Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.
Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt
2009-05-30
The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information.
Large-scale electrophysiology: acquisition, compression, encryption, and storage of big data.
Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt
2009-05-30
The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single-neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single-neuron action potentials, high frequency oscillations, and high amplitude ultra-slow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range-encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information. PMID:19427545
Large-scale Electrophysiology: Acquisition, Compression, Encryption, and Storage of Big Data
Brinkmann, Benjamin H.; Bower, Mark R.; Stengel, Keith A.; Worrell, Gregory A.; Stead, Matt
2009-01-01
The use of large-scale electrophysiology to obtain high spatiotemporal resolution brain recordings (>100 channels) capable of probing the range of neural activity from local field potential oscillations to single neuron action potentials presents new challenges for data acquisition, storage, and analysis. Our group is currently performing continuous, long-term electrophysiological recordings in human subjects undergoing evaluation for epilepsy surgery using hybrid intracranial electrodes composed of up to 320 micro- and clinical macroelectrode arrays. DC-capable amplifiers, sampling at 32 kHz per channel with 18-bits of A/D resolution are capable of resolving extracellular voltages spanning single neuron action potentials, high frequency oscillations, and high amplitude ultraslow activity, but this approach generates 3 terabytes of data per day (at 4 bytes per sample) using current data formats. Data compression can provide several practical benefits, but only if data can be compressed and appended to files in real-time in a format that allows random access to data segments of varying size. Here we describe a state-of-the-art, scalable, electrophysiology platform designed for acquisition, compression, encryption, and storage of large-scale data. Data are stored in a file format that incorporates lossless data compression using range encoded differences, a 32-bit cyclically redundant checksum to ensure data integrity, and 128-bit encryption for protection of patient information. PMID:19427545
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
Compressive Optical Image Encryption
NASA Astrophysics Data System (ADS)
Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong
2015-05-01
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.
Compressive sensing based ptychography image encryption
NASA Astrophysics Data System (ADS)
Rawat, Nitin
2015-09-01
A compressive sensing (CS) based ptychography combined with an optical image encryption is proposed. The diffraction pattern is recorded through ptychography technique further compressed by non-uniform sampling via CS framework. The system requires much less encrypted data and provides high security. The diffraction pattern as well as the lesser measurements of the encrypted samples serves as a secret key which make the intruder attacks more difficult. Furthermore, CS shows that the linearly projected few random samples have adequate information for decryption with a dramatic volume reduction. Experimental results validate the feasibility and effectiveness of our proposed technique compared with the existing techniques. The retrieved images do not reveal any information with the original information. In addition, the proposed system can be robust even with partial encryption and under brute-force attacks.
System using data compression and hashing adapted for use for multimedia encryption
Coffland, Douglas R.
2011-07-12
A system and method is disclosed for multimedia encryption. Within the system of the present invention, a data compression module receives and compresses a media signal into a compressed data stream. A data acquisition module receives and selects a set of data from the compressed data stream. And, a hashing module receives and hashes the set of data into a keyword. The method of the present invention includes the steps of compressing a media signal into a compressed data stream; selecting a set of data from the compressed data stream; and hashing the set of data into a keyword.
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.
Simultaneous fusion, compression, and encryption of multiple images.
Alfalou, A; Brosseau, C; Abdallah, N; Jridi, M
2011-11-21
We report a new spectral multiple image fusion analysis based on the discrete cosine transform (DCT) and a specific spectral filtering method. In order to decrease the size of the multiplexed file, we suggest a procedure of compression which is based on an adapted spectral quantization. Each frequency is encoded with an optimized number of bits according its importance and its position in the DC domain. This fusion and compression scheme constitutes a first level of encryption. A supplementary level of encryption is realized by making use of biometric information. We consider several implementations of this analysis by experimenting with sequences of gray scale images. To quantify the performance of our method we calculate the MSE (mean squared error) and the PSNR (peak signal to noise ratio). Our results consistently improve performances compared to the well-known JPEG image compression standard and provide a viable solution for simultaneous compression and encryption of multiple images.
Combined data encryption and compression using chaos functions
NASA Astrophysics Data System (ADS)
Bose, Ranjan; Pathak, Saumitr
2004-10-01
Past research in the field of cryptography has not given much consideration to arithmetic coding as a feasible encryption technique, with studies proving compression-specific arithmetic coding to be largely unsuitable for encryption. Nevertheless, adaptive modelling, which offers a huge model, variable in structure, and as completely as possible a function of the entire text that has been transmitted since the time the model was initialised, is a suitable candidate for a possible encryption-compression combine. The focus of the work presented in this paper has been to incorporate recent results of chaos theory, proven to be cryptographically secure, into arithmetic coding, to devise a convenient method to make the structure of the model unpredictable and variable in nature, and yet to retain, as far as is possible, statistical harmony, so that compression is possible. A chaos-based adaptive arithmetic coding-encryption technique has been designed, developed and tested and its implementation has been discussed. For typical text files, the proposed encoder gives compression between 67.5% and 70.5%, the zero-order compression suffering by about 6% due to encryption, and is not susceptible to previously carried out attacks on arithmetic coding algorithms.
NASA Astrophysics Data System (ADS)
Chen, Tinghuan; Zhang, Meng; Wu, Jianhui; Yuen, Chau; Tong, You
2016-10-01
Because of simple encryption and compression procedure in single step, compressed sensing (CS) is utilized to encrypt and compress an image. Difference of sparsity levels among blocks of the sparsely transformed image degrades compression performance. In this paper, motivated by this difference of sparsity levels, we propose an encryption and compression approach combining Kronecker CS (KCS) with elementary cellular automata (ECA). In the first stage of encryption, ECA is adopted to scramble the sparsely transformed image in order to uniformize sparsity levels. A simple approximate evaluation method is introduced to test the sparsity uniformity. Due to low computational complexity and storage, in the second stage of encryption, KCS is adopted to encrypt and compress the scrambled and sparsely transformed image, where the measurement matrix with a small size is constructed from the piece-wise linear chaotic map. Theoretical analysis and experimental results show that our proposed scrambling method based on ECA has great performance in terms of scrambling and uniformity of sparsity levels. And the proposed encryption and compression method can achieve better secrecy, compression performance and flexibility.
Joint compression and encryption using chaotically mutated Huffman trees
NASA Astrophysics Data System (ADS)
Hermassi, Houcemeddine; Rhouma, Rhouma; Belghith, Safya
2010-10-01
This paper introduces a new scheme for joint compression and encryption using the Huffman codec. A basic tree is first generated for a given message and then based on a keystream generated from a chaotic map and depending from the input message, the basic tree is mutated without changing the statistical model. Hence a symbol can be coded by more than one codeword having the same length. The security of the scheme is tested against the known plaintext attack and the brute force attack. Performance analysis including encryption/decryption speed, additional computational complexity and compression ratio are given.
Scrambling-based speech encryption via compressed sensing
NASA Astrophysics Data System (ADS)
Zeng, Li; Zhang, Xiongwei; Chen, Liang; Fan, Zhangjun; Wang, Yonggang
2012-12-01
Conventional speech scramblers have three disadvantages, including heavy communication overhead, signal features underexploitation, and low attack resistance. In this study, we propose a scrambling-based speech encryption scheme via compressed sensing (CS). Distinguished from conventional scramblers, the above problems are solved in a unified framework by utilizing the advantages of CS. The presented encryption idea is general and easily applies to speech communication systems. Compared with the state-of-the-art methods, the proposed scheme provides lower residual intelligibility and greater cryptanalytic efforts. Meanwhile, it ensures desirable channel usage and notable resistibility to hostile attack. Extensive experimental results also confirm the effectiveness of the proposed scheme.
NASA Astrophysics Data System (ADS)
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.
2016-02-01
We applied compressed ultrafast photography (CUP), a computational imaging technique, to acquire three-dimensional (3D) images. The approach unites image encryption, compression, and acquisition in a single measurement, thereby allowing efficient and secure data transmission. By leveraging the time-of-flight (ToF) information of pulsed light reflected by the object, we can reconstruct a volumetric image (150 mm×150 mm×1050 mm, x × y × z) from a single camera snapshot. Furthermore, we demonstrated high-speed 3D videography of a moving object at 75 frames per second using the ToF-CUP camera.
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.
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.
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V
2015-01-01
Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V
2015-10-27
Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.
NASA Astrophysics Data System (ADS)
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.
2015-10-01
Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium.
Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.
2015-01-01
Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834
Optical image encryption via photon-counting imaging and compressive sensing based ptychography
NASA Astrophysics Data System (ADS)
Rawat, Nitin; Hwang, In-Chul; Shi, Yishi; Lee, Byung-Geun
2015-06-01
In this study, we investigate the integration of compressive sensing (CS) and photon-counting imaging (PCI) techniques with a ptychography-based optical image encryption system. Primarily, the plaintext real-valued image is optically encrypted and recorded via a classical ptychography technique. Further, the sparse-based representations of the original encrypted complex data can be produced by combining CS and PCI techniques with the primary encrypted image. Such a combination takes an advantage of reduced encrypted samples (i.e., linearly projected random compressive complex samples and photon-counted complex samples) that can be exploited to realize optical decryption, which inherently serves as a secret key (i.e., independent to encryption phase keys) and makes an intruder attack futile. In addition to this, recording fewer encrypted samples provides a substantial bandwidth reduction in online transmission. We demonstrate that the fewer sparse-based complex samples have adequate information to realize decryption. To the best of our knowledge, this is the first report on integrating CS and PCI with conventional ptychography-based optical image encryption.
Simultaneous edge sensing compression and encryption for real-time video transmission
NASA Astrophysics Data System (ADS)
Al-Hayani, Nazar; Al-Jawad, Naseer; Jassim, Sabah
2014-05-01
Video compression and encryption became an essential part in multimedia application and video conferencing in particular. Applying both techniques simultaneously is one of the challenges where the size and the quality are important. In this paper we are suggesting the use of wavelet transform in order to deal with the low frequency coefficients when undertaking the encryption on the wavelet high frequency coefficients while accomplishing the compression. Applying both methods simultaneously is not new. In this paper we are suggesting a way to improve the security level of the encryption with better computational performance in both encryption and compression. Both encryption and compression in this paper are based on edges extraction from the wavelet high frequency sub-bands. Although there are some research perform the edge detection on the spatial domain, but the number of edges produced based on wavelet can be dynamic which have an effect on the compression ratio dynamically. Moreover, this kind of edge detection in wavelet domain will add different level of selective encryption.
NASA Astrophysics Data System (ADS)
Alfalou, Ayman; Elbouz, Marwa; Jridi, Maher; Loussert, Alain
2009-09-01
In some recognition form applications (which require multiple images: facial identification or sign-language), many images should be transmitted or stored. This requires the use of communication systems with a good security level (encryption) and an acceptable transmission rate (compression rate). In the literature, several encryption and compression techniques can be found. In order to use optical correlation, encryption and compression techniques cannot be deployed independently and in a cascade manner. Otherwise, our system will suffer from two major problems. In fact, we cannot simply use these techniques in a cascade manner without considering the impact of one technique over another. Secondly, a standard compression can affect the correlation decision, because the correlation is sensitive to the loss of information. To solve both problems, we developed a new technique to simultaneously compress & encrypt multiple images using a BPOF optimized filter. The main idea of our approach consists in multiplexing the spectrums of different transformed images by a Discrete Cosine Transform (DCT). To this end, the spectral plane should be divided into several areas and each of them corresponds to the spectrum of one image. On the other hand, Encryption is achieved using the multiplexing, a specific rotation functions, biometric encryption keys and random phase keys. A random phase key is widely used in optical encryption approaches. Finally, many simulations have been conducted. Obtained results corroborate the good performance of our approach. We should also mention that the recording of the multiplexed and encrypted spectra is optimized using an adapted quantification technique to improve the overall compression rate.
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.
Raeiatibanadkooki, Mahsa; Quchani, Saeed Rahati; KhalilZade, MohammadMahdi; Bahaadinbeigy, Kambiz
2016-03-01
In mobile health care monitoring, compression is an essential tool for solving storage and transmission problems. The important issue is able to recover the original signal from the compressed signal. The main purpose of this paper is compressing the ECG signal with no loss of essential data and also encrypting the signal to keep it confidential from everyone, except for physicians. In this paper, mobile processors are used and there is no need for any computers to serve this purpose. After initial preprocessing such as removal of the baseline noise, Gaussian noise, peak detection and determination of heart rate, the ECG signal is compressed. In compression stage, after 3 steps of wavelet transform (db04), thresholding techniques are used. Then, Huffman coding with chaos for compression and encryption of the ECG signal are used. The compression rates of proposed algorithm is 97.72 %. Then, the ECG signals are sent to a telemedicine center to acquire specialist diagnosis by TCP/IP protocol.
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.
General theory for the processing of compressed and encrypted imagery with taxonomic analysis
NASA Astrophysics Data System (ADS)
Schmalz, Mark S.
1992-07-01
The processing of compressed and encrypted imagery can exhibit advantages of computational efficiency as well as data security. Due to the data reduction inherent in compression, the computational speedup achieved via compressive processing can equal or exceed the compression ratio. Encryptive transformations which yield compressed ciphertext can similarly facilitate computational speedup, and are well known. However, due to analytical difficulties inherent in the derivation of operations which compute over the range space of commonly employed compressive transforms, reports of such processing paradigms are not evident in the open literature. In this introductory paper, we describe compressive and encryptive transformations in terms of functional mappings derived from abstract mathematics and image algebra (IA). An emerging technology, IA is a rigorous, concise notation which unifies linear and nonlinear mathematics in the image domain, and has been implemented on a variety of serial and parallel computers. Additionally, we derive a taxonomy of image transformations. Each taxonomic class is analyzed in terms of computational complexity and applicability to image and signal processing. We further present decompositions specific to each transformational class, which facilitate the design of operations over a given transform's range space. Examples and analysis are given for several image operations.
Compression of Encrypted Images Using Set Partitioning In Hierarchical Trees Algorithm
NASA Astrophysics Data System (ADS)
Sarika, G.; Unnithan, Harikuttan; Peter, Smitha
2011-10-01
When it is desired to transmit redundant data over an insecure channel, it is customary to encrypt the data. For encrypted real world sources such as images, the use of Markova properties in the slepian-wolf decoder does not work well for gray scale images. Here in this paper we propose a method of compression of an encrypted image. In the encoder section, the image is first encrypted and then it undergoes compression in resolution. The cipher function scrambles only the pixel values, but does not shuffle the pixel locations. After down sampling, each sub-image is encoded independently and the resulting syndrome bits are transmitted. The received image undergoes a joint decryption and decompression in the decoder section. By using the local statistics based on the image, it is recovered back. Here the decoder gets only lower resolution version of the image. In addition, this method provides only partial access to the current source at the decoder side, which improves the decoder's learning of the source statistics. The source dependency is exploited to improve the compression efficiency. This scheme provides better coding efficiency and less computational complexity.
NASA Astrophysics Data System (ADS)
Liu, Wei; Liu, Zhengjun; Liu, Shutian
2015-12-01
We report a simultaneous image compression and encryption scheme based on solving a typical optical inverse problem. The secret images to be processed are multiplexed as the input intensities of a cascaded diffractive optical system. At the output plane, a compressed complex-valued data with a lot fewer measurements can be obtained by utilizing error-reduction phase retrieval algorithm. The magnitude of the output image can serve as the final ciphertext while its phase serves as the decryption key. Therefore the compression and encryption are simultaneously completed without additional encoding and filtering operations. The proposed strategy can be straightforwardly applied to the existing optical security systems that involve diffraction and interference. Numerical simulations are performed to demonstrate the validity and security of the proposal.
Raeiatibanadkooki, Mahsa; Quchani, Saeed Rahati; KhalilZade, MohammadMahdi; Bahaadinbeigy, Kambiz
2016-03-01
In mobile health care monitoring, compression is an essential tool for solving storage and transmission problems. The important issue is able to recover the original signal from the compressed signal. The main purpose of this paper is compressing the ECG signal with no loss of essential data and also encrypting the signal to keep it confidential from everyone, except for physicians. In this paper, mobile processors are used and there is no need for any computers to serve this purpose. After initial preprocessing such as removal of the baseline noise, Gaussian noise, peak detection and determination of heart rate, the ECG signal is compressed. In compression stage, after 3 steps of wavelet transform (db04), thresholding techniques are used. Then, Huffman coding with chaos for compression and encryption of the ECG signal are used. The compression rates of proposed algorithm is 97.72 %. Then, the ECG signals are sent to a telemedicine center to acquire specialist diagnosis by TCP/IP protocol. PMID:26779641
Li, Xiangwei; Lan, Xuguang; Yang, Meng; Xue, Jianru; Zheng, Nanning
2014-12-05
Compressive Sensing Imaging (CSI) is a new framework for image acquisition, which enables the simultaneous acquisition and compression of a scene. Since the characteristics of Compressive Sensing (CS) acquisition are very different from traditional image acquisition, the general image compression solution may not work well. In this paper, we propose an efficient lossy compression solution for CS acquisition of images by considering the distinctive features of the CSI. First, we design an adaptive compressive sensing acquisition method for images according to the sampling rate, which could achieve better CS reconstruction quality for the acquired image. Second, we develop a universal quantization for the obtained CS measurements from CS acquisition without knowing any a priori information about the captured image. Finally, we apply these two methods in the CSI system for efficient lossy compression of CS acquisition. Simulation results demonstrate that the proposed solution improves the rate-distortion performance by 0.4~2 dB comparing with current state-of-the-art, while maintaining a low computational complexity.
Li, Xiangwei; Lan, Xuguang; Yang, Meng; Xue, Jianru; Zheng, Nanning
2014-01-01
Compressive Sensing Imaging (CSI) is a new framework for image acquisition, which enables the simultaneous acquisition and compression of a scene. Since the characteristics of Compressive Sensing (CS) acquisition are very different from traditional image acquisition, the general image compression solution may not work well. In this paper, we propose an efficient lossy compression solution for CS acquisition of images by considering the distinctive features of the CSI. First, we design an adaptive compressive sensing acquisition method for images according to the sampling rate, which could achieve better CS reconstruction quality for the acquired image. Second, we develop a universal quantization for the obtained CS measurements from CS acquisition without knowing any a priori information about the captured image. Finally, we apply these two methods in the CSI system for efficient lossy compression of CS acquisition. Simulation results demonstrate that the proposed solution improves the rate-distortion performance by 0.4∼2 dB comparing with current state-of-the-art, while maintaining a low computational complexity. PMID:25490597
A joint image encryption and watermarking algorithm based on compressive sensing and chaotic map
NASA Astrophysics Data System (ADS)
Xiao, Di; Cai, Hong-Kun; Zheng, Hong-Ying
2015-06-01
In this paper, a compressive sensing (CS) and chaotic map-based joint image encryption and watermarking algorithm is proposed. The transform domain coefficients of the original image are scrambled by Arnold map firstly. Then the watermark is adhered to the scrambled data. By compressive sensing, a set of watermarked measurements is obtained as the watermarked cipher image. In this algorithm, watermark embedding and data compression can be performed without knowing the original image; similarly, watermark extraction will not interfere with decryption. Due to the characteristics of CS, this algorithm features compressible cipher image size, flexible watermark capacity, and lossless watermark extraction from the compressed cipher image as well as robustness against packet loss. Simulation results and analyses show that the algorithm achieves good performance in the sense of security, watermark capacity, extraction accuracy, reconstruction, robustness, etc. Project supported by the Open Research Fund of Chongqing Key Laboratory of Emergency Communications, China (Grant No. CQKLEC, 20140504), the National Natural Science Foundation of China (Grant Nos. 61173178, 61302161, and 61472464), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 106112013CDJZR180005 and 106112014CDJZR185501).
Deepan, B; Quan, C; Wang, Y; Tay, C J
2014-07-10
In this paper, a new multiple-image encryption and decryption technique that utilizes the compressive sensing (CS) concept along with a double-random phase encryption (DRPE) has been proposed. The space multiplexing method is employed for integrating multiple-image data. The method, which results in a nonlinear encryption system, is able to overcome the vulnerability of classical DRPE. The CS technique and space multiplexing are able to provide additional key space in the proposed method. A numerical experiment of the proposed method is implemented and the results show that the proposed method has good accuracy and is more robust than classical DRPE. The proposed system is also employed against chosen-plaintext attacks and it is found that the inclusion of compressive sensing enhances robustness against the attacks.
Alfalou, A; Brosseau, C; Abdallah, N; Jridi, M
2013-04-01
We introduce a double optimization procedure for spectrally multiplexing multiple images. This technique is adapted from a recently proposed optical setup implementing the discrete cosine transformation (DCT). The new analysis technique is a combination of spectral fusion based on the properties of DCT, specific spectral filtering, and quantization of the remaining encoded frequencies using an optimal number of bits. Spectrally multiplexing multiple images defines a first level of encryption. A second level of encryption based on a real key image is used to reinforce encryption. A set of numerical simulations and a comparison with the well known JPEG (Joint Photographic Experts Group) image compression standard have been carried out to demonstrate the improved performances of this method. The focus here will differ from the method of simultaneous fusion, compression, and encryption of multiple images (SFCE) [Opt. Express 19, 24023 (2011)] in the following ways. Firstly, we shall be concerned with optimizing the compression rate by adapting the size of the spectral block to each target image and decreasing the number of bits required to encode each block. This size adaptation is achieved by means of the root-mean-square (RMS) time-frequency criterion. We found that this size adaptation provides a good tradeoff between bandwidth of spectral plane and number of reconstructed output images. Secondly, the encryption rate is improved by using a real biometric key and randomly changing the rotation angle of each block before spectral fusion. By using a real-valued key image we have been able to increase the compression rate of 50% over the original SFCE method. We provide numerical examples of the effects for size, rotation, and shifting of DCT-blocks which play noteworthy roles in the optimization of the bandwidth of the spectral plane. Inspection of the results for different types of attack demonstrates the robustness of our procedure.
NASA Astrophysics Data System (ADS)
Yu, Xu; Shao, Quanqin; Zhu, Yunhai; Deng, Yuejin; Yang, Haijun
2006-10-01
With the development of informationization and the separation between data management departments and application departments, spatial data sharing becomes one of the most important objectives for the spatial information infrastructure construction, and spatial metadata management system, data transmission security and data compression are the key technologies to realize spatial data sharing. This paper discusses the key technologies for metadata based on data interoperability, deeply researches the data compression algorithms such as adaptive Huffman algorithm, LZ77 and LZ78 algorithm, studies to apply digital signature technique to encrypt spatial data, which can not only identify the transmitter of spatial data, but also find timely whether the spatial data are sophisticated during the course of network transmission, and based on the analysis of symmetric encryption algorithms including 3DES,AES and asymmetric encryption algorithm - RAS, combining with HASH algorithm, presents a improved mix encryption method for spatial data. Digital signature technology and digital watermarking technology are also discussed. Then, a new solution of spatial data network distribution is put forward, which adopts three-layer architecture. Based on the framework, we give a spatial data network distribution system, which is efficient and safe, and also prove the feasibility and validity of the proposed solution.
NASA Astrophysics Data System (ADS)
Lin, Chao; Shen, Xueju; Hu, Wengang
2015-07-01
We demonstrate that a vectorial beam with a random polarization state can be used as the illumination source in a joint transform correlator configuration to encrypt and compress images. Illumination light featuring both space-variant phase and a space-variant polarization distribution can be generated using a common-path interferometric arrangement. A hybrid joint power spectrum is registered using an array of linear micro-polarizers that is closely attached to a charge-coupled device in the recording plane. Introduction of the vectorial beam into a security application enables simultaneous manipulation of multiple light wave parameters, which will significantly enlarge the key dimensions and key space of the cryptosystem. This vectorial optical cryptosystem may also provoke interest in probing optical vector encryption methods.
Review of digital fingerprint acquisition systems and wavelet compression
NASA Astrophysics Data System (ADS)
Hopper, Thomas
2003-04-01
Over the last decade many criminal justice agencies have replaced their fingerprint card based systems with electronic processing. We examine these new systems and find that image acquisition to support the identification application is consistently a challenge. Image capture and compression are widely dispersed and relatively new technologies within criminal justice information systems. Image quality assurance programs are just beginning to mature.
Brinkmann, Benjamin H.; Bower, Mark R.; Stengel, Keith A.; Worrell, Gregory A.; Stead, Matt
2010-01-01
Continuous, long-term (up to 10 days) electrophysiological monitoring using hybrid intracranial electrodes is an emerging tool for presurgical epilepsy evaluation and fundamental investigations of seizure generation. Detection of high-frequency oscillations and microseizures could provide valuable insights into causes and therapies for the treatment of epilepsy, but requires high spatial and temporal resolution. Our group is currently using hybrid arrays composed of up to 320 micro- and clinical macroelectrode arrays sampled at 32 kHz per channel with 18-bits of A/D resolution. Such recordings produce approximately 3 terabytes of data per day. Existing file formats have limited data compression capabilities, and do not offer mechanisms for protecting patient identifying information or detecting data corruption during transmission or storage. We present a novel file format that employs range encoding to provide a high degree of data compression, a three-tiered 128-bit encryption system for patient information and data security, and a 32-bit cyclic redundancy check to verify the integrity of compressed data blocks. Open-source software to read, write, and process these files are provided. PMID:19963940
Brinkmann, Benjamin H; Bower, Mark R; Stengel, Keith A; Worrell, Gregory A; Stead, Matt
2009-01-01
Continuous, long-term (up to 10 days) electrophysiological monitoring using hybrid intracranial electrodes is an emerging tool for presurgical epilepsy evaluation and fundamental investigations of seizure generation. Detection of high-frequency oscillations and microseizures could provide valuable insights into causes and therapies for the treatment of epilepsy, but requires high spatial and temporal resolution. Our group is currently using hybrid arrays composed of up to 320 micro- and clinical macroelectrode arrays sampled at 32 kHz per channel with 18-bits of A/D resolution. Such recordings produce approximately 3 terabytes of data per day. Existing file formats have limited data compression capabilities, and do not offer mechanisms for protecting patient identifying information or detecting data corruption during transmission or storage. We present a novel file format that employs range encoding to provide a high degree of data compression, a three-tiered 128-bit encryption system for patient information and data security, and a 32-bit cyclic redundancy check to verify the integrity of compressed data blocks. Open-source software to read, write, and process these files are provided.
48 CFR 352.239-71 - Standard for encryption language.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Standard for encryption... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert the following clause: Standard for Encryption Language (January 2010) (a) The Contractor shall use...
48 CFR 352.239-71 - Standard for encryption language.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Standard for encryption... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert the following clause: Standard for Encryption Language (January 2010) (a) The Contractor shall use...
48 CFR 352.239-71 - Standard for encryption language.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Standard for encryption... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert the following clause: Standard for Encryption Language (January 2010) (a) The Contractor shall use...
NASA Astrophysics Data System (ADS)
Hollingsworth, Kieren Grant
2015-11-01
MRI is often the most sensitive or appropriate technique for important measurements in clinical diagnosis and research, but lengthy acquisition times limit its use due to cost and considerations of patient comfort and compliance. Once an image field of view and resolution is chosen, the minimum scan acquisition time is normally fixed by the amount of raw data that must be acquired to meet the Nyquist criteria. Recently, there has been research interest in using the theory of compressed sensing (CS) in MR imaging to reduce scan acquisition times. The theory argues that if our target MR image is sparse, having signal information in only a small proportion of pixels (like an angiogram), or if the image can be mathematically transformed to be sparse then it is possible to use that sparsity to recover a high definition image from substantially less acquired data. This review starts by considering methods of k-space undersampling which have already been incorporated into routine clinical imaging (partial Fourier imaging and parallel imaging), and then explains the basis of using compressed sensing in MRI. The practical considerations of applying CS to MRI acquisitions are discussed, such as designing k-space undersampling schemes, optimizing adjustable parameters in reconstructions and exploiting the power of combined compressed sensing and parallel imaging (CS-PI). A selection of clinical applications that have used CS and CS-PI prospectively are considered. The review concludes by signposting other imaging acceleration techniques under present development before concluding with a consideration of the potential impact and obstacles to bringing compressed sensing into routine use in clinical MRI.
Ke, Jun; Lam, Edmund Y
2016-05-01
Compressive measurements benefit low-light-level imaging (L^{3}-imaging) due to the significantly improved measurement signal-to-noise ratio (SNR). However, as with other compressive imaging (CI) systems, compressive L^{3}-imaging is slow. To accelerate the data acquisition, we develop an algorithm to compute the optimal binary sensing matrix that can minimize the image reconstruction error. First, we make use of the measurement SNR and the reconstruction mean square error (MSE) to define the optimal gray-value sensing matrix. Then, we construct an equality-constrained optimization problem to solve for a binary sensing matrix. From several experimental results, we show that the latter delivers a similar reconstruction performance as the former, while having a smaller dynamic range requirement to system sensors.
WSNs data acquisition by combining hierarchical routing method and compressive sensing.
Zou, Zhiqiang; Hu, Cunchen; Zhang, Fei; Zhao, Hao; Shen, Shu
2014-09-09
We address the problem of data acquisition in large distributed wireless sensor networks (WSNs). We propose a method for data acquisition using the hierarchical routing method and compressive sensing for WSNs. Only a few samples are needed to recover the original signal with high probability since sparse representation technology is exploited to capture the similarities and differences of the original signal. To collect samples effectively in WSNs, a framework for the use of the hierarchical routing method and compressive sensing is proposed, using a randomized rotation of cluster-heads to evenly distribute the energy load among the sensors in the network. Furthermore, L1-minimization and Bayesian compressed sensing are used to approximate the recovery of the original signal from the smaller number of samples with a lower signal reconstruction error. We also give an extensive validation regarding coherence, compression rate, and lifetime, based on an analysis of the theory and experiments in the environment with real world signals. The results show that our solution is effective in a large distributed network, especially for energy constrained WSNs.
The experiments and analysis of several selective video encryption methods
NASA Astrophysics Data System (ADS)
Zhang, Yue; Yang, Cheng; Wang, Lei
2013-07-01
This paper presents four methods for selective video encryption based on the MPEG-2 video compression,including the slices, the I-frames, the motion vectors, and the DCT coefficients. We use the AES encryption method for simulation experiment for the four methods on VS2010 Platform, and compare the video effects and the processing speed of each frame after the video encrypted. The encryption depth can be arbitrarily selected, and design the encryption depth by using the double limit counting method, so the accuracy can be increased.
48 CFR 352.239-71 - Standard for encryption language.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Standard for encryption language. 352.239-71 Section 352.239-71 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert...
Optical image encryption topology.
Yong-Liang, Xiao; Xin, Zhou; Qiong-Hua, Wang; Sheng, Yuan; Yao-Yao, Chen
2009-10-15
Optical image encryption topology is proposed based on the principle of random-phase encoding. Various encryption topological units, involving peer-to-peer, ring, star, and tree topologies, can be realized by an optical 6f system. These topological units can be interconnected to constitute an optical image encryption network. The encryption and decryption can be performed in both digital and optical methods.
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.
Lossy cardiac x-ray image compression based on acquisition noise
NASA Astrophysics Data System (ADS)
de Bruijn, Frederik J.; Slump, Cornelis H.
1997-05-01
In lossy medical image compression, the requirements for the preservation of diagnostic integrity cannot be easily formulated in terms of a perceptual model. Especially since, in reality, human visual perception is dependent on numerous factors such as the viewing conditions and psycho-visual factors. Therefore, we investigate the possibility to develop alternative measures for data loss, based on the characteristics of the acquisition system, in our case, a digital cardiac imaging system. In general, due to the low exposure, cardiac x-ray images tend to be relatively noisy. The main noise contributions are quantum noise and electrical noise. The electrical noise is not correlated with the signal. In addition, the signal can be transformed such that the correlated Poisson-distributed quantum noise is transformed into an additional zero-mean Gaussian noise source which is uncorrelated with the signal. Furthermore, the systems modulation transfer function imposes a known spatial-frequency limitation to the output signal. In the assumption that noise which is not correlated with the signal contains no diagnostic information, we have derived a compression measure based on the acquisition parameters of a digital cardiac imaging system. The measure is used for bit- assignment and quantization of transform coefficients. We present a blockwise-DCT compression algorithm which is based on the conventional JPEG-standard. However, the bit- assignment to the transform coefficients is now determined by an assumed noise variance for each coefficient, for a given set of acquisition parameters. Experiments with the algorithm indicate that a bit rate of 0.6 bit/pixel is feasible, without apparent loss of clinical information.
