of C×3 elements, where C indicates the colors number of the image and the number 3 indicates the three columns associated with the color components: Red, Green and Blue of each pixel of the matrix of M×N) associated to the matrix of pixels to suitably represent the color information of the image. The indexed image (matrix of M×N pixels) to encrypt is placed as the phase of a complex exponential, then is transformed three times and multiplied in intermediate steps by two random phase masks statistically independent thus to obtain the encrypted image, for decrypt the coding image the encryption procedure is applied in the inverse sense to the conjugated complex of the encrypted image, then is taken the negative of the phase of the resulting function of the decryption process and the original image is obtained this way that had been encrypted; For the color map equal procedure is applied in the encryption/decryption process described previously for the matrix of M×N pixels. In the implemented cryptographic algorithm five keys are used, constituted by three fractional orders and two random phase masks, all these keys are necessary for a correct decryption providing a dependability to the transference of images by means of the communications nets.
OS2: Oblivious similarity based searching for encrypted data outsourced to an untrusted domain
Pervez, Zeeshan; Ahmad, Mahmood; Khattak, Asad Masood; Ramzan, Naeem
2017-01-01
Public cloud storage services are becoming prevalent and myriad data sharing, archiving and collaborative services have emerged which harness the pay-as-you-go business model of public cloud. To ensure privacy and confidentiality often encrypted data is outsourced to such services, which further complicates the process of accessing relevant data by using search queries. Search over encrypted data schemes solve this problem by exploiting cryptographic primitives and secure indexing to identify outsourced data that satisfy the search criteria. Almost all of these schemes rely on exact matching between the encrypted data and search criteria. A few schemes which extend the notion of exact matching to similarity based search, lack realism as those schemes rely on trusted third parties or due to increase storage and computational complexity. In this paper we propose Oblivious Similarity based Search (OS2) for encrypted data. It enables authorized users to model their own encrypted search queries which are resilient to typographical errors. Unlike conventional methodologies, OS2 ranks the search results by using similarity measure offering a better search experience than exact matching. It utilizes encrypted bloom filter and probabilistic homomorphic encryption to enable authorized users to access relevant data without revealing results of search query evaluation process to the untrusted cloud service provider. Encrypted bloom filter based search enables OS2 to reduce search space to potentially relevant encrypted data avoiding unnecessary computation on public cloud. The efficacy of OS2 is evaluated on Google App Engine for various bloom filter lengths on different cloud configurations. PMID:28692697
Evaluating Predicates over Encrypted Data
2008-10-01
order, except the fact that the conditions specified by the order were never met. Untrusted remote storage. Individual users may wish to store emails...and files on a remote server, but because the storage server is untrusted , the content must be encrypted before it is stored at the remote server...Alice stores her encrypted documents on a remote server, and would like to perform searches on the encrypted data . Ideally, Alice would like to hide
Lighten Encryption Schemes for Secure and Private RFID Systems
NASA Astrophysics Data System (ADS)
Canard, Sébastien; Coisel, Iwen; Etrog, Jonathan
We provide several concrete implementations of a generic method given by Vaudenay to construct secure privacy-preserving RFID authentication and identification systems. More precisely, we give the first instantiation of the Vaudenay's result by using the IND-CCA secure DHAES cryptosystem. Next we argue that weaker cryptosystems can also be used by recalling the WIPR RFID system and giving a new protocol based on the El Gamal encryption scheme. After that, we introduce a new generic construction based on the use of any IND-CPA secure public key cryptosystem together with a MAC scheme and describe a possibility using the Hash El Gamal cryptosystem. We finally compare all these schemes, both in terms of implementation and security, proving that, nowadays the DHAES and our Hash El Gamal based solutions appear as the most promising schemes.
Public key suppression and recovery using a PANDA ring resonator for high security communication
NASA Astrophysics Data System (ADS)
Juleang, Pakorn; Phongsanam, Prapas; Mitatha, Somsak; Yupapin, Preecha P.
2011-03-01
An interesting security technique that uses the dark-bright soliton conversion control within the microring resonator is proposed. The obtained outputs for a dark-bright soliton dynamic state can be controlled and used to form the public key suppression for communication security application. However, a good design should be possible to be fabricated; therefore, by using the parameters based on the practical device parameters, the simulation results obtained have shown that the proposed system can indeed be achieved. The public key suppression and public key recovery can be used in a highly secure communication system and has potential applications in optical cryptography.
NASA Astrophysics Data System (ADS)
Yi, Lilin; Zhang, Tao; Hu, Weisheng
2011-11-01
A novel all-optical encryption/decryption method based on stimulated Brillouin scattering (SBS) effect in optical fiber is proposed for the first time. The operation principle is explained in detail and the encryption and decryption performance is experimentally evaluated. The encryption keys could be the SBS gain amplitude, bandwidth, central wavelength and spectral shape, which are configurable and flexibly controlled by the users. We experimentally demonstrate the SBS encryption/decryption process of a 10.86-Gb/s non-return-to-zero (NRZ) data by using both phase-modulated and current-dithered Brillouin pumps for proof-of-concept. Unlike the traditional optical encryption methods of chaotic communications and optical code-division-multiplexing access (OCDMA), the SBS based encryption/decryption technique can directly upgrade the current optical communication system to a secure communication system without changing the terminal transceivers, which is completely compatible with the current optical communication systems.
Image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing
NASA Astrophysics Data System (ADS)
Zhou, Nanrun; Pan, Shumin; Cheng, Shan; Zhou, Zhihong
2016-08-01
Most image encryption algorithms based on low-dimensional chaos systems bear security risks and suffer encryption data expansion when adopting nonlinear transformation directly. To overcome these weaknesses and reduce the possible transmission burden, an efficient image compression-encryption scheme based on hyper-chaotic system and 2D compressive sensing is proposed. The original image is measured by the measurement matrices in two directions to achieve compression and encryption simultaneously, and then the resulting image is re-encrypted by the cycle shift operation controlled by a hyper-chaotic system. Cycle shift operation can change the values of the pixels efficiently. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys distribution simultaneously as a nonlinear encryption system. Simulation results verify the validity and the reliability of the proposed algorithm with acceptable compression and security performance.
Layered Multicast Encryption of Motion JPEG2000 Code Streams for Flexible Access Control
NASA Astrophysics Data System (ADS)
Nakachi, Takayuki; Toyoshima, Kan; Tonomura, Yoshihide; Fujii, Tatsuya
In this paper, we propose a layered multicast encryption scheme that provides flexible access control to motion JPEG2000 code streams. JPEG2000 generates layered code streams and offers flexible scalability in characteristics such as resolution and SNR. The layered multicast encryption proposal allows a sender to multicast the encrypted JPEG2000 code streams such that only designated groups of users can decrypt the layered code streams. While keeping the layering functionality, the proposed method offers useful properties such as 1) video quality control using only one private key, 2) guaranteed security, and 3) low computational complexity comparable to conventional non-layered encryption. Simulation results show the usefulness of the proposed method.
NASA Astrophysics Data System (ADS)
Knobler, Ron; Scheffel, Peter; Jackson, Scott; Gaj, Kris; Kaps, Jens Peter
2013-05-01
Various embedded systems, such as unattended ground sensors (UGS), are deployed in dangerous areas, where they are subject to compromise. Since numerous systems contain a network of devices that communicate with each other (often times with commercial off the shelf [COTS] radios), an adversary is able to intercept messages between system devices, which jeopardizes sensitive information transmitted by the system (e.g. location of system devices). Secret key algorithms such as AES are a very common means to encrypt all system messages to a sufficient security level, for which lightweight implementations exist for even very resource constrained devices. However, all system devices must use the appropriate key to encrypt and decrypt messages from each other. While traditional public key algorithms (PKAs), such as RSA and Elliptic Curve Cryptography (ECC), provide a sufficiently secure means to provide authentication and a means to exchange keys, these traditional PKAs are not suitable for very resource constrained embedded systems or systems which contain low reliability communication links (e.g. mesh networks), especially as the size of the network increases. Therefore, most UGS and other embedded systems resort to pre-placed keys (PPKs) or other naïve schemes which greatly reduce the security and effectiveness of the overall cryptographic approach. McQ has teamed with the Cryptographic Engineering Research Group (CERG) at George Mason University (GMU) to develop an approach using revolutionary cryptographic techniques that provides both authentication and encryption, but on resource constrained embedded devices, without the burden of large amounts of key distribution or storage.
Security encryption for video-on-radio devices
NASA Astrophysics Data System (ADS)
Perrone, Antonio L.; Basti, Gianfranco
2002-03-01
In this paper we present an encryption module included in the Subsidiary Communication Channel (SCC) System we are developing for video-on-FM radio broadcasting. This module is aimed to encrypt by symmetric key the video image archive and real-time database of the broadcaster, and by asymmetric key the video broadcasting to final users. The module includes our proprietary Techniteia Encryption Library (TEL), that is already successfully running and securing several e-commerce portals in Europe. TEL is written in C-ANSI language for its easy exportation onto all main platforms and it is optimized for real-time applications. It is based on the blowfish encryption algorithm and it is characterized by a physically separated sub-module for the automatic generation/recovering of the variable sub-keys of the blowfish algorithm. In this way, different parts of the database are encrypted by different keys, both in space and in time, for granting an optimal security.
Optical field encryption for secure transmission of data
NASA Astrophysics Data System (ADS)
Fraser, Colin B.; Harvey, Andrew R.
2004-12-01
The growing awareness of the vulnerability of information transmitted on communication systems within the government, military and commercial sectors, has stimulated a number of areas of research within the optical community to design optical hardware encryption systems providing inherent immunity to espionage techniques. This paper describes a hardware optical encryption technique that utilises off the shelf telecommunication equipment and negates the necessity for an independent key distribution system with respect to the data transmission system, as is common with alternative encryption system implementations. This method also lends itself easily to fiber optic or free space communication and is applicable within any optical waveband. The encryption-decryption of the optical signal is achieved through low coherence optical interferometry. This requires the instantaneous processing and analysis of the signal, optically, to retrieve the relevant optical phase information hidden in the transmitted optical noise. This technology allows an authorised user to transmit encrypted information at a high data rate securely, while maintaining opaqueness to an unauthorised observer that data transmission is occurring. As the instantaneous optical field properties of the signals present in the system are essential to the optical encryption - decryption process, the system is inherently protected against electronic recording and advances in computational decryption algorithms. For organisations wishing to protect sensitive data and levels of communication activity these are highly desirable features.
Securing Voice over IP Conferencing with Decentralized Group Encryption
2007-09-04
98 Appendix C Installation Guide ...Similarly, system users should peruse the installation guide . Chapter 2 defines the problem we aim to solve with this project. We review motivation...membership changes. These keys are used in Cipher Block Chaining (CBC) mode to encrypt message payloads. After a group key is distributed, PKGE can
Data publication and dissemination of interactive keys under the open access model
USDA-ARS?s Scientific Manuscript database
The concepts of publication, citation and dissemination of interactive keys and other online keys are discussed and illustrated by a sample paper published in the present issue (doi: 10.3897/zookeys.21.271). The present model is based on previous experience with several existing examples of publishi...
Secure Genomic Computation through Site-Wise Encryption.
Zhao, Yongan; Wang, XiaoFeng; Tang, Haixu
2015-01-01
Commercial clouds provide on-demand IT services for big-data analysis, which have become an attractive option for users who have no access to comparable infrastructure. However, utilizing these services for human genome analysis is highly risky, as human genomic data contains identifiable information of human individuals and their disease susceptibility. Therefore, currently, no computation on personal human genomic data is conducted on public clouds. To address this issue, here we present a site-wise encryption approach to encrypt whole human genome sequences, which can be subject to secure searching of genomic signatures on public clouds. We implemented this method within the Hadoop framework, and tested it on the case of searching disease markers retrieved from the ClinVar database against patients' genomic sequences. The secure search runs only one order of magnitude slower than the simple search without encryption, indicating our method is ready to be used for secure genomic computation on public clouds.
Public-Private Partnerships: The Key to Retaining Government and Industry Capabilities
2013-02-01
government and industry to optimize weapon system product support at best value cost. Public - Private Partnerships (PPPs) are a key component of DoD...program offices, inventory control points, and sustainment commands, may be parties to such agreements. DoD Policy on Public - Private Partnerships DoD...policy on public - private partnerships is reflected in DoDD 5000.01, The Defense Acquisition System, paragraph E1.17, certified current as of Nov. 20
Cancelable face verification using optical encryption and authentication.
Taheri, Motahareh; Mozaffari, Saeed; Keshavarzi, Parviz
2015-10-01
In a cancelable biometric system, each instance of enrollment is distorted by a transform function, and the output should not be retransformed to the original data. This paper presents a new cancelable face verification system in the encrypted domain. Encrypted facial images are generated by a double random phase encoding (DRPE) algorithm using two keys (RPM1 and RPM2). To make the system noninvertible, a photon counting (PC) method is utilized, which requires a photon distribution mask for information reduction. Verification of sparse images that are not recognizable by direct visual inspection is performed by unconstrained minimum average correlation energy filter. In the proposed method, encryption keys (RPM1, RPM2, and PDM) are used in the sender side, and the receiver needs only encrypted images and correlation filters. In this manner, the system preserves privacy if correlation filters are obtained by an adversary. Performance of PC-DRPE verification system is evaluated under illumination variation, pose changes, and facial expression. Experimental results show that utilizing encrypted images not only increases security concerns but also enhances verification performance. This improvement can be attributed to the fact that, in the proposed system, the face verification problem is converted to key verification tasks.
Streamlining taxonomic publication: a working example with Scratchpads and ZooKeys
Blagoderov, Vladimir; Brake, Irina; Georgiev, Teodor; Penev, Lyubomir; Roberts, David; Ryrcroft, Simon; Scott, Ben; Agosti, Donat; Catapano, Terry; Smith, Vincent S.
2010-01-01
Abstract We describe a method to publish nomenclatural acts described in taxonomic websites (Scratchpads) that are formally registered through publication in a printed journal (ZooKeys). This method is fully compliant with the zoological nomenclatural code. Our approach supports manuscript creation (via a Scratchpad), electronic act registration (via ZooBank), online and print publication (in the journal ZooKeys) and simultaneous dissemination (ZooKeys and Scratchpads) for nomenclatorial acts including new species descriptions. The workflow supports the generation of manuscripts directly from a database and is illustrated by two sample papers published in the present issue. PMID:21594114
Encryption and networking applications
Long, J.P.
1995-04-01
The DOE requires that sensitive unclassified data be protected while being transmitted electronically. On most large networks it is difficult and expensive to provide the required level of physical protection. At Sandia National Laboratories, we are assembling the structure necessary to protect sensitive unclassified data using software-based encryption. This approach has the advantage that the data can be protected after arrival at its destination without additional investment While Sandia has expertise in cryptography, we had not used cryptography in this field. This discussion deals with the client-server model of file-based data exchange and interactive access to on-line data bases using Unix workstations, Macs and PCs.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 47 Telecommunication 5 2010-10-01 2010-10-01 false Encryption. 90.553 Section 90.553...-805 MHz Bands § 90.553 Encryption. (a) Encryption is permitted on all but the two nationwide Interoperability calling channels. Radios employing encryption must have a readily accessible switch or...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 5 2013-10-01 2013-10-01 false Encryption. 90.553 Section 90.553...-805 MHz Bands § 90.553 Encryption. (a) Encryption is permitted on all but the two nationwide Interoperability calling channels. Radios employing encryption must have a readily accessible switch or...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 5 2011-10-01 2011-10-01 false Encryption. 90.553 Section 90.553...-805 MHz Bands § 90.553 Encryption. (a) Encryption is permitted on all but the two nationwide Interoperability calling channels. Radios employing encryption must have a readily accessible switch or...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 5 2012-10-01 2012-10-01 false Encryption. 90.553 Section 90.553...-805 MHz Bands § 90.553 Encryption. (a) Encryption is permitted on all but the two nationwide Interoperability calling channels. Radios employing encryption must have a readily accessible switch or...
Strategy for cryptanalysis of optical encryption in the Fresnel domain.
Situ, Guohai; Pedrini, Giancarlo; Osten, Wolfgang
2010-01-20
Traditionally, cryptanalysis of optical security systems attempts to find original keys. Usually, by use of this kind of method, one can find a set of keys located close to the original keys in the key space. We call such a set the region of original key (ROK). For an optical encryption system in the Fresnel domain, such a strategy is ineffective since it needs to perform an exhaustive search to determine the system geometry or to solve an extremely large set of system equations. We propose to employ an alternative search strategy: to find a region of possible key (RPK). Since there is only one ROK for a cypher system but there are many RPKs, the probability to find a key in the RPK would be higher than in the ROK. Our analysis reveals that even a Fresnel-based encryption system has larger key space, but there are also serious security problems to be resolved.
NASA Astrophysics Data System (ADS)
Su, Yonggang; Tang, Chen; Chen, Xia; Li, Biyuan; Xu, Wenjun; Lei, Zhenkun
2017-01-01
We propose an image encryption scheme using chaotic phase masks and cascaded Fresnel transform holography based on a constrained optimization algorithm. In the proposed encryption scheme, the chaotic phase masks are generated by Henon map, and the initial conditions and parameters of Henon map serve as the main secret keys during the encryption and decryption process. With the help of multiple chaotic phase masks, the original image can be encrypted into the form of a hologram. The constrained optimization algorithm makes it possible to retrieve the original image from only single frame hologram. The use of chaotic phase masks makes the key management and transmission become very convenient. In addition, the geometric parameters of optical system serve as the additional keys, which can improve the security level of the proposed scheme. Comprehensive security analysis performed on the proposed encryption scheme demonstrates that the scheme has high resistance against various potential attacks. Moreover, the proposed encryption scheme can be used to encrypt video information. And simulations performed on a video in AVI format have also verified the feasibility of the scheme for video encryption.
The application of data encryption technology in computer network communication security
NASA Astrophysics Data System (ADS)
Gong, Lina; Zhang, Li; Zhang, Wei; Li, Xuhong; Wang, Xia; Pan, Wenwen
2017-04-01
With the rapid development of Intemet and the extensive application of computer technology, the security of information becomes more and more serious, and the information security technology with data encryption technology as the core has also been developed greatly. Data encryption technology not only can encrypt and decrypt data, but also can realize digital signature, authentication and authentication and other functions, thus ensuring the confidentiality, integrity and confirmation of data transmission over the network. In order to improve the security of data in network communication, in this paper, a hybrid encryption system is used to encrypt and decrypt the triple DES algorithm with high security, and the two keys are encrypted with RSA algorithm, thus ensuring the security of the triple DES key and solving the problem of key management; At the same time to realize digital signature using Java security software, to ensure data integrity and non-repudiation. Finally, the data encryption system is developed by Java language. The data encryption system is simple and effective, with good security and practicality.
Integrating end-to-end encryption and authentication technology into broadband networks
Pierson, L.G.
1995-11-01
BISDN services will involve the integration of high speed data, voice, and video functionality delivered via technology similar to Asynchronous Transfer Mode (ATM) switching and SONET optical transmission systems. Customers of BISDN services may need a variety of data authenticity and privacy assurances, via Asynchronous Transfer Mode (ATM) services Cryptographic methods can be used to assure authenticity and privacy, but are hard to scale for implementation at high speed. The incorporation of these methods into computer networks can severely impact functionality, reliability, and performance. While there are many design issues associated with the serving of public keys for authenticated signaling and for establishment of session cryptovariables, this paper is concerned with the impact of encryption itself on such communications once the signaling and setup have been completed. Network security protections should be carefully matched to the threats against which protection is desired. Even after eliminating unnecessary protections, the remaining customer-required network security protections can impose severe performance penalties. These penalties (further discussed below) usually involve increased communication processing for authentication or encryption, increased error rate, increased communication delay, and decreased reliability/availability. Protection measures involving encryption should be carefully engineered so as to impose the least performance, reliability, and functionality penalties, while achieving the required security protection. To study these trade-offs, a prototype encryptor/decryptor was developed. This effort demonstrated the viability of implementing certain encryption techniques in high speed networks. The research prototype processes ATM cells in a SONET OC-3 payload. This paper describes the functionality, reliability, security, and performance design trade-offs investigated with the prototype.
NASA Astrophysics Data System (ADS)
Cheremkhin, Pavel A.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Rostislav S.
2016-11-01
Applications of optical methods for encryption purposes have been attracting interest of researchers for decades. The most popular are coherent techniques such as double random phase encoding. Its main advantage is high security due to transformation of spectrum of image to be encrypted into white spectrum via use of first phase random mask which allows for encrypted images with white spectra. Downsides are necessity of using holographic registration scheme and speckle noise occurring due to coherent illumination. Elimination of these disadvantages is possible via usage of incoherent illumination. In this case, phase registration no longer matters, which means that there is no need for holographic setup, and speckle noise is gone. Recently, encryption of digital information in form of binary images has become quite popular. Advantages of using quick response (QR) code in capacity of data container for optical encryption include: 1) any data represented as QR code will have close to white (excluding zero spatial frequency) Fourier spectrum which have good overlapping with encryption key spectrum; 2) built-in algorithm for image scale and orientation correction which simplifies decoding of decrypted QR codes; 3) embedded error correction code allows for successful decryption of information even in case of partial corruption of decrypted image. Optical encryption of digital data in form QR codes using spatially incoherent illumination was experimentally implemented. Two liquid crystal spatial light modulators were used in experimental setup for QR code and encrypting kinoform imaging respectively. Decryption was conducted digitally. Successful decryption of encrypted QR codes is demonstrated.
[The key role of public health medical resident education for future public health challenges].
Costantino, Claudio; Cinquetti, Sandro; Garavelli, Elena; Marcantoni, Claudio; Murru, Claudia; Pieroni, Giovanni; Privitera, Gaetano; Ricciardi, Walter; Soncini, Francesco; Tedesco, Dario; Triassi, Maria; Vitale, Francesco; Campanella, Francesca
2014-01-01
The Italian Committee of medical residents in Hygiene, Preventive Medicine and Public Health is a member of the Italian Society of Hygiene, Preventive Medicine and Public Health with the aim of developing a network among Italian resident in public health and promoting the educational path improvement through comparisons and debates between postgraduate medical schools. In this perspective, during last years account has been taken of some essential topics concerning education of public health medical residents, which represent future health-care and public health experts. Cross-sectional researches were conducted among Italian public health medical residents (PHMRs) through self-administered and web-based questionnaires. Each questionnaire was previously validated by pilot studies conducted during the 46th National Conference of the Italian Society of Hygiene, Preventive Medicine and Public Health. Seventy percent of Italian PHMRs considered the actual length of Public Health postgraduate medical school excessively long, with regard to predetermined educational goals. Confirming this statement, 90% of respondents were inclined to a reduction from 5 to 4 years of postgraduate medical school length, established by Law Decree 104/2013. Seventy seven percent of surveyed PHMRs stand up for a rearrangement on a national setting of the access contest to postgraduate medical schools. Moreover 1/3 of Italian schools performed less than 75%of learning and qualifying activities specified in Ministerial Decree of August 2005. In particular, data analysis showed considerable differences among Italian postgraduate schools. Finally, in 2015 only four Italian Universities (Napoli Federico II, Palermo, Pavia, Roma Tor Vergata) provide for the Second Level Master qualify for the functions of occupational doctor. This offer makes available 60 positions against a request of over 200 future Public Health medical doctors who have shown interest in the Master. In Italy, after the
Design and Realisation of Chaotic Encryption Systems
NASA Astrophysics Data System (ADS)
Schwarz, Wolfgang; Falk, Thomas
2002-07-01
Chaotic signal transmission systems are often claimed to be secure by itself. Using a simple example it is shown, that this is not true and that exact design criteria have to be set up before starting the design of a chaotic encryption system. Then, beginning with statistical design objectives an information encryption system is systematically designed. The structure design leads to a controlled filter structure with overflow nonlinearity, the parameter design has to assure chaotic behaviour and mixing properties of the encoded signal. This defines the limits for the choice of the parameter set representing the key for the encryption. After developing the system structure the system is realized by electronic circuitry. Discrete and IC versions of the solution are presented. In order to prove that the system meets the design requirements experimental results are provided. It can be shown that in a n-th order system the statistical characteristics up to the n-th order of the output signal will not be affected by the input signal. The paper closes with some security estimates for the designed system.
A known-plaintext heuristic attack on the Fourier plane encryption algorithm
NASA Astrophysics Data System (ADS)
Gopinathan, Unnikrishnan; Monaghan, David S.; Naughton, Thomas J.; Sheridan, John T.
2006-04-01
The Fourier plane encryption algorithm is subjected to a known-plaintext attack. The simulated annealing heuristic algorithm is used to estimate the key, using a known plaintext-ciphertext pair, which decrypts the ciphertext with arbitrarily low error. The strength of the algorithm is tested by using this estimated key to decrypt a different ciphertext which was also encrypted using the same original key. We assume that the plaintext is amplitude-encoded real-valued image, and analyze only the mathematical algorithm rather than a real optical system that can be more secure. The Fourier plane encryption algorithm is found to be susceptible to a known-plaintext heuristic attack.
NASA Astrophysics Data System (ADS)
Tan, Ru-Chao; Lei, Tong; Zhao, Qing-Min; Gong, Li-Hua; Zhou, Zhi-Hong
2016-12-01
To improve the slow processing speed of the classical image encryption algorithms and enhance the security of the private color images, a new quantum color image encryption algorithm based on a hyper-chaotic system is proposed, in which the sequences generated by the Chen's hyper-chaotic system are scrambled and diffused with three components of the original color image. Sequentially, the quantum Fourier transform is exploited to fulfill the encryption. Numerical simulations show that the presented quantum color image encryption algorithm possesses large key space to resist illegal attacks, sensitive dependence on initial keys, uniform distribution of gray values for the encrypted image and weak correlation between two adjacent pixels in the cipher-image.
Rajput, Sudheesh K; Nishchal, Naveen K
2013-06-20
In this paper, an image encryption scheme based on polarized light encoding and a phase-truncation approach in the Fresnel transform domain is proposed. The phase-truncated data obtained by an asymmetric cryptosystem is encrypted and decrypted by using the concept of the Stokes-Mueller formalism. Image encryption based on polarization of light using Stokes-Mueller formalism has the main advantage over Jones vector formalism that it manipulates only intensity information, which is measurable. Thus any intensity information can be encrypted and decrypted using this scheme. The proposed method offers several advantages: (1) a lens-free setup, (2) flexibility in the encryption key design, (3) use of asymmetric keys, and (4) immunity against special attack. We present numerical simulation results for gray-scale and color images in support of the proposed security scheme. The performance measurement parameters relative error and correlation coefficient have been calculated to check the effectiveness of the scheme.