Design and implementation of a compressive infrared sampling for motion acquisition
NASA Astrophysics Data System (ADS)
Liu, Tong; Liu, Jun
2014-12-01
This article proposes a compressive infrared sampling method in pursuit of the acquisition and processing of human motion simultaneously. The spatial-temporal changes caused by the movements of the human body are intrinsical clues for determining the semantics of motion, while the movements of short-term changes can be considered as a sparse distribution compared with the sensing region. Several pyroelectric infrared (PIR) sensors with pseudo-random-coded Fresnel lenses are introduced to acquire and compress motion information synchronously. The compressive PIR array has the ability to record the changes in the thermal radiation field caused by movements and encode the motion information into low-dimensional sensory outputs directly. Therefore, the problem of recognizing a high-dimensional image sequence is cast as a low-dimensional sequence recognition process. A database involving various kinds of motion played by several people is built. Hausdorff distance-based template matching is employed for motion recognition. Experimental studies are conducted to validate the proposed method.
48 CFR 352.239-71 - Standard for encryption language.
Code of Federal Regulations, 2010 CFR
2010-10-01
... language. 352.239-71 Section 352.239-71 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES... Standard for encryption language. As prescribed in 339.101(d)(2), the Contracting Officer shall insert the following clause: Standard for Encryption Language (January 2010) (a) The Contractor shall use...
NASA Astrophysics Data System (ADS)
Chang, Chen-Ming; Grant, Alexander M.; Lee, Brian J.; Kim, Ealgoo; Hong, KeyJo; Levin, Craig S.
2015-08-01
In the field of information theory, compressed sensing (CS) had been developed to recover signals at a lower sampling rate than suggested by the Nyquist-Shannon theorem, provided the signals have a sparse representation with respect to some base. CS has recently emerged as a method to multiplex PET detector readouts thanks to the sparse nature of 511 keV photon interactions in a typical PET study. We have shown in our previous numerical studies that, at the same multiplexing ratio, CS achieves higher signal-to-noise ratio (SNR) compared to Anger and cross-strip multiplexing. In addition, unlike Anger logic, multiplexing by CS preserves the capability to resolve multi-hit events, in which multiple pixels are triggered within the resolving time of the detector. In this work, we characterized the time, energy and intrinsic spatial resolution of two CS detectors and a data acquisition system we have developed for a PET insert system for simultaneous PET/MRI. The CS detector comprises a 2× 4 mosaic of 4× 4 arrays of 3.2× 3.2× 20 mm3 lutetium-yttrium orthosilicate crystals coupled one-to-one to eight 4× 4 silicon photomultiplier arrays. The total number of 128 pixels is multiplexed down to 16 readout channels by CS. The energy, coincidence time and intrinsic spatial resolution achieved by two CS detectors were 15.4+/- 0.1 % FWHM at 511 keV, 4.5 ns FWHM and 2.3 mm FWHM, respectively. A series of experiments were conducted to measure the sources of time jitter that limit the time resolution of the current system, which provides guidance for potential system design improvements. These findings demonstrate the feasibility of compressed sensing as a promising multiplexing method for PET detectors.
Chang, Chen-Ming; Grant, Alexander M; Lee, Brian J; Kim, Ealgoo; Hong, KeyJo; Levin, Craig S
2015-08-21
In the field of information theory, compressed sensing (CS) had been developed to recover signals at a lower sampling rate than suggested by the Nyquist-Shannon theorem, provided the signals have a sparse representation with respect to some base. CS has recently emerged as a method to multiplex PET detector readouts thanks to the sparse nature of 511 keV photon interactions in a typical PET study. We have shown in our previous numerical studies that, at the same multiplexing ratio, CS achieves higher signal-to-noise ratio (SNR) compared to Anger and cross-strip multiplexing. In addition, unlike Anger logic, multiplexing by CS preserves the capability to resolve multi-hit events, in which multiple pixels are triggered within the resolving time of the detector. In this work, we characterized the time, energy and intrinsic spatial resolution of two CS detectors and a data acquisition system we have developed for a PET insert system for simultaneous PET/MRI. The CS detector comprises a 2 x 4 mosaic of 4 x 4 arrays of 3.2 x 3.2 x 20 mm(3) lutetium-yttrium orthosilicate crystals coupled one-to-one to eight 4 x 4 silicon photomultiplier arrays. The total number of 128 pixels is multiplexed down to 16 readout channels by CS. The energy, coincidence time and intrinsic spatial resolution achieved by two CS detectors were 15.4±0.1% FWHM at 511 keV, 4.5 ns FWHM and 2.3 mm FWHM, respectively. A series of experiments were conducted to measure the sources of time jitter that limit the time resolution of the current system, which provides guidance for potential system design improvements. These findings demonstrate the feasibility of compressed sensing as a promising multiplexing method for PET detectors. PMID:26237671
Chang, Chen-Ming; Grant, Alexander M; Lee, Brian J; Kim, Ealgoo; Hong, KeyJo; Levin, Craig S
2015-08-21
In the field of information theory, compressed sensing (CS) had been developed to recover signals at a lower sampling rate than suggested by the Nyquist-Shannon theorem, provided the signals have a sparse representation with respect to some base. CS has recently emerged as a method to multiplex PET detector readouts thanks to the sparse nature of 511 keV photon interactions in a typical PET study. We have shown in our previous numerical studies that, at the same multiplexing ratio, CS achieves higher signal-to-noise ratio (SNR) compared to Anger and cross-strip multiplexing. In addition, unlike Anger logic, multiplexing by CS preserves the capability to resolve multi-hit events, in which multiple pixels are triggered within the resolving time of the detector. In this work, we characterized the time, energy and intrinsic spatial resolution of two CS detectors and a data acquisition system we have developed for a PET insert system for simultaneous PET/MRI. The CS detector comprises a 2 x 4 mosaic of 4 x 4 arrays of 3.2 x 3.2 x 20 mm(3) lutetium-yttrium orthosilicate crystals coupled one-to-one to eight 4 x 4 silicon photomultiplier arrays. The total number of 128 pixels is multiplexed down to 16 readout channels by CS. The energy, coincidence time and intrinsic spatial resolution achieved by two CS detectors were 15.4±0.1% FWHM at 511 keV, 4.5 ns FWHM and 2.3 mm FWHM, respectively. A series of experiments were conducted to measure the sources of time jitter that limit the time resolution of the current system, which provides guidance for potential system design improvements. These findings demonstrate the feasibility of compressed sensing as a promising multiplexing method for PET detectors.
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.
Guo, Qiang; Chen, Hongwei; Weng, Zhiliang; Chen, Minghua; Yang, Sigang; Xie, Shizhong
2015-11-16
In this paper, compressive sensing based high-speed time-stretch optical microscopy for two-dimensional (2D) image acquisition is proposed and experimentally demonstrated for the first time. A section of dispersion compensating fiber (DCF) is used to perform wavelength-to-time conversion and then ultrafast spectral shaping of broadband optical pulses can be achieved via high-speed intensity modulation. A 2D spatial disperser comprising a pair of orthogonally oriented dispersers is employed to produce spatially structured illumination for 2D image acquisition and a section of single mode fiber (SMF) is utilized for pulse compression in the optical domain. In our scheme, a 1.2-GHz photodetector and a 50-MHz analog-to-digital converter (ADC) are used to acquire the energy of the compressed pulses. Image reconstructions are demonstrated at a frame rate of 500 kHz and a sixteen-fold image compression is achieved in our proof-of-concept demonstration.
Sandia Scalable Encryption Software
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-linearmore » mixer which is compatible with Sandia''s hardware-based ATM encryptor.« less
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.
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.
Adsorption Compressor For Acquisition and Compression aof Atmospheric C02 on Mars
NASA Technical Reports Server (NTRS)
Rapp, Donald; Karlmann, Paul B.; Clark, David L.; Carr, Chad M.
1997-01-01
A flight-prototype zeolite adsorption compressor is being developed as a reliable, efficient, cost-effective means of extracting and compressing atmospheric C02 on the surface of Mars for use as the first stage of a Mars in-sity C02 to 02 chemical conversion process.
Geethanath, Sairam; Gulaka, Praveen K; Kodibagkar, Vikram D
2014-01-01
Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) has become a valuable clinical tool for cancer diagnosis and prognosis. DCE MRI provides pharmacokinetic parameters dependent on the extravasation of small molecular contrast agents, and thus high temporal resolution and/or spatial resolution is required for accurate estimation of parameters. In this article we investigate the efficacy of 2 undersampling approaches to speed up DCE MRI: a conventional keyhole approach and compressed sensing-based imaging. Data reconstructed from variants of these methods has been compared with the full k-space reconstruction with respect to data quality and pharmacokinetic parameters Ktrans and ve. Overall, compressive sensing provides better data quality and reproducible parametric maps than key-hole methods with higher acceleration factors. In particular, an undersampling mask based on a priori precontrast data showed high fidelity of reconstructed data and parametric maps up to 5× acceleration.
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.
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.
NASA Astrophysics Data System (ADS)
Capell, Joyce; Deeth, David
1996-01-01
This paper describes why encryption was selected by Lockheed Martin Missiles & Space as the means for securing ATM networks. The ATM encryption testing program is part of an ATM network trial provided by Pacific Bell under the California Research Education Network (CalREN). The problem being addressed is the threat to data security which results when changing from a packet switched network infrastructure to a circuit switched ATM network backbone. As organizations move to high speed cell-based networks, there is a break down in the traditional security model which is designed to protect packet switched data networks from external attacks. This is due to the fact that most data security firewalls filter IP packets, restricting inbound and outbound protocols, e.g. ftp. ATM networks, based on cell-switching over virtual circuits, does not support this method for restricting access since the protocol information is not carried by each cell. ATM switches set up multiple virtual connections, thus there is no longer a single point of entry into the internal network. The problem is further complicated by the fact that ATM networks support high speed multi-media applications, including real time video and video teleconferencing which are incompatible with packet switched networks. The ability to restrict access to Lockheed Martin networks in support of both unclassified and classified communications is required before ATM network technology can be fully deployed. The Lockheed Martin CalREN ATM testbed provides the opportunity to test ATM encryption prototypes with actual applications to assess the viability of ATM encryption methodologies prior to installing large scale ATM networks. Two prototype ATM encryptors are being tested: (1) `MILKBUSH' a prototype encryptor developed by NSA for transmission of government classified data over ATM networks, and (2) a prototype ATM encryptor developed by Sandia National Labs in New Mexico, for the encryption of proprietary data.
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.
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.
NASA Astrophysics Data System (ADS)
Chuang, Cheng-Hung; Chen, Yen-Lin
2013-02-01
This study presents a steganographic optical image encryption system based on reversible data hiding and double random phase encoding (DRPE) techniques. Conventional optical image encryption systems can securely transmit valuable images using an encryption method for possible application in optical transmission systems. The steganographic optical image encryption system based on the DRPE technique has been investigated to hide secret data in encrypted images. However, the DRPE techniques vulnerable to attacks and many of the data hiding methods in the DRPE system can distort the decrypted images. The proposed system, based on reversible data hiding, uses a JBIG2 compression scheme to achieve lossless decrypted image quality and perform a prior encryption process. Thus, the DRPE technique enables a more secured optical encryption process. The proposed method extracts and compresses the bit planes of the original image using the lossless JBIG2 technique. The secret data are embedded in the remaining storage space. The RSA algorithm can cipher the compressed binary bits and secret data for advanced security. Experimental results show that the proposed system achieves a high data embedding capacity and lossless reconstruction of the original images.
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.
Optical asymmetric image encryption using gyrator wavelet transform
NASA Astrophysics Data System (ADS)
Mehra, Isha; Nishchal, Naveen K.
2015-11-01
In this paper, we propose a new optical information processing tool termed as gyrator wavelet transform to secure a fully phase image, based on amplitude- and phase-truncation approach. The gyrator wavelet transform constitutes four basic parameters; gyrator transform order, type and level of mother wavelet, and position of different frequency bands. These parameters are used as encryption keys in addition to the random phase codes to the optical cryptosystem. This tool has also been applied for simultaneous compression and encryption of an image. The system's performance and its sensitivity to the encryption parameters, such as, gyrator transform order, and robustness has also been analyzed. It is expected that this tool will not only update current optical security systems, but may also shed some light on future developments. The computer simulation results demonstrate the abilities of the gyrator wavelet transform as an effective tool, which can be used in various optical information processing applications, including image encryption, and image compression. Also this tool can be applied for securing the color image, multispectral, and three-dimensional images.
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.
Image encryption in the wavelet domain
NASA Astrophysics Data System (ADS)
Bao, Long; Zhou, Yicong; Chen, C. L. Philip
2013-05-01
Most existing image encryption algorithms often transfer the original image into a noise-like image which is an apparent visual sign indicating the presence of an encrypted image. Motivated by the data hiding technologies, this paper proposes a novel concept of image encryption, namely transforming an encrypted original image into another meaningful image which is the final resulting encrypted image and visually the same as the cover image, overcoming the mentioned problem. Using this concept, we introduce a new image encryption algorithm based on the wavelet decomposition. Simulations and security analysis are given to show the excellent performance of the proposed concept and algorithm.
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.
Code of Federal Regulations, 2011 CFR
2011-10-01
...) and 1 CFR part 51. Copies of the standard listed in this section that are incorporated by reference... employed then the following encryption protocol must be used: Project 25 DES Encryption Protocol,...
Code of Federal Regulations, 2010 CFR
2010-10-01
...) and 1 CFR part 51. Copies of the standard listed in this section that are incorporated by reference... employed then the following encryption protocol must be used: Project 25 DES Encryption Protocol,...
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.
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.
Optical image encryption in phase space
NASA Astrophysics Data System (ADS)
Liu, Jun; Xu, Xiaobin; Situ, Guohai; Wu, Quanying
2014-11-01
In the field of optical information security, the research of double random phase encoding is becoming deeper with each passing day, however the encryption system is linear, and the dependencies between plaintext and ciphertext is not complicated, with leaving a great hidden danger to the security of the encryption system. In this paper, we encrypted the higher dimensional Wigner distribution function of low dimensional plaintext by using the bilinear property of Wigner distribution function. Computer simulation results show that this method can not only enlarge the key space, but also break through the linear characteristic of the traditional optical encryption technology. So it can significantly improve the safety of the encryption system.
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.
Halving the dimension of a single image to be encrypted optically to avoid data expansion
NASA Astrophysics Data System (ADS)
Yi, Jiawang; Tan, Guanzheng
2016-06-01
When directly applying optical transforms, such as fractional Fourier transform (FrFT), to a single image or real image (input image), the resulting image will become complex-valued, which leads to the doubling of data volume. This data expansion problem can be found in many existing single-image optical encryption schemes. We propose a folding technique to offset the data expansion by constructing a complex input image of half size. And we devise an optical single-image encryption scheme based on double FrFTs, in which this technique together with compressed sensing can bring about the possible maximum compression of encrypted images. Moreover, the chaos-based random circular shift for scrambling is introduced to enhance security. The chaotic random signum matrix is also tried as the measurement matrix, and it displays a good performance. Simulation results demonstrate the validity and security of the proposed scheme.
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.
Advanced technologies for encryption of satellite links
NASA Astrophysics Data System (ADS)
McMahan, Sherry S.
The use of encryption on satellite links is discussed. Advanced technology exists to provide transmission security for large earth station with data rates up to 50 megabits per second. One of the major concerns in the use of encryption equipment with very small aperture terminals (VSAT) is the key management issue and the related operational costs. The low cost requirement and the lack of physical protection of remote VSATs place severe constraints on the design of encryption equipment. Encryption may be accomplished by embedding a tamper proof encryption module into the baseband unit of each VSAT. VSAT networks are usually star networks where there is a single large earth station that serves as a hub and all satellite communications takes place between each VSAT and the hub earth station. The hub earth station has the secret master key of each VSAT. These master keys are used to downline load encrypted session keys to each VSAT. A more secure alternative is to use public key techniques where each embedded VSAT encryption module internally generates its own secret and public numbers. The secret number never leaves the module while the public number is sent to the hub at the time of initialization of the encryption module into the VSAT. Physical access control to encryption modules of VSAT systems can be implemented using passwords, smart cards or biometrics.
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
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.
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.
15 CFR 742.15 - Encryption items.
Code of Federal Regulations, 2011 CFR
2011-01-01
... where the change is limited to updates of encryption software components where the product is otherwise... Memorandum of November 15, 1996, exports and reexports of encryption software, like exports and reexports of... because of any informational or theoretical value that such software may reflect, contain, or...
15 CFR 742.15 - Encryption items.
Code of Federal Regulations, 2013 CFR
2013-01-01
... where the change is limited to updates of encryption software components where the product is otherwise... Memorandum of November 15, 1996, exports and reexports of encryption software, like exports and reexports of... because of any informational or theoretical value that such software may reflect, contain, or...
15 CFR 742.15 - Encryption items.
Code of Federal Regulations, 2014 CFR
2014-01-01
... where the change is limited to updates of encryption software components where the product is otherwise... Memorandum of November 15, 1996, exports and reexports of encryption software, like exports and reexports of... because of any informational or theoretical value that such software may reflect, contain, or...
15 CFR 742.15 - Encryption items.
Code of Federal Regulations, 2012 CFR
2012-01-01
... where the change is limited to updates of encryption software components where the product is otherwise... Memorandum of November 15, 1996, exports and reexports of encryption software, like exports and reexports of... because of any informational or theoretical value that such software may reflect, contain, or...
Knight-Greenfield, Ashley; Jajamovich, Guido; Besa, Cecilia; Cui, Yong; Stalder, Aurélien; Markl, Michael; Taouli, Bachir
2015-01-01
Purpose To develop a highly accelerated phase-contrast cardiac-gated volume flow measurement (four-dimensional [4D] flow) magnetic resonance (MR) imaging technique based on spiral sampling and dynamic compressed sensing and to compare this technique with established phase-contrast imaging techniques for the quantification of blood flow in abdominal vessels. Materials and Methods This single-center prospective study was compliant with HIPAA and approved by the institutional review board. Ten subjects (nine men, one woman; mean age, 51 years; age range, 30–70 years) were enrolled. Seven patients had liver disease. Written informed consent was obtained from all participants. Two 4D flow acquisitions were performed in each subject, one with use of Cartesian sampling with respiratory tracking and the other with use of spiral sampling and a breath hold. Cartesian two-dimensional (2D) cine phase-contrast images were also acquired in the portal vein. Two observers independently assessed vessel conspicuity on phase-contrast three-dimensional angiograms. Quantitative flow parameters were measured by two independent observers in major abdominal vessels. Intertechnique concordance was quantified by using Bland-Altman and logistic regression analyses. Results There was moderate to substantial agreement in vessel conspicuity between 4D flow acquisitions in arteries and veins (κ = 0.71 and 0.61, respectively, for observer 1; κ = 0.71 and 0.44 for observer 2), whereas more artifacts were observed with spiral 4D flow (κ = 0.30 and 0.20). Quantitative measurements in abdominal vessels showed good equivalence between spiral and Cartesian 4D flow techniques (lower bound of the 95% confidence interval: 63%, 77%, 60%, and 64% for flow, area, average velocity, and peak velocity, respectively). For portal venous flow, spiral 4D flow was in better agreement with 2D cine phase-contrast flow (95% limits of agreement: −8.8 and 9.3 mL/sec, respectively) than was Cartesian 4D flow (95
Selective encryption for H.264/AVC video coding
NASA Astrophysics Data System (ADS)
Shi, Tuo; King, Brian; Salama, Paul
2006-02-01
Due to the ease with which digital data can be manipulated and due to the ongoing advancements that have brought us closer to pervasive computing, the secure delivery of video and images has become a challenging problem. Despite the advantages and opportunities that digital video provide, illegal copying and distribution as well as plagiarism of digital audio, images, and video is still ongoing. In this paper we describe two techniques for securing H.264 coded video streams. The first technique, SEH264Algorithm1, groups the data into the following blocks of data: (1) a block that contains the sequence parameter set and the picture parameter set, (2) a block containing a compressed intra coded frame, (3) a block containing the slice header of a P slice, all the headers of the macroblock within the same P slice, and all the luma and chroma DC coefficients belonging to the all the macroblocks within the same slice, (4) a block containing all the ac coefficients, and (5) a block containing all the motion vectors. The first three are encrypted whereas the last two are not. The second method, SEH264Algorithm2, relies on the use of multiple slices per coded frame. The algorithm searches the compressed video sequence for start codes (0x000001) and then encrypts the next N bits of data.
Optical encryption in single shot digital holography
NASA Astrophysics Data System (ADS)
Lin, Ching-Yang; Chen, Gu-Liang; Kuo, Ming-Kuei; Chang, Chi-Ching; Yau, Hon-Fai
2007-09-01
We propose a novel optical encryption approach using a lenticular lens array (LLA) as a deterministic phase modulator and the single-shot digital holographic scheme. In the proposed scheme, the input amplitude image is encrypted and interferes with the reference wave phase, which is modulated by a LLA, then recorded holographically by a digital CCD camera to form an encrypted hologram. A decryption key is obtained from the key hologram using numerical reconstruction. The image is decrypted using a digital holographic approach after which the encrypted hologram is multiplying the numerical reconstructed key for decryption. The experimental results show that only an encrypted hologram is needed. Moreover with this approach, the decryption procedure can be rapidly accomplished using a personal computer, presenting a decrypted image of satisfactory image quality. Finally the selective sensitivity of the key rotation is also investigated.
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.
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.
Optical image encryption based on diffractive imaging.
Chen, Wen; Chen, Xudong; Sheppard, Colin J R
2010-11-15
In this Letter, we propose a method for optical image encryption based on diffractive imaging. An optical multiple random phase mask encoding system is applied, and one of the phase-only masks is selected and laterally translated along a preset direction during the encryption process. For image decryption, a phase retrieval algorithm is proposed to extract a high-quality plaintext. The feasibility and effectiveness of the proposed method are demonstrated by numerical results. The proposed method can provide a new strategy instead of conventional interference methods, and it may open up a new research perspective for optical image encryption.
Joint reversible data hiding and image encryption
NASA Astrophysics Data System (ADS)
Yang, Bian; Busch, Christoph; Niu, Xiamu
2010-01-01
Image encryption process is jointed with reversible data hiding in this paper, where the data to be hided are modulated by different secret keys selected for encryption. To extract the hided data from the cipher-text, the different tentative decrypted results are tested against typical random distribution in both spatial and frequency domain and the goodnessof- fit degrees are compared to extract one hided bit. The encryption based data hiding process is inherently reversible. Experiments demonstrate the proposed scheme's effectiveness on natural and textural images, both in gray-level and binary forms.
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.
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
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.
Dual-Layer Video Encryption using RSA Algorithm
NASA Astrophysics Data System (ADS)
Chadha, Aman; Mallik, Sushmit; Chadha, Ankit; Johar, Ravdeep; Mani Roja, M.
2015-04-01
This paper proposes a video encryption algorithm using RSA and Pseudo Noise (PN) sequence, aimed at applications requiring sensitive video information transfers. The system is primarily designed to work with files encoded using the Audio Video Interleaved (AVI) codec, although it can be easily ported for use with Moving Picture Experts Group (MPEG) encoded files. The audio and video components of the source separately undergo two layers of encryption to ensure a reasonable level of security. Encryption of the video component involves applying the RSA algorithm followed by the PN-based encryption. Similarly, the audio component is first encrypted using PN and further subjected to encryption using the Discrete Cosine Transform. Combining these techniques, an efficient system, invulnerable to security breaches and attacks with favorable values of parameters such as encryption/decryption speed, encryption/decryption ratio and visual degradation; has been put forth. For applications requiring encryption of sensitive data wherein stringent security requirements are of prime concern, the system is found to yield negligible similarities in visual perception between the original and the encrypted video sequence. For applications wherein visual similarity is not of major concern, we limit the encryption task to a single level of encryption which is accomplished by using RSA, thereby quickening the encryption process. Although some similarity between the original and encrypted video is observed in this case, it is not enough to comprehend the happenings in the video.
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.
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
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... (h) Smartcards or other identity management (i) Computer or network forensics (j) Software...
15 CFR Supplement No. 5 to Part 742 - Encryption Registration
Code of Federal Regulations, 2013 CFR
2013-01-01
... classification requests and self-classification reports for encryption items must be supported by an encryption... (h) Smartcards or other identity management (i) Computer or network forensics (j) Software...
15 CFR Supplement No. 5 to Part 742 - Encryption Registration
Code of Federal Regulations, 2011 CFR
2011-01-01
... classification requests and self-classification reports for encryption items must be supported by an encryption... (h) Smartcards or other identity management (i) Computer or network forensics (j) Software...
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.
Optimal Symmetric Ternary Quantum Encryption Schemes
NASA Astrophysics Data System (ADS)
Wang, Yu-qi; She, Kun; Huang, Ru-fen; Ouyang, Zhong
2016-07-01
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.
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.
NASA Astrophysics Data System (ADS)
Bondareva, A. P.; Cheremkhin, P. A.; Evtikhiev, N. N.; Krasnov, V. V.; Starikov, S. N.
Scheme of optical image encryption with digital information input and dynamic encryption key based on two liquid crystal spatial light modulators and operating with spatially-incoherent monochromatic illumination is experimentally implemented. Results of experiments on images optical encryption and numerical decryption are presented. Satisfactory decryption error of 0.20÷0.27 is achieved.
Binary DNA Nanostructures for Data Encryption
Halvorsen, Ken; Wong, Wesley P.
2012-01-01
We present a simple and secure system for encrypting and decrypting information using DNA self-assembly. Binary data is encoded in the geometry of DNA nanostructures with two distinct conformations. Removing or leaving out a single component reduces these structures to an encrypted solution of ssDNA, whereas adding back this missing “decryption key” causes the spontaneous formation of the message through self-assembly, enabling rapid read out via gel electrophoresis. Applications include authentication, secure messaging, and barcoding. PMID:22984477
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
Identity-Based Verifiably Encrypted Signatures without Random Oracles
NASA Astrophysics Data System (ADS)
Zhang, Lei; Wu, Qianhong; Qin, Bo
Fair exchange protocol plays an important role in electronic commerce in the case of exchanging digital contracts. Verifiably encrypted signatures provide an optimistic solution to these scenarios with an off-line trusted third party. In this paper, we propose an identity-based verifiably encrypted signature scheme. The scheme is non-interactive to generate verifiably encrypted signatures and the resulting encrypted signature consists of only four group elements. Based on the computational Diffie-Hellman assumption, our scheme is proven secure without using random oracles. To the best of our knowledge, this is the first identity-based verifiably encrypted signature scheme provably secure in the standard model.
Error function attack of chaos synchronization based encryption schemes.
Wang, Xingang; Zhan, Meng; Lai, C-H; Gang, Hu
2004-03-01
Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor.
Database security and encryption technology research and application
NASA Astrophysics Data System (ADS)
Zhu, Li-juan
2013-03-01
The main purpose of this paper is to discuss the current database information leakage problem, and discuss the important role played by the message encryption techniques in database security, As well as MD5 encryption technology principle and the use in the field of website or application. This article is divided into introduction, the overview of the MD5 encryption technology, the use of MD5 encryption technology and the final summary. In the field of requirements and application, this paper makes readers more detailed and clearly understood the principle, the importance in database security, and the use of MD5 encryption technology.
Code of Federal Regulations, 2014 CFR
2014-10-01
... incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The standard can also be... approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of...) or Triple Data Encryption Algorithm (TDEA), in addition to but not in place of AES, for...
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.
Optical encryption with selective computational ghost imaging
NASA Astrophysics Data System (ADS)
Zafari, Mohammad; kheradmand, Reza; Ahmadi-Kandjani, Sohrab
2014-10-01
Selective computational ghost imaging (SCGI) is a technique which enables the reconstruction of an N-pixel image from N measurements or less. In this paper we propose an optical encryption method based on SCGI and experimentally demonstrate that this method has much higher security under eavesdropping and unauthorized accesses compared with previous reported methods.
NES++: number system for encryption based privacy preserving speaker verification
NASA Astrophysics Data System (ADS)
Xu, Lei; Feng, Tao; Zhao, Xi; Shi, Weidong
2014-05-01
As speech based operation becomes a main hand-free interaction solution between human and mobile devices (i.e., smartphones, Google Glass), privacy preserving speaker verification receives much attention nowadays. Privacy preserving speaker verification can be achieved through many different ways, such as fuzzy vault and encryption. Encryption based solutions are promising as cryptography is based on solid mathematic foundations and the security properties can be easily analyzed in a well established framework. Most current asymmetric encryption schemes work on finite algebraic structures, such as finite group and finite fields. However, the encryption scheme for privacy preserving speaker verification must handle floating point numbers. This gap must be filled to make the overall scheme practical. In this paper, we propose a number system that meets the requirements of both speaker verification and the encryption scheme used in the process. It also supports addition homomorphic property of Pailliers encryption, which is crucial for privacy preserving speaker verification. As asymmetric encryption is expensive, we propose a method of packing several numbers into one plain-text and the computation overhead is greatly reduced. To evaluate the performance of this method, we implement Pailliers encryption scheme over proposed number system and the packing technique. Our findings show that the proposed solution can fulfill the gap between speaker verification and encryption scheme very well, and the packing technique improves the overall performance. Furthermore, our solution is a building block of encryption based privacy preserving speaker verification, the privacy protection and accuracy rate are not affected.
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.
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. PMID:25549257
Image encryption using P-Fibonacci transform and decomposition
NASA Astrophysics Data System (ADS)
Zhou, Yicong; Panetta, Karen; Agaian, Sos; Chen, C. L. Philip
2012-03-01
Image encryption is an effective method to protect images or videos by transferring them into unrecognizable formats for different security purposes. To improve the security level of bit-plane decomposition based encryption approaches, this paper introduces a new image encryption algorithm by using a combination of parametric bit-plane decomposition along with bit-plane shuffling and resizing, pixel scrambling and data mapping. The algorithm utilizes the Fibonacci P-code for image bit-plane decomposition and the 2D P-Fibonacci transform for image encryption because they are parameter dependent. Any new or existing method can be used for shuffling the order of the bit-planes. Simulation analysis and comparisons are provided to demonstrate the algorithm's performance for image encryption. Security analysis shows the algorithm's ability against several common attacks. The algorithm can be used to encrypt images, biometrics and videos.
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 OFDM-Based Speech Encryption System without Residual Intelligibility
NASA Astrophysics Data System (ADS)
Tseng, Der-Chang; Chiu, Jung-Hui
Since an FFT-based speech encryption system retains a considerable residual intelligibility, such as talk spurts and the original intonation in the encrypted speech, this makes it easy for eavesdroppers to deduce the information contents from the encrypted speech. In this letter, we propose a new technique based on the combination of an orthogonal frequency division multiplexing (OFDM) scheme and an appropriate QAM mapping method to remove the residual intelligibility from the encrypted speech by permuting several frequency components. In addition, the proposed OFDM-based speech encryption system needs only two FFT operations instead of the four required by the FFT-based speech encryption system. Simulation results are presented to show the effectiveness of this proposed technique.
A high performance hardware implementation image encryption with AES algorithm
NASA Astrophysics Data System (ADS)
Farmani, Ali; Jafari, Mohamad; Miremadi, Seyed Sohrab
2011-06-01
This paper describes implementation of a high-speed encryption algorithm with high throughput for encrypting the image. Therefore, we select a highly secured symmetric key encryption algorithm AES(Advanced Encryption Standard), in order to increase the speed and throughput using pipeline technique in four stages, control unit based on logic gates, optimal design of multiplier blocks in mixcolumn phase and simultaneous production keys and rounds. Such procedure makes AES suitable for fast image encryption. Implementation of a 128-bit AES on FPGA of Altra company has been done and the results are as follow: throughput, 6 Gbps in 471MHz. The time of encrypting in tested image with 32*32 size is 1.15ms.
NASA Astrophysics Data System (ADS)
Levanon, Assaf; Konstantinovsky, Michael; Kopeika, Natan S.; Yitzhaky, Yitzhak; Stern, A.; Turak, Svetlana; Abramovich, Amir
2015-05-01
In this article we present preliminary results for the combination of two interesting fields in the last few years: 1) Compressed imaging (CI), which is a joint sensing and compressing process, that attempts to exploit the large redundancy in typical images in order to capture fewer samples than usual. 2) Millimeter Waves (MMW) imaging. MMW based imaging systems are required for a large variety of applications in many growing fields such as medical treatments, homeland security, concealed weapon detection, and space technology. Moreover, the possibility to create a reliable imaging in low visibility conditions such as heavy cloud, smoke, fog and sandstorms in the MMW region, generate high interest from military groups in order to be ready for new combat. The lack of inexpensive room temperature imaging sensors makes it difficult to provide a suitable MMW system for many of the above applications. A system based on Glow Discharge Detector (GDD) Focal Plane Arrays (FPA) can be very efficient in real time imaging with significant results. The GDD is located in free space and it can detect MMW radiation almost isotropically. In this article, we present a new approach of reconstruction MMW imaging by rotation scanning of the target. The Collection process here, based on Radon projections allows implementation of the compressive sensing principles into the MMW region. Feasibility of concept was obtained as radon line imaging results. MMW imaging results with our resent sensor are also presented for the first time. The multiplexing frame rate of 16×16 GDD FPA permits real time video rate imaging of 30 frames per second and comprehensive 3D MMW imaging. It uses commercial GDD lamps with 3mm diameter, Ne indicator lamps as pixel detectors. Combination of these two fields should make significant improvement in MMW region imaging research, and new various of possibilities in compressing sensing technique.
Steganography and encrypting based on immunochemical systems.
Kim, Kyung-Woo; Bocharova, Vera; Halámek, Jan; Oh, Min-Kyu; Katz, Evgeny
2011-05-01
Steganography and encrypting were demonstrated with immuno-specific systems. IgG-proteins were used as invisible ink developed with complementary antibodies labeled with enzymes producing color spots. The information security was achieved by mixing the target protein-antigens used for the text encoding with masking proteins of similar composition but having different bioaffinity. Two different texts were simultaneously encoded by using two different encoding proteins in a mixture. Various encrypting techniques were exemplified with the immuno-systems used for the steganography. Future use of the developed approach for information protection and watermark-technology was proposed. Scaling down the encoded text to a micro-size is feasible with the use of nanotechnology.
Novel permutation measures for image encryption algorithms
NASA Astrophysics Data System (ADS)
Abd-El-Hafiz, Salwa K.; AbdElHaleem, Sherif H.; Radwan, Ahmed G.
2016-10-01
This paper proposes two measures for the evaluation of permutation techniques used in image encryption. First, a general mathematical framework for describing the permutation phase used in image encryption is presented. Using this framework, six different permutation techniques, based on chaotic and non-chaotic generators, are described. The two new measures are, then, introduced to evaluate the effectiveness of permutation techniques. These measures are (1) Percentage of Adjacent Pixels Count (PAPC) and (2) Distance Between Adjacent Pixels (DBAP). The proposed measures are used to evaluate and compare the six permutation techniques in different scenarios. The permutation techniques are applied on several standard images and the resulting scrambled images are analyzed. Moreover, the new measures are used to compare the permutation algorithms on different matrix sizes irrespective of the actual parameters used in each algorithm. The analysis results show that the proposed measures are good indicators of the effectiveness of the permutation technique.
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.
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)
Leihong, Zhang; Zilan, Pan; Luying, Wu; Xiuhua, Ma
2016-11-01
To solve the problem that large images can hardly be retrieved for stringent hardware restrictions and the security level is low, a method based on compressive ghost imaging (CGI) with Fast Fourier Transform (FFT) is proposed, named FFT-CGI. Initially, the information is encrypted by the sender with FFT, and the FFT-coded image is encrypted by the system of CGI with a secret key. Then the receiver decrypts the image with the aid of compressive sensing (CS) and FFT. Simulation results are given to verify the feasibility, security, and compression of the proposed encryption scheme. The experiment suggests the method can improve the quality of large images compared with conventional ghost imaging and achieve the imaging for large-sized images, further the amount of data transmitted largely reduced because of the combination of compressive sensing and FFT, and improve the security level of ghost images through ciphertext-only attack (COA), chosen-plaintext attack (CPA), and noise attack. This technique can be immediately applied to encryption and data storage with the advantages of high security, fast transmission, and high quality of reconstructed information.
Broadcast encryption: paving the road to practical content protection systems
NASA Astrophysics Data System (ADS)
Deen, G.; Ponceleon, D.; Leake, Donald, Jr.
2009-02-01
Broadcast encryption is a well established alternative to public key encryption for use in content protection systems. It offers significant performance benefits, as well as useful features such a one-to-many delivery, dynamic membership in the authorized receivers group, and provides anonymous access to content, permitting content protection systems to preserve privacy for consumers. Broadcast encryption has been successfully deployed to users for protection of commercial content on digital media such as flash memory devices and optical media for both standard-definition and high-definition content. In this paper, we present the Advanced Secure Content Cluster Technology which applies broadcast encryption to content protection for home media networks
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.
NASA Astrophysics Data System (ADS)
Kadhem, Hasan; Amagasa, Toshiyuki; Kitagawa, Hiroyuki
Encryption can provide strong security for sensitive data against inside and outside attacks. This is especially true in the “Database as Service” model, where confidentiality and privacy are important issues for the client. In fact, existing encryption approaches are vulnerable to a statistical attack because each value is encrypted to another fixed value. This paper presents a novel database encryption scheme called MV-OPES (Multivalued — Order Preserving Encryption Scheme), which allows privacy-preserving queries over encrypted databases with an improved security level. Our idea is to encrypt a value to different multiple values to prevent statistical attacks. At the same time, MV-OPES preserves the order of the integer values to allow comparison operations to be directly applied on encrypted data. Using calculated distance (range), we propose a novel method that allows a join query between relations based on inequality over encrypted values. We also present techniques to offload query execution load to a database server as much as possible, thereby making a better use of server resources in a database outsourcing environment. Our scheme can easily be integrated with current database systems as it is designed to work with existing indexing structures. It is robust against statistical attack and the estimation of true values. MV-OPES experiments show that security for sensitive data can be achieved with reasonable overhead, establishing the practicability of the scheme.
P-code enhanced method for processing encrypted GPS signals without knowledge of the encryption code
NASA Technical Reports Server (NTRS)
Meehan, Thomas K. (Inventor); Thomas, Jr., Jess Brooks (Inventor); Young, Lawrence E. (Inventor)
2000-01-01
In the preferred embodiment, an encrypted GPS signal is down-converted from RF to baseband to generate two quadrature components for each RF signal (L1 and L2). Separately and independently for each RF signal and each quadrature component, the four down-converted signals are counter-rotated with a respective model phase, correlated with a respective model P code, and then successively summed and dumped over presum intervals substantially coincident with chips of the respective encryption code. Without knowledge of the encryption-code signs, the effect of encryption-code sign flips is then substantially reduced by selected combinations of the resulting presums between associated quadrature components for each RF signal, separately and independently for the L1 and L2 signals. The resulting combined presums are then summed and dumped over longer intervals and further processed to extract amplitude, phase and delay for each RF signal. Precision of the resulting phase and delay values is approximately four times better than that obtained from straight cross-correlation of L1 and L2. This improved method provides the following options: separate and independent tracking of the L1-Y and L2-Y channels; separate and independent measurement of amplitude, phase and delay L1-Y channel; and removal of the half-cycle ambiguity in L1-Y and L2-Y carrier phase.
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.
Phase encryption of biometrics in diffractive optical elements.
Johnson, E G; Brasher, J D
1996-08-15
A new technique for the optical encoding of images is presented. The method of generalized projections is used to design diffractive optical elements for the phase encryption of biometrics for security applications. The encryption algorithm converges rapidly, and the decryption is seen to be secure and tolerant to additive noise. PMID:19876322
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…
Stego Optical Encryption Based on Chaotic Baker's Map Transformation
NASA Astrophysics Data System (ADS)
Hussain, Iqtadar; Gondal, Muhammad Asif
2014-06-01
In this article, an optical image encryption algorithm based on chaotic baker's map is presented. The stego-image is encrypted with the help of double random phase encoding algorithm and then produced disorder with the help of chaotic transformation. Security test shows that the reading of proposed algorithm is very close to the optimal values.
77 FR 51496 - Federal Acquisition Regulation; Basic Safeguarding of Contractor Information Systems
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-24
... Acquisition Regulation (FAR) to protect against the compromise of contractor computer networks on which... public meeting in the Federal Register at 75 FR 9563 on March 3, 2010, under Defense Federal Acquisition... included requirements for encryption and network intrusion protection. Resulting public comments of...
Three-dimensional optical encryption based on ptychography
NASA Astrophysics Data System (ADS)
Zhang, Jun; Li, Tuo; Wang, Yali; Qiao, Liang; Yang, Xiubo; Shi, Yishi
2015-10-01
We propose a novel optical encryption system for three-dimension imaging combined with three-dimension Ptychography. Employing the proposed cryptosystem, a 3D object can be encrypted and decrypted successfully. Compared with the conventional three-dimensional cryptosystem, not only encrypting the pure amplitude 3D object is available, but also the encryption of complex amplitude 3D object 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. Varies of simulation results demonstrate that the feasibility and robust of the cryptosystem. Furthermore, the proposed system could also be used for other potential applications, such as three-dimensional information hiding and multiple images encryption.
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.
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.
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.
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
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.
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
NASA Astrophysics Data System (ADS)
Qin, Yi; Wang, Hongjuan; Wang, Zhipeng; Gong, Qiong; Wang, Danchen
2016-09-01
In optical interference-based encryption (IBE) scheme, the currently available methods have to employ the iterative algorithms in order to encrypt two images and retrieve cross-talk free decrypted images. In this paper, we shall show that this goal can be achieved via an analytical process if one of the two images is QR code. For decryption, the QR code is decrypted in the conventional architecture and the decryption has a noisy appearance. Nevertheless, the robustness of QR code against noise enables the accurate acquisition of its content from the noisy retrieval, as a result of which the primary QR code can be exactly regenerated. Thereafter, a novel optical architecture is proposed to recover the grayscale image by aid of the QR code. In addition, the proposal has totally eliminated the silhouette problem existing in the previous IBE schemes, and its effectiveness and feasibility have been demonstrated by numerical simulations.
Perceptual security of encrypted images based on wavelet scaling analysis
NASA Astrophysics Data System (ADS)
Vargas-Olmos, C.; Murguía, J. S.; Ramírez-Torres, M. T.; Mejía Carlos, M.; Rosu, H. C.; González-Aguilar, H.
2016-08-01
The scaling behavior of the pixel fluctuations of encrypted images is evaluated by using the detrended fluctuation analysis based on wavelets, a modern technique that has been successfully used recently for a wide range of natural phenomena and technological processes. As encryption algorithms, we use the Advanced Encryption System (AES) in RBT mode and two versions of a cryptosystem based on cellular automata, with the encryption process applied both fully and partially by selecting different bitplanes. In all cases, the results show that the encrypted images in which no understandable information can be visually appreciated and whose pixels look totally random present a persistent scaling behavior with the scaling exponent α close to 0.5, implying no correlation between pixels when the DFA with wavelets is applied. This suggests that the scaling exponents of the encrypted images can be used as a perceptual security criterion in the sense that when their values are close to 0.5 (the white noise value) the encrypted images are more secure also from the perceptual point of view.
Multiple Lookup Table-Based AES Encryption Algorithm Implementation
NASA Astrophysics Data System (ADS)
Gong, Jin; Liu, Wenyi; Zhang, Huixin
Anew AES (Advanced Encryption Standard) encryption algorithm implementation was proposed in this paper. It is based on five lookup tables, which are generated from S-box(the substitution table in AES). The obvious advantages are reducing the code-size, improving the implementation efficiency, and helping new learners to understand the AES encryption algorithm and GF(28) multiplication which are necessary to correctly implement AES[1]. This method can be applied on processors with word length 32 or above, FPGA and others. And correspondingly we can implement it by VHDL, Verilog, VB and other languages.
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.
Stego optical encryption based on chaotic S-box transformation
NASA Astrophysics Data System (ADS)
Hussain, Iqtadar; Azam, Naveed Ahmed; Shah, Tariq
2014-09-01
In this article, an optical image encryption algorithm with an information hiding technique is presented. In this algorithm, a secret image is implanted into the cover image. After that the stego-image is encrypted with the help of double random phase encoding algorithm and chaotic substitution box transformation. Also, we present a comparative analysis between images “without substitution box transformation”, “with substitution box transformation” and “with chaotic substitution box transformation”. Security test shows that image transform with chaotic substitution box transformation is better than others. Furthermore we analyze proposed encryption scheme with other existing techniques and come to close that our algorithm is better than others.
Securing electronic health records with broadcast encryption schemes.
Susilo, Willy; Win, Khin Than
2006-01-01
Information security is a concern in integrated electronic health record systems (EHRs). This paper discusses the development of a mathematical model to secure the access of EHRs. In this paper, we incorporate the notion of a broadcast encryption scheme for securing EHRs. We present a novel solution to allow a secure access to the EHRs whilst minimising the number of the encrypted ciphertexts. In a nutshell, our proposed solution enjoys shorter ciphertexts compared to having multiple ciphertexts encrypted for several different participants. Our proposed solution is applicable in practice to solve an existing open problem in the effort of securing EHRs.
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.
A lossless encryption method for medical images using edge maps.
Zhou, Yicong; Panetta, Karen; Agaian, Sos
2009-01-01
Image encryption is an effective approach for providing security and privacy protection for medical images. This paper introduces a new lossless approach, called EdgeCrypt, to encrypt medical images using the information contained within an edge map. The algorithm can fully protect the selected objects/regions within medical images or the entire medical images. It can also encrypt other types of images such as grayscale images or color images. The algorithm can be used for privacy protection in the real-time medical applications such as wireless medical networking and mobile medical services.
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.
System for processing an encrypted instruction stream in hardware
Griswold, Richard L.; Nickless, William K.; Conrad, Ryan C.
2016-04-12
A system and method of processing an encrypted instruction stream in hardware is disclosed. Main memory stores the encrypted instruction stream and unencrypted data. A central processing unit (CPU) is operatively coupled to the main memory. A decryptor is operatively coupled to the main memory and located within the CPU. The decryptor decrypts the encrypted instruction stream upon receipt of an instruction fetch signal from a CPU core. Unencrypted data is passed through to the CPU core without decryption upon receipt of a data fetch signal.
A layered searchable encryption scheme with functional components independent of encryption methods.
Luo, Guangchun; Peng, Ningduo; Qin, Ke; Chen, Aiguo
2014-01-01
Searchable encryption technique enables the users to securely store and search their documents over the remote semitrusted server, which is especially suitable for protecting sensitive data in the cloud. However, various settings (based on symmetric or asymmetric encryption) and functionalities (ranked keyword query, range query, phrase query, etc.) are often realized by different methods with different searchable structures that are generally not compatible with each other, which limits the scope of application and hinders the functional extensions. We prove that asymmetric searchable structure could be converted to symmetric structure, and functions could be modeled separately apart from the core searchable structure. Based on this observation, we propose a layered searchable encryption (LSE) scheme, which provides compatibility, flexibility, and security for various settings and functionalities. In this scheme, the outputs of the core searchable component based on either symmetric or asymmetric setting are converted to some uniform mappings, which are then transmitted to loosely coupled functional components to further filter the results. In such a way, all functional components could directly support both symmetric and asymmetric settings. Based on LSE, we propose two representative and novel constructions for ranked keyword query (previously only available in symmetric scheme) and range query (previously only available in asymmetric scheme).
Compressive sensing of sparse tensors.
Friedland, Shmuel; Li, Qun; Schonfeld, Dan
2014-10-01
Compressive sensing (CS) has triggered an enormous research activity since its first appearance. CS exploits the signal's sparsity or compressibility in a particular domain and integrates data compression and acquisition, thus allowing exact reconstruction through relatively few nonadaptive linear measurements. While conventional CS theory relies on data representation in the form of vectors, many data types in various applications, such as color imaging, video sequences, and multisensor networks, are intrinsically represented by higher order tensors. Application of CS to higher order data representation is typically performed by conversion of the data to very long vectors that must be measured using very large sampling matrices, thus imposing a huge computational and memory burden. In this paper, we propose generalized tensor compressive sensing (GTCS)-a unified framework for CS of higher order tensors, which preserves the intrinsic structure of tensor data with reduced computational complexity at reconstruction. GTCS offers an efficient means for representation of multidimensional data by providing simultaneous acquisition and compression from all tensor modes. In addition, we propound two reconstruction procedures, a serial method and a parallelizable method. We then compare the performance of the proposed method with Kronecker compressive sensing (KCS) and multiway compressive sensing (MWCS). We demonstrate experimentally that GTCS outperforms KCS and MWCS in terms of both reconstruction accuracy (within a range of compression ratios) and processing speed. The major disadvantage of our methods (and of MWCS as well) is that the compression ratios may be worse than that offered by KCS.
Computed Tomography Image Compressibility and Limitations of Compression Ratio-Based Guidelines.
Pambrun, Jean-François; Noumeir, Rita
2015-12-01
Finding optimal compression levels for diagnostic imaging is not an easy task. Significant compressibility variations exist between modalities, but little is known about compressibility variations within modalities. Moreover, compressibility is affected by acquisition parameters. In this study, we evaluate the compressibility of thousands of computed tomography (CT) slices acquired with different slice thicknesses, exposures, reconstruction filters, slice collimations, and pitches. We demonstrate that exposure, slice thickness, and reconstruction filters have a significant impact on image compressibility due to an increased high frequency content and a lower acquisition signal-to-noise ratio. We also show that compression ratio is not a good fidelity measure. Therefore, guidelines based on compression ratio should ideally be replaced with other compression measures better correlated with image fidelity. Value-of-interest (VOI) transformations also affect the perception of quality. We have studied the effect of value-of-interest transformation and found significant masking of artifacts when window is widened. PMID:25804842
DNABIT Compress - Genome compression algorithm.
Rajarajeswari, Pothuraju; Apparao, Allam
2011-01-01
Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, "DNABIT Compress" for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that "DNABIT Compress" algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases.
Research on medical image encryption in telemedicine systems.
Dai, Yin; Wang, Huanzhen; Zhou, Zixia; Jin, Ziyi
2016-04-29
Recently, advances in computers and high-speed communication tools have led to enhancements in remote medical consultation research. Laws in some localities require hospitals to encrypt patient information (including images of the patient) before transferring the data over a network. Therefore, developing suitable encryption algorithms is quite important for modern medicine. This paper demonstrates a digital image encryption algorithm based on chaotic mapping, which uses the no-period and no-convergence properties of a chaotic sequence to create image chaos and pixel averaging. Then, the chaotic sequence is used to encrypt the image, thereby improving data security. With this method, the security of data and images can be improved. PMID:27163302
Photon-counting multifactor optical encryption and authentication
NASA Astrophysics Data System (ADS)
Pérez-Cabré, E.; Mohammed, E. A.; Millán, M. S.; Saadon, H. L.
2015-02-01
The multifactor optical encryption authentication method [Opt. Lett., 31 721-3 (2006)] reinforces optical security by allowing the simultaneous authentication of up to four factors. In this work, the photon-counting imaging technique is applied to the multifactor encrypted function so that a sparse phase-only distribution is generated for the encrypted data. The integration of both techniques permits an increased capacity for signal hiding with simultaneous data reduction for better fulfilling the general requirements of protection, storage and transmission. Cryptanalysis of the proposed method is carried out in terms of chosen-plaintext and chosen-ciphertext attacks. Although the multifactor authentication process is not substantially altered by those attacks, its integration with the photon-counting imaging technique prevents from possible partial disclosure of any encrypted factor, thus increasing the security level of the overall process. Numerical experiments and results are provided and discussed.
Video encryption using chaotic masks in joint transform correlator
NASA Astrophysics Data System (ADS)
Saini, Nirmala; Sinha, Aloka
2015-03-01
A real-time optical video encryption technique using a chaotic map has been reported. In the proposed technique, each frame of video is encrypted using two different chaotic random phase masks in the joint transform correlator architecture. The different chaotic random phase masks can be obtained either by using different iteration levels or by using different seed values of the chaotic map. The use of different chaotic random phase masks makes the decryption process very complex for an unauthorized person. Optical, as well as digital, methods can be used for video encryption but the decryption is possible only digitally. To further enhance the security of the system, the key parameters of the chaotic map are encoded using RSA (Rivest-Shamir-Adleman) public key encryption. Numerical simulations are carried out to validate the proposed technique.
Optical image encryption by random shifting in fractional Fourier domains.
Hennelly, B; Sheridan, J T
2003-02-15
A number of methods have recently been proposed in the literature for the encryption of two-dimensional information by use of optical systems based on the fractional Fourier transform. Typically, these methods require random phase screen keys for decrypting the data, which must be stored at the receiver and must be carefully aligned with the received encrypted data. A new technique based on a random shifting, or jigsaw, algorithm is proposed. This method does not require the use of phase keys. The image is encrypted by juxtaposition of sections of the image in fractional Fourier domains. The new method has been compared with existing methods and shows comparable or superior robustness to blind decryption. Optical implementation is discussed, and the sensitivity of the various encryption keys to blind decryption is examined.
Optical image encryption using multilevel Arnold transform and noninterferometric imaging
NASA Astrophysics Data System (ADS)
Chen, Wen; Chen, Xudong
2011-11-01
Information security has attracted much current attention due to the rapid development of modern technologies, such as computer and internet. We propose a novel method for optical image encryption using multilevel Arnold transform and rotatable-phase-mask noninterferometric imaging. An optical image encryption scheme is developed in the gyrator transform domain, and one phase-only mask (i.e., phase grating) is rotated and updated during image encryption. For the decryption, an iterative retrieval algorithm is proposed to extract high-quality plaintexts. Conventional encoding methods (such as digital holography) have been proven vulnerably to the attacks, and the proposed optical encoding scheme can effectively eliminate security deficiency and significantly enhance cryptosystem security. The proposed strategy based on the rotatable phase-only mask can provide a new alternative for data/image encryption in the noninterferometric imaging.
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.
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.
Noise removing in encrypted color images by statistical analysis
NASA Astrophysics Data System (ADS)
Islam, N.; Puech, W.
2012-03-01
Cryptographic techniques are used to secure confidential data from unauthorized access but these techniques are very sensitive to noise. A single bit change in encrypted data can have catastrophic impact over the decrypted data. This paper addresses the problem of removing bit error in visual data which are encrypted using AES algorithm in the CBC mode. In order to remove the noise, a method is proposed which is based on the statistical analysis of each block during the decryption. The proposed method exploits local statistics of the visual data and confusion/diffusion properties of the encryption algorithm to remove the errors. Experimental results show that the proposed method can be used at the receiving end for the possible solution for noise removing in visual data in encrypted domain.
Toward nanoworld-based secure encryption for enduring data storage.
Grosges, Thomas; Barchiesi, Dominique
2010-07-15
The generation of encryption secret keys with a high level of security is crucial to ensure secure enduring data storage and is a challenging topic of investigation. We show that the use of nano-objects and optical response permits us to produce a complex optical tomography map, which can be used as a pseudorandom generator that satisfies the basic requirements for encryption based on the secret key.
Authentication and encryption in the Snow disease surveillance network.
Bellika, Johan Gustav; Ilebrekke, Lars; Bakkevoll, Per Atle; Johansen, Håvard; Scholl, Jeremiah; Johansen, Monika Alise
2009-01-01
The paper presents how authentication and encryption is implemented in the Snow disease surveillance network. Requirements for the authentication mechanism were collected from General Practitioners (GPs). The identity of each Snow user is preserved across health institutions allowing GPs to move freely between health institutions and use the system independent of location. This ability is combined with close to zero user account administration within the participating institutions. The system provides global user certificate revocation and end-to-end encryption.
Cryptanalysis of an information encryption in phase space
NASA Astrophysics Data System (ADS)
Wang, Y.; Quan, C.; Tay, C. J.
2016-10-01
In this paper, we evaluate the security of an information encryption in phase space. We show that the scheme is vulnerable to two kinds of attack, namely, a chosen-ciphertext attack and a known-plaintext attack which is based on an iterative phase-retrieval algorithm using multiple plaintext-ciphertext pairs. The validity of the proposed methods of attack is verified by numerical simulations. The results cast doubts on the present security of information encryption in phase space.
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 New Quaternion-Based Encryption Method for DICOM Images.
Dzwonkowski, Mariusz; Papaj, Michal; Rykaczewski, Roman
2015-11-01
In this paper, a new quaternion-based lossless encryption technique for digital image and communication on medicine (DICOM) images is proposed. We have scrutinized and slightly modified the concept of the DICOM network to point out the best location for the proposed encryption scheme, which significantly improves speed of DICOM images encryption in comparison with those originally embedded into DICOM advanced encryption standard and triple data encryption standard algorithms. The proposed algorithm decomposes a DICOM image into two 8-bit gray-tone images in order to perform encryption. The algorithm implements Feistel network like the scheme proposed by Sastry and Kumar. It uses special properties of quaternions to perform rotations of data sequences in 3D space for each of the cipher rounds. The images are written as Lipschitz quaternions, and modular arithmetic was implemented for operations with the quaternions. A computer-based analysis has been carried out, and the obtained results are shown at the end of this paper. PMID:26276993
Secure data aggregation in wireless sensor networks using homomorphic encryption
NASA Astrophysics Data System (ADS)
Kumar, Manish; Verma, Shekhar; Lata, Kusum
2015-04-01
In a Wireless Sensor Network (WSN), aggregation exploits the correlation between spatially and temporally proximate sensor data to reduce the total data volume to be transmitted to the sink. Mobile agents (MAs) fit into this paradigm, and data can be aggregated and collected by an MA from different sensor nodes using context specific codes. The MA-based data collection suffers due to large size of a typical WSN and is prone to security problems. In this article, homomorphic encryption in a clustered WSN has been proposed for secure and efficient data collection using MAs. The nodes keep encrypted data that are given to an MA for data aggregation tasks. The MA performs all the data aggregation operations upon encrypted data as it migrates between nodes in a tree-like structure in which the nodes are leafs and the cluster head is the root of the tree. It returns and deposits the encrypted aggregated data to the cluster head after traversing through all the intra cluster nodes over a shortest path route. The homomorphic encryption and aggregation processing in encrypted domain makes the data collection process secure. Simulation results confirm the effectiveness of the proposed secure data aggregation mechanism. In addition to security, MA-based mechanism leads to lesser delay and bandwidth requirements.
Bouslimi, D; Coatrieux, G; Roux, Ch
2011-01-01
In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to the outcomes of the image integrity and of its origins even though the image is stored encrypted. Experimental results achieved on 8 bits encoded Ultrasound images illustrate the overall performances of the proposed scheme. By making use of the AES block cipher in CBC mode, the proposed solution is compliant with or transparent to the DICOM standard.
Bouslimi, D; Coatrieux, G; Roux, Ch
2011-01-01
In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to the outcomes of the image integrity and of its origins even though the image is stored encrypted. Experimental results achieved on 8 bits encoded Ultrasound images illustrate the overall performances of the proposed scheme. By making use of the AES block cipher in CBC mode, the proposed solution is compliant with or transparent to the DICOM standard. PMID:22256213
Forensic watermarking and bit-rate conversion of partially encrypted AAC bitstreams
NASA Astrophysics Data System (ADS)
Lemma, Aweke; Katzenbeisser, Stefan; Celik, Mehmet U.; Kirbiz, S.
2008-02-01
Electronic Music Distribution (EMD) is undergoing two fundamental shifts. The delivery over wired broadband networks to personal computers is being replaced by delivery over heterogeneous wired and wireless networks, e.g. 3G and Wi-Fi, to a range of devices such as mobile phones, game consoles and in-car players. Moreover, restrictive DRM models bound to a limited set of devices are being replaced by flexible standards-based DRM schemes and increasingly forensic tracking technologies based on watermarking. Success of these EMD services will partially depend on scalable, low-complexity and bandwidth eficient content protection systems. In this context, we propose a new partial encryption scheme for Advanced Audio Coding (AAC) compressed audio which is particularly suitable for emerging EMD applications. The scheme encrypts only the scale-factor information in the AAC bitstream with an additive one-time-pad. This allows intermediate network nodes to transcode the bitstream to lower data rates without accessing the decryption keys, by increasing the scale-factor values and re-quantizing the corresponding spectral coeficients. Furthermore, the decryption key for each user is customized such that the decryption process imprints the audio with a unique forensic tracking watermark. This constitutes a secure, low-complexity watermark embedding process at the destination node, i.e. the player. As opposed to server-side embedding methods, the proposed scheme lowers the computational burden on servers and allows for network level bandwidth saving measures such as multi-casting and caching.
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
Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.
1998-01-01
A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%.
Sandford, M.T. II; Handel, T.G.; Bradley, J.N.
1998-07-07
A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.
Image encryption based on nonlinear encryption system and public-key cryptography
NASA Astrophysics Data System (ADS)
Zhao, Tieyu; Ran, Qiwen; Chi, Yingying
2015-03-01
Recently, optical asymmetric cryptosystem (OACS) has became the focus of discussion and concern of researchers. Some researchers pointed out that OACS was not tenable because of misunderstanding the concept of asymmetric cryptosystem (ACS). We propose an improved cryptosystem using RSA public-key algorithm based on existing OACS and the new system conforms to the basic agreement of public key cryptosystem. At the beginning of the encryption process, the system will produce an independent phase matrix and allocate the input image, which also conforms to one-time pad cryptosystem. The simulation results show that the validity of the improved cryptosystem and the high robustness against attack scheme using phase retrieval technique.
A blind robust watermarking scheme with non-cascade iterative encrypted kinoform.
Deng, Ke; Yang, Guanglin; Xie, Haiyan
2011-05-23
A blind robust watermarking scheme is proposed. A watermark is firstly transformed into a non-cascade iterative encrypted kinoform with non-cascade phase retrieve algorithm and random fractional Fourier transform (RFrFT). An iterative algorithm and Human Visual System (HVS) are both presented to adaptively embed the kinoform watermark into corresponding 2-level DWT coefficients of the cover image. The kinoform accounts for much less data amount to be embedded than regular computer-generated hologram (CGH). And the kinoform can be extracted with the only right phase key and right fractional order, and reconstructed to represent original watermark without original cover image. The experiments have shown the scheme's high security, good imperceptibility, and robustness to resist attacks such as noise, compression, filtering, cropping.
Sandford, M.T. II; Handel, T.G.; Bradley, J.N.
1998-03-10
A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique is disclosed. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method. 11 figs.
Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.
1998-01-01
A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method.
Biomolecular optical data storage and data encryption.
Fischer, Thorsten; Neebe, Martin; Juchem, Thorsten; Hampp, Norbert A
2003-03-01
The use of bacteriorhodopsin (BR) as an active layer in write-once-read-many optical storage is presented. This novel feature of BR materials may be used on a wide variety of substrates, among them transparent substrates but also paper and plastics. The physical basis of the recording process is polarization-sensitive two-photon absorption. As an example for this new BR application, an identification card equipped with an optical recording strip is presented, which has a capacity of about 1 MB of data. The recording density currently used is 125 kB/cm2, which is far from the optical limits but allows operation with cheap terminals using plastic optics. In the examples given, data are stored in blocks of 10 kB each. A special optical encryption procedure allows the stored data to be protected from unauthorized reading. The molecular basis of this property is again the polarization-sensitive recording mechanism. The unique combination of optical storage, photochromism, and traceability of the BR material is combined on the single-molecule level. BR introduces a new quality of storage capability for applications with increased security and anticounterfeiting requirements.
Enabling location privacy and medical data encryption in patient telemonitoring systems.
Maglogiannis, Ilias; Kazatzopoulos, Leonidas; Delakouridis, Konstantinos; Hadjiefthymiades, Stathes
2009-11-01
Patient telemonitoring systems (PTS) deal with the acquisition, processing, and secure transmission of a patient's physiological and physical parameters to a remote location, where expert medical knowledge is available. In emergency situations, when the patient's life is threatened, the trend in modern PTS is to transmit the current location of the patient. Although research in communications security has led to mechanisms that sufficiently protect medical data, research related to location privacy area is still in its early stages. This paper proposes an architecture that enhances PTS through location privacy and data encryption. We study the most popular PTS technologies in conjunction with location privacy architectures and propose an innovative scheme that exploits a point-to-point protocol called Mist. We describe a prototype implementation, developed for validating the proposed framework along with the corresponding evaluation results.
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
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. PMID:26479930
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.
Content-based image retrieval in homomorphic encryption domain.