An asymmetric color image encryption method by using deduced gyrator transform
NASA Astrophysics Data System (ADS)
Yao, Lili; Yuan, Caojin; Qiang, Junjie; Feng, Shaotong; Nie, Shouping
2017-02-01
An encryption algorithm is proposed by using the properties of deduced gyrator transform (GT). After being transformed by the GT algorithm and multiplied by a phase distribution p*, the spectrum modulus of the input image is considered to be the encrypted image by further performing Fourier transformation. To resist the attack from iterative phase retrieval, the red, green and blue components of the input image is modulated by a random phase mask and then combined using convolution. The encryption result is real-valued, which is convenient for display, transmission and storage. In the decryption process, the three original color components can be recovered with decryption keys which are different from the encryption keys. An optoelectronic hybrid system for the encryption process is also presented. Computer simulations are presented to demonstrate its performance, and the security of the proposed system is analyzed as well.
An improved key agreement protocol based on chaos
NASA Astrophysics Data System (ADS)
Wang, Xingyuan; Zhao, Jianfeng
2010-12-01
Cryptography based on chaos theory has developed fast in the past few years, but most of the researches focus on secret key cryptography. There are few public key encryption algorithms and cryptographic protocols based on chaos, which are also of great importance for network security. We introduce an enhanced key agreement protocol based on Chebyshev chaotic map. Utilizing the semi-group property of Chebyshev polynomials, the proposed key exchange algorithm works like Diffie-Hellman algorithm. The improved protocol overcomes the drawbacks of several previously proposed chaotic key agreement protocols. Both analytical and experimental results show that it is effective and secure.
Lensless multiple-image optical encryption based on improved phase retrieval algorithm.
Huang, Jian-Ji; Hwang, Hone-Ene; Chen, Chun-Yuan; Chen, Ching-Mu
2012-05-01
A novel architecture of the optical multiple-image encryption based on the modified Gerchberg-Saxton algorithm (MGSA) by using cascading phase only functions (POFs) in the Fresnel transform (FrT) domain is presented. This proposed method can greatly increase the capacity of the system by avoiding the crosstalk, completely, between the encrypted target images. Each present stage encrypted target image is encoded as to a complex function by using the MGSA with constraining the encrypted target image of the previous stage. Not only the wavelength and position parameters in the FrT domain can be keys to increase system security, the created POFs are also served mutually as the encryption keys to decrypt target image from present stage into next stage in the cascaded scheme. Compared with a prior method [Appl. Opt.48, 2686-2692 (2009)], the main advantages of this proposed encryption system is that it does not need any transformative lenses and this makes it very efficient and easy to implement optically. Simulation results show that this proposed encryption system can successfully achieve the multiple-image encryption via fewer POFs, which is more advantageous in simpler implementation and efficiency than a prior method where each decryption stage requires two POFs to accomplish this task.
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.
Optical image encryption technique based on deterministic phase masks
NASA Astrophysics Data System (ADS)
Zamrani, Wiam; Ahouzi, Esmail; Lizana, Angel; Campos, Juan; Yzuel, María J.
2016-10-01
The double-random phase encoding (DRPE) scheme, which is based on a 4f optical correlator system, is considered as a reference for the optical encryption field. We propose a modification of the classical DRPE scheme based on the use of a class of structured phase masks, the deterministic phase masks. In particular, we propose to conduct the encryption process by using two deterministic phase masks, which are built from linear combinations of several subkeys. For the decryption step, the input image is retrieved by using the complex conjugate of the deterministic phase masks, which were set in the encryption process. This concept of structured masks gives rise to encryption-decryption keys which are smaller and more compact than those required in the classical DRPE. In addition, we show that our method significantly improves the tolerance of the DRPE method to shifts of the decrypting phase mask-when no shift is applied, it provides similar performance to the DRPE scheme in terms of encryption-decryption results. This enhanced tolerance to the shift, which is proven by providing numerical simulation results for grayscale and binary images, may relax the rigidity of an encryption-decryption experimental implementation setup. To evaluate the effectiveness of the described method, the mean-square-error and the peak signal-to-noise ratio between the input images and the recovered images are calculated. Different studies based on simulated data are also provided to highlight the suitability and robustness of the method when applied to the image encryption-decryption processes.
2007-11-02
Common Criteria for Information Technology Security Evaluation Department of Defense Public Key Infrastructure and Key Management ...for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and...Infrastructure and Key Management Infrastructure Token Protection Profile (Medium Reobustness) 5. FUNDING NUMBERS 6. AUTHOR(S) 7. PERFORMING ORGANIZATION
Formalizing GDOI Group Key Management Requirements in NPATRL
2001-01-01
Controller and Key Server ( GCKS ) to distribute keys to members of a group. Although it does not specify any mechanisms such as key hierarchies [2] for...soundness. GDOI uses three categories of keys. Category 1 keys are the pairwise keys shared between the GCKS and potential members. Category 2 keys are key...Phase 1, which is described in [7, 5]. Key-encryption keys and traffic-encryption keys are created by the GCKS . The GCKS distributes these keys to
Optical multiple-image encryption based on phase encoding algorithm in the Fresnel transform domain
NASA Astrophysics Data System (ADS)
Huang, Jian-Ji; Hwang, Hone-Ene; Chen, Chun-Yuan; Chen, Ching-Mu
2012-10-01
A novel method of the optical multiple-image encryption based on the modified Gerchberg-Saxton algorithm (MGSA) is presented. This proposed method with an architecture of two adjacent phase only functions (POFs) in the Fresnel transform (FrT) domain that can extremely increase capacity of system for completely avoiding the crosstalk between the decrypted images. Each encrypted target image is separately encoded into a POF by using the MGSA which is with constraining the encrypted target image. Each created POF is then added to a prescribed fixed POF composed of a proposed MGSA-based phase encoding algorithm. Not only the wavelength and multiple-position parameters in the FrT domain as keys to increase system security, the created POFs are also served mutually as the encryption keys to decrypt target image based on cascading two POFs scheme. Compared with prior methods [23,24], the main advantages of this proposed encryption system is that it does not need any transformative lenses and that makes it very efficient and easy to implement optically. Simulation results show that this proposed encryption system can successfully achieve the multiple-image encryption with multiple-position keys, which is more advantageous in security than previous work [24] for its decryption process with only two POFs keys to accomplish this task.
Optimal encryption of quantum bits
Boykin, P. Oscar; Roychowdhury, Vwani
2003-04-01
We show that 2n random classical bits are both necessary and sufficient for encrypting any unknown state of n quantum bits in an informationally secure manner. We also characterize the complete set of optimal protocols in terms of a set of unitary operations that comprise an orthonormal basis in a canonical inner product space. Moreover, a connection is made between quantum encryption and quantum teleportation that allows for a different proof of optimality of teleportation.
Helping Students Adapt to Computer-Based Encrypted Examinations
ERIC Educational Resources Information Center
Baker-Eveleth, Lori; Eveleth, Daniel M.; O'Neill, Michele; Stone, Robert W.
2006-01-01
The College of Business and Economics at the University of Idaho conducted a pilot study that used commercially available encryption software called Securexam to deliver computer-based examinations. A multi-step implementation procedure was developed, implemented, and then evaluated on the basis of what students viewed as valuable. Two key aspects…
Helping Students Adapt to Computer-Based Encrypted Examinations
ERIC Educational Resources Information Center
Baker-Eveleth, Lori; Eveleth, Daniel M.; O'Neill, Michele; Stone, Robert W.
2006-01-01
The College of Business and Economics at the University of Idaho conducted a pilot study that used commercially available encryption software called Securexam to deliver computer-based examinations. A multi-step implementation procedure was developed, implemented, and then evaluated on the basis of what students viewed as valuable. Two key aspects…
Scalable encryption using alpha rooting
NASA Astrophysics Data System (ADS)
Wharton, Eric J.; Panetta, Karen A.; Agaian, Sos S.
2008-04-01
Full and partial encryption methods are important for subscription based content providers, such as internet and cable TV pay channels. Providers need to be able to protect their products while at the same time being able to provide demonstrations to attract new customers without giving away the full value of the content. If an algorithm were introduced which could provide any level of full or partial encryption in a fast and cost effective manner, the applications to real-time commercial implementation would be numerous. In this paper, we present a novel application of alpha rooting, using it to achieve fast and straightforward scalable encryption with a single algorithm. We further present use of the measure of enhancement, the Logarithmic AME, to select optimal parameters for the partial encryption. When parameters are selected using the measure, the output image achieves a balance between protecting the important data in the image while still containing a good overall representation of the image. We will show results for this encryption method on a number of images, using histograms to evaluate the effectiveness of the encryption.
Pierson, L.G.; Witzke, E.L.
1999-01-01
This effort studied the integration of innovative methods of key management crypto synchronization, and key agility while scaling encryption speed. Viability of these methods for encryption of ATM cell payloads at the SONET OC- 192 data rate (10 Gb/s), and for operation at OC-48 rates (2.5 Gb/s) was shown. An SNL-Developed pipelined DES design was adapted for the encryption of ATM cells. A proof-of-principle prototype circuit board containing 11 Electronically Programmable Logic Devices (each holding the equivalent of 100,000 gates) was designed, built, and used to prototype a high speed encryptor.
Optical encryption/decryption of 8PSK signal using FWM-based modified XOR.
Zhang, Min; Cui, Yue; Zhan, Yueying; Zhang, Zhiguo; Chen, Xue
2015-09-01
A scheme for optical encryption/decryption of an eight-phase-shift keying (8PSK) signal is proposed, and this scheme applies modified optical XOR gates based on four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). Theoretical analyses and simulations are conducted. Both the performance and the parameter design of a 40-Gbit/s all-optical encryption/decryption system under various key parameters are studied. The results are useful for designing optical encryption/decryption for complex modulated signals.
Fast encryption of image data using chaotic Kolmogorov flows
NASA Astrophysics Data System (ADS)
Scharinger, Josef
1997-01-01
To guarantee security and privacy in image transmission and archival applications, adequate efficient bulk encryption techniques are necessary which are able to cope with the vast amounts of image data involved. Experience has shown that block-oriented symmetric product ciphers constitute an adequate design paradigm for resolving this task, since they can offer a very high level of security as well as very high encryption rates. In this contribution we introduce a new product cipher which encrypts large blocks of plain-text (images) by repeated intertwined application of substitution and permutation operations. While almost all of the current product ciphers used fixed (predefined) permutation operations on small data blocks, our approach involves parameterizable (keyed) permutations on large data blocks (whole images) induced by specific chaotic systems (Kolmogorov flows). By combining these highly unstable dynamics with an adaption of a very fast shift register based pseudo-random number generator we obtain a new class of computationally secure product ciphers which are firmly grounded on systems theoretic concepts, offering many features that make them superior to contemporary bulk encryption systems when aiming at efficient image data encryption.
Color image encryption based on gyrator transform and Arnold transform
NASA Astrophysics Data System (ADS)
Sui, Liansheng; Gao, Bo
2013-06-01
A color image encryption scheme using gyrator transform and Arnold transform is proposed, which has two security levels. In the first level, the color image is separated into three components: red, green and blue, which are normalized and scrambled using the Arnold transform. The green component is combined with the first random phase mask and transformed to an interim using the gyrator transform. The first random phase mask is generated with the sum of the blue component and a logistic map. Similarly, the red component is combined with the second random phase mask and transformed to three-channel-related data. The second random phase mask is generated with the sum of the phase of the interim and an asymmetrical tent map. In the second level, the three-channel-related data are scrambled again and combined with the third random phase mask generated with the sum of the previous chaotic maps, and then encrypted into a gray scale ciphertext. The encryption result has stationary white noise distribution and camouflage property to some extent. In the process of encryption and decryption, the rotation angle of gyrator transform, the iterative numbers of Arnold transform, the parameters of the chaotic map and generated accompanied phase function serve as encryption keys, and hence enhance the security of the system. Simulation results and security analysis are presented to confirm the security, validity and feasibility of the proposed scheme.
Encryption in TECB Mode: Modeling, Simulation and Synthesis
NASA Astrophysics Data System (ADS)
Reaz, M. B. I.; Ibrahimy, M. I.; Mohd-Yasin, F.; Wei, C. S.; Kamada, M.
The growth of the Internet as a vehicle for secure communication has resulted in Data Encryption Standard (DES) no longer capable of providing high-level security for data protection. Triple Data Encryption Standard (3DES) is a symmetric block cipher with 192 bits key proposed to further enhance DES. Many applications crave for the speed of a hardware encryption implementation while trying to preserve the flexibility and low cost of a software implementation. This project used single core module to implement encryption in Triple DES Electronic Code Book (TECB) mode, which was modeled using hardware description language VHDL. The architecture was mapped in Altera EPF10K100EFC484-1 and EP20K200EFC672-1X for performance investigations and resulted in achieving encryption rate of 102.56 Mbps, area utilization of 2111 logic cells (25%) and a higher maximum operating frequency of 78.59 MHz by implementing on the larger FPGA device EP20K200EFC672-1X. It also suggested that 3DES hardware was 2.4 times faster than its software counterpart.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-03
... Department of the Army Requirement for Commercial Users To Use Commercial Public Key Information (PKI... commercial accounts accessing transportation systems and applications to use a commercial PKI certificate or... commercial entities by the Surface Deployment and Distribution Command, the United States Department of...
A Training Framework for the Department of Defense Public Key Infrastructure
2001-09-01
and the growth of electronic commerce within the Department of Defense (DoD) has led to the development and implementation of the DoD Public Key...also grown within the Department of Defense. Electronic commerce and business to business transactions have become more commonplace and have
The End of "Keyes": Resegregation Trends and Achievement in Denver Public Schools
ERIC Educational Resources Information Center
Horn, Catherine L.; Kurlaender, Michal
2006-01-01
This report describes the academic achievement trends of students in Denver's elementary schools from 1994 to 2000. It begins with a brief introduction to the original 1973 Keyes decision and the path to its conclusion in 1995. It then presents a chronology of the standardized measures of academic achievement used by the Denver Public Schools and…
Management of PEM public key certificates using X.500 directory service: Some problems and solutions
Cheung, Terry C.
1993-08-01
Internet Privacy Enhanced Mail (PEM) provides security services to users of Internet electronic mail. While the prevalent PEM implementation uses a public key certificate-based strategy, certificates are mostly distributed vie e-mail exchanges, which raises several security and performance issues. This paper discusses some problems with this strategy, explores the relevant issues, and develops an approach to address them.
Optical stream-cipher-like system for image encryption based on Michelson interferometer.
Yang, Bing; Liu, Zhengjun; Wang, Bo; Zhang, Yan; Liu, Shutian
2011-01-31
A novel optical image encryption scheme based on interference is proposed. The original image is digitally encoded into one phase-only mask by employing an improved Gerchberg-Saxton phase retrieval algorithm together with another predefined random phase mask which serves as the encryption key. The decryption process can be implemented optically based on Michelson interferometer by using the same key. The scheme can be regarded as a stream-cipher-like encryption system, the encryption and decryption keys are the same, however the operations are different. The position coordinates and light wavelength can also be used as additional keys during the decryption. Numerical simulations have demonstrated the validity and robustness of the proposed method.
Public perceptions of key performance indicators of healthcare in Alberta, Canada.
Northcott, Herbert C; Harvey, Michael D
2012-06-01
To examine the relationship between public perceptions of key performance indicators assessing various aspects of the health-care system. Cross-sequential survey research. Annual telephone surveys of random samples of adult Albertans selected by random digit dialing and stratified according to age, sex and region (n = 4000 for each survey year). The survey questionnaires included single-item measures of key performance indicators to assess public perceptions of availability, accessibility, quality, outcome and satisfaction with healthcare. Cronbach's α and factor analysis were used to assess the relationship between key performance indicators focusing on the health-care system overall and on a recent interaction with the health-care system. The province of Alberta, Canada during the years 1996-2004. Four thousand adults randomly selected each survey year. Survey questions measuring public perceptions of healthcare availability, accessibility, quality, outcome and satisfaction with healthcare. Factor analysis identified two principal components with key performance indicators focusing on the health system overall loading most strongly on the first component and key performance indicators focusing on the most recent health-care encounter loading most strongly on the second component. Assessments of the quality of care most recently received, accessibility of that care and perceived outcome of care tended to be higher than the more general assessments of overall health system quality and accessibility. Assessments of specific health-care encounters and more general assessments of the overall health-care system, while related, nevertheless comprise separate dimensions for health-care evaluation.
NASA Astrophysics Data System (ADS)
Xi, Si-xing; Wang, Xiaolei; Sun, Xin; Chang, Shengjiang; Lin, Lie
2014-01-01
We propose a new method of image encryption using Fourier computer-generated hologram (CGH) in the encryption system of multiple Fresnel diffraction transforms with phase masks. The digital image to be encrypted is modulated by a series of three random-phase masks in Fresnel diffraction system and finally is transformed into a complex-amplitude image which is stationary white noise (in which the information is like stationary-white-noise). Because the complex-amplitude information is not easy to be directly saved, the binary real value Fourier CGH is applied to record it. Compared with the traditional double random-phase image encryption technology, this method adds new keys which enhance the image encryption security and the Fourier CGH greatly improves the antinoise performance.
Optical retrieval of encrypted digital holograms for secure real-time display.
Matoba, Osamu; Javidi, Bahram
2002-03-01
Secure data transmission by use of encrypted digital holograms and an optical retrieval system for secure real-time display are proposed. Original images are encrypted by a double-random phase encryption technique and then are recorded as digital holograms in a CCD, together with a reference plane wave. This digital hologram of the encrypted image can be transmitted to receivers via any conventional electronic or digital communication channels. The decryption key is also recorded as a digital hologram. At the receiver, the original image can be retrieved by an optical correlation-based reconstruction process. Both encryption and retrieval can be performed by all-optical means, and thus a real-time secure display can be implemented. We demonstrate the proposed system numerically and experimentally.
Fully phase-encrypted memory using cascaded extended fractional Fourier transform
NASA Astrophysics Data System (ADS)
Nishchal, Naveen Kumar; Joseph, Joby; Singh, Kehar
2004-08-01
In this paper, we implement a fully phase-encrypted memory system using cascaded extended fractional Fourier transform (FRT). We encrypt and decrypt a two-dimensional image obtained from an amplitude image. The full phase image to be encrypted is fractional Fourier transformed three times and random phase masks are placed in the two intermediate planes. Performing the FRT three times increases the key size, at an added complexity of one more lens. The encrypted image is holographically recorded in a photorefractive crystal and is then decrypted by generating through phase conjugation, the conjugate of the encrypted image. A lithium niobate crystal has been used as a phase contrast filter to reconstruct the decrypted phase image, alleviating the need of alignment in the Fourier plane making the system rugged.
Remote-sensing image encryption in hybrid domains
NASA Astrophysics Data System (ADS)
Zhang, Xiaoqiang; Zhu, Guiliang; Ma, Shilong
2012-04-01
Remote-sensing technology plays an important role in military and industrial fields. Remote-sensing image is the main means of acquiring information from satellites, which always contain some confidential information. To securely transmit and store remote-sensing images, we propose a new image encryption algorithm in hybrid domains. This algorithm makes full use of the advantages of image encryption in both spatial domain and transform domain. First, the low-pass subband coefficients of image DWT (discrete wavelet transform) decomposition are sorted by a PWLCM system in transform domain. Second, the image after IDWT (inverse discrete wavelet transform) reconstruction is diffused with 2D (two-dimensional) Logistic map and XOR operation in spatial domain. The experiment results and algorithm analyses show that the new algorithm possesses a large key space and can resist brute-force, statistical and differential attacks. Meanwhile, the proposed algorithm has the desirable encryption efficiency to satisfy requirements in practice.
Quantum image encryption based on restricted geometric and color transformations
NASA Astrophysics Data System (ADS)
Song, Xian-Hua; Wang, Shen; Abd El-Latif, Ahmed A.; Niu, Xia-Mu
2014-08-01
A novel encryption scheme for quantum images based on restricted geometric and color transformations is proposed. The new strategy comprises efficient permutation and diffusion properties for quantum image encryption. The core idea of the permutation stage is to scramble the codes of the pixel positions through restricted geometric transformations. Then, a new quantum diffusion operation is implemented on the permutated quantum image based on restricted color transformations. The encryption keys of the two stages are generated by two sensitive chaotic maps, which can ensure the security of the scheme. The final step, measurement, is built by the probabilistic model. Experiments conducted on statistical analysis demonstrate that significant improvements in the results are in favor of the proposed approach.
Cryptanalysis of an image encryption algorithm based on DNA encoding
NASA Astrophysics Data System (ADS)
Akhavan, A.; Samsudin, A.; Akhshani, A.
2017-10-01
Recently an image encryption algorithm based on DNA encoding and the Elliptic Curve Cryptography (ECC) is proposed. This paper aims to investigate the security the DNA-based image encryption algorithm and its resistance against chosen plaintext attack. The results of the analysis demonstrate that security of the algorithm mainly relies on one static shuffling step, with a simple confusion operation. In this study, a practical plain image recovery method is proposed, and it is shown that the images encrypted with the same key could easily be recovered using the suggested cryptanalysis method with as low as two chosen plain images. Also, a strategy to improve the security of the algorithm is presented in this paper.
Arbitrarily modulated beam for phase-only optical encryption
NASA Astrophysics Data System (ADS)
Chen, Wen; Chen, Xudong
2014-10-01
Optical encryption has attracted more and more attention recently due to its remarkable advantages, such as parallel processing and multiple-dimensional characteristics. In this paper, we propose to apply an arbitrarily modulated beam for phase-only optical encryption. In optical security systems, the plane wave is commonly used for the illumination, and unauthorized receivers may easily obtain or estimate the information related to the illumination beam. The proposed strategy with an arbitrarily modulated illumination beam can effectively enhance system security, since a beam modulation pattern (such as a pinhole-array pattern or a random phase-only pattern) can be considered an additional security key. The phase-only optical encryption is taken as an example for illustrating the validity of the proposed method; however it could be straightforward to apply the proposed strategy to other optical security systems.
Optical image encryption using Kronecker product and hybrid phase masks
NASA Astrophysics Data System (ADS)
Kumar, Ravi; Bhaduri, Basanta
2017-10-01
In this paper, we propose a new technique for security enhancement in optical image encryption system. In this technique we have used the Kronecker product of two random matrices along with the double random phase encoding (DRPE) scheme in the Fresnel domain for optical image encryption. The phase masks used here are different than the random masks used in conventional DRPE scheme. These hybrid phase masks are generated by using the combination of random phase masks and a secondary image. For encryption, the input image is first randomized and then the DRPE in the Fresnel domain is performed using the hybrid phase masks. Secondly, the Kronecker product of two random matrices is multiplied with the DRPE output to get the final encoded image for transmission. The proposed technique consists of more unknown keys for enhanced security and robust against various attacks. The simulation results along with effects under various attacks are presented in support of the proposed technique.
Asymmetric color image encryption based on singular value decomposition
NASA Astrophysics Data System (ADS)
Yao, Lili; Yuan, Caojin; Qiang, Junjie; Feng, Shaotong; Nie, Shouping
2017-02-01
A novel asymmetric color image encryption approach by using singular value decomposition (SVD) is proposed. The original color image is encrypted into a ciphertext shown as an indexed image by using the proposed method. The red, green and blue components of the color image are subsequently encoded into a complex function which is then separated into U, S and V parts by SVD. The data matrix of the ciphertext is obtained by multiplying orthogonal matrices U and V while implementing phase-truncation. Diagonal entries of the three diagonal matrices of the SVD results are abstracted and scrambling combined to construct the colormap of the ciphertext. Thus, the encrypted indexed image covers less space than the original image. For decryption, the original color image cannot be recovered without private keys which are obtained from phase-truncation and the orthogonality of V. Computer simulations are presented to evaluate the performance of the proposed algorithm. We also analyze the security of the proposed system.
Algorithms for Lightweight Key Exchange †
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
The Development of a Portable Hard Disk Encryption/Decryption System with a MEMS Coded Lock.
Zhang, Weiping; Chen, Wenyuan; Tang, Jian; Xu, Peng; Li, Yibin; Li, Shengyong
2009-01-01
In this paper, a novel portable hard-disk encryption/decryption system with a MEMS coded lock is presented, which can authenticate the user and provide the key for the AES encryption/decryption module. The portable hard-disk encryption/decryption system is composed of the authentication module, the USB portable hard-disk interface card, the ATA protocol command decoder module, the data encryption/decryption module, the cipher key management module, the MEMS coded lock controlling circuit module, the MEMS coded lock and the hard disk. The ATA protocol circuit, the MEMS control circuit and AES encryption/decryption circuit are designed and realized by FPGA(Field Programmable Gate Array). The MEMS coded lock with two couplers and two groups of counter-meshing-gears (CMGs) are fabricated by a LIGA-like process and precision engineering method. The whole prototype was fabricated and tested. The test results show that the user's password could be correctly discriminated by the MEMS coded lock, and the AES encryption module could get the key from the MEMS coded lock. Moreover, the data in the hard-disk could be encrypted or decrypted, and the read-write speed of the dataflow could reach 17 MB/s in Ultra DMA mode.
The Development of a Portable Hard Disk Encryption/Decryption System with a MEMS Coded Lock
Zhang, Weiping; Chen, Wenyuan; Tang, Jian; Xu, Peng; Li, Yibin; Li, Shengyong
2009-01-01
In this paper, a novel portable hard-disk encryption/decryption system with a MEMS coded lock is presented, which can authenticate the user and provide the key for the AES encryption/decryption module. The portable hard-disk encryption/decryption system is composed of the authentication module, the USB portable hard-disk interface card, the ATA protocol command decoder module, the data encryption/decryption module, the cipher key management module, the MEMS coded lock controlling circuit module, the MEMS coded lock and the hard disk. The ATA protocol circuit, the MEMS control circuit and AES encryption/decryption circuit are designed and realized by FPGA(Field Programmable Gate Array). The MEMS coded lock with two couplers and two groups of counter-meshing-gears (CMGs) are fabricated by a LIGA-like process and precision engineering method. The whole prototype was fabricated and tested. The test results show that the user's password could be correctly discriminated by the MEMS coded lock, and the AES encryption module could get the key from the MEMS coded lock. Moreover, the data in the hard-disk could be encrypted or decrypted, and the read-write speed of the dataflow could reach 17 MB/s in Ultra DMA mode. PMID:22291566
[Screening on key techniques used for surveillance and disposal of public health emergencies].