Bellafqira, Reda; Coatrieux, Gouenou; Bouslimi, Dalel; Quellec, Gwenole
2015-08-01
In this paper, we propose a secure implementation of a content-based image retrieval (CBIR) method that makes possible diagnosis aid systems to work in externalized environment and with outsourced data as in cloud computing. This one works with homomorphic encrypted images from which it extracts wavelet based image features next used for subsequent image comparison. By doing so, our system allows a physician to retrieve the most similar images to a query image in an outsourced database while preserving data confidentiality. Our Secure CBIR is the first one that proposes to work with global image features extracted from encrypted images and does not induce extra communications in-between the client and the server. Experimental results show it achieves retrieval performance as good as if images were processed non-encrypted. PMID:26736909
A palmprint-based cryptosystem using double encryption
NASA Astrophysics Data System (ADS)
Kumar, Amioy; Kumar, Ajay
2008-03-01
We propose a novel cryptographic construct incorporating biometrics which insures a secure communication between two channels just by using Palmprint. The cryptosystem utilizes the advantages of both symmetric and asymmetric cryptographic approaches simultaneously; we denote it as double encryption. Any document in communication is first encrypted using symmetric cryptographic approach; the symmetric key involved is then encrypted using Asymmetric approach. Finally, the concept of fuzzy vault is explored to create a secure vault around the asymmetric key. We investigate the possible usage of palmprints in fuzzy vault to develop a user friendly and reliable crypto system. The experimental results from the proposed approach on the real palmprint images suggest its possible usage in an automated palmprint based key generation system.
Image encryption using random sequence generated from generalized information domain
NASA Astrophysics Data System (ADS)
Xia-Yan, Zhang; Guo-Ji, Zhang; Xuan, Li; Ya-Zhou, Ren; Jie-Hua, Wu
2016-05-01
A novel image encryption method based on the random sequence generated from the generalized information domain and permutation–diffusion architecture is proposed. The random sequence is generated by reconstruction from the generalized information file and discrete trajectory extraction from the data stream. The trajectory address sequence is used to generate a P-box to shuffle the plain image while random sequences are treated as keystreams. A new factor called drift factor is employed to accelerate and enhance the performance of the random sequence generator. An initial value is introduced to make the encryption method an approximately one-time pad. Experimental results show that the random sequences pass the NIST statistical test with a high ratio and extensive analysis demonstrates that the new encryption scheme has superior security.
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. PMID:24955430
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.
Privacy preserving index for encrypted electronic medical records.
Chen, Yu-Chi; Horng, Gwoboa; Lin, Yi-Jheng; Chen, Kuo-Chang
2013-12-01
With the development of electronic systems, privacy has become an important security issue in real-life. In medical systems, privacy of patients' electronic medical records (EMRs) must be fully protected. However, to combine the efficiency and privacy, privacy preserving index is introduced to preserve the privacy, where the EMR can be efficiently accessed by this patient or specific doctor. In the literature, Goh first proposed a secure index scheme with keyword search over encrypted data based on a well-known primitive, Bloom filter. In this paper, we propose a new privacy preserving index scheme, called position index (P-index), with keyword search over the encrypted data. The proposed index scheme is semantically secure against the adaptive chosen keyword attack, and it also provides flexible space, lower false positive rate, and search privacy. Moreover, it does not rely on pairing, a complicate computation, and thus can search over encrypted electronic medical records from the cloud server efficiently.
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.
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. PMID:26306278
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. PMID:26306278
Efficient medical information retrieval in encrypted Electronic Health Records.
Pruski, Cédric; Wisniewski, François
2012-01-01
The recent development of eHealth platforms across the world, whose main objective is to centralize patient's healthcare information to ensure the best continuity of care, requires the development of advanced tools and techniques for supporting health professionals in retrieving relevant information in this vast quantity of data. However, for preserving patient's privacy, some countries decided to de-identify and encrypt data contained in the shared Electronic Health Records, which reinforces the complexity of proposing efficient medical information retrieval approach. In this paper, we describe an original approach exploiting standards metadata as well as knowledge organizing systems to overcome the barriers of data encryption for improving the results of medical information retrieval in centralized and encrypted Electronic Health Records. This is done through the exploitation of semantic properties provided by knowledge organizing systems, which enable query expansion. Furthermore, we provide an overview of the approach together with illustrating examples and a discussion on the advantages and limitations of the provided framework.
Compressive passive millimeter wave imager
Gopalsami, Nachappa; Liao, Shaolin; Elmer, Thomas W; Koehl, Eugene R; Heifetz, Alexander; Raptis, Apostolos C
2015-01-27
A compressive scanning approach for millimeter wave imaging and sensing. A Hadamard mask is positioned to receive millimeter waves from an object to be imaged. A subset of the full set of Hadamard acquisitions is sampled. The subset is used to reconstruct an image representing the object.
Fractional Hartley transform applied to optical image encryption
NASA Astrophysics Data System (ADS)
Jimenez, C.; Torres, C.; Mattos, L.
2011-01-01
A new method for image encryption is introduced on the basis of two-dimensional (2-D) generalization of 1-D fractional Hartley transform that has been redefined recently in search of its inverse transform We encrypt the image by two fractional orders and random phase codes. It has an advantage over Hartley transform, for its fractional orders can also be used as addictional keys, and that, of course, strengthens image security. Only when all of these keys are correct, can the image be well decrypted. Computer simulations are also perfomed to confirm the possibilty of proposed method.
Image/video encryption using single shot digital holography
NASA Astrophysics Data System (ADS)
Li, Xiaoyu; Tang, Chen; Zhu, Xinjun; Li, Biyuan; Wang, Linlin; Yan, Xiusheng
2015-05-01
We propose a method for image/video encryption that combines double random-phase encoding in the Fresnel domain with a single shot digital holography. In this method, a complex object field can be reconstructed with only single frame hologram based on a constrained optimization method. The system without multiple shots and Fourier lens is simple, and allows to dynamically encrypt information. We test the proposed method on a computer simulated image, a grayscale image and a video in AVI format. Also we investigate the quality of the decryption process and the performance against noise attacks. The experimental results demonstrate the performance of the method.
Fok, Mable P; Prucnal, Paul R
2009-05-01
All-optical encryption for optical code-division multiple-access systems with interleaved waveband-switching modulation is experimentally demonstrated. The scheme explores dual-pump four-wave mixing in a 35 cm highly nonlinear bismuth oxide fiber to achieve XOR operation of the plaintext and the encryption key. Bit 0 and bit 1 of the encrypted data are represented by two different wavebands. Unlike on-off keying encryption methods, the encrypted data in this approach has the same intensity for both bit 0 and bit 1. Thus no plaintext or ciphertext signatures are observed.
An arbitrated quantum signature protocol based on the chained CNOT operations encryption
NASA Astrophysics Data System (ADS)
Li, Feng-Guang; Shi, Jian-Hong
2015-06-01
At present, the encryption scheme used by most arbitrated quantum signature (AQS) protocols is quantum one-time pad (QOTP) which encrypts data qubit by qubit. Though QOTP can achieve high security for data encryption, it is not suitable for AQS. There are many attacks on AQS using QOTP. In this paper, we propose an AQS protocol based on another encryption scheme called the chained CNOT operations, which encrypts quantum message ensemble. Our protocol preserves all merits in the similar AQS schemes and has better security. Security analysis shows that our protocol cannot be forged and disavowed under the existing attacks.
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. PMID:24663832
Progressive compressive imager
NASA Astrophysics Data System (ADS)
Evladov, Sergei; Levi, Ofer; Stern, Adrian
2012-06-01
We have designed and built a working automatic progressive sampling imaging system based on the vector sensor concept, which utilizes a unique sampling scheme of Radon projections. This sampling scheme makes it possible to progressively add information resulting in tradeoff between compression and the quality of reconstruction. The uniqueness of our sampling is that in any moment of the acquisition process the reconstruction can produce a reasonable version of the image. The advantage of the gradual addition of the samples is seen when the sparsity rate of the object is unknown, and thus the number of needed measurements. We have developed the iterative algorithm OSO (Ordered Sets Optimization) which employs our sampling scheme for creation of nearly uniform distributed sets of samples, which allows the reconstruction of Mega-Pixel images. We present the good quality reconstruction from compressed data ratios of 1:20.
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
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.
Portable RSA encryption-decryption subprogram for protecting proprietary text
Hanson, R.J.
1981-09-01
A virtually portable (FORTRAN) version of the RSA (Rivest, Shamir, Adleman) algorithm for encryption and decryption of proprietary text has been written. This system uses three previously developed software packages. These are an extended precision integer arithmetic package, an error processing package, and machine-sensitive input/output subprograms from the Text Exchange System.
Lithographically Encrypted Inverse Opals for Anti-Counterfeiting Applications.
Heo, Yongjoon; Kang, Hyelim; Lee, Joon-Seok; Oh, You-Kwan; Kim, Shin-Hyun
2016-07-01
Colloidal photonic crystals possess inimitable optical properties of iridescent structural colors and unique spectral shape, which render them useful for security materials. This work reports a novel method to encrypt graphical and spectral codes in polymeric inverse opals to provide advanced security. To accomplish this, this study prepares lithographically featured micropatterns on the top surface of hydrophobic inverse opals, which serve as shadow masks against the surface modification of air cavities to achieve hydrophilicity. The resultant inverse opals allow rapid infiltration of aqueous solution into the hydrophilic cavities while retaining air in the hydrophobic cavities. Therefore, the structural color of inverse opals is regioselectively red-shifted, disclosing the encrypted graphical codes. The decoded inverse opals also deliver unique reflectance spectral codes originated from two distinct regions. The combinatorial code composed of graphical and optical codes is revealed only when the aqueous solution agreed in advance is used for decoding. In addition, the encrypted inverse opals are chemically stable, providing invariant codes with high reproducibility. In addition, high mechanical stability enables the transfer of the films onto any surfaces. This novel encryption technology will provide a new opportunity in a wide range of security applications. PMID:27259060
Deterministic phase encoding encryption in single shot digital holography
NASA Astrophysics Data System (ADS)
Chen, G.-L.; Yang, W.-K.; Wang, J. C.; Chang, C.-C.
2008-11-01
We demonstrate a deterministic phase-encoded encryption system based on the digital holography and adopted a lenticular lens array (LLA) sheet as a phase modulator. In the proposed scheme the holographic patterns of encrypted images are captured digitally by a digital CCD. This work also adopt a novel, simple and effective technique that is used to suppress numerically the major blurring caused by the zero-order image in the numerical reconstruction. The decryption key is acquired as a digital hologram, called the key hologram. Therefore, the retrieval of the original information can be achieved by multiplying the encrypted hologram with a numerical generated phase-encoded wave. The storage and transmission of all holograms can be carried out by all-digital means. Simulation and experimental results demonstrate that the proposed approach can be operated in single procedure only and represent the satisfactory decrypted image. Finally, rotating and shifting the LLA is applied to investigate the tolerance of decryption to demonstrate the feasibility in the holographic encryption, as well as can also be used to provide the higher security.
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.
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.
Image encryption using the two-dimensional logistic chaotic map
NASA Astrophysics Data System (ADS)
Wu, Yue; Yang, Gelan; Jin, Huixia; Noonan, Joseph P.
2012-01-01
Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.
Selectively Encrypted Pull-Up Based Watermarking of Biometric data
NASA Astrophysics Data System (ADS)
Shinde, S. A.; Patel, Kushal S.
2012-10-01
Biometric authentication systems are becoming increasingly popular due to their potential usage in information security. However, digital biometric data (e.g. thumb impression) are themselves vulnerable to security attacks. There are various methods are available to secure biometric data. In biometric watermarking the data are embedded in an image container and are only retrieved if the secrete key is available. This container image is encrypted to have more security against the attack. As wireless devices are equipped with battery as their power supply, they have limited computational capabilities; therefore to reduce energy consumption we use the method of selective encryption of container image. The bit pull-up-based biometric watermarking scheme is based on amplitude modulation and bit priority which reduces the retrieval error rate to great extent. By using selective Encryption mechanism we expect more efficiency in time at the time of encryption as well as decryption. Significant reduction in error rate is expected to be achieved by the bit pull-up method.
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…
A joint signal processing and cryptographic approach to multimedia encryption.
Mao, Yinian; Wu, Min
2006-07-01
In recent years, there has been an increasing trend for multimedia applications to use delegate service providers for content distribution, archiving, search, and retrieval. These delegate services have brought new challenges to the protection of multimedia content confidentiality. This paper discusses the importance and feasibility of applying a joint signal processing and cryptographic approach to multimedia encryption, in order to address the access control issues unique to multimedia applications. We propose two atomic encryption operations that can preserve standard compliance and are friendly to delegate processing. Quantitative analysis for these operations is presented to demonstrate that a good tradeoff can be made between security and bitrate overhead. In assisting the design and evaluation of media security systems, we also propose a set of multimedia-oriented security scores to quantify the security against approximation attacks and to complement the existing notion of generic data security. Using video as an example, we present a systematic study on how to strategically integrate different atomic operations to build a video encryption system. The resulting system can provide superior performance over both generic encryption and its simple adaptation to video in terms of a joint consideration of security, bitrate overhead, and friendliness to delegate processing.
15 CFR Supplement No. 5 to Part 742 - Encryption Registration
Code of Federal Regulations, 2012 CFR
2012-01-01
... (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS CONTROL POLICY-CCL BASED CONTROLS Pt. 742, Supp. 5 Supplement No. 5 to Part 742—Encryption Registration Certain... algorithms or protocols that have not been adopted or approved by a duly recognized international...
Lithographically Encrypted Inverse Opals for Anti-Counterfeiting Applications.
Heo, Yongjoon; Kang, Hyelim; Lee, Joon-Seok; Oh, You-Kwan; Kim, Shin-Hyun
2016-07-01
Colloidal photonic crystals possess inimitable optical properties of iridescent structural colors and unique spectral shape, which render them useful for security materials. This work reports a novel method to encrypt graphical and spectral codes in polymeric inverse opals to provide advanced security. To accomplish this, this study prepares lithographically featured micropatterns on the top surface of hydrophobic inverse opals, which serve as shadow masks against the surface modification of air cavities to achieve hydrophilicity. The resultant inverse opals allow rapid infiltration of aqueous solution into the hydrophilic cavities while retaining air in the hydrophobic cavities. Therefore, the structural color of inverse opals is regioselectively red-shifted, disclosing the encrypted graphical codes. The decoded inverse opals also deliver unique reflectance spectral codes originated from two distinct regions. The combinatorial code composed of graphical and optical codes is revealed only when the aqueous solution agreed in advance is used for decoding. In addition, the encrypted inverse opals are chemically stable, providing invariant codes with high reproducibility. In addition, high mechanical stability enables the transfer of the films onto any surfaces. This novel encryption technology will provide a new opportunity in a wide range of security applications.
Fast Video Encryption Using the H.264 Error Propagation Property for Smart Mobile Devices
Chung, Yongwha; Lee, Sungju; Jeon, Taewoong; Park, Daihee
2015-01-01
In transmitting video data securely over Video Sensor Networks (VSNs), since mobile handheld devices have limited resources in terms of processor clock speed and battery size, it is necessary to develop an efficient method to encrypt video data to meet the increasing demand for secure connections. Selective encryption methods can reduce the amount of computation needed while satisfying high-level security requirements. This is achieved by selecting an important part of the video data and encrypting it. In this paper, to ensure format compliance and security, we propose a special encryption method for H.264, which encrypts only the DC/ACs of I-macroblocks and the motion vectors of P-macroblocks. In particular, the proposed new selective encryption method exploits the error propagation property in an H.264 decoder and improves the collective performance by analyzing the tradeoff between the visual security level and the processing speed compared to typical selective encryption methods (i.e., I-frame, P-frame encryption, and combined I-/P-frame encryption). Experimental results show that the proposed method can significantly reduce the encryption workload without any significant degradation of visual security. PMID:25850068
Fast video encryption using the H.264 error propagation property for smart mobile devices.
Chung, Yongwha; Lee, Sungju; Jeon, Taewoong; Park, Daihee
2015-01-01
In transmitting video data securely over Video Sensor Networks (VSNs), since mobile handheld devices have limited resources in terms of processor clock speed and battery size, it is necessary to develop an efficient method to encrypt video data to meet the increasing demand for secure connections. Selective encryption methods can reduce the amount of computation needed while satisfying high-level security requirements. This is achieved by selecting an important part of the video data and encrypting it. In this paper, to ensure format compliance and security, we propose a special encryption method for H.264, which encrypts only the DC/ACs of I-macroblocks and the motion vectors of P-macroblocks. In particular, the proposed new selective encryption method exploits the error propagation property in an H.264 decoder and improves the collective performance by analyzing the tradeoff between the visual security level and the processing speed compared to typical selective encryption methods (i.e., I-frame, P-frame encryption, and combined I-/P-frame encryption). Experimental results show that the proposed method can significantly reduce the encryption workload without any significant degradation of visual security. PMID:25850068
Fast video encryption using the H.264 error propagation property for smart mobile devices.
Chung, Yongwha; Lee, Sungju; Jeon, Taewoong; Park, Daihee
2015-04-02
In transmitting video data securely over Video Sensor Networks (VSNs), since mobile handheld devices have limited resources in terms of processor clock speed and battery size, it is necessary to develop an efficient method to encrypt video data to meet the increasing demand for secure connections. Selective encryption methods can reduce the amount of computation needed while satisfying high-level security requirements. This is achieved by selecting an important part of the video data and encrypting it. In this paper, to ensure format compliance and security, we propose a special encryption method for H.264, which encrypts only the DC/ACs of I-macroblocks and the motion vectors of P-macroblocks. In particular, the proposed new selective encryption method exploits the error propagation property in an H.264 decoder and improves the collective performance by analyzing the tradeoff between the visual security level and the processing speed compared to typical selective encryption methods (i.e., I-frame, P-frame encryption, and combined I-/P-frame encryption). Experimental results show that the proposed method can significantly reduce the encryption workload without any significant degradation of visual security.
NASA Technical Reports Server (NTRS)
1996-01-01
Optivision developed two PC-compatible boards and associated software under a Goddard Space Flight Center Small Business Innovation Research grant for NASA applications in areas such as telerobotics, telesciences and spaceborne experimentation. From this technology, the company used its own funds to develop commercial products, the OPTIVideo MPEG Encoder and Decoder, which are used for realtime video compression and decompression. They are used in commercial applications including interactive video databases and video transmission. The encoder converts video source material to a compressed digital form that can be stored or transmitted, and the decoder decompresses bit streams to provide high quality playback.
Stevens, Andrew J.; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.
2015-08-02
One of the main limitations of imaging at high spatial and temporal resolution during in-situ TEM experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing methods [1, 2, 3, 4] to increase the framerate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical compressive sensing inversion. Our simulations show that it should be possible to increase the speed of any camera by at least an order of magnitude. Compressive Sensing (CS) combines sensing and compression in one operation, and thus provides an approach that could further improve the temporal resolution while correspondingly reducing the electron dose rate. Because the signal is measured in a compressive manner, fewer total measurements are required. When applied to TEM video capture, compressive imaging couled improve acquisition speed and reduce the electron dose rate. CS is a recent concept, and has come to the forefront due the seminal work of Candès [5]. Since the publication of Candès, there has been enormous growth in the application of CS and development of CS variants. For electron microscopy applications, the concept of CS has also been recently applied to electron tomography [6], and reduction of electron dose in scanning transmission electron microscopy (STEM) imaging [7]. To demonstrate the applicability of coded aperture CS video reconstruction for atomic level imaging, we simulate compressive sensing on observations of Pd nanoparticles and Ag nanoparticles during exposure to high temperatures and other environmental
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.
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.
Data encryption standard ASIC design and development report.
Robertson, Perry J.; Pierson, Lyndon George; Witzke, Edward L.
2003-10-01
This document describes the design, fabrication, and testing of the SNL Data Encryption Standard (DES) ASIC. This device was fabricated in Sandia's Microelectronics Development Laboratory using 0.6 {micro}m CMOS technology. The SNL DES ASIC was modeled using VHDL, then simulated, and synthesized using Synopsys, Inc. software and finally IC layout was performed using Compass Design Automation's CAE tools. IC testing was performed by Sandia's Microelectronic Validation Department using a HP 82000 computer aided test system. The device is a single integrated circuit, pipelined realization of DES encryption and decryption capable of throughputs greater than 6.5 Gb/s. Several enhancements accommodate ATM or IP network operation and performance scaling. This design is the latest step in the evolution of DES modules.
An image encryption scheme based on quantum logistic map
NASA Astrophysics Data System (ADS)
Akhshani, A.; Akhavan, A.; Lim, S.-C.; Hassan, Z.
2012-12-01
The topic of quantum chaos has begun to draw increasing attention in recent years. While a satisfactory definition for it is not settled yet in order to differentiate between its classical counterparts. Dissipative quantum maps can be characterized by sensitive dependence on initial conditions, like classical maps. Considering this property, an implementation of image encryption scheme based on the quantum logistic map is proposed. The security and performance analysis of the proposed image encryption is performed using well-known methods. The results of the reliability analysis are encouraging and it can be concluded that, the proposed scheme is efficient and secure. The results of this study also suggest application of other quantum maps such as quantum standard map and quantum baker map in cryptography and other aspects of security and privacy.
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.
Novel implementation of memristive systems for data encryption and obfuscation
NASA Astrophysics Data System (ADS)
Du, Nan; Manjunath, Niveditha; Shuai, Yao; Bürger, Danilo; Skorupa, Ilona; Schüffny, René; Mayr, Christian; Basov, Dimitri N.; Di Ventra, Massimiliano; Schmidt, Oliver G.; Schmidt, Heidemarie
2014-03-01
With the rise of big data handling, new solutions are required to drive cryptographic algorithms for maintaining data security. Here, we exploit the nonvolatile, nonlinear resistance change in BiFeO3 memristors [Shuai et al., J. Appl. Phys. 109, 124117 (2011)] by applying a voltage for the generation of second and higher harmonics and develop a new memristor-based encoding system from it to encrypt and obfuscate data. It is found that a BiFeO3 memristor in high and low resistance state can be used to generate two clearly distinguishable sets of second and higher harmonics as recently predicted theoretically [Cohen et al., Appl. Phys. Lett. 100, 133109 (2012)]. The computed autocorrelation of encrypted data using higher harmonics generated by a BiFeO3 memristor shows that the encoded data distribute randomly.
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. PMID:27500035
NASA Astrophysics Data System (ADS)
Sharma, K. K.; Jain, Heena
2013-01-01
The security of digital data including images has attracted more attention recently, and many different image encryption methods have been proposed in the literature for this purpose. In this paper, a new image encryption method using wavelet packet decomposition and discrete linear canonical transform is proposed. The use of wavelet packet decomposition and DLCT increases the key size significantly making the encryption more robust. Simulation results of the proposed technique are also presented.
Optics based biometric encryption using log polar transform
NASA Astrophysics Data System (ADS)
Saini, Nirmala; Sinha, Aloka
2010-01-01
We propose an optics based biometric encryption technique using log polar transform. In this method, the key of the encryption process has been linked to the fingerprint of the enrolled person. The order of fractional Fourier transform and the seed values of the chaotic random phase masks in combination act as the key for the encryption process. In order to link the combined key to the fingerprint, a lookup table has been formed by the key and the log polar transform of the fingerprint. The linking algorithm not only encrypts the image of the enrolled person but also authenticates the input image. The main advantage of this method is its capability to retrieve the same key in the decryption process by using the live fingerprint. The key is not required to be communicated to the receiver side. The retrieval of the image is possible only when the live fingerprint of the enrolled person is presented at the decryption side. The real life fingerprints have been used to demonstrate the proposed technique. Simulations have been performed on the Matlab platform to validate the proposed technique. The signal to noise ratio and mean square error has been calculated in order to support the proposed technique. The effect of the rotation and the scaling of the fingerprints have been studied to check the key retrieval from the live fingerprint of the enrolled person. The study of the different whorl types of fingerprint of different persons has also been done to check the efficacy of the key retrieval from the whorl types of the live fingerprints of different person.
On applying molecular computation to the data encryption standard.
Adleman, L M; Rothemund, P W; Roweis, S; Winfree, E
1999-01-01
Recently, Boneh, Dunworth, and Lipton (1996) described the potential use of molecular computation in attacking the United States Data Encryption Standard (DES). Here, we provide a description of such an attack using the sticker model of molecular computation. Our analysis suggests that such an attack might be mounted on a tabletop machine using approximately a gram of DNA and might succeed even in the presence of a large number of errors.
Resistance of the double random phase encryption against various attacks.
Frauel, Yann; Castro, Albertina; Naughton, Thomas J; Javidi, Bahram
2007-08-01
Several attacks are proposed against the double random phase encryption scheme. These attacks are demonstrated on computer-generated ciphered images. The scheme is shown to be resistant against brute force attacks but susceptible to chosen and known plaintext attacks. In particular, we describe a technique to recover the exact keys with only two known plain images. We compare this technique to other attacks proposed in the literature.
SNLL materials testing compression facility
Kawahara, W.A.; Brandon, S.L.; Korellis, J.S.
1986-04-01
This report explains software enhancements and fixture modifications which expand the capabilities of a servo-hydraulic test system to include static computer-controlled ''constant true strain rate'' compression testing on cylindrical specimens. True strains in excess of -1.0 are accessible. Special software features include schemes to correct for system compliance and the ability to perform strain-rate changes; all software for test control and data acquisition/reduction is documented.
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.
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.
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
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.
Erlich, Yaniv; Gordon, Assaf; Brand, Michael; Hannon, Gregory J.; Mitra, Partha P.
2011-01-01
Over the past three decades we have steadily increased our knowledge on the genetic basis of many severe disorders. Nevertheless, there are still great challenges in applying this knowledge routinely in the clinic, mainly due to the relatively tedious and expensive process of genotyping. Since the genetic variations that underlie the disorders are relatively rare in the population, they can be thought of as a sparse signal. Using methods and ideas from compressed sensing and group testing, we have developed a cost-effective genotyping protocol to detect carriers for severe genetic disorders. In particular, we have adapted our scheme to a recently developed class of high throughput DNA sequencing technologies. The mathematical framework presented here has some important distinctions from the ’traditional’ compressed sensing and group testing frameworks in order to address biological and technical constraints of our setting. PMID:21451737
Optical multiple-image encryption based on multiplane phase retrieval and interference
NASA Astrophysics Data System (ADS)
Chen, Wen; Chen, Xudong
2011-11-01
In this paper, we propose a new method for optical multiple-image encryption based on multiplane phase retrieval and interference. An optical encoding system is developed in the Fresnel domain. A phase-only map is iteratively extracted based on a multiplane phase retrieval algorithm, and multiple plaintexts are simultaneously encrypted. Subsequently, the extracted phase-only map is further encrypted into two phase-only masks based on a non-iterative interference algorithm. During image decryption, the advantages and security of the proposed optical cryptosystem are analyzed. Numerical results are presented to demonstrate the validity of the proposed optical multiple-image encryption method.
Interference-based multiple-image encryption with silhouette removal by position multiplexing.
Qin, Yi; Gong, Qiong
2013-06-10
An approach for multiple-image encryption based on interference and position multiplexing is proposed. In the encryption process, multiple images are analytically hidden into three phase-only masks (POMs). The encryption algorithm for this method is quite simple and does not need iterative encoding. For decryption, both the digital method and optical method could be employed. Also, we analyze the multiplexing capacity through the correlation coefficient. In addition, the silhouette problem that exists in previous interference-based encryption methods with two POMs can be eliminated during the generation procedure of POMs based on the interference principle. Simulation results are presented to verify the validity of the proposed approach.
Olama, Mohammed M; Matalgah, Mustafa M; Bobrek, Miljko
2015-01-01
Traditional encryption techniques require packet overhead, produce processing time delay, and suffer from severe quality of service deterioration due to fades and interference in wireless channels. These issues reduce the effective transmission data rate (throughput) considerably in wireless communications, where data rate with limited bandwidth is the main constraint. In this paper, performance evaluation analyses are conducted for an integrated signaling-encryption mechanism that is secure and enables improved throughput and probability of bit-error in wireless channels. This mechanism eliminates the drawbacks stated herein by encrypting only a small portion of an entire transmitted frame, while the rest is not subject to traditional encryption but goes through a signaling process (designed transformation) with the plaintext of the portion selected for encryption. We also propose to incorporate error correction coding solely on the small encrypted portion of the data to drastically improve the overall bit-error rate performance while not noticeably increasing the required bit-rate. We focus on validating the signaling-encryption mechanism utilizing Hamming and convolutional error correction coding by conducting an end-to-end system-level simulation-based study. The average probability of bit-error and throughput of the encryption mechanism are evaluated over standard Gaussian and Rayleigh fading-type channels and compared to the ones of the conventional advanced encryption standard (AES).
Image encryption algorithm based on the random local phase encoding in gyrator transform domains
NASA Astrophysics Data System (ADS)
Liu, Zhengjun; Yang, Meng; Liu, Wei; Li, She; Gong, Min; Liu, Wanyu; Liu, Shutian
2012-09-01
A random local phase encoding method is presented for encrypting a secret image. Some random polygons are introduced to control the local regions of random phase encoding. The data located in the random polygon is encoded by random phase encoding. The random phase data is the main key in this encryption method. The different random phases calculated by using a monotonous function are employed. The random data defining random polygon serves as an additional key for enhancing the security of the image encryption scheme. Numerical simulations are given for demonstrating the performance of the proposed encryption approach.
A novel color image encryption scheme using alternate chaotic mapping structure
NASA Astrophysics Data System (ADS)
Wang, Xingyuan; Zhao, Yuanyuan; Zhang, Huili; Guo, Kang
2016-07-01
This paper proposes an color image encryption algorithm using alternate chaotic mapping structure. Initially, we use the R, G and B components to form a matrix. Then one-dimension logistic and two-dimension logistic mapping is used to generate a chaotic matrix, then iterate two chaotic mappings alternately to permute the matrix. For every iteration, XOR operation is adopted to encrypt plain-image matrix, then make further transformation to diffuse the matrix. At last, the encrypted color image is obtained from the confused matrix. Theoretical analysis and experimental results has proved the cryptosystem is secure and practical, and it is suitable for encrypting color images.
Opto-digital image encryption by using Baker mapping and 1-D fractional Fourier transform
NASA Astrophysics Data System (ADS)
Liu, Zhengjun; Li, She; Liu, Wei; Liu, Shutian
2013-03-01
We present an optical encryption method based on the Baker mapping in one-dimensional fractional Fourier transform (1D FrFT) domains. A thin cylinder lens is controlled by computer for implementing 1D FrFT at horizontal direction or vertical direction. The Baker mapping is introduced to scramble the amplitude distribution of complex function. The amplitude and phase of the output of encryption system are regarded as encrypted image and key. Numerical simulation has been performed for testing the validity of this encryption scheme.
Polans, James; McNabb, Ryan P.; Izatt, Joseph A.; Farsiu, Sina
2014-01-01
We report on an algorithm for fast wavefront sensing that incorporates sparse representation for the first time in practice. The partial derivatives of optical wavefronts were sampled sparsely with a Shack-Hartmann wavefront sensor (SHWFS) by randomly subsampling the original SHWFS data to as little as 5%. Reconstruction was performed by a sparse representation algorithm that utilized the Zernike basis. We name this method SPARZER. Experiments on real and simulated data attest to the accuracy of the proposed techniques as compared to traditional sampling and reconstruction methods. We have made the corresponding data set and software freely available online. Compressed wavefront sensing offers the potential to increase the speed of wavefront acquisition and to defray the cost of SHWFS devices. PMID:24690703
Jiang, Xiaoye; Yao, Yuan; Liu, Han; Guibas, Leonidas
2014-01-01
Modern data acquisition routinely produces massive amounts of network data. Though many methods and models have been proposed to analyze such data, the research of network data is largely disconnected with the classical theory of statistical learning and signal processing. In this paper, we present a new framework for modeling network data, which connects two seemingly different areas: network data analysis and compressed sensing. From a nonparametric perspective, we model an observed network using a large dictionary. In particular, we consider the network clique detection problem and show connections between our formulation with a new algebraic tool, namely Randon basis pursuit in homogeneous spaces. Such a connection allows us to identify rigorous recovery conditions for clique detection problems. Though this paper is mainly conceptual, we also develop practical approximation algorithms for solving empirical problems and demonstrate their usefulness on real-world datasets. PMID:25620806
Spread spectrum image data hiding in the encrypted discrete cosine transform coefficients
NASA Astrophysics Data System (ADS)
Zhang, Xiaoqiang; Wang, Z. Jane
2013-10-01
Digital watermarking and data hiding are important tools for digital rights protection of media data. Spread spectrum (SS)-based watermarking and data-hiding approaches are popular due to their outstanding robustness, but their security might not be sufficient. To improve the security of SS, a SS-based image data-hiding approach is proposed by encrypting the discrete cosine transform coefficients of the host image with the piecewise linear chaotic map, before the operation of watermark embedding. To evaluate the performance of the proposed approach, simulations and analyses of its robustness and security are carried out. The average bit-error-rate values on 100 real images from the Berkeley segmentation dataset under the JPEG compression, additive Gaussian noise, salt and pepper noise, and cropping attacks are reported. Experimental results show that the proposed approach can maintain the high robustness of traditional SS schemes and, meanwhile, also improve the security. The proposed approach can extend the key space of traditional SS schemes from 10 to 10 and thus can resist brute-force attack and unauthorized detection watermark attack.
Ma, JiaLi; Zhang, TanTan; Dong, MingChui
2015-05-01
This paper presents a novel electrocardiogram (ECG) compression method for e-health applications by adapting an adaptive Fourier decomposition (AFD) algorithm hybridized with a symbol substitution (SS) technique. The compression consists of two stages: first stage AFD executes efficient lossy compression with high fidelity; second stage SS performs lossless compression enhancement and built-in data encryption, which is pivotal for e-health. Validated with 48 ECG records from MIT-BIH arrhythmia benchmark database, the proposed method achieves averaged compression ratio (CR) of 17.6-44.5 and percentage root mean square difference (PRD) of 0.8-2.0% with a highly linear and robust PRD-CR relationship, pushing forward the compression performance to an unexploited region. As such, this paper provides an attractive candidate of ECG compression method for pervasive e-health applications. PMID:25222961
Ma, JiaLi; Zhang, TanTan; Dong, MingChui
2015-05-01
This paper presents a novel electrocardiogram (ECG) compression method for e-health applications by adapting an adaptive Fourier decomposition (AFD) algorithm hybridized with a symbol substitution (SS) technique. The compression consists of two stages: first stage AFD executes efficient lossy compression with high fidelity; second stage SS performs lossless compression enhancement and built-in data encryption, which is pivotal for e-health. Validated with 48 ECG records from MIT-BIH arrhythmia benchmark database, the proposed method achieves averaged compression ratio (CR) of 17.6-44.5 and percentage root mean square difference (PRD) of 0.8-2.0% with a highly linear and robust PRD-CR relationship, pushing forward the compression performance to an unexploited region. As such, this paper provides an attractive candidate of ECG compression method for pervasive e-health applications.
Zimmer, M.J.; Lynch, P.W. )
1993-11-01
Acquiring projects takes careful planning, research and consideration. Picking the right opportunities and avoiding the pitfalls will lead to a more valuable portfolio. This article describes the steps to take in evaluating an acquisition and what items need to be considered in an evaluation.
Double-image encryption based on discrete fractional random transform and chaotic maps
NASA Astrophysics Data System (ADS)
Li, Huijuan; Wang, Yurong
2011-07-01
A novel double-image encryption algorithm is proposed, based on discrete fractional random transform and chaotic maps. The random matrices used in the discrete fractional random transform are generated by using a chaotic map. One of the two original images is scrambled by using another chaotic map, and then encoded into the phase of a complex matrix with the other original image as its amplitude. Then this complex matrix is encrypted by the discrete fractional random transform. By applying the correct keys which consist of initial values, control parameters, and truncated positions of the chaotic maps, and fractional orders, the two original images can be recovered without cross-talk. Numerical simulation has been performed to test the validity and the security of the proposed encryption algorithm. Encrypting two images together by this algorithm creates only one encrypted image, whereas other single-image encryption methods create two encrypted images. Furthermore, this algorithm requires neither the use of phase keys nor the use of matrix keys. In this sense, this algorithm can raise the efficiency when encrypting, storing or transmitting.
Gray-scale and color optical encryption based on computational ghost imaging
NASA Astrophysics Data System (ADS)
Tanha, Mehrdad; Kheradmand, Reza; Ahmadi-Kandjani, Sohrab
2012-09-01
We propose two approaches for optical encryption based on computational ghost imaging. These methods have the capability of encoding ghost images reconstructed from gray-scale images and colored objects. We experimentally demonstrate our approaches under eavesdropping in two different setups, thereby proving the robustness and simplicity thereof for encryption compared with previous algorithms.
15 CFR 748.3 - Classification requests, advisory opinions, and encryption review requests.
Code of Federal Regulations, 2010 CFR
2010-01-01
... opinions, and encryption review requests. 748.3 Section 748.3 Commerce and Foreign Trade Regulations... § 748.3 Classification requests, advisory opinions, and encryption review requests. (a) Introduction... determination based on the submission of a review request prepared in accordance with the instructions...
75 FR 43819 - Clarification of Grace Period for Encryption Registration Requirement
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-27
... of Industry and Security (BIS) published a final rule (75 FR 36482) that, inter alia, established an... Encryption Registration Requirement AGENCY: Bureau of Industry and Security, Commerce. ACTION: Final rule; correcting amendments. SUMMARY: This rule clarifies the intent of the encryption registration...
An Anti-Cheating Visual Cryptography Scheme Based on Chaotic Encryption System
NASA Astrophysics Data System (ADS)
Han, Yanyan; Xu, Zhuolin; Ge, Xiaonan; He, Wencai
By chaotic encryption system and introducing the trusted third party (TTP), in this paper, an anti-cheating visual cryptography scheme (VCS) is proposed. The scheme solved the problem of dishonest participants and improved the security of chaotic encryption system. Simulation results and analysis show that the recovery image is acceptable, the system can detect the cheating in participants effectively and with high security.
NASA Astrophysics Data System (ADS)
Liang, Yaru; Liu, Guoping; Zhou, Nanrun; Wu, Jianhua
2015-02-01
Based on the fractional discrete cosine transform with multiple generating sequences (MGSFrDCT) and the dependent scrambling and diffusion (DSD), an image encryption algorithm is proposed, in which the multiple-generating sequences greatly enlarge the key space of the encryption system. The real-valued output of MGSFrDCT is beneficial to storage, display and transmission of the cipher-text. During the stage of confusion and diffusion, the locations and values of all MGSFrDCT transformed coefficients change due to DSD, and the initial values and fractional orders of encryption system depend not only on the cipher keys but also on the plain-image due to introduction of a disturbance factor, which allows the encryption system to resist the known-plaintext and chosen-plaintext attacks. Experimental results demonstrate that the proposed encryption algorithm is feasible, effective and secure and able to resist common classical attacks.
Encrypted imaging based on algebraic implementation of double random phase encoding.
Nakano, Kazuya; Takeda, Masafumi; Suzuki, Hiroyuki; Yamaguchi, Masahiro
2014-05-10
The security of important information captured by sensors and cameras is currently a growing concern as information theft via techniques such as side-channel attacks become increasingly more prevalent. Double random phase encoding (DRPE) is an optical encryption method based on optical Fourier transform that is currently being used to implement secure coherent optical systems. In this paper, we propose a new DRPE implementation for incoherent optical systems based on integral photography that can be applied to "encrypted imaging (EI)" to optically encrypt an image before it is captured by an image sensor. Because the proposed incoherent DRPE is constituted from conventional DRPE by rewriting the optical encryption via discretization and Euler's formula, its security level is the same as that of conventional DRPE. The results of an experiment in which we encrypted a plaintext image optically and then decrypted it numerically demonstrate that our proposed incoherent optical security system is feasible.
Optical image encryption and hiding based on a modified Mach-Zehnder interferometer.
Li, Jun; Li, Jiaosheng; Shen, Lina; Pan, Yangyang; Li, Rong
2014-02-24
A method for optical image hiding and for optical image encryption and hiding in the Fresnel domain via completely optical means is proposed, which encodes original object image into the encrypted image and then embeds it into host image in our modified Mach-Zehnder interferometer architecture. The modified Mach-Zehnder interferometer not only provides phase shifts to record complex amplitude of final encrypted object image on CCD plane but also introduces host image into reference path of the interferometer to hide it. The final encrypted object image is registered as interference patterns, which resemble a Fresnel diffraction pattern of the host image, and thus the secure information is imperceptible to unauthorized receivers. The method can simultaneously realize image encryption and image hiding at a high speed in pure optical system. The validity of the method and its robustness against some common attacks are investigated by numerical simulations and experiments.
The effect of algorithm-agile encryption on ATM quality of service
Sholander, P.; Tarman, T.; Pierson, L.; Hutchinson, R.
1997-04-01
Asynchronous Transfer Mode (ATM) users often open multiple ATM Virtual Circuits (VCs) to multiple ATM users on multiple ATM networks. Each network and user may implement a different encryption policy. Hence ATM users may need shared, flexible hardware-based 3encryption that supports multiple encryption algorithms for multiple concurrent ATM users and VCs. An algorithm-agile encryption architecture, that uses multiple, parallel encryption-pipelines, is proposed. That algorithm-agile encryptor`s effect on the ATM Quality of Service (QoS) metrics, such as Cell Transfer Delay (CTD) and Cell Delay Variation (CDV), is analyzed. Bounds on the maximum CDV and the CDV`s probability density are derived.
NASA Astrophysics Data System (ADS)
Tan, Ru-Chao; Lei, Tong; Zhao, Qing-Min; Gong, Li-Hua; Zhou, Zhi-Hong
2016-09-01
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.
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.
Error-reduction techniques and error analysis for fully phase- and amplitude-based encryption.
Javidi, B; Towghi, N; Maghzi, N; Verrall, S C
2000-08-10
The performance of fully phase- and amplitude-based encryption processors is analyzed. The effects of noise perturbations on the encrypted information are considered. A thresholding method of decryption that further reduces the mean-squared error (MSE) for the fully phase- and amplitude-based encryption processes is provided. The proposed thresholding scheme significantly improves the performance of fully phase- and amplitude-based encryption, as measured by the MSE metric. We obtain analytical MSE bounds when thresholding is used for both decryption methods, and we also present computer-simulation results. These results show that the fully phase-based method is more robust. We also give a formal proof of a conjecture about the decrypted distribution of distorted encrypted information. This allows the analytical bounds of the MSE to be extended to more general non-Gaussian, nonadditive, nonstationary distortions. Computer simulations support this extension.
Image encryption based on the reality-preserving multiple-parameter fractional Fourier transform
NASA Astrophysics Data System (ADS)
Lang, Jun
2012-05-01
In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by using the fractional Fourier transform, but most of their encryptions are complex values and need digital hologram technique to record information, which is inconvenient for digital transmission. In this paper, we propose a new approach for image encryption based on the real-valuedness and decorrelation property of the reality-preserving multiple-parameter fractional Fourier transform in order to meet the requirements of the secure image transmission. In the proposed scheme, the original and encrypted images are respectively in the spatial domain and the reality-preserving multiple-parameter fractional Fourier transformed domain determined by the encryption keys. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods.
VIRTEX-5 Fpga Implementation of Advanced Encryption Standard Algorithm
NASA Astrophysics Data System (ADS)
Rais, Muhammad H.; Qasim, Syed M.
2010-06-01
In this paper, we present an implementation of Advanced Encryption Standard (AES) cryptographic algorithm using state-of-the-art Virtex-5 Field Programmable Gate Array (FPGA). The design is coded in Very High Speed Integrated Circuit Hardware Description Language (VHDL). Timing simulation is performed to verify the functionality of the designed circuit. Performance evaluation is also done in terms of throughput and area. The design implemented on Virtex-5 (XC5VLX50FFG676-3) FPGA achieves a maximum throughput of 4.34 Gbps utilizing a total of 399 slices.
'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages.
Rosemeyer, Helmut; Paululat, Achim; Heinisch, Jürgen J
2014-09-01
The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages.
NASA Astrophysics Data System (ADS)
Weber, Robert E.
2001-11-01
The widespread deployment of wireless networks using the 802.11(b) standard across the country presents a rebirth of age-old network security problems along with a number of new ones. The wireless network, much like a shared network using broadcast devices such as network hubs, travels across a shared medium. Because of the structure any member of the wireless network can observe and intercept data being sent or received by other members. Unlike 'wired' networks there is no means to isolate traffic from other network members. The second security issue for wireless networks is the transmission of data 'clear text' so that if it is intercepted it can be read and used. Wireless networks bring about another problem that compounds the first two concerns that all shared networks must deal with, that is, anyone within the transmission range of the wireless network can join. No longer must a person enter a building to infiltrate a business network, they need only park across the street. The first implementation of network security for wireless was the WEP (Wired Equivalent Privacy) protocol. WEP attempts to make a wireless network at least as secure as a switched 'wired' network. The WEP protocol intends to secure the traffic integrity with the use of a RC4 cipher and a CSC-32 checksum. In the passphrase used for the RC4 encryption is also used as a form of access control. There are several critical faults in the WEP implementation that allow both passive data acquisition and active data modification. At 11 Mbit, capturing approximately 5 hours of clear text data can guarantee the capture of two packets with the same initialization vector (IV). Once the packets are used to get the clear text packet, that information can be used to decrypt any packets with the same IV. Since the IV's are only 24 bits the decryption of entire network becomes only an exercise in patience, with a 24 hours of continuous monitoring the WEP encryption can be defeated completely and a simple
On-line structure-lossless digital mammogram image compression
NASA Astrophysics Data System (ADS)
Wang, Jun; Huang, H. K.
1996-04-01
This paper proposes a novel on-line structure lossless compression method for digital mammograms during the film digitization process. The structure-lossless compression segments the breast and the background, compresses the former with a predictive lossless coding method and discards the latter. This compression scheme is carried out during the film digitization process and no additional time is required for the compression. Digital mammograms are compressed on-the-fly while they are created. During digitization, lines of scanned data are first acquired into a small temporary buffer in the scanner, then they are transferred to a large image buffer in an acquisition computer which is connected to the scanner. The compression process, running concurrently with the digitization process in the acquisition computer, constantly checks the image buffer and compresses any newly arrived data. Since compression is faster than digitization, data compression is completed as soon as digitization is finished. On-line compression during digitization does not increase overall digitizing time. Additionally, it reduces the mammogram image size by a factor of 3 to 9 with no loss of information. This algorithm has been implemented in a film digitizer. Statistics were obtained based on digitizing 46 mammograms at four sampling distances from 50 to 200 microns.
Context adaptive binary arithmetic coding-based data hiding in partially encrypted H.264/AVC videos
NASA Astrophysics Data System (ADS)
Xu, Dawen; Wang, Rangding
2015-05-01
A scheme of data hiding directly in a partially encrypted version of H.264/AVC videos is proposed which includes three parts, i.e., selective encryption, data embedding and data extraction. Selective encryption is performed on context adaptive binary arithmetic coding (CABAC) bin-strings via stream ciphers. By careful selection of CABAC entropy coder syntax elements for selective encryption, the encrypted bitstream is format-compliant and has exactly the same bit rate. Then a data-hider embeds the additional data into partially encrypted H.264/AVC videos using a CABAC bin-string substitution technique without accessing the plaintext of the video content. Since bin-string substitution is carried out on those residual coefficients with approximately the same magnitude, the quality of the decrypted video is satisfactory. Video file size is strictly preserved even after data embedding. In order to adapt to different application scenarios, data extraction can be done either in the encrypted domain or in the decrypted domain. Experimental results have demonstrated the feasibility and efficiency of the proposed scheme.
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.
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
Unsupervised Language Acquisition
NASA Astrophysics Data System (ADS)
de Marcken, Carl
1996-11-01
This thesis presents a computational theory of unsupervised language acquisition, precisely defining procedures for learning language from ordinary spoken or written utterances, with no explicit help from a teacher. The theory is based heavily on concepts borrowed from machine learning and statistical estimation. In particular, learning takes place by fitting a stochastic, generative model of language to the evidence. Much of the thesis is devoted to explaining conditions that must hold for this general learning strategy to arrive at linguistically desirable grammars. The thesis introduces a variety of technical innovations, among them a common representation for evidence and grammars, and a learning strategy that separates the ``content'' of linguistic parameters from their representation. Algorithms based on it suffer from few of the search problems that have plagued other computational approaches to language acquisition. The theory has been tested on problems of learning vocabularies and grammars from unsegmented text and continuous speech, and mappings between sound and representations of meaning. It performs extremely well on various objective criteria, acquiring knowledge that causes it to assign almost exactly the same structure to utterances as humans do. This work has application to data compression, language modeling, speech recognition, machine translation, information retrieval, and other tasks that rely on either structural or stochastic descriptions of language.
Research on an E-mail Encryption Protocol Based on Quantum Teleportation
NASA Astrophysics Data System (ADS)
Shufen, Xiao; Yumin, Dong; Hongyang, Ma; Libo, Chen
2016-07-01
With the rapid development of information technology (IT), E-mail has become an important communication tool between human beings. Meanwhile, E-mail safety becomes increasingly important because of its universal applications. In order to overcome shortages of classical E-mail encryption, an E-mail encryption protocol based on quantum teleportation was proposed. It makes quantum encryption of E-mails during sending and receiving processes by taking advantages of entanglement and nonclonability of quantum, thus ensuring safety and reliability of E-mail transmission.
Opto-digital spectrum encryption by using Baker mapping and gyrator transform
NASA Astrophysics Data System (ADS)
Chen, Hang; Zhao, Jiguang; Liu, Zhengjun; Du, Xiaoping
2015-03-01
A concept of spectrum information hidden technology is proposed in this paper. We present an optical encryption algorithm for hiding both the spatial and spectrum information by using the Baker mapping in gyrator transform domains. The Baker mapping is introduced for scrambling the every single band of the hyperspectral image before adding the random phase functions. Subsequently, three thin cylinder lenses are controlled by PC for implementing the gyrator transform. The amplitude and phase information in the output plane can be regarded as the encrypted information and main key. Some numerical simulations are made to test the validity and capability of the proposed encryption algorithm.
Optical holographic encrypted data storage using lenticular lens array phase-encoded multiplexing
NASA Astrophysics Data System (ADS)
Chang, C. C.; Chen, G. L.; Teng, P. C.; Young, W. K.
2006-04-01
We propose a novel optical holographic encrypted data storage scheme based on phase encoding multiplexed scheme. In the proposed data storage scheme, patterns of encrypted images are stored holographically in a photorefractive LiNbO 3:Fe crystal by using lenticular lens array (LLA) sheet phase-encoded multiplexing. Experimental results show that rotating a LLA placed as a phase modulator in the path of the reference beam provides a simple yet effective method of increasing the holographic storage capabilities of the crystal. Combining this rotational multiplexing with two-axis tilting multiplexing offers not only further data storage capabilities but also data encryption possibilities.
Optical encryption and QR codes: secure and noise-free information retrieval.
Barrera, John Fredy; Mira, Alejandro; Torroba, Roberto
2013-03-11
We introduce for the first time the concept of an information "container" before a standard optical encrypting procedure. The "container" selected is a QR code which offers the main advantage of being tolerant to pollutant speckle noise. Besides, the QR code can be read by smartphones, a massively used device. Additionally, QR code includes another secure step to the encrypting benefits the optical methods provide. The QR is generated by means of worldwide free available software. The concept development probes that speckle noise polluting the outcomes of normal optical encrypting procedures can be avoided, then making more attractive the adoption of these techniques. Actual smartphone collected results are shown to validate our proposal.
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.
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.
The Telecommunications and Data Acquisition Report
NASA Technical Reports Server (NTRS)
Posner, E. C. (Editor)
1987-01-01
Developments in programs managed by the Jet Propulsion Laboratory's Office of Telecommunications and Data Acquisition are discussed. Topics discussed include sorption compression/mechanical expanded hybrid refrigeration, calculated 70-meter antenna performance for offset L-band, systolic arrays and stack decoding, and calibrations of Deep Space Network antennas.
Positron Emission Mammography with Multiple Angle Acquisition
Mark F. Smith; Stan Majewski; Raymond R. Raylman
2002-11-01
Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.
Positron Emission Mammography with Multiple Angle Acquisition
Mark F. Smith; Stan Majewski; Raymond R. Raylman
2002-11-01
Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.
Compressive sampling for time critical microwave imaging applications
O'Halloran, Martin; McGinley, Brian; Conceicao, Raquel C.; Kilmartin, Liam; Jones, Edward; Glavin, Martin
2014-01-01
Across all biomedical imaging applications, there is a growing emphasis placed on reducing data acquisition and imaging times. This research explores the use of a technique, known as compressive sampling or compressed sensing (CS), as an efficient technique to minimise the data acquisition time for time critical microwave imaging (MWI) applications. Where a signal exhibits sparsity in the time domain, the proposed CS implementation allows for sub-sampling acquisition in the frequency domain and consequently shorter imaging times, albeit at the expense of a slight degradation in reconstruction quality of the signals as the compression increases. This Letter focuses on ultra wideband (UWB) radar MWI applications where reducing acquisition is of critical importance therefore a slight degradation in reconstruction quality may be acceptable. The analysis demonstrates the effectiveness and suitability of CS with UWB applications. PMID:26609368
A fast image encryption algorithm based on chaotic map
NASA Astrophysics Data System (ADS)
Liu, Wenhao; Sun, Kehui; Zhu, Congxu
2016-09-01
Derived from Sine map and iterative chaotic map with infinite collapse (ICMIC), a new two-dimensional Sine ICMIC modulation map (2D-SIMM) is proposed based on a close-loop modulation coupling (CMC) model, and its chaotic performance is analyzed by means of phase diagram, Lyapunov exponent spectrum and complexity. It shows that this map has good ergodicity, hyperchaotic behavior, large maximum Lyapunov exponent and high complexity. Based on this map, a fast image encryption algorithm is proposed. In this algorithm, the confusion and diffusion processes are combined for one stage. Chaotic shift transform (CST) is proposed to efficiently change the image pixel positions, and the row and column substitutions are applied to scramble the pixel values simultaneously. The simulation and analysis results show that this algorithm has high security, low time complexity, and the abilities of resisting statistical analysis, differential, brute-force, known-plaintext and chosen-plaintext attacks.
Restricted Authentication and Encryption for Cyber-physical Systems
Kirkpatrick, Michael S; Bertino, Elisa; Sheldon, Frederick T
2009-01-01
Cyber-physical systems (CPS) are characterized by the close linkage of computational resources and physical devices. These systems can be deployed in a number of critical infrastructure settings. As a result, the security requirements of CPS are different than traditional computing architectures. For example, critical functions must be identified and isolated from interference by other functions. Similarly, lightweight schemes may be required, as CPS can include devices with limited computing power. One approach that offers promise for CPS security is the use of lightweight, hardware-based authentication. Specifically, we consider the use of Physically Unclonable Functions (PUFs) to bind an access request to specific hardware with device-specific keys. PUFs are implemented in hardware, such as SRAM, and can be used to uniquely identify the device. This technology could be used in CPS to ensure location-based access control and encryption, both of which would be desirable for CPS implementations.
Tunable solid-state fluorescent materials for supramolecular encryption
Hou, Xisen; Ke, Chenfeng; Bruns, Carson J.; McGonigal, Paul R.; Pettman, Roger B.; Stoddart, J. Fraser
2015-01-01
Tunable solid-state fluorescent materials are ideal for applications in security printing technologies. A document possesses a high level of security if its encrypted information can be authenticated without being decoded, while also being resistant to counterfeiting. Herein, we describe a heterorotaxane with tunable solid-state fluorescent emissions enabled through reversible manipulation of its aggregation by supramolecular encapsulation. The dynamic nature of this fluorescent material is based on a complex set of equilibria, whose fluorescence output depends non-linearly on the chemical inputs and the composition of the paper. By applying this system in fluorescent security inks, the information encoded in polychromic images can be protected in such a way that it is close to impossible to reverse engineer, as well as being easy to verify. This system constitutes a unique application of responsive complex equilibria in the form of a cryptographic algorithm that protects valuable information printed using tunable solid-state fluorescent materials. PMID:25901677
Turbulence in Compressible Flows
NASA Technical Reports Server (NTRS)
1997-01-01
Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.
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. PMID:25634700
Deterministic phase encoding encryption in arbitrary phase-step digital holography
NASA Astrophysics Data System (ADS)
Chang, Chi-Ching; Hsieh, Wang Ta; Kuo, Ming Kuei
2010-05-01
A deterministic phase-encoded encryption system, which adopts a lenticular lens array (LLA) sheet as a phase modulator (key), based on arbitrary two-step phase-shift interferometry (PSI), with an unknown phase step, is presented. The principle of encryption and decryption which is using a LLA in arbitrary unknown two-step PSI is given. With the aid of key holograms (right key), it can be theoretically shown that only the reconstructed object wavefront term will be left in the image plane, and all the accompany undesired terms be eliminated. Thus the hidden information of object wavefront in this encryption system can be numerically and successfully decrypted using arbitrary unknown two-step PSI with right key. For comparisons, computer simulations are carried out to verify the principle of encryption and decryption without key, with wrong key and with right key, respectively.
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.
15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items
Code of Federal Regulations, 2013 CFR
2013-01-01
... non-technical description of the type of product (e.g., routers, disk drives, cell phones, and chips... (Commodity Classification Automated Tracking System (CCATS) number, Encryption Registration Number...
15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items
Code of Federal Regulations, 2011 CFR
2011-01-01
... non-technical description of the type of product (e.g., routers, disk drives, cell phones, and chips... (Commodity Classification Automated Tracking System (CCATS) number, Encryption Registration Number...
15 CFR Supplement No. 6 to Part 742 - Technical Questionnaire for Encryption Items
Code of Federal Regulations, 2012 CFR
2012-01-01
... non-technical description of the type of product (e.g., routers, disk drives, cell phones, and chips... (Commodity Classification Automated Tracking System (CCATS) number, Encryption Registration Number...
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.
Improved decryption quality and security of a joint transform correlator-based encryption system
NASA Astrophysics Data System (ADS)
Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet
2013-02-01
Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to significantly improve the quality of the decrypted image by introducing a simple nonlinear operation in the encrypted function that contains the joint power spectrum. This nonlinearity also makes the system more resistant to chosen-plaintext attacks. We additionally explore the system resistance against this type of attack when a variety of probability density functions are used to generate the two random phase masks of the encryption-decryption process. Numerical results are presented and discussed.
Chen, Wen; Chen, Xudong; Sheppard, Colin J R
2012-02-13
We propose a new method using coherent diffractive imaging for optical color-image encryption and synthesis in the Fresnel domain. An optical multiple-random-phase-mask encryption system is applied, and a strategy based on lateral translations of a phase-only mask is employed during image encryption. For the decryption, an iterative phase retrieval algorithm is applied to extract high-quality decrypted color images from diffraction intensity maps (i.e., ciphertexts). In addition, optical color-image synthesis is also investigated based on coherent diffractive imaging. Numerical results are presented to demonstrate feasibility and effectiveness of the proposed method. Compared with conventional interference methods, coherent diffractive imaging approach may open up a new research perspective or can provide an effective alternative for optical color-image encryption and synthesis.
Experimental scrambling and noise reduction applied to the optical encryption of QR codes.
Barrera, John Fredy; Vélez, Alejandro; Torroba, Roberto
2014-08-25
In this contribution, we implement two techniques to reinforce optical encryption, which we restrict in particular to the QR codes, but could be applied in a general encoding situation. To our knowledge, we present the first experimental-positional optical scrambling merged with an optical encryption procedure. The inclusion of an experimental scrambling technique in an optical encryption protocol, in particular dealing with a QR code "container", adds more protection to the encoding proposal. Additionally, a nonlinear normalization technique is applied to reduce the noise over the recovered images besides increasing the security against attacks. The opto-digital techniques employ an interferometric arrangement and a joint transform correlator encrypting architecture. The experimental results demonstrate the capability of the methods to accomplish the task.
Optical color image encryption based on an asymmetric cryptosystem in the Fresnel domain
NASA Astrophysics Data System (ADS)
Chen, Wen; Chen, Xudong
2011-08-01
In recent years, optical color image encryption has attracted much attention in the information security field. Some approaches, such as digital holography, have been proposed to encrypt color images, but the previously proposed methods are developed based on optical symmetric cryptographic strategies. In this paper, we apply an optical asymmetric cryptosystem for the color image encryption instead of conventional symmetric cryptosystems. A phase-truncated strategy is applied in the Fresnel domain, and multiple-wavelength and indexed image methods are further employed. The security of optical asymmetric cryptosystem is also analyzed during the decryption. Numerical results are presented to demonstrate the feasibility and effectiveness of the proposed optical asymmetric cryptosystem for color image encryption.
A pipelined FPGA implementation of an encryption algorithm based on genetic algorithm
NASA Astrophysics Data System (ADS)
Thirer, Nonel
2013-05-01
With the evolution of digital data storage and exchange, it is essential to protect the confidential information from every unauthorized access. High performance encryption algorithms were developed and implemented by software and hardware. Also many methods to attack the cipher text were developed. In the last years, the genetic algorithm has gained much interest in cryptanalysis of cipher texts and also in encryption ciphers. This paper analyses the possibility to use the genetic algorithm as a multiple key sequence generator for an AES (Advanced Encryption Standard) cryptographic system, and also to use a three stages pipeline (with four main blocks: Input data, AES Core, Key generator, Output data) to provide a fast encryption and storage/transmission of a large amount of data.
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.
A novel chaotic map and an improved chaos-based image encryption scheme.
Zhang, Xianhan; Cao, Yang
2014-01-01
In this paper, we present a novel approach to create the new chaotic map and propose an improved image encryption scheme based on it. Compared with traditional classic one-dimensional chaotic maps like Logistic Map and Tent Map, this newly created chaotic map demonstrates many better chaotic properties for encryption, implied by a much larger maximal Lyapunov exponent. Furthermore, the new chaotic map and Arnold's Cat Map based image encryption method is designed and proved to be of solid robustness. The simulation results and security analysis indicate that such method not only can meet the requirement of imagine encryption, but also can result in a preferable effectiveness and security, which is usable for general applications.
Separable and Error-Free Reversible Data Hiding in Encrypted Image with High Payload
Yin, Zhaoxia; Luo, Bin; Hong, Wien
2014-01-01
This paper proposes a separable reversible data-hiding scheme in encrypted image which offers high payload and error-free data extraction. The cover image is partitioned into nonoverlapping blocks and multigranularity encryption is applied to obtain the encrypted image. The data hider preprocesses the encrypted image and randomly selects two basic pixels in each block to estimate the block smoothness and indicate peak points. Additional data are embedded into blocks in the sorted order of block smoothness by using local histogram shifting under the guidance of the peak points. At the receiver side, image decryption and data extraction are separable and can be free to choose. Compared to previous approaches, the proposed method is simpler in calculation while offering better performance: larger payload, better embedding quality, and error-free data extraction, as well as image recovery. PMID:24977214
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
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.
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.
A new optical image encryption method based on multi-beams interference and vector composition
NASA Astrophysics Data System (ADS)
Chen, Linfei; Liu, Jingyu; Wen, Jisen; Gao, Xiong; Mao, Haidan; Shi, Xiaoyan; Qu, Qingling
2015-06-01
In this paper, a new method for optical image encryption based on multi-beams interference principle and vector composition is proposed. In this encryption, the original image is encoded into n-1 phase only masks which are regarded as the keys of the encryption system and a ciphertext according to multi-beams interference principle and vector composition. In decryption process, n beams of parallel incident light illuminate at the phase only masks and the ciphertext, and we can obtain the decrypted image at output plane after Fourier transforms. The security of the proposed method is discussed, finding that no decrypted image can be obtained only when all the keys used are right. Furthermore, the keys can be stored separately resulting in improving the security of encryption system. Computer simulation results are presented to verify the validity of the proposed method.
Carnicer, Arturo; Montes-Usategui, Mario; Arcos, Sergio; Juvells, Ignacio
2005-07-01
We show how optical encryption methods based on double random phase keys are vulnerable to an organized attack of the chosen-ciphertext type. The decryption key can be easily obtained by an opponent who has repeated access to either the encryption or decryption machines. However, we have also devised a solution that prevents the attack. Our results cast doubts on the present security of these techniques.