Zhu, Q R; Yang, L; Ma, H Y; Xie, W Q; Cong, L M; Xu, L W
2017-06-10
Objective: To explore the key techniques used for surveillance and disposal of infectious diseases, food poisoning and hospital infection to improve the ability of surveillance and disposal on public health emergency. Methods: Framework on surveillance and disposal of infectious diseases, food poisoning and hospital infection was set up, based on literature review and expert group discussion. Delphi method and technique for order preference by similarity to ideal solution comprehensive evaluation method were used for ordering preference by similarity, to screen key techniques set for surveillance and disposal of the above said events. Results: Framework to be used for selecting key techniques was designed, based on the classification of emergency events, processing cycle of emergency events and level of techniques. Twenty six public health experts were selected for a 2-round consultation, with their authority as 0.796. Ten key techniques with important significance for surveillance and disposal of infectious diseases, food poisoning and hospital infection were selected from each event. Among these key techniques, the early-warning system was recognized as the key technique, important for the surveillance and disposal of all three emergency events. Items as technology used for unknown pathogenic microorganism detection, personal protection, gene sequencing and tracing technology, microorganism molecular typing technology, nucleic acid detection technology etc. were the key techniques and need to develop for the surveillance and disposal of infectious diseases and iatrogenic infection. Data regarding key technologies on security and privacy, early warning and forecasting, field rapid detection were sorted out that all in need to improve the surveillance programs on disposal of infectious diseases and food poisoning. Data exchange appeared another key technique on infectious diseases, with toxin detection and other 5 techniques the key techniques for food poisoning
Photonic encryption : modeling and functional analysis of all optical logic.
Tang, Jason D.; Schroeppel, Richard Crabtree; Robertson, Perry J.
2004-10-01
With the build-out of large transport networks utilizing optical technologies, more and more capacity is being made available. Innovations in Dense Wave Division Multiplexing (DWDM) and the elimination of optical-electrical-optical conversions have brought on advances in communication speeds as we move into 10 Gigabit Ethernet and above. Of course, there is a need to encrypt data on these optical links as the data traverses public and private network backbones. Unfortunately, as the communications infrastructure becomes increasingly optical, advances in encryption (done electronically) have failed to keep up. This project examines the use of optical logic for implementing encryption in the photonic domain to achieve the requisite encryption rates. This paper documents the innovations and advances of work first detailed in 'Photonic Encryption using All Optical Logic,' [1]. A discussion of underlying concepts can be found in SAND2003-4474. In order to realize photonic encryption designs, technology developed for electrical logic circuits must be translated to the photonic regime. This paper examines S-SEED devices and how discrete logic elements can be interconnected and cascaded to form an optical circuit. Because there is no known software that can model these devices at a circuit level, the functionality of S-SEED devices in an optical circuit was modeled in PSpice. PSpice allows modeling of the macro characteristics of the devices in context of a logic element as opposed to device level computational modeling. By representing light intensity as voltage, 'black box' models are generated that accurately represent the intensity response and logic levels in both technologies. By modeling the behavior at the systems level, one can incorporate systems design tools and a simulation environment to aid in the overall functional design. Each black box model takes certain parameters (reflectance, intensity, input response), and models the optical ripple and time delay
Experimental protocol for packaging and encrypting multiple data
NASA Astrophysics Data System (ADS)
Fredy Barrera, John; Trejos, Sorayda; Tebaldi, Myrian; Torroba, Roberto
2013-05-01
We present a novel single optical packaging and encryption (SOPE) procedure for multiple inputs. This procedure is based on a merging of a 2f scheme with a digital holographic technique to achieve efficient handling of multiple data. Through the 2f system with a random phase mask attached in its input plane, and the holographic technique, we obtain each processed input. A posteriori filtering and repositioning protocol on each hologram followed by an addition of all processed data, allows storing these data to form a single package. The final package is digitally multiplied by a second random phase mask acting as an encryption mask. In this way, the final user receives only one encrypted information unit and a single key, instead of a conventional multiple-image collecting method and several keys. Processing of individual images is cast into an optimization problem. The proposed optimization aims to simplify the handling and recovery of images while packing all of them into a single unit. The decoding process does not have the usual cross-talk or noise problems involved in other methods, as filtering and repositioning precedes the encryption step. All data are recovered in just one step at the same time by applying a simple Fourier transform operation and the decoding key. The proposed protocol takes advantage of optical processing and the versatility of the digital format. Experiments have been conducted using a Mach-Zehnder interferometer. An application is subsequently demonstrated to illustrate the feasibility of the SOPE procedure.
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet
2017-02-01
A novel nonlinear image encryption scheme based on a fully phase nonzero-order joint transform correlator architecture (JTC) in the Gyrator domain (GD) is proposed. In this encryption scheme, the two non-overlapping data distributions of the input plane of the JTC are fully encoded in phase and this input plane is transformed using the Gyrator transform (GT); the intensity distribution captured in the GD represents a new definition of the joint Gyrator power distribution (JGPD). The JGPD is modified by two nonlinear operations with the purpose of retrieving the encrypted image, with enhancement of the decrypted signal quality and improvement of the overall security. There are three keys used in the encryption scheme, two random phase masks and the rotation angle of the GT, which are all necessary for a proper decryption. Decryption is highly sensitivity to changes of the rotation angle of the GT as well as to little changes in other parameters or keys. The proposed encryption scheme in the GD still preserves the shift-invariance properties originated in the JTC-based encryption in the Fourier domain. The proposed encryption scheme is more resistant to brute force attacks, chosen-plaintext attacks, known-plaintext attacks, and ciphertext-only attacks, as they have been introduced in the cryptanalysis of the JTC-based encryption system. Numerical results are presented and discussed in order to verify and analyze the feasibility and validity of the novel encryption-decryption scheme.
NASA Astrophysics Data System (ADS)
Zhang, Miao; Tong, Xiaojun
2017-07-01
This paper proposes a joint image encryption and compression scheme based on a new hyperchaotic system and curvelet transform. A new five-dimensional hyperchaotic system based on the Rabinovich system is presented. By means of the proposed hyperchaotic system, a new pseudorandom key stream generator is constructed. The algorithm adopts diffusion and confusion structure to perform encryption, which is based on the key stream generator and the proposed hyperchaotic system. The key sequence used for image encryption is relation to plain text. By means of the second generation curvelet transform, run-length coding, and Huffman coding, the image data are compressed. The joint operation of compression and encryption in a single process is performed. The security test results indicate the proposed methods have high security and good compression effect.
Testing a Variety of Encryption Technologies
Henson, T J
2001-04-09
Review and test speeds of various encryption technologies using Entrust Software. Multiple encryption algorithms are included in the product. Algorithms tested were IDEA, CAST, DES, and RC2. Test consisted of taking a 7.7 MB Word document file which included complex graphics and timing encryption, decryption and signing. Encryption is discussed in the GIAC Kickstart section: Information Security: The Big Picture--Part VI.
Nghiem, Nhung; Wilson, Nick; Genç, Murat; Blakely, Tony
2013-11-01
Pricing policies such as taxes and subsidies are important tools in preventing and controlling a range of threats to public health. This is particularly so in tobacco and alcohol control efforts and efforts to change dietary patterns and physical activity levels as a means of addressing increases in noncommunicable diseases. To understand the potential impact of pricing policies, it is critical to understand the nature of price elasticities for consumer products. For example, price elasticities are key parameters in models of any food tax or subsidy that aims to quantify health impacts and cost-effectiveness. We detail relevant terms and discuss key issues surrounding price elasticities to inform public health research and intervention studies.
Li, Jiguo
2014-01-01
Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature. PMID:24959606
Lu, Yang; Li, Jiguo
2014-01-01
Signcryption is a useful cryptographic primitive that achieves confidentiality and authentication in an efficient manner. As an extension of signcryption in certificate-based cryptography, certificate-based signcryption preserves the merits of certificate-based cryptography and signcryption simultaneously. In this paper, we present an improved security model of certificate-based signcryption that covers both public key replacement attack and insider security. We show that an existing certificate-based signcryption scheme is insecure in our model. We also propose a new certificate-based signcryption scheme that achieves security against both public key replacement attacks and insider attacks. We prove in the random oracle model that the proposed scheme is chosen-ciphertext secure and existentially unforgeable. Performance analysis shows that the proposed scheme outperforms all the previous certificate-based signcryption schemes in the literature.
Flear, Mark L
2016-03-01
The replacement of the European Union (EU) Clinical Trials Directive by the new Clinical Trials Regulation (CTR), which entered into force on 16 June 2014 but will not apply before 28 May 2016, provides an opportunity to review the legal and political context within which this important aspect of research law and policy sits and to reflect on the implications for public health. My aim in this article is to relate the context to the key purposes and aims of EU law and policy on clinical trials in order to explain and clarify its orientation. On that basis, I argue that the CTR and the changes it introduces to the law on clinical trials are part of the EU's continued focus on market optimisation. It is this focus that orients and directs the wider pharmaceutical development pipeline, but that undermines the achievement of key public health objectives.
Nghiem, Nhung; Genç, Murat; Blakely, Tony
2013-01-01
Pricing policies such as taxes and subsidies are important tools in preventing and controlling a range of threats to public health. This is particularly so in tobacco and alcohol control efforts and efforts to change dietary patterns and physical activity levels as a means of addressing increases in noncommunicable diseases. To understand the potential impact of pricing policies, it is critical to understand the nature of price elasticities for consumer products. For example, price elasticities are key parameters in models of any food tax or subsidy that aims to quantify health impacts and cost-effectiveness. We detail relevant terms and discuss key issues surrounding price elasticities to inform public health research and intervention studies. PMID:24028228
[Translational research in geriatrics? A plea based on current biomedical key publications].
Bollheimer, L C; Volkert, D; Bertsch, T; Bauer, J; Klucken, J; Sieber, C C; Büttner, R
2013-08-01
Contemporary geriatric research focuses mainly on observational clinical studies and epidemiological surveys and the translation of basic scientific results from biogerontology into a clinical context is often neglected. Following a definition of translational research the article gives an overview of recent key publications in experimental biogerontology with a special emphasis on their relevance for clinical geriatrics. The topics dealt with include age-induced loss of skeletal muscle (sarcopenia), the aging immune system (immunosenescence) and neurodegenerative disorders (Alzheimer's and Parkinson's disease).
Encrypting three-dimensional information system based on integral imaging and multiple chaotic maps
NASA Astrophysics Data System (ADS)
Xing, Yan; Wang, Qiong-Hua; Xiong, Zhao-Long; Deng, Huan
2016-02-01
An encrypting three-dimensional (3-D) information system based on integral imaging (II) and multiple chaotic maps is proposed. In the encrypting process, the elemental image array (EIA) which represents spatial and angular information of the real 3-D scene is picked up by a microlens array. Subsequently, R, G, and B color components decomposed by the EIA are encrypted using multiple chaotic maps. Finally, these three encrypted components are interwoven to obtain the cipher information. The decryption process implements the reverse operation of the encryption process for retrieving the high-quality 3-D images. Since the encrypted EIA has the data redundancy property due to II, and all parameters of the pickup part are the secret keys of the encrypting system, the system sensitivity on the changes of the plaintext and secret keys can be significantly improved. Moreover, the algorithm based on multiple chaotic maps can effectively enhance the security. A preliminary experiment is carried out, and the experimental results verify the effectiveness, robustness, and security of the proposed system.
Private genome analysis through homomorphic encryption
2015-01-01
Background The rapid development of genome sequencing technology allows researchers to access large genome datasets. However, outsourcing the data processing o the cloud poses high risks for personal privacy. The aim of this paper is to give a practical solution for this problem using homomorphic encryption. In our approach, all the computations can be performed in an untrusted cloud without requiring the decryption key or any interaction with the data owner, which preserves the privacy of genome data. Methods We present evaluation algorithms for secure computation of the minor allele frequencies and χ2 statistic in a genome-wide association studies setting. We also describe how to privately compute the Hamming distance and approximate Edit distance between encrypted DNA sequences. Finally, we compare performance details of using two practical homomorphic encryption schemes - the BGV scheme by Gentry, Halevi and Smart and the YASHE scheme by Bos, Lauter, Loftus and Naehrig. Results The approach with the YASHE scheme analyzes data from 400 people within about 2 seconds and picks a variant associated with disease from 311 spots. For another task, using the BGV scheme, it took about 65 seconds to securely compute the approximate Edit distance for DNA sequences of size 5K and figure out the differences between them. Conclusions The performance numbers for BGV are better than YASHE when homomorphically evaluating deep circuits (like the Hamming distance algorithm or approximate Edit distance algorithm). On the other hand, it is more efficient to use the YASHE scheme for a low-degree computation, such as minor allele frequencies or χ2 test statistic in a case-control study. PMID:26733152
A DES ASIC Suitable for Network Encryption at 10 Gbps and Beyond
Gass, Karl; Pierson, Lyndon G.; Robertson, Perry J.; Wilcox, D. Craig; Witzke, Edward L.
1999-04-30
The Sandia National Laboratories (SNL) Data Encryption Standard (DES) Application Specific Integrated Circuit (ASIC) is the fastest known implementation of the DES algorithm as defined in the Federal Information Processing Standards (FIPS) Publication 46-2. DES is used for protecting data by cryptographic means. The SNL DES ASIC, over 10 times faster than other currently available DES chips, is a high-speed, filly pipelined implementation offering encryption, decryption, unique key input, or algorithm bypassing on each clock cycle. Operating beyond 105 MHz on 64 bit words, this device is capable of data throughputs greater than 6.7 Billion bits per second (tester limited). Simulations predict proper operation up to 9.28 Billion bits per second. In low frequency, low data rate applications, the ASIC consumes less that one milliwatt of power. The device has features for passing control signals synchronized to throughput data. Three SNL DES ASICS may be easily cascaded to provide the much greater security of triple-key, triple-DES.
Pervez, Zeeshan; Ahmad, Mahmood; Khattak, Asad Masood; Ramzan, Naeem; Khan, Wajahat Ali
2017-01-01
Public cloud storage services are becoming prevalent and myriad data sharing, archiving and collaborative services have emerged which harness the pay-as-you-go business model of public cloud. To ensure privacy and confidentiality often encrypted data is outsourced to such services, which further complicates the process of accessing relevant data by using search queries. Search over encrypted data schemes solve this problem by exploiting cryptographic primitives and secure indexing to identify outsourced data that satisfy the search criteria. Almost all of these schemes rely on exact matching between the encrypted data and search criteria. A few schemes which extend the notion of exact matching to similarity based search, lack realism as those schemes rely on trusted third parties or due to increase storage and computational complexity. In this paper we propose Oblivious Similarity based Search ([Formula: see text]) for encrypted data. It enables authorized users to model their own encrypted search queries which are resilient to typographical errors. Unlike conventional methodologies, [Formula: see text] ranks the search results by using similarity measure offering a better search experience than exact matching. It utilizes encrypted bloom filter and probabilistic homomorphic encryption to enable authorized users to access relevant data without revealing results of search query evaluation process to the untrusted cloud service provider. Encrypted bloom filter based search enables [Formula: see text] to reduce search space to potentially relevant encrypted data avoiding unnecessary computation on public cloud. The efficacy of [Formula: see text] is evaluated on Google App Engine for various bloom filter lengths on different cloud configurations.
Public Health Preparedness Funding: Key Programs and Trends From 2001 to 2017.
Watson, Crystal R; Watson, Matthew; Sell, Tara Kirk
2017-09-01
To evaluate trends in funding over the past 16 years for key federal public health preparedness and response programs at the US Department of Health and Human Services, to improve understanding of federal funding history in this area, and to provide context for future resource allocation decisions for public health preparedness. In this 2017 analysis, we examined the funding history of key federal programs critical to public health preparedness by reviewing program budget data collected for our annual examination of federal funding for biodefense and health security programs since fiscal year (FY) 2001. State and local preparedness at the Centers for Disease Control and Prevention initially received $940 million in FY2002 and resulted in significant preparedness gains, but funding levels have since decreased by 31%. Similarly, the Hospital Preparedness Program within the Office of the Assistant Secretary for Preparedness and Response was funded at a high of $515 million in FY2003, but funding was reduced by 50%. Investments in medical countermeasure development and stockpiling remained relatively stable. The United States has made significant progress in preparing for disasters and advancing public health infrastructure. To enable continued advancement, federal funding commitments must be sustained.
Public Health Preparedness Funding: Key Programs and Trends From 2001 to 2017
Sell, Tara Kirk
2017-01-01
Objectives. To evaluate trends in funding over the past 16 years for key federal public health preparedness and response programs at the US Department of Health and Human Services, to improve understanding of federal funding history in this area, and to provide context for future resource allocation decisions for public health preparedness. Methods. In this 2017 analysis, we examined the funding history of key federal programs critical to public health preparedness by reviewing program budget data collected for our annual examination of federal funding for biodefense and health security programs since fiscal year (FY) 2001. Results. State and local preparedness at the Centers for Disease Control and Prevention initially received $940 million in FY2002 and resulted in significant preparedness gains, but funding levels have since decreased by 31%. Similarly, the Hospital Preparedness Program within the Office of the Assistant Secretary for Preparedness and Response was funded at a high of $515 million in FY2003, but funding was reduced by 50%. Investments in medical countermeasure development and stockpiling remained relatively stable. Conclusions. The United States has made significant progress in preparing for disasters and advancing public health infrastructure. To enable continued advancement, federal funding commitments must be sustained. PMID:28892451
Key Data Gaps Regarding the Public Health Issues Associated with Opioid Analgesics.
Schmidt, Teresa D; Haddox, J David; Nielsen, Alexandra E; Wakeland, Wayne; Fitzgerald, John
2015-10-01
Most pharmaceutical opioids are used to treat pain, and they have been demonstrated to be effective medications for many. Their abuse and misuse pose significant public health concerns in the USA. Research has provided much insight into the prevalence, scope, and drivers of opioid abuse, but a holistic understanding is limited by a lack of available data regarding key aspects of this public health problem. Twelve data gaps were revealed during the creation of a systems-level computer model of medical use, diversion, nonmedical use, and the adverse outcomes associated with opioid analgesics in the USA. Data specific to these gaps would enhance the validity and real-world applications of systems-level models of this public health problem and would increase understanding of the complex system in which use and abuse occur. This paper provides an overview of these gaps, argues for the importance of closing them, and provides specific recommendations for future data collection efforts.
Key Data Gaps Regarding the Public Health Issues Associated with Opioid Analgesics
Schmidt, Teresa D.; Haddox, J. David; Nielsen, Alexandra E.; Wakeland, Wayne; Fitzgerald, John
2014-01-01
Most pharmaceutical opioids are used to treat pain and they have been demonstrated to be effective medications for many. Their abuse and misuse pose significant public health concerns in the United States. Research has provided much insight into the prevalence, scope, and drivers of opioid abuse, but a holistic understanding is limited by a lack of available data regarding key aspects of this public health problem. Twelve data gaps were revealed during the creation of a systems-level computer model of medical use, diversion, nonmedical use, and the adverse outcomes associated with opioid analgesics in the United States. Data specific to these gaps would enhance the validity and real-world applications of systems-level models of this public health problem, and would increase understanding of the complex system in which use and abuse occur. This paper provides an overview of these gaps, argues for the importance of closing them, and provides specific recommendations for future data collection efforts. PMID:24554390
Double image encryption by using iterative random binary encoding in gyrator domains.
Liu, Zhengjun; Guo, Qing; Xu, Lie; Ahmad, Muhammad Ashfaq; Liu, Shutian
2010-05-24
We propose a double image encryption by using random binary encoding and gyrator transform. Two secret images are first regarded as the real part and imaginary part of complex function. Chaotic map is used for obtaining random binary matrix. The real part and imaginary part of complex function are exchanged under the control of random binary data. An iterative structure composed of the random binary encoding method is designed and employed for enhancing the security of encryption algorithm. The parameters in chaotic map and gyrator transform serve as the keys of this encryption scheme. Some numerical simulations have been made, to demonstrate the performance this algorithm.
A new image encryption algorithm based on logistic chaotic map with varying parameter.
Liu, Lingfeng; Miao, Suoxia
2016-01-01
In this paper, we proposed a new image encryption algorithm based on parameter-varied logistic chaotic map and dynamical algorithm. The parameter-varied logistic map can cure the weaknesses of logistic map and resist the phase space reconstruction attack. We use the parameter-varied logistic map to shuffle the plain image, and then use a dynamical algorithm to encrypt the image. We carry out several experiments, including Histogram analysis, information entropy analysis, sensitivity analysis, key space analysis, correlation analysis and computational complexity to evaluate its performances. The experiment results show that this algorithm is with high security and can be competitive for image encryption.
NASA Astrophysics Data System (ADS)
Wang, Yong-Ying; Wang, Yu-Rong; Wang, Yong; Li, Hui-Juan; Sun, Wen-Jia
2007-07-01
A new method of optical image encryption with binary Fourier transform computer-generated hologram (CGH) and pixel-scrambling technology is presented. In this method, the orders of the pixel scrambling, as well as the encrypted image, are used as the keys to decrypt the original image. Therefore, higher security is achieved. Furthermore, the encrypted image is binary, so it is easy to be fabricated and robust against noise and distortion. Computer simulation results are given to verify the feasibility of this method and its robustness against occlusion and additional noise.
Multichanneled puzzle-like encryption
NASA Astrophysics Data System (ADS)
Amaya, Dafne; Tebaldi, Myrian; Torroba, Roberto; Bolognini, Néstor
2008-07-01
In order to increase data security transmission we propose a multichanneled puzzle-like encryption method. The basic principle relies on the input information decomposition, in the same way as the pieces of a puzzle. Each decomposed part of the input object is encrypted separately in a 4 f double random phase mask architecture, by setting the optical parameters in a determined status. Each parameter set defines a channel. In order to retrieve the whole information it is necessary to properly decrypt and compose all channels. Computer simulations that confirm our proposal are presented.
Enhancement of utilization of encryption engine
Robertson, Robert J.; Witzke, Edward L.
2008-04-22
A method of enhancing throughput of a pipelined encryption/decryption engine for an encryption/decryption process has a predetermined number of stages and provides feedback around the stages (and of such an encryption/decryption engine) by receiving a source datablock for a given stage and encryption/decryption context identifier; indexing according to the encryption/decryption context identifier into a bank of initial variables to retrieve an initial variable for the source datablock; and generating an output datablock from the source datablock and its corresponding initial variable.
Ensemble of Chaotic and Naive Approaches for Performance Enhancement in Video Encryption
Chandrasekaran, Jeyamala; Thiruvengadam, S. J.
2015-01-01
Owing to the growth of high performance network technologies, multimedia applications over the Internet are increasing exponentially. Applications like video conferencing, video-on-demand, and pay-per-view depend upon encryption algorithms for providing confidentiality. Video communication is characterized by distinct features such as large volume, high redundancy between adjacent frames, video codec compliance, syntax compliance, and application specific requirements. Naive approaches for video encryption encrypt the entire video stream with conventional text based cryptographic algorithms. Although naive approaches are the most secure for video encryption, the computational cost associated with them is very high. This research work aims at enhancing the speed of naive approaches through chaos based S-box design. Chaotic equations are popularly known for randomness, extreme sensitivity to initial conditions, and ergodicity. The proposed methodology employs two-dimensional discrete Henon map for (i) generation of dynamic and key-dependent S-box that could be integrated with symmetric algorithms like Blowfish and Data Encryption Standard (DES) and (ii) generation of one-time keys for simple substitution ciphers. The proposed design is tested for randomness, nonlinearity, avalanche effect, bit independence criterion, and key sensitivity. Experimental results confirm that chaos based S-box design and key generation significantly reduce the computational cost of video encryption with no compromise in security. PMID:26550603
Ensemble of Chaotic and Naive Approaches for Performance Enhancement in Video Encryption.
Chandrasekaran, Jeyamala; Thiruvengadam, S J
2015-01-01
Owing to the growth of high performance network technologies, multimedia applications over the Internet are increasing exponentially. Applications like video conferencing, video-on-demand, and pay-per-view depend upon encryption algorithms for providing confidentiality. Video communication is characterized by distinct features such as large volume, high redundancy between adjacent frames, video codec compliance, syntax compliance, and application specific requirements. Naive approaches for video encryption encrypt the entire video stream with conventional text based cryptographic algorithms. Although naive approaches are the most secure for video encryption, the computational cost associated with them is very high. This research work aims at enhancing the speed of naive approaches through chaos based S-box design. Chaotic equations are popularly known for randomness, extreme sensitivity to initial conditions, and ergodicity. The proposed methodology employs two-dimensional discrete Henon map for (i) generation of dynamic and key-dependent S-box that could be integrated with symmetric algorithms like Blowfish and Data Encryption Standard (DES) and (ii) generation of one-time keys for simple substitution ciphers. The proposed design is tested for randomness, nonlinearity, avalanche effect, bit independence criterion, and key sensitivity. Experimental results confirm that chaos based S-box design and key generation significantly reduce the computational cost of video encryption with no compromise in security.
Optical image encryption based on a joint Fresnel transform correlator with double optical wedges.
Shen, Xueju; Dou, Shuaifeng; Lei, Ming; Chen, Yudan
2016-10-20
An optical cryptosystem based on the joint Fresnel transform correlator (JFTC) with double optical wedges is designed. The designed cryptosystem retains the two major advantages of JTC-based optical cryptosystems. First, the encrypted image is real-valued and therefore is easier to record and transmit. Second, the encryption process is simplified, since it doesn't require accurate alignment of optical elements or the generation of the complex conjugate of the key. Also, the designed optical cryptosystem can produce a decrypted image with higher quality than a JTC-based optical cryptosystem, because the original encrypted image is divided by the Fresnel transform power distribution of the key mask to generate the new encrypted image, which significantly reduces the noise during the decryption process. Simulation results showed that the correlation coefficient of the decrypted image and the original image can reach as large as 0.9819 after denoising and adequately selecting half-central interval a and encrypted image width w. Another improvement relative to JTC-based optical cryptosystems is that the attack resistibility gets enhanced due to the nonlinearity of the encryption process as well as the additional key parameter a, which enlarges the key space.
Fractional fourier domain encrypted holographic memory by use of an anamorphic optical system.
Unnikrishnan, G; Joseph, J; Singh, K
2001-01-10
We propose and demonstrate a fractional Fourier domain encrypted holographic memory using an anamorphic optical system. The encryption is done by use of two statistically independent random-phase codes in the fractional Fourier domain. If the two random-phase codes are statistically independent white sequences, the encrypted data are stationary white noise. We exploit the capability of an optical system to process information in two dimensions by using two different sets of parameters along the two orthogonal axes to encode the data. The fractional Fourier transform parameters along with the random-phase codes constitute the key to the encrypted data. The knowledge of the key is essential to the successful decryption of data. The decoding of the encoded data is done by use of phase conjugation. We present a few experimental results.
Chang, Hsuan T; Shui, J-W; Lin, K-P
2017-02-01
In this paper, a joint multiple-image encryption and multiplexing system, which utilizes both the nonnegative matrix factorization (NMF) scheme and digital holography, is proposed. A number of images are transformed into noise-like digital holograms, which are then decomposed into a defined number of basis images and a corresponding weighting matrix using the NMF scheme. The determined basis images are similar to the digital holograms and appear as noise-like patterns, which are then stored as encrypted data and serve as the lock in an encryption system. On the other hand, the column vectors in the weighting matrix serve as the keys for the corresponding plain images or the addresses of the multiplexed images. Both the increased uniformity of the column weighting factors and the parameters used in the digital holography enhance the security of the distributed keys. The experimental results show that the proposed method can successfully perform multiple-image encryption with high-level security.
Choice of optical system is critical for the security of double random phase encryption systems
NASA Astrophysics Data System (ADS)
Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Cassidy, Derek; Zhao, Liang; Ryle, James P.; Healy, John J.; Sheridan, John T.
2017-06-01
The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.
NASA Astrophysics Data System (ADS)
Hu, Yiqun; Xie, Xinwen; Liu, Xingbin; Zhou, Nanrun
2017-07-01
A novel quantum multi-image encryption algorithm based on iteration Arnold transform with parameters and image correlation decomposition is proposed, and a quantum realization of the iteration Arnold transform with parameters is designed. The corresponding low frequency images are obtained by performing 2-D discrete wavelet transform on each image respectively, and then the corresponding low frequency images are spliced randomly to one image. The new image is scrambled by the iteration Arnold transform with parameters, and the gray-level information of the scrambled image is encoded by quantum image correlation decomposition. For the encryption algorithm, the keys are iterative times, added parameters, classical binary and orthonormal basis states. The key space, the security and the computational complexity are analyzed, and all of the analyses show that the proposed encryption algorithm could encrypt multiple images simultaneously with lower computational complexity compared with its classical counterparts.
Asymmetric multiple-image encryption based on the cascaded fractional Fourier transform
NASA Astrophysics Data System (ADS)
Li, Yanbin; Zhang, Feng; Li, Yuanchao; Tao, Ran
2015-09-01
A multiple-image cryptosystem is proposed based on the cascaded fractional Fourier transform. During an encryption procedure, each of the original images is directly separated into two phase masks. A portion of the masks is subsequently modulated into an interim mask, which is encrypted into the ciphertext image; the others are used as the encryption keys. Using phase truncation in the fractional Fourier domain, one can use an asymmetric cryptosystem to produce a real-valued noise-like ciphertext, while a legal user can reconstruct all of the original images using a different group of phase masks. The encryption key is an indivisible part of the corresponding original image and is still useful during decryption. The proposed system has high resistance to various potential attacks, including the chosen-plaintext attack. Numerical simulations also demonstrate the security and feasibility of the proposed scheme.
Security enhancement of double-random phase encryption by iterative algorithm
NASA Astrophysics Data System (ADS)
Qian, Sheng-Xia; Li, Yongnan; Kong, Ling-Jun; Li, Si-Min; Ren, Zhi-Cheng; Tu, Chenghou; Wang, Hui-Tian
2014-08-01
We propose an approach to enhance the security of optical encryption based on double-random phase encryption in a 4f system. The phase key in the input plane of the 4f system is generated by the Yang-Gu algorithm to control the phase of the encrypted information in the output plane of the 4f system, until the phase in the output plane converges to a predesigned distribution. Only the amplitude of the encrypted information must be recorded as a ciphertext. The information, which needs to be transmitted, is greatly reduced. We can decrypt the ciphertext with the aid of the predesigned phase distribution and the phase key in the Fourier plane. Our approach can resist various attacks.
Secure Obfuscation for Encrypted Group Signatures
Fan, Hongfei; Liu, Qin
2015-01-01
In recent years, group signature techniques are widely used in constructing privacy-preserving security schemes for various information systems. However, conventional techniques keep the schemes secure only in normal black-box attack contexts. In other words, these schemes suppose that (the implementation of) the group signature generation algorithm is running in a platform that is perfectly protected from various intrusions and attacks. As a complementary to existing studies, how to generate group signatures securely in a more austere security context, such as a white-box attack context, is studied in this paper. We use obfuscation as an approach to acquire a higher level of security. Concretely, we introduce a special group signature functionality-an encrypted group signature, and then provide an obfuscator for the proposed functionality. A series of new security notions for both the functionality and its obfuscator has been introduced. The most important one is the average-case secure virtual black-box property w.r.t. dependent oracles and restricted dependent oracles which captures the requirement of protecting the output of the proposed obfuscator against collision attacks from group members. The security notions fit for many other specialized obfuscators, such as obfuscators for identity-based signatures, threshold signatures and key-insulated signatures. Finally, the correctness and security of the proposed obfuscator have been proven. Thereby, the obfuscated encrypted group signature functionality can be applied to variants of privacy-preserving security schemes and enhance the security level of these schemes. PMID:26167686
Symmetric weak ternary quantum homomorphic encryption schemes
NASA Astrophysics Data System (ADS)
Wang, Yuqi; She, Kun; Luo, Qingbin; Yang, Fan; Zhao, Chao
2016-03-01
Based on a ternary quantum logic circuit, four symmetric weak ternary quantum homomorphic encryption (QHE) schemes were proposed. First, for a one-qutrit rotation gate, a QHE scheme was constructed. Second, in view of the synthesis of a general 3 × 3 unitary transformation, another one-qutrit QHE scheme was proposed. Third, according to the one-qutrit scheme, the two-qutrit QHE scheme about generalized controlled X (GCX(m,n)) gate was constructed and further generalized to the n-qutrit unitary matrix case. Finally, the security of these schemes was analyzed in two respects. It can be concluded that the attacker can correctly guess the encryption key with a maximum probability pk = 1/33n, thus it can better protect the privacy of users’ data. Moreover, these schemes can be well integrated into the future quantum remote server architecture, and thus the computational security of the users’ private quantum information can be well protected in a distributed computing environment.
Discrete Logarithms in Finite Fields Some Algorithms for Computing New Public Key Cryptosystem
NASA Astrophysics Data System (ADS)
Trendafilov, Ivan D.; Durcheva, Mariana I.
2010-10-01
Let p be a prime, Fp be a finite field, g be a primitive element of Fp and let h be a nonzero element of Fp. The discrete logarithm problem (DLP) is the problem of finding that an exponent k for which gk≡h (mod p). The well-known problem of computing discrete logarithms has additional importance in recent years due to its applicability in cryptography. Several cryptographic systems would become insecure if an efficient discrete logarithm algorithm were discovered. In this paper are discused some known algorithms in this area. Most public key cryptosystems have been constructed based on abelian groups. Here we introduce how the discrete logarithm problem over a group can be seen as a special instance of an action by an abelian semigroup on finite set. The proposed new public key cryptosystem generalized the semigroup action problem due to Rosenlicht (see [8]) and shows how every semigroup action by an abelian semigroup gives rise to a Diffie-Hellman key exchange.
a Novel Algorithm for Image Encryption Based on Couple Chaotic Systems
NASA Astrophysics Data System (ADS)
Wang, Xing-Yuan; Wang, Tian
2012-12-01
In this paper, an image encryption algorithm based on couple multiple chaotic systems is presented. It made the one-dimensional Coupled Map Lattice (CML) formed by Skew Tent map as spatiotemporal chaotic system and made its output sequence as the initial value of logistic and meanwhile did iterative of specific times to get the final key sequence, and then did XOR operations with corresponding pixels to finish the encryption. Numerical analysis expresses that this algorithm has large enough space and high security.
Encrypted IP video communication system
NASA Astrophysics Data System (ADS)
Bogdan, Apetrechioaie; Luminiţa, Mateescu
2010-11-01
Digital video transmission is a permanent subject of development, research and improvement. This field of research has an exponentially growing market in civil, surveillance, security and military aplications. A lot of solutions: FPGA, ASIC, DSP have been used for this purpose. The paper presents the implementation of an encrypted, IP based, video communication system having a competitive performance/cost ratio .
Automated information extraction of key trial design elements from clinical trial publications.
de Bruijn, Berry; Carini, Simona; Kiritchenko, Svetlana; Martin, Joel; Sim, Ida
2008-11-06
Clinical trials are one of the most valuable sources of scientific evidence for improving the practice of medicine. The Trial Bank project aims to improve structured access to trial findings by including formalized trial information into a knowledge base. Manually extracting trial information from published articles is costly, but automated information extraction techniques can assist. The current study highlights a single architecture to extract a wide array of information elements from full-text publications of randomized clinical trials (RCTs). This architecture combines a text classifier with a weak regular expression matcher. We tested this two-stage architecture on 88 RCT reports from 5 leading medical journals, extracting 23 elements of key trial information such as eligibility rules, sample size, intervention, and outcome names. Results prove this to be a promising avenue to help critical appraisers, systematic reviewers, and curators quickly identify key information elements in published RCT articles.
Wang, Xiaogang; Zhao, Daomu; Chen, Yixiang
2014-08-10
We present a study about information disclosure in phase-truncation-based cryptosystems. The main information of the original image to be encoded can be obtained by using a decryption key in the worst case. The problem cannot be thoroughly solved by imaginary part truncating, keeping the encryption keys as private keys, or applying different phase keys for different plaintexts during each encryption process as well as the phase modulation in the frequency domain. In order to eliminate the risk of unintended information disclosure, we further propose a nonlinear spatial and spectral encoding technique using a random amplitude mask (RAM). The encryption process involving two security layers can be fully controlled by a RAM. The spatial encoding of the plaintext images and the simultaneous encryption of the plaintext images and the encryption key greatly enhance the security of system, avoiding several attacks that have cracked the phase-truncation-based cryptosystems. Besides, the hybrid encryption system retains the advantage of a trap door one-way function of phase truncation. Numerical results have demonstrated the feasibility and effectiveness of the proposed encryption algorithm.
Volumetric Light-field Encryption at the Microscopic Scale
NASA Astrophysics Data System (ADS)
Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu
2017-01-01
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.
Volumetric Light-field Encryption at the Microscopic Scale
Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C.; Sheridan, John T.; Jia, Shu
2017-01-01
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale. PMID:28059149
Masking property of quantum random cipher with phase mask encryption
NASA Astrophysics Data System (ADS)
Sohma, Masaki; Hirota, Osamu
2014-10-01
The security analysis of physical encryption protocol based on coherent pulse position modulation (CPPM) originated by Yuen is one of the most interesting topics in the study of cryptosystem with a security level beyond the Shannon limit. Although the implementation of CPPM scheme has certain difficulty, several methods have been proposed recently. This paper deals with the CPPM encryption in terms of symplectic transformation, which includes a phase mask encryption as a special example, and formulates a unified security analysis for such encryption schemes. Specifically, we give a lower bound of Eve's symbol error probability using reliability function theory to ensure that our proposed system exceeds the Shannon limit. Then we assume the secret key is given to Eve after her heterodyne measurement. Since this assumption means that Eve has a great advantage in the sense of the conventional cryptography, the lower bound of her error indeed ensures the security level beyond the Shannon limit. In addition, we show some numerical examples of the security performance.
A symmetrical image encryption scheme in wavelet and time domain
NASA Astrophysics Data System (ADS)
Luo, Yuling; Du, Minghui; Liu, Junxiu
2015-02-01
There has been an increasing concern for effective storages and secure transactions of multimedia information over the Internet. Then a great variety of encryption schemes have been proposed to ensure the information security while transmitting, but most of current approaches are designed to diffuse the data only in spatial domain which result in reducing storage efficiency. A lightweight image encryption strategy based on chaos is proposed in this paper. The encryption process is designed in transform domain. The original image is decomposed into approximation and detail components using integer wavelet transform (IWT); then as the more important component of the image, the approximation coefficients are diffused by secret keys generated from a spatiotemporal chaotic system followed by inverse IWT to construct the diffused image; finally a plain permutation is performed for diffusion image by the Logistic mapping in order to reduce the correlation between adjacent pixels further. Experimental results and performance analysis demonstrate the proposed scheme is an efficient, secure and robust encryption mechanism and it realizes effective coding compression to satisfy desirable storage.
Volumetric Light-field Encryption at the Microscopic Scale.
Li, Haoyu; Guo, Changliang; Muniraj, Inbarasan; Schroeder, Bryce C; Sheridan, John T; Jia, Shu
2017-01-06
We report a light-field based method that allows the optical encryption of three-dimensional (3D) volumetric information at the microscopic scale in a single 2D light-field image. The system consists of a microlens array and an array of random phase/amplitude masks. The method utilizes a wave optics model to account for the dominant diffraction effect at this new scale, and the system point-spread function (PSF) serves as the key for encryption and decryption. We successfully developed and demonstrated a deconvolution algorithm to retrieve both spatially multiplexed discrete data and continuous volumetric data from 2D light-field images. Showing that the method is practical for data transmission and storage, we obtained a faithful reconstruction of the 3D volumetric information from a digital copy of the encrypted light-field image. The method represents a new level of optical encryption, paving the way for broad industrial and biomedical applications in processing and securing 3D data at the microscopic scale.
Suldovsky, Brianne
2016-05-01
Despite mounting criticism, the deficit model remains an integral part of science communication research and practice. In this article, I advance three key factors that contribute to the idea of the public deficit in science communication, including the purpose of science communication, how communication processes and outcomes are conceptualized, and how science and scientific knowledge are defined. Affording science absolute epistemic privilege, I argue, is the most compelling factor contributing to the continued use of the deficit model. In addition, I contend that the deficit model plays a necessary, though not sufficient, role in science communication research and practice. Areas for future research are discussed.
NASA Astrophysics Data System (ADS)
Belazi, Akram; Abd El-Latif, Ahmed A.; Diaconu, Adrian-Viorel; Rhouma, Rhouma; Belghith, Safya
2017-01-01
In this paper, a new chaos-based partial image encryption scheme based on Substitution-boxes (S-box) constructed by chaotic system and Linear Fractional Transform (LFT) is proposed. It encrypts only the requisite parts of the sensitive information in Lifting-Wavelet Transform (LWT) frequency domain based on hybrid of chaotic maps and a new S-box. In the proposed encryption scheme, the characteristics of confusion and diffusion are accomplished in three phases: block permutation, substitution, and diffusion. Then, we used dynamic keys instead of fixed keys used in other approaches, to control the encryption process and make any attack impossible. The new S-box was constructed by mixing of chaotic map and LFT to insure the high confidentiality in the inner encryption of the proposed approach. In addition, the hybrid compound of S-box and chaotic systems strengthened the whole encryption performance and enlarged the key space required to resist the brute force attacks. Extensive experiments were conducted to evaluate the security and efficiency of the proposed approach. In comparison with previous schemes, the proposed cryptosystem scheme showed high performances and great potential for prominent prevalence in cryptographic applications.
Quantization-based semi-fragile public-key watermarking for secure image authentication
NASA Astrophysics Data System (ADS)
Schlauweg, Mathias; Proefrock, Dima; Palfner, Torsten; Mueller, Erika
2005-09-01
Authentication watermarking approaches can be classified into two kinds: fragile and semi-fragile. In contrast to the latter one, fragile watermarking does not tolerate modifications of any single bit of the watermarked data. Since the transmission of digital data often requires lossy compression, an authentication system should accept non-malicious modifications such as JPEG compression. Semi-fragile techniques aim to discriminate malicious manipulations from admissible manipulations. In our approach, we extract image content dependent information, which is hashed afterwards and encrypted using secure methods known from the classical cryptography. The image data is partitioned into nonoverlapping 4x4 pixel blocks in the spatial domain. The mean values of these blocks form n-dimensional vectors, which are quantized to the nearest lattice point neighbours. Based on the changed vector values, a hash is calculated and asymmetrically encrypted, resulting in a digital signature. Traditional dual subspace approaches divide the signal space into a region for signature generation and a region for signature embedding. To ensure the security of the whole image, we join the two subspaces. The vectors, where to embed the bits using quantization-based data hiding techniques, are predistorted and also used for the signature generation. Our scheme applies error correction coding to gain the robustness of the embedded signature to non-malicious distortions. A second quantization run finally embeds the signature.
Distributed Factorization Computation on Multiple Volunteered Mobile Resource to Break RSA Key
NASA Astrophysics Data System (ADS)
Jaya, I.; Hardi, S. M.; Tarigan, J. T.; Zamzami, E. M.; Sihombing, P.
2017-01-01
Similar to common asymmeric encryption, RSA can be cracked by usmg a series mathematical calculation. The private key used to decrypt the massage can be computed using the public key. However, finding the private key may require a massive amount of calculation. In this paper, we propose a method to perform a distributed computing to calculate RSA’s private key. The proposed method uses multiple volunteered mobile devices to contribute during the calculation process. Our objective is to demonstrate how the use of volunteered computing on mobile devices may be a feasible option to reduce the time required to break a weak RSA encryption and observe the behavior and running time of the application on mobile devices.
Encryption for Remote Control via Internet or Intranet
NASA Technical Reports Server (NTRS)
Lineberger, Lewis
2005-01-01
A data-communication protocol has been devised to enable secure, reliable remote control of processes and equipment via a collision-based network, while using minimal bandwidth and computation. The network could be the Internet or an intranet. Control is made secure by use of both a password and a dynamic key, which is sent transparently to a remote user by the controlled computer (that is, the computer, located at the site of the equipment or process to be controlled, that exerts direct control over the process). The protocol functions in the presence of network latency, overcomes errors caused by missed dynamic keys, and defeats attempts by unauthorized remote users to gain control. The protocol is not suitable for real-time control, but is well suited for applications in which control latencies up to about 0.5 second are acceptable. The encryption scheme involves the use of both a dynamic and a private key, without any additional overhead that would degrade performance. The dynamic key is embedded in the equipment- or process-monitor data packets sent out by the controlled computer: in other words, the dynamic key is a subset of the data in each such data packet. The controlled computer maintains a history of the last 3 to 5 data packets for use in decrypting incoming control commands. In addition, the controlled computer records a private key (password) that is given to the remote computer. The encrypted incoming command is permuted by both the dynamic and private key. A person who records the command data in a given packet for hostile purposes cannot use that packet after the public key expires (typically within 3 seconds). Even a person in possession of an unauthorized copy of the command/remote-display software cannot use that software in the absence of the password. The use of a dynamic key embedded in the outgoing data makes the central-processing unit overhead very small. The use of a National Instruments DataSocket(TradeMark) (or equivalent) protocol or
Encryption of color images using MSVD in DCST domain
NASA Astrophysics Data System (ADS)
Kumar, Manoj; Vaish, Ankita
2017-01-01
In this paper, a new image encryption and decryption algorithm based on Multiresolution Singular Value Decomposition (MSVD) and Discrete Cosine Stockwell Transform (DCST) is proposed. An original image is first transformed in DCST domain and then decomposed into four subbands using MSVD, all the four subbands are further decomposed into four subimages according to their indexing and masked by the parameters generated by MSVD. We have used number of bands of DCST, arrangement of MSVD subbands, arrangement of various subimages obtained from MSVD subbands, values and arrangement of a 4×4 matrix generated by MSVD and the arrangement of masked subimages as encryption and decryption keys. To ensure the correct decryption of encrypted image, it is indeed necessary to have correct knowledge of all keys in correct order along with their exact values. If all the keys are correct but a single key is wrong even though it would be almost impossible to guess the original image. The efficiency of proposed algorithm is evaluated by comparing it with some recent published works and it is evident from the experimental results and analysis that the proposed algorithm can transmit the images more securely and efficiently over the network.
Fast numerical generation and encryption of computer-generated Fresnel holograms.
Tsang, P W M; Poon, T-C; Cheung, K W K
2011-03-01
In the past two decades, generation and encryption of holographic images have been identified as two important areas of investigation in digital holography. The integration of these two technologies has enabled images to be encrypted with more dimensions of freedom on top of simply employing the encryption keys. Despite the moderate success attained to date, and the rapid advancement of computing technology in recent years, the heavy computation load involved in these two processes remains a major bottleneck in the evolution of the digital holography technology. To alleviate this problem, we have proposed a fast and economical solution which is capable of generating, and at the same time encrypting, holograms with numerical means. In our method, the hologram formation mechanism is decomposed into a pair of one-dimensional (1D) processes. In the first stage, a given three-dimensional (3D) scene is partitioned into a stack of uniformed spaced horizontal planes and converted into a set of hologram sublines. Next, the sublines are expanded to a hologram by convolving it with a 1D reference signal. To encrypt the hologram, the reference signal is first convolved with a key function in the form of a maximum length sequence (also known as MLS, or M-sequence). The use of a MLS has two advantages. First, an MLS is spectrally flat so that it will not jeopardize the frequency spectrum of the hologram. Second, the autocorrelation function of an MLS is close to a train of Kronecker delta function. As a result, the encrypted hologram can be decoded by correlating it with the same key that is adopted in the encoding process. Experimental results reveal that the proposed method can be applied to generate and encrypt holograms with a small number of computations. In addition, the encrypted hologram can be decoded and reconstructed to the original 3D scene with good fidelity. © 2010 Optical Society of America
Quantum-noise randomized data encryption for wavelength-division-multiplexed fiber-optic networks
Corndorf, Eric; Liang Chuang; Kanter, Gregory S.; Kumar, Prem; Yuen, Horace P.
2005-06-15
We demonstrate high-rate randomized data-encryption through optical fibers using the inherent quantum-measurement noise of coherent states of light. Specifically, we demonstrate 650 Mbit/s data encryption through a 10 Gbit/s data-bearing, in-line amplified 200-km-long line. In our protocol, legitimate users (who share a short secret key) communicate using an M-ry signal set while an attacker (who does not share the secret key) is forced to contend with the fundamental and irreducible quantum-measurement noise of coherent states. Implementations of our protocol using both polarization-encoded signal sets as well as polarization-insensitive phase-keyed signal sets are experimentally and theoretically evaluated. Different from the performance criteria for the cryptographic objective of key generation (quantum key-generation), one possible set of performance criteria for the cryptographic objective of data encryption is established and carefully considered.
Secure Data Aggregation with Fully Homomorphic Encryption in Large-Scale Wireless Sensor Networks.
Li, Xing; Chen, Dexin; Li, Chunyan; Wang, Liangmin
2015-07-03
With the rapid development of wireless communication technology, sensor technology, information acquisition and processing technology, sensor networks will finally have a deep influence on all aspects of people's lives. The battery resources of sensor nodes should be managed efficiently in order to prolong network lifetime in large-scale wireless sensor networks (LWSNs). Data aggregation represents an important method to remove redundancy as well as unnecessary data transmission and hence cut down the energy used in communication. As sensor nodes are deployed in hostile environments, the security of the sensitive information such as confidentiality and integrity should be considered. This paper proposes Fully homomorphic Encryption based Secure data Aggregation (FESA) in LWSNs which can protect end-to-end data confidentiality and support arbitrary aggregation operations over encrypted data. In addition, by utilizing message authentication codes (MACs), this scheme can also verify data integrity during data aggregation and forwarding processes so that false data can be detected as early as possible. Although the FHE increase the computation overhead due to its large public key size, simulation results show that it is implementable in LWSNs and performs well. Compared with other protocols, the transmitted data and network overhead are reduced in our scheme.
Secure Data Aggregation with Fully Homomorphic Encryption in Large-Scale Wireless Sensor Networks
Li, Xing; Chen, Dexin; Li, Chunyan; Wang, Liangmin
2015-01-01
With the rapid development of wireless communication technology, sensor technology, information acquisition and processing technology, sensor networks will finally have a deep influence on all aspects of people’s lives. The battery resources of sensor nodes should be managed efficiently in order to prolong network lifetime in large-scale wireless sensor networks (LWSNs). Data aggregation represents an important method to remove redundancy as well as unnecessary data transmission and hence cut down the energy used in communication. As sensor nodes are deployed in hostile environments, the security of the sensitive information such as confidentiality and integrity should be considered. This paper proposes Fully homomorphic Encryption based Secure data Aggregation (FESA) in LWSNs which can protect end-to-end data confidentiality and support arbitrary aggregation operations over encrypted data. In addition, by utilizing message authentication codes (MACs), this scheme can also verify data integrity during data aggregation and forwarding processes so that false data can be detected as early as possible. Although the FHE increase the computation overhead due to its large public key size, simulation results show that it is implementable in LWSNs and performs well. Compared with other protocols, the transmitted data and network overhead are reduced in our scheme. PMID:26151208
Novel Authentication of Monitoring Data Through the use of Secret and Public Cryptographic Keys
Benz, Jacob M.; Tolk, Keith; Tanner, Jennifer E.
2014-07-21
The Office of Nuclear Verification (ONV) is supporting the development of a piece of equipment to provide data authentication and protection for a suite of monitoring sensors as part of a larger effort to create an arms control technology toolkit. This device, currently called the Red Box, leverages the strengths of both secret and public cryptographic keys to authenticate, digitally sign, and pass along monitoring data to allow for host review, and redaction if necessary, without the loss of confidence in the authenticity of the data by the monitoring party. The design of the Red Box will allow for the addition and removal of monitoring equipment and can also verify that the data was collected by authentic monitoring equipment prior to signing the data and sending it to the host and for review. The host will then forward the data to the monitor for review and inspection. This paper will highlight the progress to date of the Red Box development, and will explain the novel method of leveraging both symmetric and asymmetric (secret and public key) cryptography to authenticate data within a warhead monitoring regime.
Global trade, public health, and health services: stakeholders' constructions of the key issues.
Waitzkin, Howard; Jasso-Aguilar, Rebeca; Landwehr, Angela; Mountain, Carolyn
2005-09-01
Focusing mainly on the United States and Latin America, we aimed to identify the constructions of social reality held by the major stakeholders participating in policy debates about global trade, public health, and health services. In a multi-method, qualitative design, we used three sources of data: research and archival literature, 1980-2004; interviews with key informants who represented major organizations participating in these debates, 2002-2004; and organizational reports, 1980-2004. We targeted several types of organizations: government agencies, international financial institutions (IFIs) and trade organizations, international health organizations, multinational corporations, and advocacy groups. Many governments in Latin America define health as a right and health services as a public good. Thus, the government bears responsibility for that right. In contrast, the US government's philosophy of free trade and promoting a market economy assumes that by expanding the private sector, improved economic conditions will improve overall health with a minimum government provision of health care. US government agencies also view promotion of global health as a means to serve US interests. IFIs have emphasized reforms that include reduction and privatization of public sector services. International health organizations have tended to adopt the policy perspectives of IFIs and trade organizations. Advocacy groups have emphasized the deleterious effects of international trade agreements on public health and health services. Organizational stakeholders hold widely divergent constructions of reality regarding trade, public health, and health services. Social constructions concerning trade and health reflect broad ideologies concerning the impacts of market processes. Such constructions manifest features of "creed," regarding the role of the market in advancing human purposes and meeting human needs. Differences in constructions of trade and health constrain policies to
An Improved Piecewise Linear Chaotic Map Based Image Encryption Algorithm
Hu, Yuping; Wang, Zhijian
2014-01-01
An image encryption algorithm based on improved piecewise linear chaotic map (MPWLCM) model was proposed. The algorithm uses the MPWLCM to permute and diffuse plain image simultaneously. Due to the sensitivity to initial key values, system parameters, and ergodicity in chaotic system, two pseudorandom sequences are designed and used in the processes of permutation and diffusion. The order of processing pixels is not in accordance with the index of pixels, but it is from beginning or end alternately. The cipher feedback was introduced in diffusion process. Test results and security analysis show that not only the scheme can achieve good encryption results but also its key space is large enough to resist against brute attack. PMID:24592159
An improved piecewise linear chaotic map based image encryption algorithm.