Analysis of S-box in Image Encryption Using Root Mean Square Error Method
NASA Astrophysics Data System (ADS)
Hussain, Iqtadar; Shah, Tariq; Gondal, Muhammad Asif; Mahmood, Hasan
2012-07-01
The use of substitution boxes (S-boxes) in encryption applications has proven to be an effective nonlinear component in creating confusion and randomness. The S-box is evolving and many variants appear in literature, which include advanced encryption standard (AES) S-box, affine power affine (APA) S-box, Skipjack S-box, Gray S-box, Lui J S-box, residue prime number S-box, Xyi S-box, and S8 S-box. These S-boxes have algebraic and statistical properties which distinguish them from each other in terms of encryption strength. In some circumstances, the parameters from algebraic and statistical analysis yield results which do not provide clear evidence in distinguishing an S-box for an application to a particular set of data. In image encryption applications, the use of S-boxes needs special care because the visual analysis and perception of a viewer can sometimes identify artifacts embedded in the image. In addition to existing algebraic and statistical analysis already used for image encryption applications, we propose an application of root mean square error technique, which further elaborates the results and enables the analyst to vividly distinguish between the performances of various S-boxes. While the use of the root mean square error analysis in statistics has proven to be effective in determining the difference in original data and the processed data, its use in image encryption has shown promising results in estimating the strength of the encryption method. In this paper, we show the application of the root mean square error analysis to S-box image encryption. The parameters from this analysis are used in determining the strength of S-boxes
Cryptanalysis of "an improvement over an image encryption method based on total shuffling"
NASA Astrophysics Data System (ADS)
Akhavan, A.; Samsudin, A.; Akhshani, A.
2015-09-01
In the past two decades, several image encryption algorithms based on chaotic systems had been proposed. Many of the proposed algorithms are meant to improve other chaos based and conventional cryptographic algorithms. Whereas, many of the proposed improvement methods suffer from serious security problems. In this paper, the security of the recently proposed improvement method for a chaos-based image encryption algorithm is analyzed. The results indicate the weakness of the analyzed algorithm against chosen plain-text.
An image encryption algorithm based on 3D cellular automata and chaotic maps
NASA Astrophysics Data System (ADS)
Del Rey, A. Martín; Sánchez, G. Rodríguez
2015-05-01
A novel encryption algorithm to cipher digital images is presented in this work. The digital image is rendering into a three-dimensional (3D) lattice and the protocol consists of two phases: the confusion phase where 24 chaotic Cat maps are applied and the diffusion phase where a 3D cellular automata is evolved. The encryption method is shown to be secure against the most important cryptanalytic attacks.
Hyperspectral fluorescence microscopy based on compressed sensing
NASA Astrophysics Data System (ADS)
Studer, Vincent; Bobin, Jérome; Chahid, Makhlad; Mousavi, Hamed; Candes, Emmanuel; Dahan, Maxime
2012-03-01
In fluorescence microscopy, one can distinguish two kinds of imaging approaches, wide field and raster scan microscopy, differing by their excitation and detection scheme. In both imaging modalities the acquisition is independent of the information content of the image. Rather, the number of acquisitions N, is imposed by the Nyquist-Shannon theorem. However, in practice, many biological images are compressible (or, equivalently here, sparse), meaning that they depend on a number of degrees of freedom K that is smaller that their size N. Recently, the mathematical theory of compressed sensing (CS) has shown how the sensing modality could take advantage of the image sparsity to reconstruct images with no loss of information while largely reducing the number M of acquisition. Here we present a novel fluorescence microscope designed along the principles of CS. It uses a spatial light modulator (DMD) to create structured wide field excitation patterns and a sensitive point detector to measure the emitted fluorescence. On sparse fluorescent samples, we could achieve compression ratio N/M of up to 64, meaning that an image can be reconstructed with a number of measurements of only 1.5 % of its pixel number. Furthemore, we extend our CS acquisition scheme to an hyperspectral imaging system.
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.
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.
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. PMID:26550603
Fast spectrophotometry with compressive sensing
NASA Astrophysics Data System (ADS)
Starling, David; Storer, Ian
2015-03-01
Spectrophotometers and spectrometers have numerous applications in the physical sciences and engineering, resulting in a plethora of designs and requirements. A good spectrophotometer balances the need for high photometric precision, high spectral resolution, high durability and low cost. One way to address these design objectives is to take advantage of modern scanning and detection techniques. A common imaging method that has improved signal acquisition speed and sensitivity in limited signal scenarios is the single pixel camera. Such cameras utilize the sparsity of a signal to sample below the Nyquist rate via a process known as compressive sensing. Here, we show that a single pixel camera using compressive sensing algorithms and a digital micromirror device can replace the common scanning mechanisms found in virtually all spectrophotometers, providing a very low cost solution and improving data acquisition time. We evaluate this single pixel spectrophotometer by studying a variety of samples tested against commercial products. We conclude with an analysis of flame spectra and possible improvements for future designs.
NASA Astrophysics Data System (ADS)
Anees, Amir; Khan, Waqar Ahmad; Gondal, Muhammad Asif; Hussain, Iqtadar
2013-07-01
The aim of this work is to make use of the mean of absolute deviation (MAD) method for the evaluation process of substitution boxes used in the advanced encryption standard. In this paper, we use the MAD technique to analyze some popular and prevailing substitution boxes used in encryption processes. In particular, MAD is applied to advanced encryption standard (AES), affine power affine (APA), Gray, Lui J., Residue Prime, S8 AES, SKIPJACK, and Xyi substitution boxes.
NASA Astrophysics Data System (ADS)
Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.
2014-05-01
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 light. This leads to complex optical schemes and low decryption quality. To eliminate these disadvantages it is possible to implement optical encryption using spatially incoherent illumination which requires registration of light intensity distribution only. However this applies new restrictions on encryption keys: Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Therefore it seems that best key should have white spectrum. On the other hand due to fact that only light intensity distribution is registered, spectra of image to be encrypted and encryption key always have peaks at zero frequency and their heights depend on corresponding total energy. Since encrypted image contains noise, ratio of its average spectrum energy to noise average energy determines signal to noise ratio of decrypted image. Therefore ratio of amplitude at zero frequency to average spectrum amplitude (RZA) of encryption key defines decrypted images quality. For generation of encryption keys with low RZA method of direct search with random trajectory (DSRT) was used. To estimate impact of key RZA on decrypted images error numerical experiments were conducted. For experiments keys with different RZA values but with same energy value were generated and used. Numerically simulated optical encryption and decryption of set of test images was conducted. Results of experiment demonstrate that application of keys with low RZA generated by DSRT method leads to up to 20% lower error in comparison to keys generated by means of uniform random
Quantum cryptography using coherent states: Randomized encryption and key generation
NASA Astrophysics Data System (ADS)
Corndorf, Eric
objectives of key generation and direct data-encryption, a new quantum cryptographic principle is demonstrated wherein keyed coherent-state signal sets are employed. Taking advantage of the fundamental and irreducible quantum-measurement noise of coherent states, these schemes do not require the users to measure the influence of an attacker. Experimental key-generation and data encryption schemes based on these techniques, which are compatible with today's WDM fiber-optic telecommunications infrastructure, are implemented and analyzed.
Crain, Stephen; Thornton, Rosalind
2012-03-01
Every normal child acquires a language in just a few years. By 3- or 4-years-old, children have effectively become adults in their abilities to produce and understand endlessly many sentences in a variety of conversational contexts. There are two alternative accounts of the course of children's language development. These different perspectives can be traced back to the nature versus nurture debate about how knowledge is acquired in any cognitive domain. One perspective dates back to Plato's dialog 'The Meno'. In this dialog, the protagonist, Socrates, demonstrates to Meno, an aristocrat in Ancient Greece, that a young slave knows more about geometry than he could have learned from experience. By extension, Plato's Problem refers to any gap between experience and knowledge. How children fill in the gap in the case of language continues to be the subject of much controversy in cognitive science. Any model of language acquisition must address three factors, inter alia: 1. The knowledge children accrue; 2. The input children receive (often called the primary linguistic data); 3. The nonlinguistic capacities of children to form and test generalizations based on the input. According to the famous linguist Noam Chomsky, the main task of linguistics is to explain how children bridge the gap-Chomsky calls it a 'chasm'-between what they come to know about language, and what they could have learned from experience, even given optimistic assumptions about their cognitive abilities. Proponents of the alternative 'nurture' approach accuse nativists like Chomsky of overestimating the complexity of what children learn, underestimating the data children have to work with, and manifesting undue pessimism about children's abilities to extract information based on the input. The modern 'nurture' approach is often referred to as the usage-based account. We discuss the usage-based account first, and then the nativist account. After that, we report and discuss the findings of several
Crain, Stephen; Thornton, Rosalind
2012-03-01
Every normal child acquires a language in just a few years. By 3- or 4-years-old, children have effectively become adults in their abilities to produce and understand endlessly many sentences in a variety of conversational contexts. There are two alternative accounts of the course of children's language development. These different perspectives can be traced back to the nature versus nurture debate about how knowledge is acquired in any cognitive domain. One perspective dates back to Plato's dialog 'The Meno'. In this dialog, the protagonist, Socrates, demonstrates to Meno, an aristocrat in Ancient Greece, that a young slave knows more about geometry than he could have learned from experience. By extension, Plato's Problem refers to any gap between experience and knowledge. How children fill in the gap in the case of language continues to be the subject of much controversy in cognitive science. Any model of language acquisition must address three factors, inter alia: 1. The knowledge children accrue; 2. The input children receive (often called the primary linguistic data); 3. The nonlinguistic capacities of children to form and test generalizations based on the input. According to the famous linguist Noam Chomsky, the main task of linguistics is to explain how children bridge the gap-Chomsky calls it a 'chasm'-between what they come to know about language, and what they could have learned from experience, even given optimistic assumptions about their cognitive abilities. Proponents of the alternative 'nurture' approach accuse nativists like Chomsky of overestimating the complexity of what children learn, underestimating the data children have to work with, and manifesting undue pessimism about children's abilities to extract information based on the input. The modern 'nurture' approach is often referred to as the usage-based account. We discuss the usage-based account first, and then the nativist account. After that, we report and discuss the findings of several
Optical Data Compression in Time Stretch Imaging
Chen, Claire Lifan; Mahjoubfar, Ata; Jalali, Bahram
2015-01-01
Time stretch imaging offers real-time image acquisition at millions of frames per second and subnanosecond shutter speed, and has enabled detection of rare cancer cells in blood with record throughput and specificity. An unintended consequence of high throughput image acquisition is the massive amount of digital data generated by the instrument. Here we report the first experimental demonstration of real-time optical image compression applied to time stretch imaging. By exploiting the sparsity of the image, we reduce the number of samples and the amount of data generated by the time stretch camera in our proof-of-concept experiments by about three times. Optical data compression addresses the big data predicament in such systems. PMID:25906244
Microbunching and RF Compression
Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.
2010-05-23
Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.
Hildebrand, Richard J.; Wozniak, John J.
2001-01-01
A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.
Compressible turbulent mixing: Effects of compressibility
NASA Astrophysics Data System (ADS)
Ni, Qionglin
2016-04-01
We studied by numerical simulations the effects of compressibility on passive scalar transport in stationary compressible turbulence. The turbulent Mach number varied from zero to unity. The difference in driven forcing was the magnitude ratio of compressive to solenoidal modes. In the inertial range, the scalar spectrum followed the k-5 /3 scaling and suffered negligible influence from the compressibility. The growth of the Mach number showed (1) a first reduction and second enhancement in the transfer of scalar flux; (2) an increase in the skewness and flatness of the scalar derivative and a decrease in the mixed skewness and flatness of the velocity-scalar derivatives; (3) a first stronger and second weaker intermittency of scalar relative to that of velocity; and (4) an increase in the intermittency parameter which measures the intermittency of scalar in the dissipative range. Furthermore, the growth of the compressive mode of forcing indicated (1) a decrease in the intermittency parameter and (2) less efficiency in enhancing scalar mixing. The visualization of scalar dissipation showed that, in the solenoidal-forced flow, the field was filled with the small-scale, highly convoluted structures, while in the compressive-forced flow, the field was exhibited as the regions dominated by the large-scale motions of rarefaction and compression.
Digital breast tomosynthesis with minimal breast compression
NASA Astrophysics Data System (ADS)
Scaduto, David A.; Yang, Min; Ripton-Snyder, Jennifer; Fisher, Paul R.; Zhao, Wei
2015-03-01
Breast compression is utilized in mammography to improve image quality and reduce radiation dose. Lesion conspicuity is improved by reducing scatter effects on contrast and by reducing the superposition of tissue structures. However, patient discomfort due to breast compression has been cited as a potential cause of noncompliance with recommended screening practices. Further, compression may also occlude blood flow in the breast, complicating imaging with intravenous contrast agents and preventing accurate quantification of contrast enhancement and kinetics. Previous studies have investigated reducing breast compression in planar mammography and digital breast tomosynthesis (DBT), though this typically comes at the expense of degradation in image quality or increase in mean glandular dose (MGD). We propose to optimize the image acquisition technique for reduced compression in DBT without compromising image quality or increasing MGD. A zero-frequency signal-difference-to-noise ratio model is employed to investigate the relationship between tube potential, SDNR and MGD. Phantom and patient images are acquired on a prototype DBT system using the optimized imaging parameters and are assessed for image quality and lesion conspicuity. A preliminary assessment of patient motion during DBT with minimal compression is presented.
Efficient Hardware Implementation of the Lightweight Block Encryption Algorithm LEA
Lee, Donggeon; Kim, Dong-Chan; Kwon, Daesung; Kim, Howon
2014-01-01
Recently, due to the advent of resource-constrained trends, such as smartphones and smart devices, the computing environment is changing. Because our daily life is deeply intertwined with ubiquitous networks, the importance of security is growing. A lightweight encryption algorithm is essential for secure communication between these kinds of resource-constrained devices, and many researchers have been investigating this field. Recently, a lightweight block cipher called LEA was proposed. LEA was originally targeted for efficient implementation on microprocessors, as it is fast when implemented in software and furthermore, it has a small memory footprint. To reflect on recent technology, all required calculations utilize 32-bit wide operations. In addition, the algorithm is comprised of not complex S-Box-like structures but simple Addition, Rotation, and XOR operations. To the best of our knowledge, this paper is the first report on a comprehensive hardware implementation of LEA. We present various hardware structures and their implementation results according to key sizes. Even though LEA was originally targeted at software efficiency, it also shows high efficiency when implemented as hardware. PMID:24406859
Investigating Second Language Acquisition.
ERIC Educational Resources Information Center
Jordens, Peter, Ed.; Lalleman, Josine, Ed.
Essays in second language acquisition include: "The State of the Art in Second Language Acquisition Research" (Josine Lalleman); "Crosslinguistic Influence with Special Reference to the Acquisition of Grammar" (Michael Sharwood Smith); "Second Language Acquisition by Adult Immigrants: A Multiple Case Study of Turkish and Moroccan Learners of…
A joint encryption/watermarking system for verifying the reliability of medical images.
Bouslimi, Dalel; Coatrieux, Gouenou; Cozic, Michel; Roux, Christian
2012-09-01
In this paper, we propose a joint encryption/water-marking system for the purpose of protecting medical images. This system is based on an approach which combines a substitutive watermarking algorithm, the quantization index modulation, with an encryption algorithm: a stream cipher algorithm (e.g., the RC4) or a block cipher algorithm (e.g., the AES in cipher block chaining (CBC) mode of operation). Our objective is to give access to the outcomes of the image integrity and of its origin even though the image is stored encrypted. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. The security analysis of our scheme and experimental results achieved on 8-bit depth ultrasound images as well as on 16-bit encoded positron emission tomography images demonstrate the capability of our system to securely make available security attributes in both spatial and encrypted domains while minimizing image distortion. Furthermore, by making use of the AES block cipher in CBC mode, the proposed system is compliant with or transparent to the DICOM standard.
NASA Astrophysics Data System (ADS)
Konnik, Mikhail V.
2012-04-01
Wavefront coding paradigm can be used not only for compensation of aberrations and depth-of-field improvement but also for an optical encryption. An optical convolution of the image with the PSF occurs when a diffractive optical element (DOE) with a known point spread function (PSF) is placed in the optical path. In this case, an optically encoded image is registered instead of the true image. Decoding of the registered image can be performed using standard digital deconvolution methods. In such class of optical-digital systems, the PSF of the DOE is used as an encryption key. Therefore, a reliability and cryptographic resistance of such an encryption method depends on the size and complexity of the PSF used for optical encoding. This paper gives a preliminary analysis on reliability and possible vulnerabilities of such an encryption method. Experimental results on brute-force attack on the optically encrypted images are presented. Reliability estimation of optical coding based on wavefront coding paradigm is evaluated. An analysis of possible vulnerabilities is provided.
A joint encryption/watermarking system for verifying the reliability of medical images.
Bouslimi, Dalel; Coatrieux, Gouenou; Cozic, Michel; Roux, Christian
2012-09-01
In this paper, we propose a joint encryption/water-marking system for the purpose of protecting medical images. This system is based on an approach which combines a substitutive watermarking algorithm, the quantization index modulation, with an encryption algorithm: a stream cipher algorithm (e.g., the RC4) or a block cipher algorithm (e.g., the AES in cipher block chaining (CBC) mode of operation). Our objective is to give access to the outcomes of the image integrity and of its origin even though the image is stored encrypted. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. The security analysis of our scheme and experimental results achieved on 8-bit depth ultrasound images as well as on 16-bit encoded positron emission tomography images demonstrate the capability of our system to securely make available security attributes in both spatial and encrypted domains while minimizing image distortion. Furthermore, by making use of the AES block cipher in CBC mode, the proposed system is compliant with or transparent to the DICOM standard. PMID:22801525
Hardware accelerated compression of LIDAR data using FPGA devices.
Biasizzo, Anton; Novak, Franc
2013-05-14
Airborne Light Detection and Ranging (LIDAR) has become a mainstream technology for terrain data acquisition and mapping. High sampling density of LIDAR enables the acquisition of high details of the terrain, but on the other hand, it results in a vast amount of gathered data, which requires huge storage space as well as substantial processing effort. The data are usually stored in the LAS format which has become the de facto standard for LIDAR data storage and exchange. In the paper, a hardware accelerated compression of LIDAR data is presented. The compression and decompression of LIDAR data is performed by a dedicated FPGA-based circuit and interfaced to the computer via a PCI-E general bus. The hardware compressor consists of three modules: LIDAR data predictor, variable length coder, and arithmetic coder. Hardware compression is considerably faster than software compression, while it also alleviates the processor load.
Compressive hyperspectral and multispectral imaging fusion
NASA Astrophysics Data System (ADS)
Espitia, Óscar; Castillo, Sergio; Arguello, Henry
2016-05-01
Image fusion is a valuable framework which combines two or more images of the same scene from one or multiple sensors, allowing to improve the resolution of the images and increase the interpretable content. In remote sensing a common fusion problem consists of merging hyperspectral (HS) and multispectral (MS) images that involve large amount of redundant data, which ignores the highly correlated structure of the datacube along the spatial and spectral dimensions. Compressive HS and MS systems compress the spectral data in the acquisition step allowing to reduce the data redundancy by using different sampling patterns. This work presents a compressed HS and MS image fusion approach, which uses a high dimensional joint sparse model. The joint sparse model is formulated by combining HS and MS compressive acquisition models. The high spectral and spatial resolution image is reconstructed by using sparse optimization algorithms. Different fusion spectral image scenarios are used to explore the performance of the proposed scheme. Several simulations with synthetic and real datacubes show promising results as the reliable reconstruction of a high spectral and spatial resolution image can be achieved by using as few as just the 50% of the datacube.
An Encryption Scheme for Communication Internet SCADA Components
NASA Astrophysics Data System (ADS)
Robles, Rosslin John; Kim, Tai-Hoon
The trend in most systems is that they are connected through the Internet. Traditional Supervisory Control and Data Acquisition Systems (SCADA) is connected only in a limited private network. SCADA is considered a critical infrastructure, and connecting to the internet is putting the society on jeopardy, some operators hold back on connecting it to the internet. But since the internet Supervisory Control and Data Acquisition Systems (SCADA) facility has brought a lot of advantages in terms of control, data viewing and generation. Along with these advantages, are security issues regarding web SCADA, operators are pushed to connect Supervisory Control and Data Acquisition Systems (SCADA) through the internet. Because of this, many issues regarding security surfaced. In this paper, we discuss web SCADA and the issues regarding security. As a countermeasure, a web SCADA security solution using crossed-crypto-scheme is proposed to be used in the communication of SCADA components.
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
Security enhanced optical encryption system by random phase key and permutation key.
He, Mingzhao; Tan, Qiaofeng; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2009-12-01
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. PMID:20052170
Graphics processing unit-accelerated double random phase encoding for fast image encryption
NASA Astrophysics Data System (ADS)
Lee, Jieun; Yi, Faliu; Saifullah, Rao; Moon, Inkyu
2014-11-01
We propose a fast double random phase encoding (DRPE) algorithm using a graphics processing unit (GPU)-based stream-processing model. A performance analysis of the accelerated DRPE implementation that employs the Compute Unified Device Architecture programming environment is presented. We show that the proposed methodology executed on a GPU can dramatically increase encryption speed compared with central processing unit sequential computing. Our experimental results demonstrate that in encryption data of an image with a pixel size of 1000×1000, where one pixel has a 32-bit depth, our GPU version of the DRPE scheme can be approximately two times faster than the advanced encryption standard algorithm implemented on a GPU. In addition, the quality of parallel processing on the presented DRPE acceleration method is evaluated with performance parameters, such as speedup, efficiency, and redundancy.
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.
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.
P-Code-Enhanced Encryption-Mode Processing of GPS Signals
NASA Technical Reports Server (NTRS)
Young, Lawrence; Meehan, Thomas; Thomas, Jess B.
2003-01-01
A method of processing signals in a Global Positioning System (GPS) receiver has been invented to enable the receiver to recover some of the information that is otherwise lost when GPS signals are encrypted at the transmitters. The need for this method arises because, at the option of the military, precision GPS code (P-code) is sometimes encrypted by a secret binary code, denoted the A code. Authorized users can recover the full signal with knowledge of the A-code. However, even in the absence of knowledge of the A-code, one can track the encrypted signal by use of an estimate of the A-code. The present invention is a method of making and using such an estimate. In comparison with prior such methods, this method makes it possible to recover more of the lost information and obtain greater accuracy.
A hybrid heuristic algorithm to improve known-plaintext attack on Fourier plane encryption.
Liu, Wensi; Yang, Guanglin; Xie, Haiyan
2009-08-01
A hybrid heuristic attack scheme that combines the hill climbing algorithm and the simulated annealing algorithm is proposed to speed up the search procedure and to obtain a more accurate solution to the original key in the Fourier plane encryption algorithm. And a unit cycle is adopted to analyze the value space of the random phase. The experimental result shows that our scheme can obtain more accurate solution to the key that can achieve better decryption result both for the selected encrypted image and another unseen ciphertext image. The searching time is significantly reduced while without any exceptional case in searching procedure. For an image of 64x64 pixels, our algorithm costs a comparatively short computing time, about 1 minute, can retrieve the approximated key with the normalized root mean squared error 0.1, therefore, our scheme makes the known-plaintext attack on the Fourier plane image encryption more practical, stable, and effective.
Security enhanced optical encryption system by random phase key and permutation key.
He, Mingzhao; Tan, Qiaofeng; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2009-12-01
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.
Investigating the structure preserving encryption of high efficiency video coding (HEVC)
NASA Astrophysics Data System (ADS)
Shahid, Zafar; Puech, William
2013-02-01
This paper presents a novel method for the real-time protection of new emerging High Efficiency Video Coding (HEVC) standard. Structure preserving selective encryption is being performed in CABAC entropy coding module of HEVC, which is significantly different from CABAC entropy coding of H.264/AVC. In CABAC of HEVC, exponential Golomb coding is replaced by truncated Rice (TR) up to a specific value for binarization of transform coefficients. Selective encryption is performed using AES cipher in cipher feedback mode on a plaintext of binstrings in a context aware manner. The encrypted bitstream has exactly the same bit-rate and is format complaint. Experimental evaluation and security analysis of the proposed algorithm is performed on several benchmark video sequences containing different combinations of motion, texture and objects.
Optical image encryption based on multi-beam interference and common vector decomposition
NASA Astrophysics Data System (ADS)
Chen, Linfei; He, Bingyu; Chen, Xudong; Gao, Xiong; Liu, Jingyu
2016-02-01
Based on multi-beam interference and common vector decomposition, we propose a new method for optical image encryption. In encryption process, the information of an original image is encoded into n amplitude masks and n phase masks which are regarded as a ciphertext and many keys. In decryption process, parallel light irradiates the amplitude masks and phase masks, then passes through lens that takes place Fourier transform, and finally we obtain the original image at the output plane after interference. The security of the encryption system is also discussed in the paper, and we find that only when all the keys are correct, can the information of the original image be recovered. Computer simulation results are presented to verify the validity and the security of the proposed method.
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
Compression and storage of multiple images with modulating blazed gratings
NASA Astrophysics Data System (ADS)
Yin, Shen; Tao, Shaohua
2013-07-01
A method for compressing, storing and reconstructing high-volume data is presented in this paper. Blazed gratings with different orientations and blaze angles are used to superpose many grayscaled images, and customized spatial filters are used to selectively recover the corresponding images from the diffraction spots of the superposed images. The simulation shows that as many as 198 images with a size of 512 pixels × 512 pixels can be stored in a diffractive optical element (DOE) with complex amplitudes of the same size, and the recovered images from the DOE are discernible with high visual quality. Optical encryption/decryption can also be added to the digitized DOE to enhance the security of the stored data.
Photon counting compressive depth mapping.
Howland, Gregory A; Lum, Daniel J; Ware, Matthew R; Howell, John C
2013-10-01
We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 × 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 × 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second. PMID:24104293
Advanced data compression promises the next big leap in network performance
NASA Astrophysics Data System (ADS)
Holtz, Klaus E.; Holtz, Eric S.; Kalienky, Diana
1998-09-01
Three recently introduced technologies: a new Autosophy information theory; fast Content Addressable Memories; and Packet Switching protocols, are combined in data compression chipsets to improve network throughput with real-time lossless text and image compression. Compared with the cost of putting new cables into the ground or launching new satellites, data compression chipsets offer a much less expensive alternative for improving the bandwidth of broadband communication networks. Data compression is based on a new Autosophy information theory in which, in contrast to Shannon's theory, communication is determined only by the data content. In addition to high lossless data compression, this also provides virtually unbreakable 'codebook' encryption and easier communication via packet switching networks. The Autosophy theories provide eight known classes of self-learning Omni Dimensional Networks. Only the serial network is explained here for use in compressed text and video communications. A new Content Addressable Read Only Memory (CAROM) may increase data compression speed to more than 20 Million symbols per second, fast enough for virtually any network speed.
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.
Multi-image encryption based on synchronization of chaotic lasers and iris authentication
NASA Astrophysics Data System (ADS)
Banerjee, Santo; Mukhopadhyay, Sumona; Rondoni, Lamberto
2012-07-01
A new technique of transmitting encrypted combinations of gray scaled and chromatic images using chaotic lasers derived from Maxwell-Bloch's equations has been proposed. This novel scheme utilizes the general method of solution of a set of linear equations to transmit similar sized heterogeneous images which are a combination of monochrome and chromatic images. The chaos encrypted gray scaled images are concatenated along the three color planes resulting in color images. These are then transmitted over a secure channel along with a cover image which is an iris scan. The entire cryptology is augmented with an iris-based authentication scheme. The secret messages are retrieved once the authentication is successful. The objective of our work is briefly outlined as (a) the biometric information is the iris which is encrypted before transmission, (b) the iris is used for personal identification and verifying for message integrity, (c) the information is transmitted securely which are colored images resulting from a combination of gray images, (d) each of the images transmitted are encrypted through chaos based cryptography, (e) these encrypted multiple images are then coupled with the iris through linear combination of images before being communicated over the network. The several layers of encryption together with the ergodicity and randomness of chaos render enough confusion and diffusion properties which guarantee a fool-proof approach in achieving secure communication as demonstrated by exhaustive statistical methods. The result is vital from the perspective of opening a fundamental new dimension in multiplexing and simultaneous transmission of several monochromatic and chromatic images along with biometry based authentication and cryptography.
Encryption and authentication for scalable multimedia: current state of the art and challenges
NASA Astrophysics Data System (ADS)
Zhu, Bin B.; Swanson, Mitchell D.; Li, Shipeng
2004-10-01
Scalable coding is a technology that encodes a multimedia signal in a scalable manner where various representations can be extracted from a single codestream to fit a wide range of applications. Many new scalable coders such as JPEG 2000 and MPEG-4 FGS offer fine granularity scalability to provide near continuous optimal tradeoff between quality and rates in a large range. This fine granularity scalability poses great new challenges to the design of encryption and authentication systems for scalable media in Digital Rights Management (DRM) and other applications. It may be desirable or even mandatory to maintain a certain level of scalability in the encrypted or signed codestream so that no decryption or re-signing is needed when legitimate adaptations are applied. In other words, the encryption and authentication should be scalable, i.e., adaptation friendly. Otherwise secrets have to be shared with every intermediate stage along the content delivery system which performs adaptation manipulations. Sharing secrets with many parties would jeopardize the overall security of a system since the security depends on the weakest component of the system. In this paper, we first describe general requirements and desirable features for an encryption or authentication system for scalable media, esp. those not encountered with the non-scalable case. Then we present an overview of the current state of the art of technologies in scalable encryption and authentication. These technologies include full and selective encryption schemes that maintain the original or coarser granularity of scalability offered by an unencrypted scalable codestream, layered access control and block level authentication that reduce the fine granularity of scalability to a block level, among others. Finally, we summarize existing challenges and propose future research directions.
Novel image encryption scheme based on Chebyshev polynomial and Duffing map.
Stoyanov, Borislav; Kordov, Krasimir
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 10(113) key space and desirable level of security based on the good statistical results and theoretical arguments. PMID:25143970
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
Optical encryption of unlimited-size images based on ptychographic scanning digital holography.
Gao, Qiankun; Wang, Yali; Li, Tuo; Shi, Yishi
2014-07-20
The ptychographic scanning operation is introduced into digital holography to expand the field-of-view (FOV). An optical image encryption method based on this technique is further proposed and analyzed. The plaintext is moved sequentially in the way of ptychographic scanning and corresponding pairs of phase-shifted interferograms are recorded as ciphertexts. Then the holographic processing and the ptychographic iterative reconstruction are both employed to retrieve the plaintext. Numerical experiments demonstrate that the proposed system possesses high security level and wide FOV. The proposed method might also be used for other potential applications, such as three-dimensional information encryption and image hiding.
Wen, Shiping; Zeng, Zhigang; Huang, Tingwen; Meng, Qinggang; Yao, Wei
2015-07-01
This paper investigates the problem of global exponential lag synchronization of a class of switched neural networks with time-varying delays via neural activation function and applications in image encryption. The controller is dependent on the output of the system in the case of packed circuits, since it is hard to measure the inner state of the circuits. Thus, it is critical to design the controller based on the neuron activation function. Comparing the results, in this paper, with the existing ones shows that we improve and generalize the results derived in the previous literature. Several examples are also given to illustrate the effectiveness and potential applications in image encryption.
Multiplexed encryption using chaotic systems with multiple stochastic-delayed feedbacks.
Rontani, D; Sciamanna, M; Locquet, A; Citrin, D S
2009-12-01
We propose an efficient and fast bit-multiplexed encryption scheme exploiting hyperchaotic regimes of a single nonlinear oscillator with multiple time-delay feedback loops. Each data stream is encrypted by digitally modulating the values of the various time delays and decrypted using chaos synchronization and cross-correlation measurements. We have numerically applied our approach to an optoelectronic chaotic oscillator based on standard semiconductor lasers subjected to multiple feedbacks and have demonstrated successful data transmission and recovery between multiple users at several Gbits/s on a single communication channel.
Optical binary image encryption using aperture-key and dual wavelengths.
Wang, Xiaogang; Chen, Wen; Chen, Xudong
2014-11-17
We described a method where the secret binary image that has been encoded into a single amplitude pattern in Fresnel domain can be recovered based on phase retrieval with an aperture-key and wavelength keys, and no holographic recording is needed in the encryption. The predesigned aperture-key not only realizes the intensity modulation of the encrypted image, but also helps to retrieve the secret image with high quality. All the necessary decryption keys can be kept in digital form that facilitates data transmission and loading in image retrieval process. Numerical simulation results are given for testing the validity and security of the proposed approach.