Hu, Yuping; Zhu, Congxu; Wang, Zhijian
2014-01-01
An image encryption algorithm based on improved piecewise linear chaotic map (MPWLCM) model was proposed. The algorithm uses the MPWLCM to permute and diffuse plain image simultaneously. Due to the sensitivity to initial key values, system parameters, and ergodicity in chaotic system, two pseudorandom sequences are designed and used in the processes of permutation and diffusion. The order of processing pixels is not in accordance with the index of pixels, but it is from beginning or end alternately. The cipher feedback was introduced in diffusion process. Test results and security analysis show that not only the scheme can achieve good encryption results but also its key space is large enough to resist against brute attack.
Raine, Kim D; Nykiforuk, Candace I J; Vu-Nguyen, Karen; Nieuwendyk, Laura M; VanSpronsen, Eric; Reed, Shandy; Wild, T Cameron
2014-11-01
As overweight and obesity is a risk factor for chronic diseases, the development of environmental and healthy public policy interventions across multiple sectors has been identified as a key strategy to address this issue. In 2009, a survey was developed to assess the attitudes and beliefs regarding health promotion principles, and the priority and acceptability of policy actions to prevent obesity and chronic diseases, among key policy influencers in Alberta and Manitoba, Canada. Surveys were mailed to 1,765 key influencers from five settings: provincial government, municipal government, school boards, print media companies, and workplaces with greater than 500 employees. A total of 236 surveys were completed with a response rate of 15.0%. Findings indicate nearly unanimous influencer support for individual-focused policy approaches and high support for some environmental policies. Restrictive environmental and economic policies received weakest support. Obesity was comparable to smoking with respect to perceptions as a societal responsibility versus a personal responsibility, boding well for the potential of environmental policy interventions for obesity prevention. This level of influencer support provides a platform for more evidence to be brokered to policy influencers about the effectiveness of environmental policy approaches to obesity prevention. © 2014 The Obesity Society.
Optical encryption using pseudorandom complex spatial modulation.
Sarkadi, Tamás; Koppa, Pál
2012-12-01
In this paper we propose a new (to our knowledge) complex spatial modulation method to encode data pages applicable in double random phase encryption (DRPE) to make the system more resistant to brute-force attack. The proposed modulation method uses data page pixels with random phase and amplitude values with the condition that the intensity of the interference of light from two adjacent pixels should correspond to the encoded information. A differential phase contrast technique is applied to recover the data page at the output of the system. We show that the proposed modulation method can enhance the robustness of the DRPE technique using point spread function analysis. Key space expansion is determined by numeric model calculations.
Public/private partners. Key factors in creating a strategic alliance for community health.
Nelson, J C; Rashid, H; Galvin, V G; Essien, J D; Levine, L M
1999-04-01
The rapidly evolving American health system creates economic and societal incentives for public and private health organizations to collaborate. Despite the apparent benefits of collaboration, there is a paucity of information available to help local agencies develop partnerships. This study, itself a collaboration between a school of public health (SPH) and a Georgia health district, was undertaken to identify critical factors necessary to successfully initiate and sustain a public/private community health collaboration. Professional staff at the SPH conducted 26 standardized interviews involving participants from Cobb and Douglas counties Boards of Health; Promina Northwest (now known as Wellstar), a not-for-profit health system; and community stakeholders. Content analysis of each interview question was performed and comparisons were made both within each group and across groups. Trends were identified in the following key areas: vision of health care for Cobb and Douglas counties, forces driving collaboration, strengths of each organization, critical negotiating issues, and potential community gain resulting from the partnership. A shared vision between potential collaborators facilitates communication regarding strategies to achieve common goals. A previous history of working together in limited capacities allowed the partners to develop trust and respect for one another prior to entering negotiations. These factors, when taken in conjunction with each organization's strong leadership and knowledge of the community, build a strong foundation for a successful partnership.
Double random phase encryption scheme to multiplex and simultaneous encode multiple images.
Alfalou, Ayman; Mansour, Ali
2009-11-01
Here we present a new approach of multiplexing and simultaneous encoding of target images. Our approach can enhance the encryption level of a classical double random phase (DRP) encryption system by adding a supplementary security layer. The new approach can be divided into two security layers. The first layer is called the multiplexing level, which consists in using iterative Fourier transformations along with several encryption key images. These latter can be a set of biometric images. At the second layer, we use a classical DRP system. The two layers enable us to encode several target images (multi-encryption) and to reduce, at the same time, the requested decoded information (transmitted or storage information).
Optical image encryption based on compressive sensing and chaos in the fractional Fourier domain
NASA Astrophysics Data System (ADS)
Liu, Xingbin; Mei, Wenbo; Du, Huiqian
2014-11-01
We propose a novel image encryption algorithm based on compressive sensing (CS) and chaos in the fractional Fourier domain. The original image is dimensionality reduction measured using CS. The measured values are then encrypted using chaotic-based double-random-phase encoding technique in the fractional Fourier transform domain. The measurement matrix and the random-phase masks used in the encryption process are formed from pseudo-random sequences generated by the chaotic map. In this proposed algorithm, the final result is compressed and encrypted. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys for distribution simultaneously. Numerical experiments verify the validity and security of the proposed algorithm.
Dual-channel in-line digital holographic double random phase encryption.
Das, Bhargab; Yelleswarapu, Chandra S; Rao, D V G L N
2012-10-01
We present a robust encryption method for the encoding of 2D/3D objects using digital holography and virtual optics. Using our recently developed dual-plane in-line digital holography technique, two in-line digital holograms are recorded at two different planes and are encrypted using two different double random phase encryption configurations, independently. The process of using two mutually exclusive encryption channels makes the system more robust against attacks since both the channels should be decrypted accurately in order to get a recognizable reconstruction. Results show that the reconstructed object is unrecognizable even when the portion of the correct phase keys used during decryption is close to 75%. The system is verified against blind decryptions by evaluating the SNR and MSE. Validation of the proposed method and sensitivities of the associated parameters are quantitatively analyzed and illustrated.
Multiple-image encryption scheme based on cascaded fractional Fourier transform.
Kong, Dezhao; Shen, Xueju; Xu, Qinzu; Xin, Wang; Guo, Haiqiong
2013-04-20
A multiple-image encryption scheme based on cascaded fractional Fourier transform is proposed. In the scheme, images are successively coded into the amplitude and phase of the input by cascading stages, which ends up with an encrypted image and a series of keys. The scheme takes full advantage of multikeys and the cascaded relationships of all stages, and it not only realizes image encryption but also achieves higher safety and more diverse applications. So multiuser authentication and hierarchical encryption are achieved. Numerical simulation verifies the feasibility of the method and demonstrates the security of the scheme and decryption characteristics. Finally, flexibility and variability of the scheme in application are discussed, and the simple photoelectric mixed devices to realize the scheme are proposed.
Xi, Sixing; Wang, Xiaolei; Song, Lipei; Zhu, Zhuqing; Zhu, Bowen; Huang, Shuai; Yu, Nana; Wang, Huaying
2017-04-03
Optical image encryption, especially double-random-phase-based, is of great interest in information security. In this work, we experimentally demonstrate the security and feasibility of optical image encryption with asymmetric double random phase and computer-generated hologram (CGH) by using spatial light modulator. First of all, the encrypted image modulated by asymmetric double random phase is numerically encoded into real-value CGH. Then, the encoded real-value CGH is loaded on the spatial light modulator and optically decrypted in self-designed experimental system. Experimental decryption results are in agreement with numerical calculations under the prober/mistaken phase keys condition. This optical decryption technology opens a window of optical encryption practical application and shows great potential for digital multimedia product copyright protection and holographic false trademark.
Dual-channel in-line digital holographic double random phase encryption
Das, Bhargab; Yelleswarapu, Chandra S; Rao, D V G L N
2012-01-01
We present a robust encryption method for the encoding of 2D/3D objects using digital holography and virtual optics. Using our recently developed dual-plane in-line digital holography technique, two in-line digital holograms are recorded at two different planes and are encrypted using two different double random phase encryption configurations, independently. The process of using two mutually exclusive encryption channels makes the system more robust against attacks since both the channels should be decrypted accurately in order to get a recognizable reconstruction. Results show that the reconstructed object is unrecognizable even when the portion of the correct phase keys used during decryption is close to 75%. The system is verified against blind decryptions by evaluating the SNR and MSE. Validation of the proposed method and sensitivities of the associated parameters are quantitatively analyzed and illustrated. PMID:23471012
NASA Astrophysics Data System (ADS)
Wang, Xiaogang; Zhao, Daomu
2012-10-01
We propose an optoelectronic image encryption and decryption technique based on coherent superposition principle and digital holography. With the help of a chaotic random phase mask (CRPM) that is generated by using logistic map, a real-valued primary image is encoded into a phase-only version and then recorded as an encoded hologram. As for multiple-image encryption, only one digital hologram is to be transmitted as the encrypted result by using the multiplexing technique changing the reference wave angle. The bifurcation parameters, the initial values for the logistic maps, the number of the removed elements and the reference wave parameters are kept and transmitted as private keys. Both the encryption and decryption processes can be implemented in opto-digital manner or fully digital manner. Simulation results are given for testing the feasibility of the proposed approach.
NASA Astrophysics Data System (ADS)
Zhong, Shenlu; Li, Mengjiao; Tang, Xiajie; He, Weiqing; Wang, Xiaogang
2017-01-01
A novel optical information verification and encryption method is proposed based on inference principle and phase retrieval with sparsity constraints. In this method, a target image is encrypted into two phase-only masks (POMs), which comprise sparse phase data used for verification. Both of the two POMs need to be authenticated before being applied for decrypting. The target image can be optically reconstructed when the two authenticated POMs are Fourier transformed and convolved by the correct decryption key, which is also generated in encryption process. No holographic scheme is involved in the proposed optical verification and encryption system and there is also no problem of information disclosure in the two authenticable POMs. Numerical simulation results demonstrate the validity and good performance of this new proposed method.
An improvement over an image encryption method based on total shuffling
NASA Astrophysics Data System (ADS)
Eslami, Ziba; Bakhshandeh, Atieh
2013-01-01
Confidentiality is an important issue in transmitting digital images over public networks such as the Internet. Image encryption is a useful solution to achieve confidentiality. Among existing encryption schemes, chaos-based approach has suggested fast, efficient and highly secure algorithms. Recently an efficient image encryption method based on chaos and permutation-diffusion architecture is suggested in [G. Zhang, Q. Liu, Opt. Commun. 284 (2011) 2775-2780]. However, the plain-text sensitivity, as reported by the authors, is not satisfying and it is recommended to iterate the algorithm more than twice to get a good ability to resist differential attack. The aim of this paper is to promote the plain-text sensitivity of their approach. As a result, the diffusion performance is significantly enhanced and the overall security of the image cryptosystem is improved. Results of various analyses and computer simulations confirm that the new algorithm has high security and is suitable for practical image encryption.
Fault tolerant channel-encrypting quantum dialogue against collective noise
NASA Astrophysics Data System (ADS)
Ye, TianYu
2015-04-01
In this paper, two fault tolerant channel-encrypting quantum dialogue (QD) protocols against collective noise are presented. One is against collective-dephasing noise, while the other is against collective-rotation noise. The decoherent-free states, each of which is composed of two physical qubits, act as traveling states combating collective noise. Einstein-Podolsky-Rosen pairs, which play the role of private quantum key, are securely shared between two participants over a collective-noise channel in advance. Through encryption and decryption with private quantum key, the initial state of each traveling two-photon logical qubit is privately shared between two participants. Due to quantum encryption sharing of the initial state of each traveling logical qubit, the issue of information leakage is overcome. The private quantum key can be repeatedly used after rotation as long as the rotation angle is properly chosen, making quantum resource economized. As a result, their information-theoretical efficiency is nearly up to 66.7%. The proposed QD protocols only need single-photon measurements rather than two-photon joint measurements for quantum measurements. Security analysis shows that an eavesdropper cannot obtain anything useful about secret messages during the dialogue process without being discovered. Furthermore, the proposed QD protocols can be implemented with current techniques in experiment.
Butterfly Encryption Scheme for Resource-Constrained Wireless Networks.
Sampangi, Raghav V; Sampalli, Srinivas
2015-09-15
Resource-constrained wireless networks are emerging networks such as Radio Frequency Identification (RFID) and Wireless Body Area Networks (WBAN) that might have restrictions on the available resources and the computations that can be performed. These emerging technologies are increasing in popularity, particularly in defence, anti-counterfeiting, logistics and medical applications, and in consumer applications with growing popularity of the Internet of Things. With communication over wireless channels, it is essential to focus attention on securing data. In this paper, we present an encryption scheme called Butterfly encryption scheme. We first discuss a seed update mechanism for pseudorandom number generators (PRNG), and employ this technique to generate keys and authentication parameters for resource-constrained wireless networks. Our scheme is lightweight, as in it requires less resource when implemented and offers high security through increased unpredictability, owing to continuously changing parameters. Our work focuses on accomplishing high security through simplicity and reuse. We evaluate our encryption scheme using simulation, key similarity assessment, key sequence randomness assessment, protocol analysis and security analysis.
Butterfly Encryption Scheme for Resource-Constrained Wireless Networks †
Sampangi, Raghav V.; Sampalli, Srinivas
2015-01-01
Resource-constrained wireless networks are emerging networks such as Radio Frequency Identification (RFID) and Wireless Body Area Networks (WBAN) that might have restrictions on the available resources and the computations that can be performed. These emerging technologies are increasing in popularity, particularly in defence, anti-counterfeiting, logistics and medical applications, and in consumer applications with growing popularity of the Internet of Things. With communication over wireless channels, it is essential to focus attention on securing data. In this paper, we present an encryption scheme called Butterfly encryption scheme. We first discuss a seed update mechanism for pseudorandom number generators (PRNG), and employ this technique to generate keys and authentication parameters for resource-constrained wireless networks. Our scheme is lightweight, as in it requires less resource when implemented and offers high security through increased unpredictability, owing to continuously changing parameters. Our work focuses on accomplishing high security through simplicity and reuse. We evaluate our encryption scheme using simulation, key similarity assessment, key sequence randomness assessment, protocol analysis and security analysis. PMID:26389899
Pure optical dynamical color encryption
NASA Astrophysics Data System (ADS)
Mosso, Fabian; Tebaldi, Myrian; Fredy Barrera, John; Bolognini, Néstor; Torroba, Roberto
2011-07-01
We introduce a way to encrypt-decrypt a color dynamical phenomenon using a pure optical alternative. We split the three basic chromatic channels composing the input, and then each channel is processed through a 4f encoding method and a theta modulation applied to the each encrypted frame in every channel. All frames for a single channel are multiplexed. The same phase mask is used to encode all the information. Unlike the usual procedure we do not multiplex the three chromatic channels into a single encoding media, because we want to decrypt the information in real time. Then, we send to the decoding station the phase mask and the three packages each one containing the multiplexing of a single channel. The end user synchronizes and decodes the information contained in the separate channels. Finally, the decoding information is conveyed together to bring the decoded dynamical color phenomenon in real-time. We present material that supports our concepts.
Pure optical dynamical color encryption.
Mosso, Fabian; Tebaldi, Myrian; Barrera, John Fredy; Bolognini, Néstor; Torroba, Roberto
2011-07-18
We introduce a way to encrypt-decrypt a color dynamical phenomenon using a pure optical alternative. We split the three basic chromatic channels composing the input, and then each channel is processed through a 4f encoding method and a theta modulation applied to the each encrypted frame in every channel. All frames for a single channel are multiplexed. The same phase mask is used to encode all the information. Unlike the usual procedure we do not multiplex the three chromatic channels into a single encoding media, because we want to decrypt the information in real time. Then, we send to the decoding station the phase mask and the three packages each one containing the multiplexing of a single channel. The end user synchronizes and decodes the information contained in the separate channels. Finally, the decoding information is conveyed together to bring the decoded dynamical color phenomenon in real-time. We present material that supports our concepts.
Image encryption with chaotic map and Arnold transform in the gyrator transform domains
NASA Astrophysics Data System (ADS)
Sang, Jun; Luo, Hongling; Zhao, Jun; Alam, Mohammad S.; Cai, Bin
2017-05-01
An image encryption method combing chaotic map and Arnold transform in the gyrator transform domains was proposed. Firstly, the original secret image is XOR-ed with a random binary sequence generated by a logistic map. Then, the gyrator transform is performed. Finally, the amplitude and phase of the gyrator transform are permutated by Arnold transform. The decryption procedure is the inverse operation of encryption. The secret keys used in the proposed method include the control parameter and the initial value of the logistic map, the rotation angle of the gyrator transform, and the transform number of the Arnold transform. Therefore, the key space is large, while the key data volume is small. The numerical simulation was conducted to demonstrate the effectiveness of the proposed method and the security analysis was performed in terms of the histogram of the encrypted image, the sensitiveness to the secret keys, decryption upon ciphertext loss, and resistance to the chosen-plaintext attack.
An enhanced sub-image encryption method
NASA Astrophysics Data System (ADS)
Wang, Xing-Yuan; Zhang, Ying-Qian; Liu, Lin-Tao
2016-11-01
Recently a parallel sub-image encryption method is proposed by Mirzaei et al., which is based on a total shuffling and parallel encryption algorithm. In this paper, we firstly show that the method can be attacked by chosen plaintext attack and then propose an enhanced sub-image algorithm, which can completely resist the chosen plaintext attack. Moreover, our improved algorithm can reduce the encryption time dramatically. The experimental results also prove that the improved encryption algorithm is secure enough. So the improved method can be used in image transmission system.
Takeda, Hiroshi; Matsumura, Yasushi; Nakagawa, Katsuhiko; Teratani, Tadamasa; Qiyan, Zhang; Kusuoka, Hideo; Matsuoka, Masami
2004-01-01
To share healthcare information and to promote cooperation among healthcare providers and customers (patients) under computerized network environment, a non-profit organization (NPO), named as OCHIS, was established at Osaka, Japan in 2003. Since security and confidentiality issues on the Internet have been major concerns in the OCHIS, the system has been based on healthcare public key infrastructure (HPKI), and found that there remained problems to be solved technically and operationally. An experimental study was conducted to elucidate the central and the local function in terms of a registration authority and a time stamp authority by contracting with the Ministry of Economics and Trading Industries in 2003. This paper describes the experimental design with NPO and the results of the study concerning message security and HPKI. The developed system has been operated practically in Osaka urban area.
Bollheimer, L C; Volkert, D; Bertsch, T; Sieber, C C; Büttner, R
2013-08-01
Biological aging means a time-dependent accumulation of changes to which a living organism is being exposed during its lifetime. Biological aging normally concurs with chronological aging the time frame of which is set by an upper limit, the lifespan (in humans approximately 120 years). New findings in experimental biogerontology are challenging both the dogma of irreversibility of biological aging and the preset species-specific limitations of life. The present overview first explains the general principle of rejuvenation and reversal of biological aging with paradigms from stem cell research. Secondly, recent key publications on artificial telomerase elongation and (alleged) lifespan enhancement by sirtuins and resveratrol will be discussed with an emphasis on the implications for (future) geriatric medicine.
Modular multiplication in GF(p) for public-key cryptography
NASA Astrophysics Data System (ADS)
Olszyna, Jakub
Modular multiplication forms the basis of modular exponentiation which is the core operation of the RSA cryptosystem. It is also present in many other cryptographic algorithms including those based on ECC and HECC. Hence, an efficient implementation of PKC relies on efficient implementation of modular multiplication. The paper presents a survey of most common algorithms for modular multiplication along with hardware architectures especially suitable for cryptographic applications in energy constrained environments. The motivation for studying low-power and areaefficient modular multiplication algorithms comes from enabling public-key security for ultra-low power devices that can perform under constrained environments like wireless sensor networks. Serial architectures for GF(p) are analyzed and presented. Finally proposed architectures are verified and compared according to the amount of power dissipated throughout the operation.
Deng, Xiaopeng; Zhao, Daomu
2011-11-01
A single-channel color image encryption is proposed based on the modified Gerchberg-Saxton algorithm (MGSA) and mutual encoding in the Fresnel domain. Similar to the double random phase encoding (DRPE), this encryption scheme also employs a pair of phase-only functions (POFs) as encryption keys. But the two POFs are generated by the use of the MGSA rather than a random function generator. In the encryption process, only one color component is needed to be encrypted when these POFs are mutually served as the second encryption keys. As a result, a more compact and simple color encryption system based on one-time-pad, enabling only one gray cipheretext to be recorded and transmitted when holographic recording is used, is obtained. Moreover, the optical setup is lensless, thus easy to be implemented and the system parameters and wavelength can be served as additional keys to further enhance the security of the system. The feasibility and effectiveness of the proposed method are demonstrated by numerical results.
Novel Image Encryption Scheme Based on Chebyshev Polynomial and Duffing Map
2014-01-01
We present a novel image encryption algorithm using Chebyshev polynomial based on permutation and substitution and Duffing map based on substitution. Comprehensive security analysis has been performed on the designed scheme using key space analysis, visual testing, histogram analysis, information entropy calculation, correlation coefficient analysis, differential analysis, key sensitivity test, and speed test. The study demonstrates that the proposed image encryption algorithm shows advantages of more than 10113 key space and desirable level of security based on the good statistical results and theoretical arguments. PMID:25143970
The construction of a public key infrastructure for healthcare information networks in Japan.
Sakamoto, N
2001-01-01
The digital signature is a key technology in the forthcoming Internet society for electronic healthcare as well as for electronic commerce. Efficient exchanges of authorized information with a digital signature in healthcare information networks require a construction of a public key infrastructure (PKI). In order to introduce a PKI to healthcare information networks in Japan, we proposed a development of a user authentication system based on a PKI for user management, user authentication and privilege management of healthcare information systems. In this paper, we describe the design of the user authentication system and its implementation. The user authentication system provides a certification authority service and a privilege management service while it is comprised of a user authentication client and user authentication serves. It is designed on a basis of an X.509 PKI and is implemented with using OpenSSL and OpenLDAP. It was incorporated into the financial information management system for the national university hospitals and has been successfully working for about one year. The hospitals plan to use it as a user authentication method for their whole healthcare information systems. One implementation of the system is free to the national university hospitals with permission of the Japanese Ministry of Education, Culture, Sports, Science and Technology. Another implementation is open to the other healthcare institutes by support of the Medical Information System Development Center (MEDIS-DC). We are moving forward to a nation-wide construction of a PKI for healthcare information networks based on it.
Mapping the key issues shaping the landscape of global public health.
Ager, Alastair; Yu, Gary; Hermosilla, Sabrina
2012-01-01
A survey of global health experts attending an invited meeting provided a means to map key issues perceived to be shaping emerging global public health agendas. Eighty-five participants proposed three major issues likely to have the most significant impact on the field of global health in the coming years. Six raters grouped the resultant items, with multi-dimensional scaling (MDS) analysis producing a composite two-dimensional map depicting the overall patterning of items. Thematic clusters were incorporated within four major domains: changing health and prevention needs (15% of items), globalisation and global health governance (33% of items), transforming health systems (30% of items) and innovations in science and technology (7% of items). The remaining 15% of items addressed forms of environmental change. The distribution of items across domains was not significantly influenced by the current professional role of participants, their current location in the 'global north' or 'global south' or their region of focus (although the latter approached threshold significance). The constraints on interpretation imposed by the biases influencing participation in the survey are noted. However, the exercise suggests the potential for coherently defining shared agendas for diverse stakeholders to address emerging priorities. The closer integration of environmental concerns with other global public issues is clearly warranted.
Key roles of government in genomics and proteomics: a public health perspective.
Noonan, Allan S
2002-01-01
This paper is based on the presentation of Dr. Allan Noonan at the third biennial Asan-Harvard Medical International Symposium on "Genomics and Proteomics: Impact on Medicine and Health" that took place in Seoul, Korea, July 3-4, 2001. Dr. Noonan is a senior advisor to the Surgeon General of the United States and was representing the then Surgeon General, Dr. David Satcher. In this final presentation of the symposium, Dr. Noonan reviews the key roles of government in US health care and discusses several areas where genomic- and proteomic-based information will necessitate changes in the functions of public health. In particular, Dr. Noonan discusses the need for appropriate training to meet the challenges of the genomic future; for sensitivity in the development of policies to address the ethical, legal, and social implications of genomic information; and for dissemination of genomic information to both the professionals and the public. Dr. Noonan concludes with a vision of the genomic future of the next 30 years and a reiteration of the need for partnership among health professionals, educators, and social services professionals.
Analysis of common attacks in public-key cryptosystems based on low-density parity-check codes
NASA Astrophysics Data System (ADS)
Skantzos, N. S.; Saad, D.; Kabashima, Y.
2003-11-01
We analyze the security and reliability of a recently proposed class of public-key cryptosystems against attacks by unauthorized parties who have acquired partial knowledge of one or more of the private key components and/or of the plaintext. Phase diagrams are presented, showing critical partial knowledge levels required for unauthorized decryption.
Time Delay Measurements of Key Generation Process on Smart Cards
2015-03-01
defines, compares, and contrasts two algorithms: Rivest-Shamir-Adleman (RSA) and Elliptic Curve Cryptography (ECC), and then provides test data for...cards, elliptic curve cryptography , mobile technology, encryption algorithms, certification key PAGES processes 17. SECURITY 18. SECURITY... Cryptography (ECC), and then provides test data for encryption algorithms tested on particular certification key processes in an attempt to show that the
ERIC Educational Resources Information Center
Biesma, R. G.; Pavlova, M.; van Merode, G. G.; Groot, W.