Analyses of S-Box in Image Encryption Applications Based on Fuzzy Decision Making Criterion
NASA Astrophysics Data System (ADS)
Rehman, Inayatur; Shah, Tariq; Hussain, Iqtadar
2014-06-01
In this manuscript, we put forward a standard based on fuzzy decision making criterion to examine the current substitution boxes and study their strengths and weaknesses in order to decide their appropriateness in image encryption applications. The proposed standard utilizes the results of correlation analysis, entropy analysis, contrast analysis, homogeneity analysis, energy analysis, and mean of absolute deviation analysis. These analyses are applied to well-known substitution boxes. The outcome of these analyses are additional observed and a fuzzy soft set decision making criterion is used to decide the suitability of an S-box to image encryption applications.
Cryptanalysis of a novel image encryption scheme based on improved hyperchaotic sequences
NASA Astrophysics Data System (ADS)
Özkaynak, Fatih; Özer, Ahmet Bedri; Yavuz, Sırma
2012-11-01
Chaotic cryptography is a new field that has seen a significant amount of research activity during the last 20 years. Despite the many proposals that use various methods in the design of encryption algorithms, there is a definite need for a mathematically rigorous cryptanalysis of these designs. In this study, we analyze the security weaknesses of the "C. Zhu, A novel image encryption scheme based on improved hyperchaotic sequences, Optics Communications 285 (2012) 29-37". By applying chosen plaintext attacks, we show that all the secret parameters can be revealed.
Fast and secure encryption-decryption method based on chaotic dynamics
Protopopescu, Vladimir A.; Santoro, Robert T.; Tolliver, Johnny S.
1995-01-01
A method and system for the secure encryption of information. The method comprises the steps of dividing a message of length L into its character components; generating m chaotic iterates from m independent chaotic maps; producing an "initial" value based upon the m chaotic iterates; transforming the "initial" value to create a pseudo-random integer; repeating the steps of generating, producing and transforming until a pseudo-random integer sequence of length L is created; and encrypting the message as ciphertext based upon the pseudo random integer sequence. A system for accomplishing the invention is also provided.
NASA Astrophysics Data System (ADS)
Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi
2015-08-01
Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.
Language Acquisition without an Acquisition Device
ERIC Educational Resources Information Center
O'Grady, William
2012-01-01
Most explanatory work on first and second language learning assumes the primacy of the acquisition phenomenon itself, and a good deal of work has been devoted to the search for an "acquisition device" that is specific to humans, and perhaps even to language. I will consider the possibility that this strategy is misguided and that language…
NASA Technical Reports Server (NTRS)
Reif, John H.
1987-01-01
A parallel compression algorithm for the 16,384 processor MPP machine was developed. The serial version of the algorithm can be viewed as a combination of on-line dynamic lossless test compression techniques (which employ simple learning strategies) and vector quantization. These concepts are described. How these concepts are combined to form a new strategy for performing dynamic on-line lossy compression is discussed. Finally, the implementation of this algorithm in a massively parallel fashion on the MPP is discussed.
Sequential neural text compression.
Schmidhuber, J; Heil, S
1996-01-01
The purpose of this paper is to show that neural networks may be promising tools for data compression without loss of information. We combine predictive neural nets and statistical coding techniques to compress text files. We apply our methods to certain short newspaper articles and obtain compression ratios exceeding those of the widely used Lempel-Ziv algorithms (which build the basis of the UNIX functions "compress" and "gzip"). The main disadvantage of our methods is that they are about three orders of magnitude slower than standard methods.
Imaging With Nature: Compressive Imaging Using a Multiply Scattering Medium
Liutkus, Antoine; Martina, David; Popoff, Sébastien; Chardon, Gilles; Katz, Ori; Lerosey, Geoffroy; Gigan, Sylvain; Daudet, Laurent; Carron, Igor
2014-01-01
The recent theory of compressive sensing leverages upon the structure of signals to acquire them with much fewer measurements than was previously thought necessary, and certainly well below the traditional Nyquist-Shannon sampling rate. However, most implementations developed to take advantage of this framework revolve around controlling the measurements with carefully engineered material or acquisition sequences. Instead, we use the natural randomness of wave propagation through multiply scattering media as an optimal and instantaneous compressive imaging mechanism. Waves reflected from an object are detected after propagation through a well-characterized complex medium. Each local measurement thus contains global information about the object, yielding a purely analog compressive sensing method. We experimentally demonstrate the effectiveness of the proposed approach for optical imaging by using a 300-micrometer thick layer of white paint as the compressive imaging device. Scattering media are thus promising candidates for designing efficient and compact compressive imagers. PMID:25005695
A study of the environmental information acquisition system based on smart phones
NASA Astrophysics Data System (ADS)
Xu, Lingyan; Chen, Feixiang; Ni, Shaoliang; Wang, Ling; Wei, Chao; Gong, Bowen
2010-08-01
In this paper, it proposed a new environmental information acquisition system based on smart phones (Smartphone / Pocket PC) which combined with Geographic Information System (GIS), Global Positioning System (GPS), wireless communication technology in allusion to the current actual situation of environmental protection information acquisition in city environmental protection department. System architecture and working principle is analyzed, and it designs the main modules of the software and hardware. In addition, transport protocols and application of the implementation method have been discussed. Experiments show that the environmental information acquisition system has high precision, easy to use, information transfer with high efficiency and reliability. Not only have that, the paper also discusses the effective strategies of network transmission of data encryption and the image transmission rate improvement. In brief, it can effectively enhance the work efficiency of the city environmental protection department when they collect relevant information.
Security Encryption Scheme for Communication of Web Based Control Systems
NASA Astrophysics Data System (ADS)
Robles, Rosslin John; Kim, Tai-Hoon
A control system is a device or set of devices to manage, command, direct or regulate the behavior of other devices or systems. The trend in most systems is that they are connected through the Internet. Traditional Supervisory Control and Data Acquisition Systems (SCADA) is connected only in a limited private network Since the internet Supervisory Control and Data Acquisition Systems (SCADA) facility has brought a lot of advantages in terms of control, data viewing and generation. Along with these advantages, are security issues regarding web SCADA, operators are pushed to connect Control Systems through the internet. Because of this, many issues regarding security surfaced. In this paper, we discuss web SCADA and the issues regarding security. As a countermeasure, a web SCADA security solution using crossed-crypto-scheme is proposed to be used in the communication of SCADA components.
NASA Astrophysics Data System (ADS)
Kasem, Hossam M.; Nasr, Mohamed E.; Sallam, Elsayed A.; Abd El-Samie, F. E.
2011-10-01
Image transmission takes place as an important research branch in multimedia broadcasting communication systems in the last decade. Our paper presents image transmission over a FFT-OFDM (Fast Fourier Transform Orthogonal Frequency Division Multiplexing). The need for encryption techniques increase with the appearance of the expression which said that our world became small village, and the use of image application such as conference and World Wide Web which increase rapidly in recent years. Encryption is an effective method for protecting the transmitted data by converting it into a form being invisible over transmission path and visible in receiver side. This paper presents a new hybrid encryption technique based on combination of Backer maps and logistic map. This proposed technique aims to increase PSNR and reduce the noise in the received image. The encryption is done by shuffling the positions of a pixel image using two dimensional Baker maps then encrypt using XOR operation with logistic map to generate cipher image over orthogonal frequency multiplexing (OFDM). The encryption approach adopted in this paper is based on chaotic Baker maps because the encoding and decoding steps in this approach are simple and fast enough for HDTV applications. The experimental results reveal the superiority of the proposed chaotic based image encryption technique using two logistic maps and two dimensional Backer map over normal Backer map.
NASA Technical Reports Server (NTRS)
Akkerman, J. W.
1982-01-01
New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.
On the security of gyrator transform-based image encryption by chosen-plaintext attack
NASA Astrophysics Data System (ADS)
Sang, Jun; Alam, Mohammad S.; Cai, Bin
2016-04-01
For the gyrator transform-based image encryption, besides the random operations, the rotation angles used in the gyrator transforms are also taken as the secret keys, which makes such cryptosystems to be more secure. To analyze the security of such cryptosystems, one may start from analyzing the security of a single gyrator transform. In this paper, the security of the gyrator transform-based image encryption by chosen-plaintext attack was discussed in theory. By using the impulse functions as the chosen-plaintext, it was concluded that: (1) For a single gyrator transform, by choosing a plaintext, the rotation angle can be obtained very easily and efficiently; (2) For image encryption with a single random phase encoding and a single gyrator transform, it is hard to find the rotation angle directly with a chosen-plaintext attack. However, assuming the value of one of the elements in the random phase mask is known, the rotation angle can be obtained very easily with a chosen-plaintext attack, and the random phase mask can also be recovered. Furthermore, by exhaustively searching the value of one of the elements in the random phase mask, the rotation angle as well as the random phase mask may be recovered. By obtaining the relationship between the rotation angle and the random phase mask for image encryption with a single random phase encoding and a single gyrator transform, it may be useful for further study on the security of the iterative random operations in the gyrator transform domains.
Two-chip implementation of the RSA public-key encryption algorithm
Rieden, R.F.; Snyder, J.B.; Widman, R.J.; Barnard, W.J.
1982-01-01
A system has been developed which employs two identical integrated circuits to perform the encryption algorithm developed by Rivest, Shamir, and Adleman (RSA) on a 336-bit message. The integrated circuit used in the system employs the 3-micron polysilicon gate, radiation-hard, CMOS technology developed at Sandia National Laboratories.
NASA Astrophysics Data System (ADS)
Zhu, Lijuan; Liu, Jingao
2013-07-01
This paper describes a network identity authentication protocol of bank account system based on fingerprint identification and mixed encryption. This protocol can provide every bank user a safe and effective way to manage his own bank account, and also can effectively prevent the hacker attacks and bank clerk crime, so that it is absolute to guarantee the legitimate rights and interests of bank users.
FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption
2015-01-01
Background The increasing availability of genome data motivates massive research studies in personalized treatment and precision medicine. Public cloud services provide a flexible way to mitigate the storage and computation burden in conducting genome-wide association studies (GWAS). However, data privacy has been widely concerned when sharing the sensitive information in a cloud environment. Methods We presented a novel framework (FORESEE: Fully Outsourced secuRe gEnome Study basEd on homomorphic Encryption) to fully outsource GWAS (i.e., chi-square statistic computation) using homomorphic encryption. The proposed framework enables secure divisions over encrypted data. We introduced two division protocols (i.e., secure errorless division and secure approximation division) with a trade-off between complexity and accuracy in computing chi-square statistics. Results The proposed framework was evaluated for the task of chi-square statistic computation with two case-control datasets from the 2015 iDASH genome privacy protection challenge. Experimental results show that the performance of FORESEE can be significantly improved through algorithmic optimization and parallel computation. Remarkably, the secure approximation division provides significant performance gain, but without missing any significance SNPs in the chi-square association test using the aforementioned datasets. Conclusions Unlike many existing HME based studies, in which final results need to be computed by the data owner due to the lack of the secure division operation, the proposed FORESEE framework support complete outsourcing to the cloud and output the final encrypted chi-square statistics. PMID:26733391
Single-channel color image encryption using phase retrieve algorithm in fractional Fourier domain
NASA Astrophysics Data System (ADS)
Sui, Liansheng; Xin, Meiting; Tian, Ailing; Jin, Haiyan
2013-12-01
A single-channel color image encryption is proposed based on a phase retrieve algorithm and a two-coupled logistic map. Firstly, a gray scale image is constituted with three channels of the color image, and then permuted by a sequence of chaotic pairs generated by the two-coupled logistic map. Secondly, the permutation image is decomposed into three new components, where each component is encoded into a phase-only function in the fractional Fourier domain with a phase retrieve algorithm that is proposed based on the iterative fractional Fourier transform. Finally, an interim image is formed by the combination of these phase-only functions and encrypted into the final gray scale ciphertext with stationary white noise distribution by using chaotic diffusion, which has camouflage property to some extent. In the process of encryption and decryption, chaotic permutation and diffusion makes the resultant image nonlinear and disorder both in spatial domain and frequency domain, and the proposed phase iterative algorithm has faster convergent speed. Additionally, the encryption scheme enlarges the key space of the cryptosystem. Simulation results and security analysis verify the feasibility and effectiveness of this method.
15 CFR 740.17 - Encryption commodities, software and technology (ENC).
Code of Federal Regulations, 2010 CFR
2010-01-01
... Network (VPN), satellite, digital packet telephony/media (voice, video, data) over internet protocol... symmetric algorithms: (A) Aggregate encrypted WAN, MAN, VPN or backhaul throughput (includes communications... Mbps; (B) Wire (line), cable or fiber-optic WAN, MAN or VPN single-channel input data rate...
15 CFR 740.17 - Encryption commodities, software and technology (ENC).
Code of Federal Regulations, 2014 CFR
2014-01-01
... Private Network (VPN), satellite, digital packet telephony/media (voice, video, data) over Internet...-bits for symmetric algorithms: (1) Aggregate encrypted WAN, MAN, VPN or backhaul throughput (including... 90 Mbps; (2) Wire (line), cable or fiber-optic WAN, MAN or VPN single-channel input data...
15 CFR 740.17 - Encryption commodities, software and technology (ENC).
Code of Federal Regulations, 2012 CFR
2012-01-01
... Private Network (VPN), satellite, digital packet telephony/media (voice, video, data) over Internet...-bits for symmetric algorithms: (1) Aggregate encrypted WAN, MAN, VPN or backhaul throughput (including... 90 Mbps; (2) Wire (line), cable or fiber-optic WAN, MAN or VPN single-channel input data...
15 CFR 740.17 - Encryption commodities, software and technology (ENC).
Code of Federal Regulations, 2011 CFR
2011-01-01
... Private Network (VPN), satellite, digital packet telephony/media (voice, video, data) over Internet...-bits for symmetric algorithms: (1) Aggregate encrypted WAN, MAN, VPN or backhaul throughput (including... 90 Mbps; (2) Wire (line), cable or fiber-optic WAN, MAN or VPN single-channel input data...
15 CFR 740.17 - Encryption commodities, software and technology (ENC).
Code of Federal Regulations, 2013 CFR
2013-01-01
... Private Network (VPN), satellite, digital packet telephony/media (voice, video, data) over Internet...-bits for symmetric algorithms: (1) Aggregate encrypted WAN, MAN, VPN or backhaul throughput (including... 90 Mbps; (2) Wire (line), cable or fiber-optic WAN, MAN or VPN single-channel input data...
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
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-09
...In this document, the Commission adopts new rules to allow cable operators to encrypt the basic service tier in all-digital systems, provided that those cable operators undertake certain consumer protection measures for a limited period of time in order to minimize any potential subscriber...
15 CFR Supplement No. 6 to Part 742 - Guidelines for Submitting Review Requests for Encryption Items
Code of Federal Regulations, 2010 CFR
2010-01-01
... asymmetric encryption algorithms and key lengths and how the algorithms are used, including relevant... cipher block chaining mode). (2) State the key management algorithms, including modulus sizes, that are supported. (3) For products with proprietary algorithms, include a textual description and the source...
A chaos-based visual encryption mechanism for clinical EEG signals.
Lin, Chin-Feng; Chung, Cheng-Hsing; Lin, Jia-Hui
2009-07-01
In this study, we have developed a chaos-based visual encryption mechanism that can be applied for clinical electroencephalography (EEG) signals. In comparison with other types of random sequences, chaos sequences were mainly used to increase unpredictability. We used a 1D chaotic scrambler and a permutation scheme to achieve EEG visual encryption. One approach of realizing the visual encryption mechanism is to scramble the signal values of the input EEG signal by multiplying a 1D chaotic signal to randomize the EEG signal values. We then applied a chaotic address scanning order encryption to the randomized reference values. Simulation results show that when the correct deciphering parameters are entered, the signal is completely recovered, and the percent root-mean-square difference (PRD) values for control and alcoholic clinical EEG signals are 4.33 x 10(-15) and 4.11 x 10(-15)%, respectively. As long as there is an input parameter error, with an initial point error of 0.00000001% as an example, thereby making these clinical EEG signals unrecoverable.
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.
Solak, Ercan; Cokal, Cahit
2008-09-01
In this paper, we comment on the chaotic encryption algorithm proposed by A. N. Pisarchik et al. [Chaos 16, 033118 (2006)]. We demonstrate that the algorithm is not invertible. We suggest simple modifications that can remedy some of the problems we identified.
Optical color-image encryption in the diffractive-imaging scheme
NASA Astrophysics Data System (ADS)
Qin, Yi; Wang, Zhipeng; Pan, Qunna; Gong, Qiong
2016-02-01
By introducing the theta modulation technique into the diffractive-imaging-based optical scheme, we propose a novel approach for color image encryption. For encryption, a color image is divided into three channels, i.e., red, green and blue, and thereafter these components are appended by redundant data before being sent to the encryption scheme. The carefully designed optical setup, which comprises of three 4f optical architectures and a diffractive-imaging-based optical scheme, could encode the three plaintexts into a single noise-like intensity pattern. For the decryption, an iterative phase retrieval algorithm, together with a filter operation, is applied to extract the primary color images from the diffraction intensity map. Compared with previous methods, our proposal has successfully encrypted a color rather than grayscale image into a single intensity pattern, as a result of which the capacity and practicability have been remarkably enhanced. In addition, the performance and the security of it are also investigated. The validity as well as feasibility of the proposed method is supported by numerical simulations.
Hybrid optical-digital encryption system based on wavefront coding paradigm
NASA Astrophysics Data System (ADS)
Konnik, Mikhail V.
2012-04-01
The wavefront coding is a widely used in the optical systems to compensate aberrations and increase the depth of field. This paper presents experimental results on application of the wavefront coding paradigm for data encryption. We use a synthesised diffractive optical element (DOE) to deliberately introduce a phase distortion during the images registration process to encode the acquired image. In this case, an optical convolution of the input image with the point spread function (PSF) of the DOE is registered. The encryption is performed optically, and is therefore is fast and secure. Since the introduced distortion is the same across the image, the decryption is performed digitally using deconvolution methods. However, due to noise and finite accuracy of a photosensor, the reconstructed image is degraded but still readable. The experimental results, which are presented in this paper, indicate that the proposed hybrid optical-digital system can be implemented as a portable device using inexpensive off-the-shelf components. We present the results of optical encryption and digital restoration with quantitative estimations of the images quality. Details of hardware optical implementation of the hybrid optical-digital encryption system are discussed.
The Application Research of MD5 Encryption Algorithm in DCT Digital Watermarking
NASA Astrophysics Data System (ADS)
Xijin, Wang; Linxiu, Fan
This article did the preliminary study of the application of algorithm for MD5 in the digital watermark. It proposed that copyright information will be encrypted using an algorithm MD5, and made rules for the second value image watermarks, through DCT algorithm that embeds an image by the carrier. The extraction algorithms can pick up the watermark and restore MD5 code.
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.
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)
Yu, Biin; Peng, Xiang; Tian, Jindong; Niu, Hanben
2006-01-01
A cascaded iterative angular spectrum approach (CIASA) based on the methodology of virtual optics is presented for optical security applications. The technique encodes the target image into two different phase only masks (POM) using a concept of free-space angular spectrum propagation. The two phase-masks are designed and located in any two arbitrary planes interrelated through the free space propagation domain in order to implement the optical encryption or authenticity verification. And both phase masks can serve as enciphered texts. Compared with previous methods, the proposed algorithm employs an improved searching strategy: modifying the phase-distributions of both masks synchronously as well as enlarging the searching space. And with such a scheme, we make use of a high performance floating-point Digital Signal Processor (DSP) to accomplish a design of multiple-locks and multiple-keys optical image encryption system. An evaluation of the system performance is made and it is shown that the algorithm results in much faster convergence and better image quality for the recovered image. And two masks and system parameters can be used to design keys for image encryption, therefore the decrypted image can be obtained only when all these keys are under authorization. This key-assignment strategy may reduce the risk of being intruded and show a high security level. These characters may introduce a high level security that makes the encrypted image more difficult to be decrypted by an unauthorized person.
Optical color image encryption based on computer generated hologram and chaotic theory
NASA Astrophysics Data System (ADS)
Liu, Jian; Jin, Hongzhen; Ma, Lihong; Li, Yong; Jin, Weimin
2013-10-01
A novel technique of optical color image encryption and decryption based on computer generated hologram (CGH) and chaotic theory is proposed. The tri-color separated images of an image to be encrypted are encoded with three random phase arrays constructed by a chaotic sequence of the deterministic non-linear system, respectively. Then Burch's encoding method using the modified off-axis reference beam is adopted to fabricate the CGH as the encryption image. A clear original color image can be reconstructed as long as the correct initial value of chaotic sequence and the correct system parameters are given. The initial value of chaotic function with a very small change will lead to the generation of an entirely different chaotic sequences. As a result, the random phase array changes dramatically and the original image cannot be recovered rightly. Serving as the secret keys, the initial values of chaotic sequence and system parameters reduce the amount of the key data. And the digital encryption image is also more favorable to be stored and transmitted. The feasibility and its robustness against occlusion and noise attacks are verified by numerical simulations.
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. PMID:26966561
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
Imaging industry expectations for compressed sensing in MRI
NASA Astrophysics Data System (ADS)
King, Kevin F.; Kanwischer, Adriana; Peters, Rob
2015-09-01
Compressed sensing requires compressible data, incoherent acquisition and a nonlinear reconstruction algorithm to force creation of a compressible image consistent with the acquired data. MRI images are compressible using various transforms (commonly total variation or wavelets). Incoherent acquisition of MRI data by appropriate selection of pseudo-random or non-Cartesian locations in k-space is straightforward. Increasingly, commercial scanners are sold with enough computing power to enable iterative reconstruction in reasonable times. Therefore integration of compressed sensing into commercial MRI products and clinical practice is beginning. MRI frequently requires the tradeoff of spatial resolution, temporal resolution and volume of spatial coverage to obtain reasonable scan times. Compressed sensing improves scan efficiency and reduces the need for this tradeoff. Benefits to the user will include shorter scans, greater patient comfort, better image quality, more contrast types per patient slot, the enabling of previously impractical applications, and higher throughput. Challenges to vendors include deciding which applications to prioritize, guaranteeing diagnostic image quality, maintaining acceptable usability and workflow, and acquisition and reconstruction algorithm details. Application choice depends on which customer needs the vendor wants to address. The changing healthcare environment is putting cost and productivity pressure on healthcare providers. The improved scan efficiency of compressed sensing can help alleviate some of this pressure. Image quality is strongly influenced by image compressibility and acceleration factor, which must be appropriately limited. Usability and workflow concerns include reconstruction time and user interface friendliness and response. Reconstruction times are limited to about one minute for acceptable workflow. The user interface should be designed to optimize workflow and minimize additional customer training. Algorithm
NASA Technical Reports Server (NTRS)
Barnsley, Michael F.; Sloan, Alan D.
1989-01-01
Fractals are geometric or data structures which do not simplify under magnification. Fractal Image Compression is a technique which associates a fractal to an image. On the one hand, the fractal can be described in terms of a few succinct rules, while on the other, the fractal contains much or all of the image information. Since the rules are described with less bits of data than the image, compression results. Data compression with fractals is an approach to reach high compression ratios for large data streams related to images. The high compression ratios are attained at a cost of large amounts of computation. Both lossless and lossy modes are supported by the technique. The technique is stable in that small errors in codes lead to small errors in image data. Applications to the NASA mission are discussed.
Texture-based medical image retrieval in compressed domain using compressive sensing.
Yadav, Kuldeep; Srivastava, Avi; Mittal, Ankush; Ansari, M A
2014-01-01
Content-based image retrieval has gained considerable attention in today's scenario as a useful tool in many applications; texture is one of them. In this paper, we focus on texture-based image retrieval in compressed domain using compressive sensing with the help of DC coefficients. Medical imaging is one of the fields which have been affected most, as there had been huge size of image database and getting out the concerned image had been a daunting task. Considering this, in this paper we propose a new model of image retrieval process using compressive sampling, since it allows accurate recovery of image from far fewer samples of unknowns and it does not require a close relation of matching between sampling pattern and characteristic image structure with increase acquisition speed and enhanced image quality.
Jared Verba; Michael Milvich
2008-05-01
Current Intrusion Detection System (IDS) technology is not suited to be widely deployed inside a Supervisory, Control and Data Acquisition (SCADA) environment. Anomaly- and signature-based IDS technologies have developed methods to cover information technology-based networks activity and protocols effectively. However, these IDS technologies do not include the fine protocol granularity required to ensure network security inside an environment with weak protocols lacking authentication and encryption. By implementing a more specific and more intelligent packet inspection mechanism, tailored traffic flow analysis, and unique packet tampering detection, IDS technology developed specifically for SCADA environments can be deployed with confidence in detecting malicious activity.
2015-01-01
Objective Developed sequencing techniques are yielding large-scale genomic data at low cost. A genome-wide association study (GWAS) targeting genetic variations that are significantly associated with a particular disease offers great potential for medical improvement. However, subjects who volunteer their genomic data expose themselves to the risk of privacy invasion; these privacy concerns prevent efficient genomic data sharing. Our goal is to presents a cryptographic solution to this problem. Methods To maintain the privacy of subjects, we propose encryption of all genotype and phenotype data. To allow the cloud to perform meaningful computation in relation to the encrypted data, we use a fully homomorphic encryption scheme. Noting that we can evaluate typical statistics for GWAS from a frequency table, our solution evaluates frequency tables with encrypted genomic and clinical data as input. We propose to use a packing technique for efficient evaluation of these frequency tables. Results Our solution supports evaluation of the D′ measure of linkage disequilibrium, the Hardy-Weinberg Equilibrium, the χ2 test, etc. In this paper, we take χ2 test and linkage disequilibrium as examples and demonstrate how we can conduct these algorithms securely and efficiently in an outsourcing setting. We demonstrate with experimentation that secure outsourcing computation of one χ2 test with 10, 000 subjects requires about 35 ms and evaluation of one linkage disequilibrium with 10, 000 subjects requires about 80 ms. Conclusions With appropriate encoding and packing technique, cryptographic solutions based on fully homomorphic encryption for secure computations of GWAS can be practical. PMID:26732892
Multiple channel data acquisition system
Crawley, H. Bert; Rosenberg, Eli I.; Meyer, W. Thomas; Gorbics, Mark S.; Thomas, William D.; McKay, Roy L.; Homer, Jr., John F.
1990-05-22
A multiple channel data acquisition system for the transfer of large amounts of data from a multiplicity of data channels has a plurality of modules which operate in parallel to convert analog signals to digital data and transfer that data to a communications host via a FASTBUS. Each module has a plurality of submodules which include a front end buffer (FEB) connected to input circuitry having an analog to digital converter with cache memory for each of a plurality of channels. The submodules are interfaced with the FASTBUS via a FASTBUS coupler which controls a module bus and a module memory. The system is triggered to effect rapid parallel data samplings which are stored to the cache memories. The cache memories are uploaded to the FEBs during which zero suppression occurs. The data in the FEBs is reformatted and compressed by a local processor during transfer to the module memory. The FASTBUS coupler is used by the communications host to upload the compressed and formatted data from the module memory. The local processor executes programs which are downloaded to the module memory through the FASTBUS coupler.
Multiple channel data acquisition system
Crawley, H.B.; Rosenberg, E.I.; Meyer, W.T.; Gorbics, M.S.; Thomas, W.D.; McKay, R.L.; Homer, J.F. Jr.
1990-05-22
A multiple channel data acquisition system for the transfer of large amounts of data from a multiplicity of data channels has a plurality of modules which operate in parallel to convert analog signals to digital data and transfer that data to a communications host via a FASTBUS. Each module has a plurality of submodules which include a front end buffer (FEB) connected to input circuitry having an analog to digital converter with cache memory for each of a plurality of channels. The submodules are interfaced with the FASTBUS via a FASTBUS coupler which controls a module bus and a module memory. The system is triggered to effect rapid parallel data samplings which are stored to the cache memories. The cache memories are uploaded to the FEBs during which zero suppression occurs. The data in the FEBs is reformatted and compressed by a local processor during transfer to the module memory. The FASTBUS coupler is used by the communications host to upload the compressed and formatted data from the module memory. The local processor executes programs which are downloaded to the module memory through the FASTBUS coupler. 25 figs.
Modeling Compressed Turbulence
Israel, Daniel M.
2012-07-13
From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.
Local compressibilities in crystals
NASA Astrophysics Data System (ADS)
Martín Pendás, A.; Costales, Aurora; Blanco, M. A.; Recio, J. M.; Luaña, Víctor
2000-12-01
An application of the atoms in molecules theory to the partitioning of static thermodynamic properties in condensed systems is presented. Attention is focused on the definition and the behavior of atomic compressibilities. Inverses of bulk moduli are found to be simple weighted averages of atomic compressibilities. Two kinds of systems are investigated as examples: four related oxide spinels and the alkali halide family. Our analyses show that the puzzling constancy of the bulk moduli of these spinels is a consequence of the value of the compressibility of an oxide ion. A functional dependence between ionic bulk moduli and ionic volume is also proposed.
Bouslimi, Dalel; Coatrieux, Gouenou; Roux, Christian
2012-04-01
In this paper we propose a joint encryption/watermarking algorithm for the purpose of protecting medical images. The proposed solution gives access to the outcomes of the image integrity and of its origins as its attachment to one patient even if the image is stored encrypted. In this study, the given solution combines the RC4 stream cipher and two substitutive watermarking modulations: the Least Significant Bit Method and the Quantization Index Modulation. If watermarking and encryption are conducted jointly at the protection stage, watermark extraction and decryption can be applied independently. Experimental results achieved on 8 bits encoded echographic images illustrate the overall performances of the proposed scheme. At least, a capacity rate of 1 and 0.5 bits of message per pixel of image can be embedded in the spatial and the encrypted domains respectively, with a peak signal to noise ratio greater than 49 dB.
NASA Astrophysics Data System (ADS)
Wang, Y.; Quan, C.; Tay, C. J.
2015-06-01
Many phase-truncation-based cryptosystems encounter an information disclosure problem. In this paper, a novel color image encryption using a phase-truncated Fresnel transform and random amplitude mask (RAM) without the risk of information disclosure is proposed. An image is first separated into three channels (red, green, and blue) and using an additional RAM channel the risk of information disclosure encountered in previous encryption methods is eliminated. Moreover unlike previous methods where each channel is encrypted independently, the four channels employed in the proposed method are encrypted using a cascading technique. Robustness of the proposed scheme against attacks is analyzed. Numerical simulations are presented to demonstrate the feasibility and effectiveness of the proposed system.
Focus on Compression Stockings
... sion apparel is used to prevent or control edema The post-thrombotic syndrome (PTS) is a complication ( ... complication. abdomen. This swelling is referred to as edema. If you have edema, compression therapy may be ...
Muon cooling: longitudinal compression.
Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David
2014-06-01
A 10 MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2 μs. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10^{7}. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10^{4}.
Muon Cooling: Longitudinal Compression
NASA Astrophysics Data System (ADS)
Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M.; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David
2014-06-01
A 10 MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2 μs. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 107. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 104.
Compressible Astrophysics Simulation Code
Howell, L.; Singer, M.
2007-07-18
This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.
Entangled-photon compressive ghost imaging
Zerom, Petros; Chan, Kam Wai Clifford; Howell, John C.; Boyd, Robert W.
2011-12-15
We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.
FTMP data acquisition environment
NASA Technical Reports Server (NTRS)
Padilla, Peter A.
1988-01-01
The Fault-Tolerant Multi-Processing (FTMP) test-bed data acquisition environment is described. The performance of two data acquisition devices available in the test environment are estimated and compared. These estimated data rates are used as measures of the devices' capabilities. A new data acquisition device was developed and added to the FTMP environment. This path increases the data rate available by approximately a factor of 8, to 379 KW/S, while simplifying the experiment development process.
In-orbit commissioning of SPOT5 image compression function
NASA Astrophysics Data System (ADS)
Moury, Gilles A.; Latry, Christophe
2003-11-01
CNES has launched in May 2002 a new high resolution (2.5m) and large swath (2 x 60km) optical remote sensing satellite: SPOT5. To achieve a high image acquisition capacity with this system, a large on-board mass memory (100 Gbits) together with a 3:1 real-time compression are being used. The quasi-lossless and fixed output rate requirements put on the on-board image compression resulted in the development of a custom algorithm. This algorithm is based on: a DCT decorrelator, a scalar quantizer, an entropy coder and a rate regulator. It has been extensively tested before launch both in terms of quantitative performances and in terms of visual performances. The objectives of the on-orbit validation of the SPOT5 image compression function were the following: (1) Perform an image quality assessment in worst case conditions for the compression. In particular, the THR mode (2.5 m resolution) is potentially sensitive to compression noise and was therefore thoroughly checked for any compression artefacts. Compression noise characteristics were taken into account in the denoising stage of the ground processing for improved performances; (2) Verify the adequacy of the compression parameters with regard to the in-flight characteristics of the instruments (MTF, radiometric spreading, ...); (3) Technological checkout of the compression unit on board the satellite. This paper will present an overview of SPOT5 mission, the methods used for on-orbit validation of the compression and, finally, all the validation results together with the lessons learned throughout this development. On-board image compression for future CNES remote sensing missions will be addressed as a conclusion.