2007-01-01
This paper uses an experimental design to estimate preferences of employers for key competencies during the transition from initial education to the labor market. The study is restricted to employers of entry-level academic graduates entering public health organizations in the Netherlands. Given the changing and complex demands in public health,…
ERIC Educational Resources Information Center
Young, Charles Keith
2010-01-01
Owing to the significant structural changes that have occurred in the global marketplace over the past 2 decades, a corresponding increase of public-private partnerships have been established among the business sector, local governments, and public community colleges. This qualitative project sought to identify and substantiate key elements that…
ERIC Educational Resources Information Center
Young, Charles Keith
2010-01-01
Owing to the significant structural changes that have occurred in the global marketplace over the past 2 decades, a corresponding increase of public-private partnerships have been established among the business sector, local governments, and public community colleges. This qualitative project sought to identify and substantiate key elements that…
A novel stream encryption scheme with avalanche effect
NASA Astrophysics Data System (ADS)
Min, Lequan; Chen, Guanrong
2013-11-01
This paper proposes a novel stream encryption scheme with avalanche effect (SESAE). Using this scheme and an ideal pseudorandom number generator (PRNG) to generate d-bit segment binary key streams, one can encrypt a plaintext such that by using any key stream generated from a different seed to decrypt the ciphertext, the decrypted plaintext will become an avalanche-like text which has 2 d - 1 consecutive one's with a high probability. As a cost, the required bits of the ciphertext are d times those of the plaintext. A corresponding avalanche-type encryption theorem is established. Two chaotic 12-bit segment PRNGs are designed. A generalized FIPS140 test and SESAE test for the two chaotic PRNGs, RC4 12-bit segment PRNG and 12-bit segment Matlab PRNG are implemented. The SESAE tests for 16-bit segment PRNGs are also compared. The results suggest that those PRNGs are able to generate the SESAEs which are similar to those generated via ideal PRNGs.
Image encryption based on synchronization of fractional chaotic systems
NASA Astrophysics Data System (ADS)
Xu, Yong; Wang, Hua; Li, Yongge; Pei, Bin
2014-10-01
This paper deals with a synchronization scheme for two fractional chaotic systems which is applied in image encryption. Based on Pecora and Carroll (PC) synchronization, fractional-order Lorenz-like system forms a master-slave configuration, and the sufficient conditions are derived to realize synchronization between these two systems via the Laplace transformation theory. An image encryption algorithm is introduced where the original image is encoded by a nonlinear function of a fractional chaotic state. Simulation results show that the original image is well masked in the cipher texts and recovered successfully through chaotic signals. Further, the cryptanalysis is conducted in detail through histogram, information entropy, key space and sensitivity to verify the high security.
Binary-tree encryption strategy for optical multiple-image encryption.
Yi, Jiawang; Tan, Guanzheng
2016-07-10
In traditional optical multiple-image encryption schemes, different images typically have almost the same encryption or decryption process. Provided that an attacker manages to correctly decrypt some image, the conventional attacks upon other images are much easier to be made. In this paper, a binary-tree encryption strategy for multiple images is proposed to resist the attacks in this case. The encryption schemes produced by this strategy can not only increase the security of multiple-image encryption, but also realize an authority management with high security among the users sharing a cipher image. For a simulation test, we devise a basic binary-tree encryption scheme, whose encryption nodes are based on an asymmetric double random phase encoding in the gyrator domain. The favorable simulation results about the tested scheme can testify to the feasibility of the strategy.
Compressive optical image encryption with two-step-only quadrature phase-shifting digital holography
NASA Astrophysics Data System (ADS)
Li, Jun; Li, Hongbing; Li, Jiaosheng; Pan, Yangyang; Li, Rong
2015-06-01
An image encryption method which combines two-step-only quadrature phase-shifting digital holography with compressive sensing (CS) has been proposed in the fully optical domain. An object image is firstly encrypted to two on-axis quadrature-phase holograms using the two random phase masks in the Mach-Zehnder interferometer. Then, the two encrypted images are highly compressed to a one-dimensional signal using the single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the two compressive encrypted holograms are exactly reconstructed from much less than the Nyquist sampling number of observations by solving an optimization problem, and the original image can be decrypted with only two reconstructed holograms and the correct keys. This method largely decreases holograms data volume for the current optical image encryption system, and it is also suitable for some special optical imaging cases such as different wavelengths imaging and weak light imaging. Numerical simulation is performed to demonstrate the feasibility and validity of this novel image encryption method.
Multiple-image encryption based on compressive holography using a multiple-beam interferometer
NASA Astrophysics Data System (ADS)
Wan, Yuhong; Wu, Fan; Yang, Jinghuan; Man, Tianlong
2015-05-01
Multiple-image encryption techniques not only improve the encryption capacity but also facilitate the transmission and storage of the ciphertext. We present a new method of multiple-image encryption based on compressive holography with enhanced data security using a multiple-beam interferometer. By modifying the Mach-Zehnder interferometer, the interference of multiple object beams and unique reference beam is implemented for encrypting multiple images simultaneously into one hologram. The original images modulated with the random phase masks are put in different positions with different distance away from the CCD camera. Each image plays the role of secret key for other images to realize the mutual encryption. Four-step phase shifting technique is combined with the holographic recording. The holographic recording is treated as a compressive sensing process, thus the decryption process is inverted as a minimization problem and the two-step iterative shrinkage/thresholding algorithm (TwIST) is employed to solve this optimization problem. The simulated results about multiple binary and grayscale images encryption are demonstrated to verify the validity and robustness of our proposed method.
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Torres, Yezid; Millán, María S.; Pérez-Cabré, Elisabet
2014-12-01
We propose a generalization of the encryption system based on double random phase encoding (DRPE) and a joint transform correlator (JTC), from the Fourier domain to the fractional Fourier domain (FrFD) by using the fractional Fourier operators, such as the fractional Fourier transform (FrFT), fractional traslation, fractional convolution and fractional correlation. Image encryption systems based on a JTC architecture in the FrFD usually produce low quality decrypted images. In this work, we present two approaches to improve the quality of the decrypted images, which are based on nonlinear processing applied to the encrypted function (that contains the joint fractional power spectrum, JFPS) and the nonzero-order JTC in the FrFD. When the two approaches are combined, the quality of the decrypted image is higher. In addition to the advantages introduced by the implementation of the DRPE using a JTC, we demonstrate that the proposed encryption system in the FrFD preserves the shift-invariance property of the JTC-based encryption system in the Fourier domain, with respect to the lateral displacement of both the key random mask in the decryption process and the retrieval of the primary image. The feasibility of this encryption system is verified and analyzed by computer simulations.
NASA Astrophysics Data System (ADS)
Singh, Hukum
2016-12-01
A cryptosystem for securing image encryption is considered by using double random phase encoding in Fresnel wavelet transform (FWT) domain. Random phase masks (RPMs) and structured phase masks (SPMs) based on devil's vortex toroidal lens (DVTL) are used in spatial as well as in Fourier planes. The images to be encrypted are first Fresnel transformed and then single-level discrete wavelet transform (DWT) is apply to decompose LL,HL, LH and HH matrices. The resulting matrices from the DWT are multiplied by additional RPMs and the resultants are subjected to inverse DWT for the encrypted images. The scheme is more secure because of many parameters used in the construction of SPM. The original images are recovered by using the correct parameters of FWT and SPM. Phase mask SPM based on DVTL increases security that enlarges the key space for encryption and decryption. The proposed encryption scheme is a lens-less optical system and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The computed value of mean-squared-error between the retrieved and the input images shows the efficacy of scheme. The sensitivity to encryption parameters, robustness against occlusion, entropy and multiplicative Gaussian noise attacks have been analysed.
Manticore and CS mode : parallelizable encryption with joint cipher-state authentication.
Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree; Miller, Russell D.; Beaver, Cheryl Lynn; Anderson, William Erik
2004-10-01
We describe a new mode of encryption with inexpensive authentication, which uses information from the internal state of the cipher to provide the authentication. Our algorithms have a number of benefits: (1) the encryption has properties similar to CBC mode, yet the encipherment and authentication can be parallelized and/or pipelined, (2) the authentication overhead is minimal, and (3) the authentication process remains resistant against some IV reuse. We offer a Manticore class of authenticated encryption algorithms based on cryptographic hash functions, which support variable block sizes up to twice the hash output length and variable key lengths. A proof of security is presented for the MTC4 and Pepper algorithms. We then generalize the construction to create the Cipher-State (CS) mode of encryption that uses the internal state of any round-based block cipher as an authenticator. We provide hardware and software performance estimates for all of our constructions and give a concrete example of the CS mode of encryption that uses AES as the encryption primitive and adds a small speed overhead (10-15%) compared to AES alone.
NASA Astrophysics Data System (ADS)
Liu, Xingbin; Mei, Wenbo; Du, Huiqian
2016-05-01
In this paper, a novel approach based on compressive sensing and chaos is proposed for simultaneously compressing, fusing and encrypting multi-modal images. The sparsely represented source images are firstly measured with the key-controlled pseudo-random measurement matrix constructed using logistic map, which reduces the data to be processed and realizes the initial encryption. Then the obtained measurements are fused by the proposed adaptive weighted fusion rule. The fused measurement is further encrypted into the ciphertext through an iterative procedure including improved random pixel exchanging technique and fractional Fourier transform. The fused image can be reconstructed by decrypting the ciphertext and using a recovery algorithm. The proposed algorithm not only reduces data volume but also simplifies keys, which improves the efficiency of transmitting data and distributing keys. Numerical results demonstrate the feasibility and security of the proposed scheme.
Rajput, Sudheesh K; Nishchal, Naveen K
2014-01-20
We propose a novel nonlinear image-encryption scheme based on a Gerchberg-Saxton (G-S) phase-retrieval algorithm in the Fresnel transform domain. The decryption process can be performed using conventional double random phase encoding (DRPE) architecture. The encryption is realized by applying G-S phase-retrieval algorithm twice, which generates two asymmetric keys from intermediate phases. The asymmetric keys are generated in such a way that decryption is possible optically with a conventional DRPE method. Due to the asymmetric nature of the keys, the proposed encryption process is nonlinear and offers enhanced security. The cryptanalysis has been carried out, which proves the robustness of proposed scheme against known-plaintext, chosen-plaintext, and special attacks. A simple optical setup for decryption has also been suggested. Results of computer simulation support the idea of the proposed cryptosystem.
Quantum image encryption based on generalized affine transform and logistic map
NASA Astrophysics Data System (ADS)
Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run
2016-07-01
Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.
Encryption of digital hologram of 3-D object by virtual optics.
Kim, Hyun; Kim, Do-Hyung; Lee, Yeon
2004-10-04
We present a simple technique to encrypt a digital hologram of a three-dimensional (3-D) object into a stationary white noise by use of virtual optics and then to decrypt it digitally. In this technique the digital hologram is encrypted by our attaching a computer-generated random phase key to it and then forcing them to Fresnel propagate to an arbitrary plane with an illuminating plane wave of a given wavelength. It is shown in experiments that the proposed system is robust to blind decryptions without knowing the correct propagation distance, wavelength, and phase key used in the encryption. Signal-to-noise ratio (SNR) and mean-square-error (MSE) of the reconstructed 3-D object are calculated for various decryption distances and wavelengths, and partial use of the correct phase key.
Fault tolerant quantum secure direct communication with quantum encryption against collective noise
NASA Astrophysics Data System (ADS)
Huang, Wei; Wen, Qiao-Yan; Jia, Heng-Yue; Qin, Su-Juan; Gao, Fei
2012-10-01
We present two novel quantum secure direct communication (QSDC) protocols over different collective-noise channels. Different from the previous QSDC schemes over collective-noise channels, which are all source-encrypting protocols, our two protocols are based on channel-encryption. In both schemes, two authorized users first share a sequence of EPR pairs as their reusable quantum key. Then they use their quantum key to encrypt and decrypt the secret message carried by the decoherence-free states over the collective-noise channel. In theory, the intrinsic efficiencies of both protocols are high since there is no need to consume any entangled states including both the quantum key and the information carriers except the ones used for eavesdropping checks. For checking eavesdropping, the two parties only need to perform two-particle measurements on the decoy states during each round. Finally, we make a security analysis of our two protocols and demonstrate that they are secure.
Encryption of digital hologram of 3-D object by virtual optics
NASA Astrophysics Data System (ADS)
Kim, Hyun; Kim, Do-Hyung; Lee, Yeon H.
2004-10-01
We present a simple technique to encrypt a digital hologram of a three-dimensional (3-D) object into a stationary white noise by use of virtual optics and then to decrypt it digitally. In this technique the digital hologram is encrypted by our attaching a computer-generated random phase key to it and then forcing them to Fresnel propagate to an arbitrary plane with an illuminating plane wave of a given wavelength. It is shown in experiments that the proposed system is robust to blind decryptions without knowing the correct propagation distance, wavelength, and phase key used in the encryption. Signal-to-noise ratio (SNR) and mean-square-error (MSE) of the reconstructed 3-D object are calculated for various decryption distances and wavelengths, and partial use of the correct phase key.
Space-based optical image encryption.
Chen, Wen; Chen, Xudong
2010-12-20
In this paper, we propose a new method based on a three-dimensional (3D) space-based strategy for the optical image encryption. The two-dimensional (2D) processing of a plaintext in the conventional optical encryption methods is extended to a 3D space-based processing. Each pixel of the plaintext is considered as one particle in the proposed space-based optical image encryption, and the diffraction of all particles forms an object wave in the phase-shifting digital holography. The effectiveness and advantages of the proposed method are demonstrated by numerical results. The proposed method can provide a new optical encryption strategy instead of the conventional 2D processing, and may open up a new research perspective for the optical image encryption.
Optical encryption for large-sized images
NASA Astrophysics Data System (ADS)
Sanpei, Takuho; Shimobaba, Tomoyoshi; Kakue, Takashi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Oikawa, Minoru; Sugie, Takashige; Ito, Tomoyoshi
2016-02-01
We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.
A time-variant approach for encrypted digital communications
NASA Astrophysics Data System (ADS)
Ng, Wai-Hung
Two new approaches, a time-variant key and a random transmission rate, are introduced to strengthen the security of encrypted digital communications in which a 'black-box' type of crypto-device is employed. These approaches not only further upgrade present cryto-methodology, but may also secure the system against the possibility of the crytographic key's falling into the hands of an unauthorized listener after initial communication has begun. Therefore, communication privacy could be maintained even under the most scrutinizing postrecorded ciphertext attack.
Quantum image encryption based on generalized Arnold transform and double random-phase encoding
NASA Astrophysics Data System (ADS)
Zhou, Nan Run; Hua, Tian Xiang; Gong, Li Hua; Pei, Dong Ju; Liao, Qing Hong
2015-04-01
A quantum realization of the generalized Arnold transform is designed. A novel quantum image encryption algorithm based on generalized Arnold transform and double random-phase encoding is proposed. The pixels are scrambled by the generalized Arnold transform, and the gray-level information of images is encoded by the double random-phase operations. The keys of the encryption algorithm include the independent parameters of coefficients matrix, iterative times and classical binary sequences, and thus, the key space is extremely large. Numerical simulations and theoretical analyses demonstrate that the proposed algorithm with good feasibility and effectiveness has lower computational complexity than its classical counterpart.
Bellemain, V
2012-08-01
Coordination between Veterinary Services and other relevant authorities is a key component of good public governance, especially for effective action and optimal management of available resources. The importance of good coordination is reflected in the World Organisation for Animal Health'Tool forthe Evaluation of Performance of Veterinary Services', which includes a critical competency on coordination. Many partners from technical, administrative and legal fields are involved. The degree of formalisation of coordination tends to depend on a country's level of organisation and development. Contingency plans against avian influenza led to breakthroughs in many countries in the mid-2000s. While interpersonal relationships remain vital, not everything should hinge on them. Organisation and management are critical to operational efficiency. The distribution of responsibilities needs to be defined clearly, avoiding duplication and areas of conflict. Lead authorities should be designated according to subject (Veterinary Services in animal health areas) and endowed with the necessary legitimacy. Lead authorities will be responsible for coordinating the drafting and updating of the relevant documents: agreements between authorities, contingency plans, standard operating procedures, etc.
A study of image encryption aritlunetic based on chaotic sequences
NASA Astrophysics Data System (ADS)
Huang, Xiaolong
2010-02-01
The multimedia information, especially video and audio information, regarded as a common data stream, with the traditional encryption technology encrypted, ignoring the characteristics of multimedia data, has some limitations. On the other hand, chaotic sequences have several good properties including the ease of their generation, their sensitive dependence on their initial condition and so on. Therefore, this paper discussed image encryption arithmetic on the basis of chaotic sequences through dispersing the real number value chaotic sequences into symbol matrix and transformation matrix, and then encrypted the image. Preliminary results proved that the image encryption arithmetic based on chaotic sequences possesses the traits, namely fast speed for encryption speed, perfect results for encryption.
NASA Astrophysics Data System (ADS)
Tian, Ye; Lu, Zhimao
2017-08-01
The development of the computer network makes image files transportation via network become more and more convenient. This paper is concerned with the image encryption algorithm design based on the chaotic S-box mechanism. This paper proposes an Image Encryption algorithm involving both chaotic dynamic S-boxes and DNA sequence operation(IESDNA). The contribution of this paper is three folded: Firstly, we design an external 256-bit key to get large key space; secondly, we design a chaotic system to scramble image pixels; thirdly, DNA sequence operations are adopted to diffuse the scrambled image pixels. Experimental results show that our proposed image encryption algorithm can meet multiple cryptographic criteria and obtain good image encryption effect.
Simcoe, Donna; Juneja, Renu; Scott, Gayle Nicholas; Sridharan, Kanaka; Williams-Hughes, Celeste
2014-03-01
During the 9th Annual Meeting of the International Society for Medical Publication Professionals (ISMPP, April 29-May 1, 2013 in Baltimore, MD), ∼650 participants attended two of 13 available roundtable sessions. Participants included medical publication professionals from industry, communication agencies, and journals. DISCUSSION TOPICS: Roundtable participants discussed how to best interpret and implement various guidances, such as Good Publication Practices 2 (GPP2), the International Committee of Medical Journal Editors (ICMJE) guidelines, and the Physician Payment Sunshine Act. The impact of and compliance with Corporate Integrity agreements (CIAs) on medical publication planning practices was debated. Roundtable participants also discussed ways of advancing both advocacy for the medical publication professional field and internal and external collaborations. The development of review manuscripts, publications from regions newly emerging in publication planning, medical devices publications, and real-world experience publications were discussed. Participants also considered the benefits and uncertainties of new technologies in medical publications such as multimedia and social media. This is the first ever article to be published following the well-attended ISMPP roundtable sessions. The objective of this manuscript is to summarize key learnings that will aid continued discussions about challenges and opportunities facing medical publication professionals.
Limitations on information-theoretically-secure quantum homomorphic encryption
NASA Astrophysics Data System (ADS)
Yu, Li; Pérez-Delgado, Carlos A.; Fitzsimons, Joseph F.
2014-11-01
Homomorphic encryption is a form of encryption which allows computation to be carried out on the encrypted data without the need for decryption. The success of quantum approaches to related tasks in a delegated computation setting has raised the question of whether quantum mechanics may be used to achieve information-theoretically-secure fully homomorphic encryption. Here we show, via an information localization argument, that deterministic fully homomorphic encryption necessarily incurs exponential overhead if perfect security is required.
Secret Key Crypto Implementations
NASA Astrophysics Data System (ADS)
Bertoni, Guido Marco; Melzani, Filippo
This chapter presents the algorithm selected in 2001 as the Advanced Encryption Standard. This algorithm is the base for implementing security and privacy based on symmetric key solutions in almost all new applications. Secret key algorithms are used in combination with modes of operation to provide different security properties. The most used modes of operation are presented in this chapter. Finally an overview of the different techniques of software and hardware implementations is given.
Multiple image encryption by phase retrieval
NASA Astrophysics Data System (ADS)
Di, Hong; Kang, Yanmei; Liu, Yueqin; Zhang, Xin
2016-07-01
Multiple image encryption (MIE) was proposed to increase the efficiency of encrypting images by processing several images simultaneously. Because of the advantage of optical technology in processing twodimensional images at high throughput, MIE has been significantly improved by use of methods originating from optics. Phase retrieval was the process of algorithmically finding solutions to the phase loss problem due to light detectors only capturing the intensity. It was to retrieve phase information for the determination of a structure from diffraction data. Error-reduction algorithm is a typical phase retrieval method. Here, we employ it to illustrate that methods in phase retrieval are able to encrypt multiple images and compress them into encrypted data simultaneously. Moreover, the decryption is also designed to handle multiple images at the same time. The whole process including both the encryption and decryption is proposed to improve MIE with respect to the compression and efficiency. The feasibility and encryption of the MIE scheme is demonstrated with encryption experiments under Gaussian white noise and unauthorized access.
Multiple information encryption by user-image-based gyrator transform hologram
NASA Astrophysics Data System (ADS)
Abuturab, Muhammad Rafiq
2017-05-01
A novel multiple information encryption by user-image-based gyrator transform hologram is proposed. In encryption process, each channel of the user image is phase encoded, modulated by random phase function and then gyrator transformed to get the gyrator spectrum of user image. Subsequently, each channel of the secret image is normalized, phase encoded, multiplied by modulated user image, and then gyrator transformed to obtain the gyrator spectrum of secret image. The encrypted digital hologram is recorded by the interference between the gyrator spectrum of user image and the spherical wave function. Similarly, the digital hologram for decryption is recorded by the interference between the gyrator spectrum of secret image and the spherical wave function. The multiple encrypted digital holograms are multiplexed into a final encoded hologram and the corresponding digital holograms for decryption are multiplexed into a final hologram for decryption. The wavelength and radius of the spherical wave function, and angle of gyrator transform are all essential keys for decryption. The proposed system has two main features. First, the encrypted hologram has no information about secret image. Second, the hologram for decryption used as identification key. Consequently the two marked security layers of information protection are achieved. The proposal can be realized by optoelectronic system. Numerical simulation results demonstrate the feasibility and security of the proposed technique.
A fast image encryption algorithm based on only blocks in cipher text
NASA Astrophysics Data System (ADS)
Wang, Xing-Yuan; Wang, Qian
2014-03-01
In this paper, a fast image encryption algorithm is proposed, in which the shuffling and diffusion is performed simultaneously. The cipher-text image is divided into blocks and each block has k ×k pixels, while the pixels of the plain-text are scanned one by one. Four logistic maps are used to generate the encryption key stream and the new place in the cipher image of plain image pixels, including the row and column of the block which the pixel belongs to and the place where the pixel would be placed in the block. After encrypting each pixel, the initial conditions of logistic maps would be changed according to the encrypted pixel's value; after encrypting each row of plain image, the initial condition would also be changed by the skew tent map. At last, it is illustrated that this algorithm has a faster speed, big key space, and better properties in withstanding differential attacks, statistical analysis, known plaintext, and chosen plaintext attacks.
Private queries on encrypted genomic data.
Çetin, Gizem S; Chen, Hao; Laine, Kim; Lauter, Kristin; Rindal, Peter; Xia, Yuhou
2017-07-26
One of the tasks in the iDASH Secure Genome Analysis Competition in 2016 was to demonstrate the feasibility of privacy-preserving queries on homomorphically encrypted genomic data. More precisely, given a list of up to 100,000 mutations, the task was to encrypt the data using homomorphic encryption in a way that allows it to be stored securely in the cloud, and enables the data owner to query the dataset for the presence of specific mutations, without revealing any information about the dataset or the queries to the cloud. We devise a novel string matching protocol to enable privacy-preserving queries on homomorphically encrypted data. Our protocol combines state-of-the-art techniques from homomorphic encryption and private set intersection protocols to minimize the computational and communication cost. We implemented our protocol using the homomorphic encryption library SEAL v2.1, and applied it to obtain an efficient solution to the iDASH competition task. For example, using 8 threads, our protocol achieves a running time of only 4 s, and a communication cost of 2 MB, when querying for the presence of 5 mutations from an encrypted dataset of 100,000 mutations. We demonstrate that homomorphic encryption can be used to enable an efficient privacy-preserving mechanism for querying the presence of particular mutations in realistic size datasets. Beyond its applications to genomics, our protocol can just as well be applied to any kind of data, and is therefore of independent interest to the homomorphic encryption community.
ERIC Educational Resources Information Center
Gould, Nora Palmer
1991-01-01
The results of a questionnaire given to child care center directors, Head Start directors, and prekindergarten directors in public schools revealed that administrators do not view public relations, or "planned communications," as a high priority. (BB)
2007-12-01
Win and Keep Big Customers. Austin: Bard Press, 2005. Kotler , Philip and Kevin Lane Keller. Marketing Management. Upper Saddle River, NJ...stimulate awareness and demand with little or no cost. Kotler and Keller describe public relations and publicity as “a variety of programs designed to...broadcast media to promote something.”13 Kotler and Keller also argue that there is an appeal to the use of public relations and publicity that is based
NASA Astrophysics Data System (ADS)
Bates, Alison Waterbury
been proposed. The essay examines how the public considers the societal tradeoffs that are made to develop small-scale, in-view demonstration wind projects instead of larger facilities farther offshore. Results indicate that a strong majority of the public supports near-shore demonstration wind projects in both states. Primary reasons for support include benefits to wildlife, cost of electricity, and job creation, while the primary reasons for opposition include wildlife impacts, aesthetics, tourism, and user conflicts. These factors differ between coastal Delaware and greater Atlantic City and highlight the importance of local, community engagement in the early stages of development. The second essay examines the interaction of a new proposed use of the ocean---offshore wind---and a key existing ocean user group---commercial fishers. A key component of offshore wind planning includes consideration of existing uses of the marine environment in order to optimally site wind projects while minimizing conflicts. Commercial fisheries comprise an important stakeholder group, and may be one of the most impacted stakeholders from offshore renewable energy development. Concern of the fishing industry stems from possible interference with productive fishing grounds and access within wind developments resulting in costs from increased effort or reduction in catch. Success of offshore wind development may in part depend on the acceptance of commercial fishers, who are concerned about loss of access to fishing grounds. Using a quantitative, marine spatial planning approach in the siting of offshore wind projects with respect to commercial fishing in the mid-Atlantic, U.S., this essay develops a spatially explicit representation of potential conflicts and compatibilities between these two industries in the mid-Atlantic region of the United States. Areas that are highly valuable to the wind industry are determined through a spatial suitability model using variable cost per unit
Video Encryption and Decryption on Quantum Computers
NASA Astrophysics Data System (ADS)
Yan, Fei; Iliyasu, Abdullah M.; Venegas-Andraca, Salvador E.; Yang, Huamin
2015-08-01
A method for video encryption and decryption on quantum computers is proposed based on color information transformations on each frame encoding the content of the encoding the content of the video. The proposed method provides a flexible operation to encrypt quantum video by means of the quantum measurement in order to enhance the security of the video. To validate the proposed approach, a tetris tile-matching puzzle game video is utilized in the experimental simulations. The results obtained suggest that the proposed method enhances the security and speed of quantum video encryption and decryption, both properties required for secure transmission and sharing of video content in quantum communication.
NASA Astrophysics Data System (ADS)
Oppenheim, Jonathan; Horodecki, Michał
2005-10-01
Quantum information is a valuable resource which can be encrypted in order to protect it. We consider the size of the one-time pad that is needed to protect quantum information in a number of cases. The situation is dramatically different from the classical case: we prove that one can recycle the one-time pad without compromising security. The protocol for recycling relies on detecting whether eavesdropping has occurred, and further relies on the fact that information contained in the encrypted quantum state cannot be fully accessed. We prove the security of recycling rates when authentication of quantum states is accepted, and when it is rejected. We note that recycling schemes respect a general law of cryptography which we introduce relating the size of private keys, sent qubits, and encrypted messages. We discuss applications for encryption of quantum information in light of the resources needed for teleportation. Potential uses include the protection of resources such as entanglement and the memory of quantum computers. We also introduce another application: encrypted secret sharing and find that one can even reuse the private key that is used to encrypt a classical message. In a number of cases, one finds that the amount of private key needed for authentication or protection is smaller than in the general case.
Oppenheim, Jonathan; Horodecki, Michal
2005-10-15
Quantum information is a valuable resource which can be encrypted in order to protect it. We consider the size of the one-time pad that is needed to protect quantum information in a number of cases. The situation is dramatically different from the classical case: we prove that one can recycle the one-time pad without compromising security. The protocol for recycling relies on detecting whether eavesdropping has occurred, and further relies on the fact that information contained in the encrypted quantum state cannot be fully accessed. We prove the security of recycling rates when authentication of quantum states is accepted, and when it is rejected. We note that recycling schemes respect a general law of cryptography which we introduce relating the size of private keys, sent qubits, and encrypted messages. We discuss applications for encryption of quantum information in light of the resources needed for teleportation. Potential uses include the protection of resources such as entanglement and the memory of quantum computers. We also introduce another application: encrypted secret sharing and find that one can even reuse the private key that is used to encrypt a classical message. In a number of cases, one finds that the amount of private key needed for authentication or protection is smaller than in the general case.
Matthias, James; Zielinski-Gutierrez, Emily C; Tisch, Daniel J; Stanek, Danielle; Blanton, Ronald E; Doyle, Michael S; Eadie, Robert B; Gazdick, Elizabeth J; Leal, Andrea L; Pattison, Kimberly J; Perez-Guerra, Carmen L; Tittel, Christopher J; Vyas, Jooi; Wagner, Todd; Blackmore, Carina G M
2014-11-01
In 2009-2010, 93 cases of dengue were identified in Key West, Florida. This was the first outbreak of autochthonous transmission of dengue in Florida since 1934. In response to this outbreak, a multifaceted public education outreach campaign was launched. The aim of this study is to compare dengue prevention knowledge, attitudes, perceptions, and prevention practices among residents of subsidized public housing to the general population in Key West and to assess whether there were barriers preventing effective outreach from reaching specific vulnerable populations. A randomized population-based evaluation of knowledge, attitudes, and behaviors toward dengue prevention consisting of 521 separate household interviews was undertaken in July of 2011. A subset analysis was performed on interviews collected from 28 public housing units within four subsidized public housing complexes. Analysis was performed to determine whether knowledge, attitudes, and behaviors exhibited by public housing residents differed from the non-public housing study population. Public housing residents recalled fewer outreach materials (p=0.01) and were 3.4 times (95% confidence interval [CI] 1.4-8.3) more likely not to recall any outreach materials. Public housing residents were less likely to correctly identify how dengue transmission occurs (61% vs. 89%), where mosquitoes lay their eggs (54% vs. 85%), or to identify any signs or symptoms related to dengue (36% vs. 64%). Public housing residents were less likely to perform dengue prevention practices such as removing standing water or always using air conditioning. Examination of public housing residents identified an at-risk population that recalled less exposure to outreach materials and had less knowledge about dengue infection and prevention than the randomized study population. This provides public health systems the opportunity to target or modify future health messages and interventions to this group. Differences identified in the
Design of an image encryption scheme based on a multiple chaotic map
NASA Astrophysics Data System (ADS)
Tong, Xiao-Jun
2013-07-01
In order to solve the problem that chaos is degenerated in limited computer precision and Cat map is the small key space, this paper presents a chaotic map based on topological conjugacy and the chaotic characteristics are proved by Devaney definition. In order to produce a large key space, a Cat map named block Cat map is also designed for permutation process based on multiple-dimensional chaotic maps. The image encryption algorithm is based on permutation-substitution, and each key is controlled by different chaotic maps. The entropy analysis, differential analysis, weak-keys analysis, statistical analysis, cipher random analysis, and cipher sensibility analysis depending on key and plaintext are introduced to test the security of the new image encryption scheme. Through the comparison to the proposed scheme with AES, DES and Logistic encryption methods, we come to the conclusion that the image encryption method solves the problem of low precision of one dimensional chaotic function and has higher speed and higher security.
A Signcryption based Light Weight Key Exchange Protocol
NASA Astrophysics Data System (ADS)
Feng, Yong; Wei, Qian; Zhang, Xing
Traditional cryptography based authenticated Diffie-Hellman key exchange protocols expose the problems of efficiency and privacy since signature-then-encryption is heavy to wireless communication special for flexible dynamic deployment, i.e., wireless mesh networks, wireless sensor networks, mobile ad hoc networks, etc., in computational cost and communicational overhead and traditional digital signature allows anyone to verify its validity using the corresponding public key. In this paper, we propose a signcryption based light weight key exchange protocol named SLWKE which can provide resistance to traditional attacks, i.e., eavesdropping, deducing, replaying, interleaving, forging and repudiating, and unknown key-share attack and save computational cost by three modular calculations, i.e., one modular inversion, one modular addition and one modular multiplicative, included in a signature s and communicational overhead by secure length of IqI in comparison to signcryption based direct key exchange using a time-stamp protocol termed Dkeuts.
Encrypted storage of medical data on a grid.
Seitz, L; Pierson, J-M; Brunie, L
2005-01-01
In this article we present grids as an architecture for medical image processing and health-care networks. We argue that confidential patient data should not be stored unprotected on a grid and explain why access control systems alone do not offer sufficient protection. The objective of our work is to propose a method that complements access control systems on a grid architecture and thus makes the storage of confidential data more secure. Effective protection can be achieved by storing confidential data in encrypted form. This raises the problem of how authorized users get access to the data, since they need to have the decryption keys. Our proposal details a key management architecture, that allows encrypted storage and still enables users to access decryption keys for data they are authorized to see. To achieve this functionality we use distributed keyservers storing redundant shares of the keys. The resulting architecture achieves our primary objective of making the storage of confidential data more secure without loosing the data sharing properties of the grid architecture. Furthermore our architecture is robust against breakdowns and denial of service attacks. It scales well with the number of users and does not introduce a single point of failure into the system.
ERIC Educational Resources Information Center
Quarles, Roger C.
2011-01-01
This multiple case qualitative study addressed the National School Board Association's (NSBA) Key Work standards for public policy leadership by local school boards, and how three elite school board chairs understood and implemented those standards. Elite board chair status was defined by experience, training, and peer recognition. The study…
Wang, Qu; Guo, Qing; Zhou, Jinyun
2013-12-20
We propose a multiple-image encryption scheme, based on polarized light encoding and the interference principle of phase-only masks (POMs), in the Fresnel-transform (FrT) domain. In this scheme, each secret image is converted into an intensity image by polarized light encoding, where a random key image and a pixilated polarizer with random angles are employed as keys. The intensity encrypted images produced by different secret images are convolved together and then inverse Fresnel-transformed. Phase and amplitude truncations are used to generate the asymmetric decryption keys. The phase-truncated inverse FrT spectrum is sent into an interference-based encryption (IBE) system to analytically obtain two POMs. To reduce the transmission and storage load on the keys, the chaotic mapping method is employed to generate random distributions of keys for encryption and decryption. One can recover all secret images successfully only if the corresponding decryption keys, the mechanism of FrTs, and correct chaotic conditions are known. The inherent silhouette problem can be thoroughly resolved by polarized light encoding in this proposal, without using any time-consuming iterative methods. The entire encryption and decryption process can be realized digitally, or in combination with optical means. Numerical simulation results are presented to verify the effectiveness and performance of the proposed scheme.
A sensitive data extraction algorithm based on the content associated encryption technology for ICS
NASA Astrophysics Data System (ADS)
Wang, Wei; Hao, Huang; Xie, Changsheng
With the development of HD video, the protection of copyright becomes more complicated. More advanced copyright protection technology is needed. Traditional digital copyright protection technology generally uses direct or selective encryption algorithm and the key does not associate with the video content [1]. Once the encryption method is cracked or the key is stolen, the copyright of the video will be violated. To address this issue, this paper proposes a Sensitive Data Extraction Algorithm (SDEA) based on the content associated encryption technology which applies to the Internet Certification Service (ICS). The principle of content associated encryption is to extract some data from the video and use this extracted data as the key to encrypt the rest data. The extracted part from video is called sensitive data, and the rest part is called the main data. After extraction, the main data will not be played or poorly played. The encrypted sensitive data reach the terminal device through the safety certificated network and the main data are through ICS disc. The terminal equipments are responsible for synthesizing and playing these two parts of data. Consequently, even if the main data on disc is illegally obtained, the video cannot be played normally due to the lack of necessary sensitive data. It is proved by experiments that ICS using SDEA can destruct the video effectively with 0.25% extraction rates and the destructed video cannot be played well. It can also guarantee the consistency of the destructive effect on different videos with different contents. The sensitive data can be transported smoothly under the home Internet bandwidth.
WEDDS: The WITS Encrypted Data Delivery System
NASA Technical Reports Server (NTRS)
Norris, J.; Backes, P.
1999-01-01
WEDDS, the WITS Encrypted Data Delivery System, is a framework for supporting distributed mission operations by automatically transferring sensitive mission data in a secure and efficient manner to and from remote mission participants over the internet.
Code of Federal Regulations, 2014 CFR
2014-10-01
... (AES) specified in ANSI/TIA-102.AAAD-A: Project 25 Digital Land Mobile Radio-Block Encryption Protocol... Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036 (or via the Internet at...
WEDDS: The WITS Encrypted Data Delivery System
NASA Technical Reports Server (NTRS)
Norris, J.; Backes, P.
1999-01-01
WEDDS, the WITS Encrypted Data Delivery System, is a framework for supporting distributed mission operations by automatically transferring sensitive mission data in a secure and efficient manner to and from remote mission participants over the internet.
Squires, Hazel; Chilcott, James; Akehurst, Ronald; Burr, Jennifer; Kelly, Michael P
2016-04-01
To identify the key methodological challenges for public health economic modelling and set an agenda for future research. An iterative literature search identified papers describing methodological challenges for developing the structure of public health economic models. Additional multidisciplinary literature searches helped expand upon important ideas raised within the review. Fifteen articles were identified within the formal literature search, highlighting three key challenges: inclusion of non-healthcare costs and outcomes; inclusion of equity; and modelling complex systems and multi-component interventions. Based upon these and multidisciplinary searches about dynamic complexity, the social determinants of health, and models of human behaviour, six areas for future research were specified. Future research should focus on: the use of systems approaches within health economic modelling; approaches to assist the systematic consideration of the social determinants of health; methods for incorporating models of behaviour and social interactions; consideration of equity; and methodology to help modellers develop valid, credible and transparent public health economic model structures.
Kotwicki, Raymond J; Compton, Michael T
2010-08-01
The Emory University Fellowship in Community Psychiatry/Public Health is a unique training opportunity whose mission is to train future leaders in the arena of community psychiatry. To complement the recent description of the Public Psychiatry Fellowship of New York State Psychiatric Institute at Columbia University Medical Center, this report describes the key features of Emory's fellowship-its academic curriculum, practicum experiences, site visits and other opportunities for collaboration, and ongoing mentoring and career development. Congruencies between these four key features and the seven core elements of Columbia's fellowship are highlighted, as are several important differences. Such descriptions of innovative training programs in community and public psychiatry are essential in promoting excellence in education, which will translate into vital enhancements in programs, policy, and community-based approaches to mental health services.
Noise-free recovery of optodigital encrypted and multiplexed images.
Henao, Rodrigo; Rueda, Edgar; Barrera, John F; Torroba, Roberto
2010-02-01
We present a method that allows storing multiple encrypted data using digital holography and a joint transform correlator architecture with a controllable angle reference wave. In this method, the information is multiplexed by using a key and a different reference wave angle for each object. In the recovering process, the use of different reference wave angles prevents noise produced by the nonrecovered objects from being superimposed on the recovered object; moreover, the position of the recovered object in the exit plane can be fully controlled. We present the theoretical analysis and the experimental results that show the potential and applicability of the method.
Best practices for interacting with the public about wildland fire: Key findings from interviews
Daniel Berkman
2012-01-01
Interviews were conducted with public information and line officers about wildland fire communications with the public. The goal of these interviews was to determine the best practices and most useful content and format for an annotated bibliography about external wildland fire communications, i.e., does the current literature reviewed address the issues of greatest...
Multiple-image encryption based on triple interferences for flexibly decrypting high-quality images.
Li, Wei-Na; Phan, Anh-Hoang; Piao, Mei-Lan; Kim, Nam
2015-04-10
We propose a multiple-image encryption (MIE) scheme based on triple interferences for flexibly decrypting high-quality images. Each image is discretionarily deciphered without decrypting a series of other images earlier. Since it does not involve any cascaded encryption orders, the image can be decrypted flexibly by using the novel method. Computer simulation demonstrated that the proposed method's running time is less than approximately 1/4 that of the previous similar MIE method. Moreover, the decrypted image is perfectly correlated with the original image, and due to many phase functions serving as decryption keys, this method is more secure and robust.
A Novel Color Image Encryption Algorithm Based on Quantum Chaos Sequence
NASA Astrophysics Data System (ADS)
Liu, Hui; Jin, Cong
2017-03-01
In this paper, a novel algorithm of image encryption based on quantum chaotic is proposed. The keystreams are generated by the two-dimensional logistic map as initial conditions and parameters. And then general Arnold scrambling algorithm with keys is exploited to permute the pixels of color components. In diffusion process, a novel encryption algorithm, folding algorithm, is proposed to modify the value of diffused pixels. In order to get the high randomness and complexity, the two-dimensional logistic map and quantum chaotic map are coupled with nearest-neighboring coupled-map lattices. Theoretical analyses and computer simulations confirm that the proposed algorithm has high level of security.
NASA Astrophysics Data System (ADS)
Li, Xin-Xin; Zhao, Dao-Mu
2008-07-01
We present a new method for image encryption on the basis of simplified fractional Hartley transform (SFRHT). SFRHT is a real transform as Hartley transform (HT) and furthermore, superior to HT in virtue of the advantage that it can also append fractional orders as additional keys for the purpose of improving the system security to some extent. With this method, one can encrypt an image with an intensity-only medium such as a photographic film or a CCD camera by spatially incoherent or coherent illumination. The optical realization is then proposed and computer simulations are also performed to verify the feasibility of this method.
Fractional Fourier transform-based optical encryption with treble random phase-encoding
NASA Astrophysics Data System (ADS)
Xin, Yi; Tao, Ran; Wang, Yue
2008-03-01
We propose a new architecture of optical encryption technique using the fractional Fourier transform with three statistically independent random phase masks. Compared with the existing double-phase encoding method in the fractional Fourier-domain, the proposed extra phase mask in the last fractional Fourier domain makes the architecture symmetrical, and additive processing to the encrypted image can be turned into complex stationary white noise after decryption, and enlarge the key space without any degradation of its robustness to blind decryption. This property can be utilized to improve the quality of the recover image. Simulation results have verified the validity.
Key management schemes using routing information frames in secure wireless sensor networks
NASA Astrophysics Data System (ADS)
Kamaev, V. A.; Finogeev, A. G.; Finogeev, A. A.; Parygin, D. S.
2017-01-01
The article considers the problems and objectives of key management for data encryption in wireless sensor networks (WSN) of SCADA systems. The structure of the key information in the ZigBee network and methods of keys obtaining are discussed. The use of a hybrid key management schemes is most suitable for WSN. The session symmetric key is used to encrypt the sensor data, asymmetric keys are used to encrypt the session key transmitted from the routing information. Three algorithms of hybrid key management using routing information frames determined by routing methods and the WSN topology are presented.
15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items
Code of Federal Regulations, 2013 CFR
2013-01-01
...) Key storage (xix) Link encryption (xx) Local area networking (LAN) (xxi) Metropolitan area networking...) Network intelligence (xxvi) Network or systems management (OAM/OAM&P) (xxvii) Network security monitoring...) Voice over Internet protocol (VoIP) (xlii) Wide area networking (WAN) (xliii) Wireless local...
15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items
Code of Federal Regulations, 2011 CFR
2011-01-01
...) Key storage (xix) Link encryption (xx) Local area networking (LAN) (xxi) Metropolitan area networking...) Network intelligence (xxvi) Network or systems management (OAM/OAM&P) (xxvii) Network security monitoring...) Voice over Internet protocol (VoIP) (xlii) Wide area networking (WAN) (xliii) Wireless local...
15 CFR Supplement No. 8 to Part 742 - Self-Classification Report for Encryption Items
Code of Federal Regulations, 2012 CFR
2012-01-01
...) Key storage (xix) Link encryption (xx) Local area networking (LAN) (xxi) Metropolitan area networking...) Network intelligence (xxvi) Network or systems management (OAM/OAM&P) (xxvii) Network security monitoring...) Voice over Internet protocol (VoIP) (xlii) Wide area networking (WAN) (xliii) Wireless local...
Comment on ‘A technique for image encryption using digital signature’
NASA Astrophysics Data System (ADS)
Hernández Encinas, L.; Peinado Domínguez, A.
2006-12-01
The security of a recently proposed technique for encryption images by Sinha and Singh [A. Sinha, K. Singh, Opt. Commun. 218 (2003) 229], based on the use of digital signatures and error correcting codes, is analyzed. The proposed cryptosystem is shown to have some weakness. In fact, the secret key and the original image can be recovered efficiently by a brute force attack.
Encrypted holographic data storage based on orthogonal-phase-code multiplexing.
Heanue, J F; Bashaw, M C; Hesselink, L
1995-09-10
We describe an encrypted holographic data-storage system that combines orthogonal-phase-code multiplexing with a random-phase key. The system offers the security advantages of random-phase coding but retains the low cross-talk performance and the minimum code storage requirements typical in an orthogonal-phase-code-multiplexing system.
Symmetric encryption algorithms using chaotic and non-chaotic generators: A review.
Radwan, Ahmed G; AbdElHaleem, Sherif H; Abd-El-Hafiz, Salwa K
2016-03-01
This paper summarizes the symmetric image encryption results of 27 different algorithms, which include substitution-only, permutation-only or both phases. The cores of these algorithms are based on several discrete chaotic maps (Arnold's cat map and a combination of three generalized maps), one continuous chaotic system (Lorenz) and two non-chaotic generators (fractals and chess-based algorithms). Each algorithm has been analyzed by the correlation coefficients between pixels (horizontal, vertical and diagonal), differential attack measures, Mean Square Error (MSE), entropy, sensitivity analyses and the 15 standard tests of the National Institute of Standards and Technology (NIST) SP-800-22 statistical suite. The analyzed algorithms include a set of new image encryption algorithms based on non-chaotic generators, either using substitution only (using fractals) and permutation only (chess-based) or both. Moreover, two different permutation scenarios are presented where the permutation-phase has or does not have a relationship with the input image through an ON/OFF switch. Different encryption-key lengths and complexities are provided from short to long key to persist brute-force attacks. In addition, sensitivities of those different techniques to a one bit change in the input parameters of the substitution key as well as the permutation key are assessed. Finally, a comparative discussion of this work versus many recent research with respect to the used generators, type of encryption, and analyses is presented to highlight the strengths and added contribution of this paper.
Symmetric encryption algorithms using chaotic and non-chaotic generators: A review
Radwan, Ahmed G.; AbdElHaleem, Sherif H.; Abd-El-Hafiz, Salwa K.
2015-01-01
This paper summarizes the symmetric image encryption results of 27 different algorithms, which include substitution-only, permutation-only or both phases. The cores of these algorithms are based on several discrete chaotic maps (Arnold’s cat map and a combination of three generalized maps), one continuous chaotic system (Lorenz) and two non-chaotic generators (fractals and chess-based algorithms). Each algorithm has been analyzed by the correlation coefficients between pixels (horizontal, vertical and diagonal), differential attack measures, Mean Square Error (MSE), entropy, sensitivity analyses and the 15 standard tests of the National Institute of Standards and Technology (NIST) SP-800-22 statistical suite. The analyzed algorithms include a set of new image encryption algorithms based on non-chaotic generators, either using substitution only (using fractals) and permutation only (chess-based) or both. Moreover, two different permutation scenarios are presented where the permutation-phase has or does not have a relationship with the input image through an ON/OFF switch. Different encryption-key lengths and complexities are provided from short to long key to persist brute-force attacks. In addition, sensitivities of those different techniques to a one bit change in the input parameters of the substitution key as well as the permutation key are assessed. Finally, a comparative discussion of this work versus many recent research with respect to the used generators, type of encryption, and analyses is presented to highlight the strengths and added contribution of this paper. PMID:26966561
Encrypting 2D/3D image using improved lensless integral imaging in Fresnel domain
NASA Astrophysics Data System (ADS)
Li, Xiao-Wei; Wang, Qiong-Hua; Kim, Seok-Tae; Lee, In-Kwon
2016-12-01
We propose a new image encryption technique, for the first time to our knowledge, combined Fresnel transform with the improved lensless integral imaging technique. In this work, before image encryption, the input image is first recorded into an elemental image array (EIA) by using the improved lensless integral imaging technique. The recorded EIA is encrypted into random noise by use of two phase masks located in the Fresnel domain. The positions of phase masks and operation wavelength, as well as the integral imaging system parameters are used as encryption keys that can ensure security. Compared with previous works, the main novelty of this proposed method resides in the fact that the elemental images possess distributed memory characteristic, which greatly improved the robustness of the image encryption algorithm. Meanwhile, the proposed pixel averaging algorithm can effectively address the overlapping problem existing in the computational integral imaging reconstruction process. Numerical simulations are presented to demonstrate the feasibility and effectiveness of the proposed method. Results also indicate the high robustness against data loss attacks.
Scalable end-to-end encryption technology for supra-gigabit/second networking
Pierson, L.G.; Tarman, T.D.; Witzke, E.L.
1997-05-01
End-to-end encryption can protect proprietary information as it passes through a complex inter-city computer network, even if the intermediate systems are untrusted. This technique involves encrypting the body of computer messages while leaving network addressing and control information unencrypted for processing by intermediate network nodes. Because high speed implementations of end-to-end encryption with easy key management for standard network protocols are unavailable, this technique is not widely used today. Specifically, no end-to-end encryptors exist to protect Asynchronous Transfer Mode (ATM) traffic, nor to protect Switched Multi-megabit Data Service (SMDS), which is the first ``Broadband Integrated Services Digital Network`` (BISDN) service now being used by long distance telephone companies. This encryption technology is required for the protection of data in transit between industrial sites and central Massively Parallel Supercomputing Centers over high bandwidth, variable bit rate (BISDN) services. This research effort investigated techniques to scale end-to-end encryption technology from today`s state of the art ({approximately} 0.001 Gb/s) to 2.4 Gb/s and higher. A cryptosystem design has been developed which scales for implementation beyond SONET OC-48 (2.4Gb/s) data rates. A prototype for use with OC-3 (0.155 Gb/s) ATM variable bit rate services was developed.
Image encryption using the Gyrator transform and random phase masks generated by using chaos
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Jimenez, Carlos J.; Perez, Ronal
2017-06-01
The Gyrator transform (GT), chaotic random phase masks (CRPMs) and a random permutation of the Jigsaw transform (JT) are utilized to design an images encryption-decryption system. The encryption-decryption system is based on the double random phase encoding (DRPE) in the Gyrator domain (GD), this technique uses two random phase masks (RPMs) to encode the image to encrypt (original image) into a random noise. The RPMs are generated by using chaos, these masks are CRPMs. The parameters of the chaotic function have the control of the generation of the CRPMs. We apply a random permutation to the resulting image of the DRPE technique, with the purpose of obtaining an encrypted image with a higher randomness. In order to successfully retrieve the original image (without errors or noise-free) at the output of the decryption system is necessary to have all the proper keys, which are: the rotation angles of the GTs, the parameters of the chaotic function utilized to generate the two CRPMs and the random permutation of the JT. We check and analyze the validity of the image encryption and decryption systems by means of computing simulations.
Public-channel cryptography using chaos synchronization.
Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang
2005-07-01
We present a key-exchange protocol that comprises two parties with chaotic dynamics that are mutually coupled and undergo a synchronization process, at the end of which they can use their identical dynamical state as an encryption key. The transferred coupling- signals are based nonlinearly on time-delayed states of the parties, and therefore they conceal the parties' current state and can be transferred over a public channel. Synchronization time is linear in the number of synchronized digits alpha, while the probability for an attacker to synchronize with the parties drops exponentially with alpha. To achieve security with finite alpha we use a network.
A novel chaos-based bit-level permutation scheme for digital image encryption
NASA Astrophysics Data System (ADS)
Fu, Chong; Lin, Bin-bin; Miao, Yu-sheng; Liu, Xiao; Chen, Jun-jie
2011-11-01
Confidentiality is an important issue when digital images are transmitted over public networks, and encryption is the most useful technique employed for this purpose. Image encryption is somehow different from text encryption due to some inherent features of image such as bulk data capacity and high correlation among pixels, which are generally difficult to handle by conventional algorithms. Recently, chaos-based encryption has suggested a new and efficient way to deal with the intractable problems of fast and highly secure image encryption. This paper proposes a novel chaos-based bit-level permutation scheme for secure and efficient image cipher. To overcome the drawbacks of conventional permutation-only type image cipher, the proposed scheme introduced a significant diffusion effect in permutation procedure through a two-stage bit-level shuffling algorithm. The two-stage permutation operations are realized by chaotic sequence sorting algorithm and Arnold Cat map, respectively. Results of various types of analysis are interesting and indicate that the security level of the new scheme is competitive with that of permutation-diffusion type image cipher, while the computational complexity is much lower. Therefore the new scheme is a good candidate for real-time secure image communication applications.
Securing information using optically generated biometric keys
NASA Astrophysics Data System (ADS)
Verma, Gaurav; Sinha, Aloka
2016-11-01
In this paper, we present a new technique to obtain biometric keys by using the fingerprint of a person for an optical image encryption system. The key generation scheme uses the fingerprint biometric information in terms of the amplitude mask (AM) and the phase mask (PM) of the reconstructed fingerprint image that is implemented using the digital holographic technique. Statistical tests have been conducted to check the randomness of the fingerprint PM key that enables its usage as an image encryption key. To explore the utility of the generated biometric keys, an optical image encryption system has been further demonstrated based on the phase retrieval algorithm and the double random phase encoding scheme in which keys for the encryption are used as the AM and the PM key. The advantage associated with the proposed scheme is that the biometric keys’ retrieval requires the simultaneous presence of the fingerprint hologram and the correct knowledge of the reconstruction parameters at the decryption stage, which not only verifies the authenticity of the person but also protects the valuable fingerprint biometric features of the keys. Numerical results are carried out to prove the feasibility and the effectiveness of the proposed encryption system.
NASA Astrophysics Data System (ADS)
Chen, Linfei; Chang, Guojun; He, Bingyu; Mao, Haidan; Zhao, Daomu
2017-01-01
In this paper, an optical encryption system is proposed based on tricolor principle, Fresnel diffraction, and phase iterative algorithms. Different from the traditional encryption system, the encrypted image of this system is a color image and the plaintext of it is a gray image, which can achieve the combination of a color image and a gray image and the conversion of one image to another image. Phase masks can be generated by using the phase iterative algorithms in this paper. The six phase masks and the six diffracting distances are all essential keys in the process of decryption, which can greatly enhance the system security. Numerical simulations are shown to prove the possibility and safety of the method.
Texture Analysis of Chaotic Coupled Map Lattices Based Image Encryption Algorithm
NASA Astrophysics Data System (ADS)
Khan, Majid; Shah, Tariq; Batool, Syeda Iram
2014-09-01
As of late, data security is key in different enclosures like web correspondence, media frameworks, therapeutic imaging, telemedicine and military correspondence. In any case, a large portion of them confronted with a few issues, for example, the absence of heartiness and security. In this letter, in the wake of exploring the fundamental purposes of the chaotic trigonometric maps and the coupled map lattices, we have presented the algorithm of chaos-based image encryption based on coupled map lattices. The proposed mechanism diminishes intermittent impact of the ergodic dynamical systems in the chaos-based image encryption. To assess the security of the encoded image of this scheme, the association of two nearby pixels and composition peculiarities were performed. This algorithm tries to minimize the problems arises in image encryption.
Fully phase image encryption using double random-structured phase masks in gyrator domain.
Singh, Hukum; Yadav, A K; Vashisth, Sunanda; Singh, Kehar
2014-10-01
We propose a method for fully phase image encryption based on double random-structured phase mask encoding in the gyrator transform (GT) domain. The security of the system is strengthened by parameters used in the construction of a structured phase mask (SPM) based on a devil's vortex Fresnel lens (DVFL). The input image is recovered using the correct parameters of the SPMs, transform orders of the GT, and conjugate of the random phase masks. The use of a DVFL-based SPM enhances security by increasing the key space for encryption, and also overcomes the problem of axis alignment associated with an optical setup. The proposed scheme can also be implemented optically. The computed values of mean squared error between the retrieved and the original image show the efficacy of the proposed scheme. We have also investigated the scheme's sensitivity to the encryption parameters, and robustness against occlusion and multiplicative Gaussian noise attacks.
Digital Image Encryption Based on the RC5 Block Cipher Algorithm
NASA Astrophysics Data System (ADS)
Faragallah, Osama S.
2011-12-01
Implementation of the RC5 block cipher algorithm for digital images in different modes of operation and its detailed encryption efficiency analysis are dealt with in this paper. The encryption efficiency analysis of the RC5 block cipher algorithm for digital images is investigated using several metrics including visual testing, maximum deviation, irregular deviation, information entropy, correlation coefficients, avalanche effect, histogram uniformity and key space analysis. The evaluation consists of theoretical derivations and practical experimentation. Experimental results have proved that the RC5 block cipher algorithm can be implemented efficiently for encryption of real-time digital images and demonstrated that the RC5 block cipher algorithm is highly secure from the strong cryptographic viewpoint.
A self-adaptive image encryption scheme with half-pixel interchange permutation operation
NASA Astrophysics Data System (ADS)
Ye, Ruisong; Liu, Li; Liao, Minyu; Li, Yafang; Liao, Zikang
2017-01-01
A plain-image dependent image encryption scheme with half-pixel-level swapping permutation strategy is proposed. In the new permutation operation, a pixel-swapping operation between four higher bit-planes and four lower bit-planes is employed to replace the traditional confusion operation, which not only improves the conventional permutation efficiency within the plain-image, but also changes all the pixel gray values. The control parameters of generalized Arnold map applied for the permutation operation are related to the plain-image content and consequently can resist chosen-plaintext and known-plaintext attacks effectively. To enhance the security of the proposed image encryption, one multimodal skew tent map is applied to generate pseudo-random gray value sequence for diffusion operation. Simulations have been carried out thoroughly to demonstrate that the proposed image encryption scheme is highly secure thanks to its large key space and efficient permutation-diffusion operations.
[Public production as a key factor for access to antivenoms in the Region of the Americas].
Temprano, Guillermo; Aprea, Patricia; Dokmetjian, José Christian
2017-08-21
Injuries caused by venomous animals affect vast areas of Latin America, Southern Asia, Southeast Asia, sub-Saharan Africa, and Oceania, and pose a serious problem for global public health. Based on an analysis of the current panorama of global production of ophidian and arachnid antivenoms, it is concluded that they are semi-orphaned products. This is a favorable scenario in which to strengthen public laboratory production. Governments should make a political decision in this regard in the interest of equity in population health. In the Region of the Americas, these actions could be part of a program led by the Pan American Health Organization to ensure the availability of these biologicals in strategically located health centers. Twelve public facilities producing antivenoms have been identified in the Region, including Brazil and Mexico, which are the biggest public producers. These laboratories should be managed like industrial operations that produce tangible goods without ignoring strategic planning. National regulatory authorities should help the public laboratories that produce them by providing necessary technical assistance and consultancy without any loss of impartiality or rigor in the evaluation of their quality management systems. New superior production technologies using hyperimmune mammalian plasma are in the experimental phase; no information on its production has been found in the literature.
Translating research for evidence-based public health: key concepts and future directions.
Rychetnik, Lucie; Bauman, Adrian; Laws, Rachel; King, Lesley; Rissel, Chris; Nutbeam, Don; Colagiuri, Stephen; Caterson, Ian
2012-12-01
Applying research to guide evidence-based practice is an ongoing and significant challenge for public health. Developments in the emerging field of 'translation' have focused on different aspects of the problem, resulting in competing frameworks and terminology. In this paper the scope of 'translation' in public health is defined, and four related but conceptually different 'translation processes' that support evidence-based practice are outlined: (1) reviewing the transferability of evidence to new settings, (2) translation research, (3) knowledge translation, and (4) knowledge translation research. Finally, an integrated framework is presented to illustrate the relationship between these domains, and priority areas for further development and empirical research are identified.
Implementation notes on bdes(1). [data encryption implementation
NASA Technical Reports Server (NTRS)
Bishop, Matt
1991-01-01
This note describes the implementation of bdes, the file encryption program being distributed in the 4.4 release of the Berkeley Software Distribution. It implements all modes of the Data Encryption Standard program.
An algorithm for encryption of secret images into meaningful images
NASA Astrophysics Data System (ADS)
Kanso, A.; Ghebleh, M.
2017-03-01
Image encryption algorithms typically transform a plain image into a noise-like cipher image, whose appearance is an indication of encrypted content. Bao and Zhou [Image encryption: Generating visually meaningful encrypted images, Information Sciences 324, 2015] propose encrypting the plain image into a visually meaningful cover image. This improves security by masking existence of encrypted content. Following their approach, we propose a lossless visually meaningful image encryption scheme which improves Bao and Zhou's algorithm by making the encrypted content, i.e. distortions to the cover image, more difficult to detect. Empirical results are presented to show high quality of the resulting images and high security of the proposed algorithm. Competence of the proposed scheme is further demonstrated by means of comparison with Bao and Zhou's scheme.
15 CFR Supplement No. 5 to Part 742 - Encryption Registration
Code of Federal Regulations, 2014 CFR
2014-01-01
... classification requests and self-classification reports for encryption items must be supported by an encryption... algorithms or protocols that have not been adopted or approved by a duly recognized international standards...
Su, Yonggang; Tang, Chen; Li, Biyuan; Chen, Xia; Xu, Wenjun; Cai, Yuanxue
2017-01-20
We propose an optical color image encryption system based on the single-lens Fourier transform, the Fresnel transform, and the chaotic random phase masks (CRPMs). The proposed encryption system contains only one optical lens, which makes it more efficient and concise to implement. The introduction of the Fresnel transform makes the first phase mask of the proposed system also act as the main secret key when the input image is a non-negative amplitude-only map. The two CRPMs generated by dual two-dimensional chaotic maps can provide more security to the proposed system. In the proposed system, the key management is more convenient and the transmission volume is reduced greatly. In addition, the secret keys can be updated conveniently in each encryption process to invalidate the chosen plaintext attack and the known plaintext attack. Numerical simulation results have demonstrated the feasibility and security of the proposed encryption system.
Interviewing Key Informants: Strategic Planning for a Global Public Health Management Program
ERIC Educational Resources Information Center
Kun, Karen E.; Kassim, Anisa; Howze, Elizabeth; MacDonald, Goldie
2013-01-01
The Centers for Disease Control and Prevention's Sustainable Management Development Program (SMDP) partners with low- and middle-resource countries to develop management capacity so that effective global public health programs can be implemented and better health outcomes can be achieved. The program's impact however, was variable. Hence, there…
ERIC Educational Resources Information Center
Kayaga, Sam
2007-01-01
The capacity of public service staff in developing countries is crucial for achieving the Millennium Development Goals. Literature from developed countries shows that, working with higher education institutions (HEIs), industries have improved their human resource capacity through continuing professional development. This paper reports on research…
Quantum Image Encryption Based on Iterative Framework of Frequency-Spatial Domain Transforms
NASA Astrophysics Data System (ADS)
Wang, Han; Wang, Jian; Geng, Ya-Cong; Song, Yan; Liu, Ji-Qiang
2017-07-01
A novel quantum image encryption and decryption algorithm based on iteration framework of frequency-spatial domain transforms is proposed. In this paper, the images are represented in the flexible representation for quantum images (FRQI). Previous quantum image encryption algorithms are realized by spatial domain transform to scramble the position information of original images and frequency domain transform to encode the color information of images. But there are some problems such as the periodicity of spatial domain transform, which will make it easy to recover the original images. Hence, we present the iterative framework of frequency-spatial domain transforms. Based on the iterative framework, the novel encryption algorithm uses Fibonacci transform and geometric transform for many times to scramble the position information of the original images and double random-phase encoding to encode the color information of the images. The encryption keys include the iterative time t of the Fibonacci transform, the iterative time l of the geometric transform, the geometric transform matrix G i which is n × n matrix, the classical binary sequences K ( k0k1{\\ldots } k_{2^{2n}-1}) and D(d0d1{\\ldots } d_{2^{2n}-1}). Here the key space of Fibonacci transform and geometric transform are both estimated to be 226. The key space of binary sequences is (2 n×n ) × (2 n×n ). Then the key space of the entire algorithm is about 2^{2{n2}+52}. Since all quantum operations are invertible, the quantum image decryption algorithm is the inverse of the encryption algorithm. The results of numerical simulation and analysis indicate that the proposed algorithm has high security and high sensitivity.
Quantum Image Encryption Based on Iterative Framework of Frequency-Spatial Domain Transforms
NASA Astrophysics Data System (ADS)
Wang, Han; Wang, Jian; Geng, Ya-Cong; Song, Yan; Liu, Ji-Qiang
2017-10-01
A novel quantum image encryption and decryption algorithm based on iteration framework of frequency-spatial domain transforms is proposed. In this paper, the images are represented in the flexible representation for quantum images (FRQI). Previous quantum image encryption algorithms are realized by spatial domain transform to scramble the position information of original images and frequency domain transform to encode the color information of images. But there are some problems such as the periodicity of spatial domain transform, which will make it easy to recover the original images. Hence, we present the iterative framework of frequency-spatial domain transforms. Based on the iterative framework, the novel encryption algorithm uses Fibonacci transform and geometric transform for many times to scramble the position information of the original images and double random-phase encoding to encode the color information of the images. The encryption keys include the iterative time t of the Fibonacci transform, the iterative time l of the geometric transform, the geometric transform matrix G i which is n × n matrix, the classical binary sequences K (k0k1{\\ldots } k_{2^{2n}-1}) and D(d0d1{\\ldots } d_{2^{2n}-1}). Here the key space of Fibonacci transform and geometric transform are both estimated to be 226. The key space of binary sequences is (2 n× n ) × (2 n× n ). Then the key space of the entire algorithm is about 2^{2{n2}+52}. Since all quantum operations are invertible, the quantum image decryption algorithm is the inverse of the encryption algorithm. The results of numerical simulation and analysis indicate that the proposed algorithm has high security and high sensitivity.
A novel block encryption scheme based on chaos and an S-box for wireless sensor networks
NASA Astrophysics Data System (ADS)
Tong, Xiao-Jun; Wang, Zhu; Zuo, Ke
2012-02-01
The wireless sensor network (WSN) has been widely used in various fields, but it still remains in the preliminary discovery and research phase with a lack of various related mature technologies. Traditional encryption schemes are not suitable for wireless sensor networks due to intrinsic features of the nodes such as low energy, limited computation capability, and lack of storage resources. In this paper, we present a novel block encryption scheme based on the integer discretization of a chaotic map, the Feistel network structure, and an S-box. The novel scheme is fast, secure, has low resource consumption and is suitable for wireless sensor network node encryption schemes. The experimental tests are carried out with detailed analysis, showing that the novel block algorithm has a large key space, very good diffusion and disruptive performances, a strict avalanche effect, excellent statistical balance, and fast encryption speed. These features enable the encryption scheme to pass the SP800-22 test. Meanwhile, the analysis and the testing of speed, time, and storage space on the simulator platform show that this new encryption scheme is well able to hide data information in wireless sensor networks.
Chaotic Image Encryption of Regions of Interest
NASA Astrophysics Data System (ADS)
Xiao, Di; Fu, Qingqing; Xiang, Tao; Zhang, Yushu
Since different regions of an image have different importance, therefore only the important information of the image regions, which the users are really interested in, needs to be encrypted and protected emphatically in some special multimedia applications. However, the regions of interest (ROI) are always some irregular parts, such as the face and the eyes. Assuming the bulk data in transmission without being damaged, we propose a chaotic image encryption algorithm for ROI. ROI with irregular shapes are chosen and detected arbitrarily. Then the chaos-based image encryption algorithm with scrambling, S-box and diffusion parts is used to encrypt the ROI. Further, the whole image is compressed with Huffman coding. At last, a message authentication code (MAC) of the compressed image is generated based on chaotic maps. The simulation results show that the encryption algorithm has a good security level and can resist various attacks. Moreover, the compression method improves the storage and transmission efficiency to some extent, and the MAC ensures the integrity of the transmission data.
2013-01-01
Background If Public Health is the science and art of how society collectively aims to improve health, and reduce inequalities in health, then Public Health Economics is the science and art of supporting decision making as to how society can use its available resources to best meet these objectives and minimise opportunity cost. A systematic review of published guidance for the economic evaluation of public health interventions within this broad public policy paradigm was conducted. Methods Electronic databases and organisation websites were searched using a 22 year time horizon (1990–2012). References of papers were hand searched for additional papers for inclusion. Government reports or peer-reviewed published papers were included if they; referred to the methods of economic evaluation of public health interventions, identified key challenges of conducting economic evaluations of public health interventions or made recommendations for conducting economic evaluations of public health interventions. Guidance was divided into three categories UK guidance, international guidance and observations or guidance provided by individual commentators in the field of public health economics. An assessment of the theoretical frameworks underpinning the guidance was made and served as a rationale for categorising the papers. Results We identified 5 international guidance documents, 7 UK guidance documents and 4 documents by individual commentators. The papers reviewed identify the main methodological challenges that face analysts when conducting such evaluations. There is a consensus within the guidance that wider social and environmental costs and benefits should be looked at due to the complex nature of public health. This was reflected in the theoretical underpinning as the majority of guidance was categorised as extra-welfarist. Conclusions In this novel review we argue that health economics may have come full circle from its roots in broad public policy economics. We may
Edwards, Rhiannon Tudor; Charles, Joanna Mary; Lloyd-Williams, Huw
2013-10-24
If Public Health is the science and art of how society collectively aims to improve health, and reduce inequalities in health, then Public Health Economics is the science and art of supporting decision making as to how society can use its available resources to best meet these objectives and minimise opportunity cost. A systematic review of published guidance for the economic evaluation of public health interventions within this broad public policy paradigm was conducted. Electronic databases and organisation websites were searched using a 22 year time horizon (1990-2012). References of papers were hand searched for additional papers for inclusion. Government reports or peer-reviewed published papers were included if they; referred to the methods of economic evaluation of public health interventions, identified key challenges of conducting economic evaluations of public health interventions or made recommendations for conducting economic evaluations of public health interventions. Guidance was divided into three categories UK guidance, international guidance and observations or guidance provided by individual commentators in the field of public health economics. An assessment of the theoretical frameworks underpinning the guidance was made and served as a rationale for categorising the papers. We identified 5 international guidance documents, 7 UK guidance documents and 4 documents by individual commentators. The papers reviewed identify the main methodological challenges that face analysts when conducting such evaluations. There is a consensus within the guidance that wider social and environmental costs and benefits should be looked at due to the complex nature of public health. This was reflected in the theoretical underpinning as the majority of guidance was categorised as extra-welfarist. In this novel review we argue that health economics may have come full circle from its roots in broad public policy economics. We may find it useful to think in this broader
On the security of a new image encryption scheme based on chaotic map lattices.
Arroyo, David; Rhouma, Rhouma; Alvarez, Gonzalo; Li, Shujun; Fernandez, Veronica
2008-09-01
This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the logistic map [A. Pisarchik et al., Chaos 16, 033118 (2006)]. Some problems are emphasized concerning the key space definition and the implementation of the cryptosystem using floating-point operations. It is also shown how it is possible to reduce considerably the key space through a ciphertext-only attack. Moreover, a timing attack allows for the estimation of part of the key due to the existent relationship between this part of the key and the encryption/decryption time. As a result, the main features of the cryptosystem do not satisfy the demands of secure communications. Some hints are offered to improve the cryptosystem under study according to those requirements. (c) 2008 American Institute of Physics.
Public-private relationships in biobanking: a still underestimated key component of open innovation.
Hofman, Paul; Bréchot, Christian; Zatloukal, Kurt; Dagher, Georges; Clément, Bruno
2014-01-01
Access to human bioresources is essential to the understanding of human diseases and to the discovery of new biomarkers aimed at improving the diagnosis, prognosis, and the predictive response of patients to treatments. The use of biospecimens is strictly controlled by ethical assessment, which complies with the laws of the country. These laws regulate the partnerships between the biobanks and industrial actors. However, private-public partnerships (PPP) can be limiting for several reasons, which can hamper the discovery of new biological tests and new active molecules targeted to human diseases. The bottlenecks and roadblocks in establishing these partnerships include: poor organization of the biobank in setting up PPP, evaluation of the cost of human samples, the absence of experience on the public side in setting up contracts with industry, and the fact that public and private partners may not share the same objectives. However, it is critical, in particular for academic biobanks, to establish strong PPP to accelerate translational research for the benefits of patients, and to allow the sustainability of the biobank. The purpose of this review is to discuss the main bottlenecks and roadblocks that can hamper the establishment of PPP based on solid and trusting relationships.
A chaos-based digital image encryption scheme with an improved diffusion strategy.
Fu, Chong; Chen, Jun-jie; Zou, Hao; Meng, Wei-hong; Zhan, Yong-feng; Yu, Ya-wen
2012-01-30
Chaos-based image cipher has been widely investigated over the last decade or so to meet the increasing demand for real-time secure image transmission over public networks. In this paper, an improved diffusion strategy is proposed to promote the efficiency of the most widely investigated permutation-diffusion type image cipher. By using the novel bidirectional diffusion strategy, the spreading process is significantly accelerated and hence the same level of security can be achieved with fewer overall encryption rounds. Moreover, to further enhance the security of the cryptosystem, a plain-text related chaotic orbit turbulence mechanism is introduced in diffusion procedure by perturbing the control parameter of the employed chaotic system according to the cipher-pixel. Extensive cryptanalysis has been performed on the proposed scheme using differential analysis, key space analysis, various statistical analyses and key sensitivity analysis. Results of our analyses indicate that the new scheme has a satisfactory security level with a low computational complexity, which renders it a good candidate for real-time secure image transmission applications.
Seo, Jung Woo; Lee, Sang Jin
2016-01-01
Weather information provides a safe working environment by contributing to the economic activity of the nation, and plays role of the prevention of natural disasters, which can cause large scaled casualties and damage of property. Especially during times of war, weather information plays a more important role than strategy, tactics and information about trends of the enemy. Also, it plays an essential role for the taking off and landing of fighter jet and the sailing of warships. If weather information, which plays a major role in national security and economy, gets misused for cyber terrorism resulting false weather information, it could be a huge threat for national security and the economy. We propose a plan to safely transmit the measured value from meteorological sensors through a meteorological telecommunication network in order to guarantee the confidentiality and integrity of the data despite cyber-attacks. Also, such a plan allows one to produce reliable weather forecasts by performing mutual authentication through authentication devices. To make sure of this, one can apply an Identity Based Signature to ensure the integrity of measured data, and transmit the encrypted weather information with mutual authentication about the authentication devices. There are merits of this research: It is not necessary to manage authentication certificates unlike the Public Key Infrastructure methodology, and it provides a powerful security measure with the capability to be realized in a small scale computing environment, such as the meteorological observation system due to the low burden on managing keys.
Aldossari, M; Alfalou, A; Brosseau, C
2014-09-22
This study presents and validates an optimized method of simultaneous compression and encryption designed to process images with close spectra. This approach is well adapted to the compression and encryption of images of a time-varying scene but also to static polarimetric images. We use the recently developed spectral fusion method [Opt. Lett.35, 1914-1916 (2010)] to deal with the close resemblance of the images. The spectral plane (containing the information to send and/or to store) is decomposed in several independent areas which are assigned according a specific way. In addition, each spectrum is shifted in order to minimize their overlap. The dual purpose of these operations is to optimize the spectral plane allowing us to keep the low- and high-frequency information (compression) and to introduce an additional noise for reconstructing the images (encryption). Our results show that not only can the control of the spectral plane enhance the number of spectra to be merged, but also that a compromise between the compression rate and the quality of the reconstructed images can be tuned. We use a root-mean-square (RMS) optimization criterion to treat compression. Image encryption is realized at different security levels. Firstly, we add a specific encryption level which is related to the different areas of the spectral plane, and then, we make use of several random phase keys. An in-depth analysis at the spectral fusion methodology is done in order to find a good trade-off between the compression rate and the quality of the reconstructed images. Our new proposal spectral shift allows us to minimize the image overlap. We further analyze the influence of the spectral shift on the reconstructed image quality and compression rate. The performance of the multiple-image optical compression and encryption method is verified by analyzing several video sequences and polarimetric images.
Mt-Isa, Shahrul; Ouwens, Mario; Robert, Veronique; Gebel, Martin; Schacht, Alexander; Hirsch, Ian
2016-07-01
Introduction The conduct of structured benefit-risk assessment (BRA) of pharmaceutical products is a key area of interest for regulatory agencies and the pharmaceutical industry. However, the acceptance of a standardized approach and implementation are slow. Statisticians play major roles in these organizations, and have a great opportunity to be involved and drive the shaping of future BRA. Method We performed a literature search of recent reviews and initiatives assessing BRA methodologies, and grouped them to assist those new to BRA in learning, understanding, and choosing methodologies. We summarized the key points and discussed the impact of this emerging field on various stakeholders, particularly statisticians in the pharmaceutical industry. Results We provide introductory, essential, special interest, and further information and initiatives materials that direct readers to the most relevant materials, which were published between 2000 and 2013. Based on recommendations in these materials we supply a toolkit of advocated BRA methodologies. Discussion Despite initiatives promoting these methodologies, there are still barriers, one of which being the lack of a consensus on the most appropriate methodologies among stakeholders. However, this opens up opportunities, for statisticians in the pharmaceutical industry especially, to champion appropriate BRA methodology use throughout the pharmaceutical product lifecycle. Conclusions This article may serve as a starting point for discussions and to reach a mutual consensus for methodology selection in a particular situation. Regulators and pharmaceutical industry should continue to collaborate to develop and take forward BRA methodologies, and by clear communication develop a mutual understanding of the key issues. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Zhao, Shengmei; Wang, Le; Liang, Wenqiang; Cheng, Weiwen; Gong, Longyan
2015-10-01
In this paper, we propose a high performance optical encryption (OE) scheme based on computational ghost imaging (GI) with QR code and compressive sensing (CS) technique, named QR-CGI-OE scheme. N random phase screens, generated by Alice, is a secret key and be shared with its authorized user, Bob. The information is first encoded by Alice with QR code, and the QR-coded image is then encrypted with the aid of computational ghost imaging optical system. Here, measurement results from the GI optical system's bucket detector are the encrypted information and be transmitted to Bob. With the key, Bob decrypts the encrypted information to obtain the QR-coded image with GI and CS techniques, and further recovers the information by QR decoding. The experimental and numerical simulated results show that the authorized users can recover completely the original image, whereas the eavesdroppers can not acquire any information about the image even the eavesdropping ratio (ER) is up to 60% at the given measurement times. For the proposed scheme, the number of bits sent from Alice to Bob are reduced considerably and the robustness is enhanced significantly. Meantime, the measurement times in GI system is reduced and the quality of the reconstructed QR-coded image is improved.
Sui, Liansheng; Duan, Kuaikuai; Liang, Junli; Hei, Xinhong
2014-05-05
A double-image encryption is proposed based on the discrete fractional random transform and logistic maps. First, an enlarged image is composited from two original images and scrambled in the confusion process which consists of a number of rounds. In each round, the pixel positions of the enlarged image are relocated by using cat maps which are generated based on two logistic maps. Then the scrambled enlarged image is decomposed into two components. Second, one of two components is directly separated into two phase masks and the other component is used to derive the ciphertext image with stationary white noise distribution by using the cascaded discrete fractional random transforms generated based on the logistic map. The cryptosystem is asymmetric and has high resistance against to the potential attacks such as chosen plaintext attack, in which the initial values of logistic maps and the fractional orders are considered as the encryption keys while two decryption keys are produced in the encryption process and directly related to the original images. Simulation results and security analysis verify the feasibility and effectiveness of the proposed encryption scheme.