Survey of data compression techniques
Gryder, R.; Hake, K.
1991-09-01
PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM's design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.
Survey of data compression techniques
Gryder, R.; Hake, K.
1991-09-01
PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM`s design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.
Fu, C.Y.; Petrich, L.I.
1997-03-25
An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.
Fu, Chi-Yung; Petrich, Loren I.
1997-01-01
An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.
Alternative Compression Garments
NASA Technical Reports Server (NTRS)
Stenger, M. B.; Lee, S. M. C.; Ribeiro, L. C.; Brown, A. K.; Westby, C. M.; Platts, S. H.
2011-01-01
Orthostatic intolerance after spaceflight is still an issue for astronauts as no in-flight countermeasure has been 100% effective. Future anti-gravity suits (AGS) may be similar to the Shuttle era inflatable AGS or may be a mechanical compression device like the Russian Kentavr. We have evaluated the above garments as well as elastic, gradient compression garments of varying magnitude and determined that breast-high elastic compression garments may be a suitable replacement to the current AGS. This new garment should be more comfortable than the AGS, easy to don and doff, and as effective a countermeasure to orthostatic intolerance. Furthermore, these new compression garments could be worn for several days after space flight as necessary if symptoms persisted. We conducted two studies to evaluate elastic, gradient compression garments. The purpose of these studies was to evaluate the comfort and efficacy of an alternative compression garment (ACG) immediately after actual space flight and 6 degree head-down tilt bed rest as a model of space flight, and to determine if they would impact recovery if worn for up to three days after bed rest.
Streamlined acquisition handbook
NASA Technical Reports Server (NTRS)
1990-01-01
NASA has always placed great emphasis on the acquisition process, recognizing it as among its most important activities. This handbook is intended to facilitate the application of streamlined acquisition procedures. The development of these procedures reflects the efforts of an action group composed of NASA Headquarters and center acquisition professionals. It is the intent to accomplish the real change in the acquisition process as a result of this effort. An important part of streamlining the acquisition process is a commitment by the people involved in the process to accomplishing acquisition activities quickly and with high quality. Too often we continue to accomplish work in 'the same old way' without considering available alternatives which would require no changes to regulations, approvals from Headquarters, or waivers of required practice. Similarly, we must be sensitive to schedule opportunities throughout the acquisition cycle, not just once the purchase request arrives at the procurement office. Techniques that have been identified as ways of reducing acquisition lead time while maintaining high quality in our acquisition process are presented.
Idbeaa, Tarik; Abdul Samad, Salina; Husain, Hafizah
2016-01-01
This paper presents a novel secure and robust steganographic technique in the compressed video domain namely embedding-based byte differencing (EBBD). Unlike most of the current video steganographic techniques which take into account only the intra frames for data embedding, the proposed EBBD technique aims to hide information in both intra and inter frames. The information is embedded into a compressed video by simultaneously manipulating the quantized AC coefficients (AC-QTCs) of luminance components of the frames during MPEG-2 encoding process. Later, during the decoding process, the embedded information can be detected and extracted completely. Furthermore, the EBBD basically deals with two security concepts: data encryption and data concealing. Hence, during the embedding process, secret data is encrypted using the simplified data encryption standard (S-DES) algorithm to provide better security to the implemented system. The security of the method lies in selecting candidate AC-QTCs within each non-overlapping 8 × 8 sub-block using a pseudo random key. Basic performance of this steganographic technique verified through experiments on various existing MPEG-2 encoded videos over a wide range of embedded payload rates. Overall, the experimental results verify the excellent performance of the proposed EBBD with a better trade-off in terms of imperceptibility and payload, as compared with previous techniques while at the same time ensuring minimal bitrate increase and negligible degradation of PSNR values.
Idbeaa, Tarik; Abdul Samad, Salina; Husain, Hafizah
2016-01-01
This paper presents a novel secure and robust steganographic technique in the compressed video domain namely embedding-based byte differencing (EBBD). Unlike most of the current video steganographic techniques which take into account only the intra frames for data embedding, the proposed EBBD technique aims to hide information in both intra and inter frames. The information is embedded into a compressed video by simultaneously manipulating the quantized AC coefficients (AC-QTCs) of luminance components of the frames during MPEG-2 encoding process. Later, during the decoding process, the embedded information can be detected and extracted completely. Furthermore, the EBBD basically deals with two security concepts: data encryption and data concealing. Hence, during the embedding process, secret data is encrypted using the simplified data encryption standard (S-DES) algorithm to provide better security to the implemented system. The security of the method lies in selecting candidate AC-QTCs within each non-overlapping 8 × 8 sub-block using a pseudo random key. Basic performance of this steganographic technique verified through experiments on various existing MPEG-2 encoded videos over a wide range of embedded payload rates. Overall, the experimental results verify the excellent performance of the proposed EBBD with a better trade-off in terms of imperceptibility and payload, as compared with previous techniques while at the same time ensuring minimal bitrate increase and negligible degradation of PSNR values. PMID:26963093
Idbeaa, Tarik; Abdul Samad, Salina; Husain, Hafizah
2016-01-01
This paper presents a novel secure and robust steganographic technique in the compressed video domain namely embedding-based byte differencing (EBBD). Unlike most of the current video steganographic techniques which take into account only the intra frames for data embedding, the proposed EBBD technique aims to hide information in both intra and inter frames. The information is embedded into a compressed video by simultaneously manipulating the quantized AC coefficients (AC-QTCs) of luminance components of the frames during MPEG-2 encoding process. Later, during the decoding process, the embedded information can be detected and extracted completely. Furthermore, the EBBD basically deals with two security concepts: data encryption and data concealing. Hence, during the embedding process, secret data is encrypted using the simplified data encryption standard (S-DES) algorithm to provide better security to the implemented system. The security of the method lies in selecting candidate AC-QTCs within each non-overlapping 8 × 8 sub-block using a pseudo random key. Basic performance of this steganographic technique verified through experiments on various existing MPEG-2 encoded videos over a wide range of embedded payload rates. Overall, the experimental results verify the excellent performance of the proposed EBBD with a better trade-off in terms of imperceptibility and payload, as compared with previous techniques while at the same time ensuring minimal bitrate increase and negligible degradation of PSNR values. PMID:26963093
An introduction to video image compression and authentication technology for safeguards applications
Johnson, C.S.
1995-07-01
Verification of a video image has been a major problem for safeguards for several years. Various verification schemes have been tried on analog video signals ever since the mid-1970`s. These schemes have provided a measure of protection but have never been widely adopted. The development of reasonably priced complex video processing integrated circuits makes it possible to digitize a video image and then compress the resulting digital file into a smaller file without noticeable loss of resolution. Authentication and/or encryption algorithms can be more easily applied to digital video files that have been compressed. The compressed video files require less time for algorithm processing and image transmission. An important safeguards application for authenticated, compressed, digital video images is in unattended video surveillance systems and remote monitoring systems. The use of digital images in the surveillance system makes it possible to develop remote monitoring systems that send images over narrow bandwidth channels such as the common telephone line. This paper discusses the video compression process, authentication algorithm, and data format selected to transmit and store the authenticated images.
An authenticated image encryption scheme based on chaotic maps and memory cellular automata
NASA Astrophysics Data System (ADS)
Bakhshandeh, Atieh; Eslami, Ziba
2013-06-01
This paper introduces a new image encryption scheme based on chaotic maps, cellular automata and permutation-diffusion architecture. In the permutation phase, a piecewise linear chaotic map is utilized to confuse the plain-image and in the diffusion phase, we employ the Logistic map as well as a reversible memory cellular automata to obtain an efficient and secure cryptosystem. The proposed method admits advantages such as highly secure diffusion mechanism, computational efficiency and ease of implementation. A novel property of the proposed scheme is its authentication ability which can detect whether the image is tampered during the transmission or not. This is particularly important in applications where image data or part of it contains highly sensitive information. Results of various analyses manifest high security of this new method and its capability for practical image encryption.
Data Division Scheme Based on Homomorphic Encryption in WSNs for Health Care.
Wang, Xiaoni; Zhang, Zhenjiang
2015-12-01
The use of wireless sensor networks for wearable computing in health care is growing quickly. Numerous applications are already in use, such as blood pressure monitors and heart rate monitors. As such, it is very important for system designers to consider how to protect patient privacy, especially in wireless sensor networks. After studying and analyzing the features of wireless sensor networks in medical systems, a data division scheme was proposed in this paper, provided the advantages of homomorphic encryption. In the proposed scheme, even if a forwarding node is compromised, the attacker will not be able to eavesdrop on the data, resulting in much stronger privacy than existing schemes. Experimental results shows that the scheme provides a good trade off in resources consumed and system security, and is efficient for encrypting or decrypting sensitive medical data. PMID:26490146
An optical authentication system based on encryption technique and multimodal biometrics
NASA Astrophysics Data System (ADS)
Yuan, Sheng; Zhang, Tong; Zhou, Xin; Liu, Xuemei; Liu, Mingtang
2013-12-01
A major concern nowadays for a biometric credential management system is its potential vulnerability to protect its information sources. To prevent a genuine user's templates from both internal and external threats, a novel and simple method combined optical encryption with multimodal biometric authentication technique is proposed. In this method, the standard biometric templates are generated real-timely by the verification keys owned by legal user so that they are unnecessary to be stored in a database. Compared with the traditional recognition algorithms, storage space and matching time are greatly saved. In addition, the verification keys are difficult to be forged due to the utilization of optical encryption technique. Although the verification keys are lost or stolen, they are useless for others in absence of the legal owner's biometric. A series of numerical simulations are performed to demonstrate the feasibility and performance of this method.
Color image encryption using iterative phase retrieve process in quaternion Fourier transform domain
NASA Astrophysics Data System (ADS)
Sui, Liansheng; Duan, Kuaikuai
2015-02-01
A single-channel color image encryption method is proposed based on iterative phase iterative process in quaternion Fourier transform domain. First, three components of the plain color image is confused respectively by using cat map. Second, the confused components are combined into a pure quaternion image, which is encode to the phase only function by using an iterative phase retrieval process. Finally, the phase only function is encrypted into the gray scale ciphertext with stationary white noise distribution based on the chaotic diffusion, which has camouflage property to some extent. The corresponding plain color image can be recovered from the ciphertext only with correct keys in the decryption process. Simulation results verify the feasibility and effectiveness of the proposed method.
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.
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
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.
An Efficient Buyer-Seller Watermarking Protocol Based on Chameleon Encryption
NASA Astrophysics Data System (ADS)
Poh, Geong Sen; Martin, Keith M.
Buyer-seller watermarking protocols are designed to deter clients from illegally distributing copies of digital content. This is achieved by allowing a distributor to insert a unique watermark into content in such a way that the distributor does not know the final watermarked copy that is given to the client. This protects both the client and distributor from attempts by one to falsely accuse the other of misuse. Buyer-seller watermarking protocols are normally based on asymmetric cryptographic primitives known as homomorphic encryption schemes. However, the computational and communication overhead of this conventional approach is high. In this paper we propose a different approach, based on the symmetric Chameleon encryption scheme. We show that this leads to significant gains in computational and operational efficiency.
Security-enhanced chaos communication with time-delay signature suppression and phase encryption.
Xue, Chenpeng; Jiang, Ning; Lv, Yunxin; Wang, Chao; Li, Guilan; Lin, Shuqing; Qiu, Kun
2016-08-15
A security-enhanced chaos communication scheme with time delay signature (TDS) suppression and phase-encrypted feedback light is proposed, in virtue of dual-loop feedback with independent high-speed phase modulation. We numerically investigate the property of TDS suppression in the intensity and phase space and quantitatively discuss security of the proposed system by calculating the bit error rate of eavesdroppers who try to crack the system by directly filtering the detected signal or by using a similar semiconductor laser to synchronize the link signal and extract the data. The results show that TDS embedded in the chaotic carrier can be well suppressed by properly setting the modulation frequency, which can keep the time delay a secret from the eavesdropper. Moreover, because the feedback light is encrypted, without the accurate time delay and key, the eavesdropper cannot reconstruct the symmetric operation conditions and decode the correct data. PMID:27519064
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.
Security enhancement of a phase-truncation based image encryption algorithm.
Wang, Xiaogang; Zhao, Daomu
2011-12-20
The asymmetric cryptosystem, which is based on phase-truncated Fourier transforms (PTFTs), can break the linearity of conventional systems. However, it has been proven to be vulnerable to a specific attack based on iterative Fourier transforms when the two random phase masks are used as public keys to encrypt different plaintexts. An improvement from the asymmetric cryptosystem may be taken by relocating the amplitude values in the output plane. In this paper, two different methods are adopted to realize the amplitude modulation of the output image. The first one is to extend the PTFT-based asymmetrical cryptosystem into the anamorphic fractional Fourier transform domain directly, and the second is to add an amplitude mask in the Fourier plane of the encryption scheme. Some numerical simulations are presented to prove the good performance of the proposed cryptosystems.
End-to-end Encryption for SMS Messages in the Health Care Domain.
Hassinen, Marko; Laitinen, Pertti
2005-01-01
The health care domain has a high level of expectation on security and privacy of patient information. The security, privacy, and confidentiality issues are consistent all over the domain. Technical development and increasing use of mobile phones has led us to a situation in which SMS messages are used in the electronic interactions between health care professionals and patients. We will show that it is possible to send, receive and store text messages securely with a mobile phone with no additional hardware required. More importantly we will show that it is possible to obtain a reliable user authentication in systems using text message communication. Programming language Java is used for realization of our goals. This paper describes the general application structure, while details for the technical implementation and encryption methods are described in the referenced articles. We also propose some crucial areas where the implementation of encrypted SMS can solve previous lack of security.
Optical image encryption with silhouette removal based on interference and phase blend processing
NASA Astrophysics Data System (ADS)
Wang, Qu
2012-10-01
To completely eliminate the silhouette problem that inherently exists in the earlier interference-based encryption scheme with two phase-only masks (POMs), we propose a simple new encryption method based on optical interference of one random POM and two analytically obtained POMs. Different from the previous methods which require time-consuming iterative computation or postprocessing of the POMs for silhouette removal, our method can resolve the problem during the production of the POMs based on interference principle. Information associated with the original image is smoothed away by modulation of the random POM. Illegal deciphers cannot retrieve the primitive image using only one or two of the POMs. Incorporated with the linear phase blend operation, our method can provide higher robustness against brute force attacks. Simulation results are presented to support the validity and feasibility of our method.
Impulse attack-free four random phase mask encryption based on a 4-f optical system.
Kumar, Pramod; Joseph, Joby; Singh, Kehar
2009-04-20
Optical encryption methods based on double random phase encryption (DRPE) have been shown to be vulnerable to different types of attacks. The Fourier plane random phase mask (RPM), which is the most important key, can be cracked with a single impulse function attack. Such an attack is viable because the Fourier transform of a delta function is a unity function. Formation of a unity function can be avoided if RPMs are placed in front of both lenses in a 4-f optical setup, thereby protecting the DRPE from an impulse attack. We have performed numerical simulations to verify the proposed scheme. Resistance of this scheme is checked against the brute force and the impulse function attacks. The experimental results validate the feasibility of the scheme.
Design of real-time encryption module for secure data protection of wearable healthcare devices.
Kim, Jungchae; Lee, Byuck Jin; Yoo, Sun K
2013-01-01
Wearable devices for biomedical instrumentation could generate the medical data and transmit to a repository on cloud service through wireless networks. In this process, the private medical data will be disclosed by man in the middle attack. Thus, the archived data for healthcare services would be protected by non-standardized security policy by healthcare service provider (HSP) because HIPAA only defines the security rules. In this paper, we adopted the Advanced Encryption Standard (AES) for security framework on wearable devices, so healthcare applications using this framework could support the confidentiality easily. The framework developed as dynamic loadable module targeted for lightweight microcontroller such as msp430 within embedded operating system. The performance was shown that the module can support the real-time encryption using electrocardiogram and photoplethysmogram. In this regard, the processing load for enabling security is distributed to wearable devices, and the customized data protection method could be composed by HSP for a trusted healthcare service. PMID:24110180
NASA Astrophysics Data System (ADS)
Chen, Jun-xin; Zhu, Zhi-liang; Fu, Chong; Zhang, Li-bo; Zhang, Yushu
2015-06-01
Recently, intrinsic image features in bit-level (e.g., higher bit-planes carry more information than lower bit-planes) have been widely accepted for building bit-level image cryptosystems. Higher bit-planes are generally handled with enhanced encryption, whereas light attention is paid to lower ones. However, the existing achievements on bit-level image features are solely based on the analyses of standard test images, and they do not hold for some special images, such as medical images. When ciphering these images, such cryptosystems may leak the important information of lower bit-planes, and other inadaptability also exists. In this paper, we firstly give out the inapplicability of the existing bit-level achievements, and then a novel chaos-based image encryption scheme using nonlinear inter-pixel computing and swapping based permutation approach is presented. Simulations and extensive security analyses demonstrate the high level of security for practical secret applications.
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.
BTM: A Single-Key, Inverse-Cipher-Free Mode for Deterministic Authenticated Encryption
NASA Astrophysics Data System (ADS)
Iwata, Tetsu; Yasuda, Kan
We present a new blockcipher mode of operation named BTM, which stands for Bivariate Tag Mixing. BTM falls into the category of Deterministic Authenticated Encryption, which we call DAE for short. BTM makes all-around improvements over the previous two DAE constructions, SIV (Eurocrypt 2006) and HBS (FSE 2009). Specifically, our BTM requires just one blockcipher key, whereas SIV requires two. Our BTM does not require the decryption algorithm of the underlying blockcipher, whereas HBS does. The BTM mode utilizes bivariate polynomial hashing for authentication, which enables us to handle vectorial inputs of dynamic dimensions. BTM then generates an initial value for its counter mode of encryption by mixing the resulting tag with one of the two variables (hash keys), which avoids the need for an implementation of the inverse cipher.
Status Report on the First Round of the Development of the Advanced Encryption Standard
Nechvatal, James; Barker, Elaine; Dodson, Donna; Dworkin, Morris; Foti, James; Roback, Edward
1999-01-01
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 has reviewed the results of this research and selected five algorithms (MARS, RC6™, Rijndael, Serpent and Twofish) as finalists. The research results and rationale for the selection of the finalists are documented in this report. The five finalists will be the subject of further study before the selection of one or more of these algorithms for inclusion in the Advanced Encryption Standard.
Fast encryption of RGB color digital images using a tweakable cellular automaton based schema
NASA Astrophysics Data System (ADS)
Faraoun, Kamel Mohamed
2014-12-01
We propose a new tweakable construction of block-enciphers using second-order reversible cellular automata, and we apply it to encipher RGB-colored images. The proposed construction permits a parallel encryption of the image content by extending the standard definition of a block cipher to take into account a supplementary parameter used as a tweak (nonce) to control the behavior of the cipher from one region of the image to the other, and hence avoid the necessity to use slow sequential encryption's operating modes. The proposed construction defines a flexible pseudorandom permutation that can be used with efficacy to solve the electronic code book problem without the need to a specific sequential mode. Obtained results from various experiments show that the proposed schema achieves high security and execution performances, and enables an interesting mode of selective area decryption due to the parallel character of the approach.
Acquisition of teleological descriptions
NASA Astrophysics Data System (ADS)
Franke, David W.
1992-03-01
Teleology descriptions capture the purpose of an entity, mechanism, or activity with which they are associated. These descriptions can be used in explanation, diagnosis, and design reuse. We describe a technique for acquiring teleological descriptions expressed in the teleology language TeD. Acquisition occurs during design by observing design modifications and design verification. We demonstrate the acquisition technique in an electronic circuit design.
Quick Ride: Acquisition Overview
NASA Technical Reports Server (NTRS)
Adams, W. James
1999-01-01
Quick Ride is an outgrowth of rapid spacecraft acquisition. It provides a variety of low-cost, short lead time satellite rides for science instruments. Task order contracts with commercial firms will permit placing a order within 30 days. Secondary objectives include a demonstration of a FAR Part 12 commercial acquisition and the exploration of the use of on-ramps.
NASA Astrophysics Data System (ADS)
Karabat, Cagatay; Kiraz, Mehmet Sabir; Erdogan, Hakan; Savas, Erkay
2015-12-01
In this paper, we introduce a new biometric verification and template protection system which we call THRIVE. The system includes novel enrollment and authentication protocols based on threshold homomorphic encryption where a private key is shared between a user and a verifier. In the THRIVE system, only encrypted binary biometric templates are stored in a database and verification is performed via homomorphically randomized templates, thus, original templates are never revealed during authentication. Due to the underlying threshold homomorphic encryption scheme, a malicious database owner cannot perform full decryption on encrypted templates of the users in the database. In addition, security of the THRIVE system is enhanced using a two-factor authentication scheme involving user's private key and biometric data. Using simulation-based techniques, the proposed system is proven secure in the malicious model. The proposed system is suitable for applications where the user does not want to reveal her biometrics to the verifier in plain form, but needs to prove her identity by using biometrics. The system can be used with any biometric modality where a feature extraction method yields a fixed size binary template and a query template is verified when its Hamming distance to the database template is less than a threshold. The overall connection time for the proposed THRIVE system is estimated to be 336 ms on average for 256-bit biometric templates on a desktop PC running with quad core 3.2 GHz CPUs at 10 Mbit/s up/down link connection speed. Consequently, the proposed system can be efficiently used in real-life applications.
Design of an Input Phase Mask of the Optical Encryption System and its Application to Certification
NASA Astrophysics Data System (ADS)
Nomura, Takanori; Ninatai, Eiji; Numata, Takuhisa
2006-10-01
The secure optical memory system based on a double-random phase-encoding optical encryption system is proposed. The quality of decrypted data can be improved by designing an input phase mask to utilize the bandwidth the bandwidth of the optical system effectively. We propose the certification method of the data recorded into the optical memory by using a designed input phase mask as a phase code. Computer simulations confirm the possibility of the proposed certification system.
Transverse Compression of Tendons.
Salisbury, S T Samuel; Buckley, C Paul; Zavatsky, Amy B
2016-04-01
A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon. PMID:26833218
Transverse Compression of Tendons.
Salisbury, S T Samuel; Buckley, C Paul; Zavatsky, Amy B
2016-04-01
A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon.
Biomedical sensor design using analog compressed sensing
NASA Astrophysics Data System (ADS)
Balouchestani, Mohammadreza; Krishnan, Sridhar
2015-05-01
The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.
Protection of privacy by third-party encryption in genetic research in Iceland.
Gulcher, J R; Kristjánsson, K; Gudbjartsson, H; Stefánsson, K
2000-10-01
As the new human genetics continues its dramatic expansion into many laboratories and medical institutions, the concern for the protection of the personal privacy of individuals who participate increases. It seems that even the smallest of laboratories must confront the issue of how to protect the genetic and phenotypic information of participants in their research. Some have promoted the use of anonymity as a way out of this dilemma. But we are reminded by others that the future cannot be predicted, and that future benefits may be lost when the links to these benevolent volunteers are gone forever. More recently, some ethical bodies have suggested, without specific recommendations, that a reversible third-party encryption system may be a solution to this problem. However, they have not provided a route or even examples of how to proceed. We present here the Icelandic approach to this issue by developing a third-party encryption system in direct collaboration with the Data Protection Commission (DPC) of Iceland. We have incorporated the encryption system within our sample collection and storage software, which minimises inconvenience but enhances security. The strategy assures a barrier between the laboratory and the outside world that can only be crossed by the DPC. PMID:11039572
Triple-image encryption based on phase-truncated Fresnel transform and basic vector operation.
Pan, Xuemei; Meng, Xiangfeng; Yang, Xiulun; Wang, Yurong; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi
2015-10-01
A triple-image encryption method is proposed that is based on phase-truncated Fresnel transform (PTFT), basic vector composition, and XOR operation. In the encryption process, two random phase masks, with one each placed at the input plane and the transform plane, are generated by basic vector resolution operations over the first and the second plaintext images, and then a ciphered image in the input plane is fabricated by XOR encoding for the third plaintext image. When the cryptosystem is illuminated by an on-axis plane, assisted by PTFT, the ciphered image is finally encrypted into an amplitude-only noise-like image in the output plane. During decryption, possessing the correct private key, decryption keys, and the assistant geometrical parameter keys, and placing them at the corresponding correct positions, the original three plaintext images can be successfully decrypted by inverse PTFT, basic vector composition, and XOR decoding. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method. PMID:26479627
A New Image Encryption Scheme Based on Dynamic S-Boxes and Chaotic Maps
NASA Astrophysics Data System (ADS)
Rehman, Atique Ur; Khan, Jan Sher; Ahmad, Jawad; Hwang, Soeng Oun
2016-03-01
Substitution box is a unique and nonlinear core component of block ciphers. A better designing technique of substitution box can boost up the quality of ciphertexts. In this paper, a new encryption method based on dynamic substitution boxes is proposed via using two chaotic maps. To break the correlation in an original image, pixels values of the original plaintext image are permuted row- and column-wise through random sequences. The aforementioned random sequences are generated by 2-D Burgers chaotic map. For the generation of dynamic substitution boxes, Logistic chaotic map is employed. In the process of diffusion, the permuted image is divided into blocks and each block is substituted via different dynamic substitution boxes. In contrast to conventional encryption schemes, the proposed scheme does not undergo the fixed block cipher and hence the security level can be enhanced. Extensive security analysis including histogram test is applied on the proposed image encryption technique. All experimental results reveal that the proposed scheme has a high level of security and robustness for transmission of digital images on insecure communication channels.
Privacy protection in HealthGrid: distributing encryption management over the VO.
Torres, Erik; de Alfonso, Carlos; Blanquer, Ignacio; Hernández, Vicente
2006-01-01
Grid technologies have proven to be very successful in tackling challenging problems in which data access and processing is a bottleneck. Notwithstanding the benefits that Grid technologies could have in Health applications, privacy leakages of current DataGrid technologies due to the sharing of data in VOs and the use of remote resources, compromise its widespreading. Privacy control for Grid technology has become a key requirement for the adoption of Grids in the Healthcare sector. Encrypted storage of confidential data effectively reduces the risk of disclosure. A self-enforcing scheme for encrypted data storage can be achieved by combining Grid security systems with distributed key management and classical cryptography techniques. Virtual Organizations, as the main unit of user management in Grid, can provide a way to organize key sharing, access control lists and secure encryption management. This paper provides programming models and discusses the value, costs and behavior of such a system implemented on top of one of the latest Grid middlewares. This work is partially funded by the Spanish Ministry of Science and Technology in the frame of the project Investigación y Desarrollo de Servicios GRID: Aplicación a Modelos Cliente-Servidor, Colaborativos y de Alta Productividad, with reference TIC2003-01318. PMID:16823130
Protection of privacy by third-party encryption in genetic research in Iceland.
Gulcher, J R; Kristjánsson, K; Gudbjartsson, H; Stefánsson, K
2000-10-01
As the new human genetics continues its dramatic expansion into many laboratories and medical institutions, the concern for the protection of the personal privacy of individuals who participate increases. It seems that even the smallest of laboratories must confront the issue of how to protect the genetic and phenotypic information of participants in their research. Some have promoted the use of anonymity as a way out of this dilemma. But we are reminded by others that the future cannot be predicted, and that future benefits may be lost when the links to these benevolent volunteers are gone forever. More recently, some ethical bodies have suggested, without specific recommendations, that a reversible third-party encryption system may be a solution to this problem. However, they have not provided a route or even examples of how to proceed. We present here the Icelandic approach to this issue by developing a third-party encryption system in direct collaboration with the Data Protection Commission (DPC) of Iceland. We have incorporated the encryption system within our sample collection and storage software, which minimises inconvenience but enhances security. The strategy assures a barrier between the laboratory and the outside world that can only be crossed by the DPC.
A novel image encryption algorithm based on chaos maps with Markov properties
NASA Astrophysics Data System (ADS)
Liu, Quan; Li, Pei-yue; Zhang, Ming-chao; Sui, Yong-xin; Yang, Huai-jiang
2015-02-01
In order to construct high complexity, secure and low cost image encryption algorithm, a class of chaos with Markov properties was researched and such algorithm was also proposed. The kind of chaos has higher complexity than the Logistic map and Tent map, which keeps the uniformity and low autocorrelation. An improved couple map lattice based on the chaos with Markov properties is also employed to cover the phase space of the chaos and enlarge the key space, which has better performance than the original one. A novel image encryption algorithm is constructed on the new couple map lattice, which is used as a key stream generator. A true random number is used to disturb the key which can dynamically change the permutation matrix and the key stream. From the experiments, it is known that the key stream can pass SP800-22 test. The novel image encryption can resist CPA and CCA attack and differential attack. The algorithm is sensitive to the initial key and can change the distribution the pixel values of the image. The correlation of the adjacent pixels can also be eliminated. When compared with the algorithm based on Logistic map, it has higher complexity and better uniformity, which is nearer to the true random number. It is also efficient to realize which showed its value in common use.
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.
Privacy protection in HealthGrid: distributing encryption management over the VO.
Torres, Erik; de Alfonso, Carlos; Blanquer, Ignacio; Hernández, Vicente
2006-01-01
Grid technologies have proven to be very successful in tackling challenging problems in which data access and processing is a bottleneck. Notwithstanding the benefits that Grid technologies could have in Health applications, privacy leakages of current DataGrid technologies due to the sharing of data in VOs and the use of remote resources, compromise its widespreading. Privacy control for Grid technology has become a key requirement for the adoption of Grids in the Healthcare sector. Encrypted storage of confidential data effectively reduces the risk of disclosure. A self-enforcing scheme for encrypted data storage can be achieved by combining Grid security systems with distributed key management and classical cryptography techniques. Virtual Organizations, as the main unit of user management in Grid, can provide a way to organize key sharing, access control lists and secure encryption management. This paper provides programming models and discusses the value, costs and behavior of such a system implemented on top of one of the latest Grid middlewares. This work is partially funded by the Spanish Ministry of Science and Technology in the frame of the project Investigación y Desarrollo de Servicios GRID: Aplicación a Modelos Cliente-Servidor, Colaborativos y de Alta Productividad, with reference TIC2003-01318.
Compressive sensing for nuclear security.
Gestner, Brian Joseph
2013-12-01
Special nuclear material (SNM) detection has applications in nuclear material control, treaty verification, and national security. The neutron and gamma-ray radiation signature of SNMs can be indirectly observed in scintillator materials, which fluoresce when exposed to this radiation. A photomultiplier tube (PMT) coupled to the scintillator material is often used to convert this weak fluorescence to an electrical output signal. The fluorescence produced by a neutron interaction event differs from that of a gamma-ray interaction event, leading to a slightly different pulse in the PMT output signal. The ability to distinguish between these pulse types, i.e., pulse shape discrimination (PSD), has enabled applications such as neutron spectroscopy, neutron scatter cameras, and dual-mode neutron/gamma-ray imagers. In this research, we explore the use of compressive sensing to guide the development of novel mixed-signal hardware for PMT output signal acquisition. Effectively, we explore smart digitizers that extract sufficient information for PSD while requiring a considerably lower sample rate than conventional digitizers. Given that we determine the feasibility of realizing these designs in custom low-power analog integrated circuits, this research enables the incorporation of SNM detection into wireless sensor networks.
NASA Technical Reports Server (NTRS)
Vandromme, Dany; Haminh, Hieu
1991-01-01
The capability of turbulence modeling correctly to handle natural unsteadiness appearing in compressible turbulent flows is investigated. Physical aspects linked to the unsteadiness problem and the role of various flow parameters are analyzed. It is found that unsteady turbulent flows can be simulated by dividing these motions into an 'organized' part for which equations of motion are solved and a remaining 'incoherent' part represented by a turbulence model. Two-equation turbulence models and second-order turbulence models can yield reasonable results. For specific compressible unsteady turbulent flow, graphic presentations of different quantities may reveal complementary physical features. Strong compression zones are observed in rapid flow parts but shocklets do not yet occur.
Isentropic Compression of Argon
H. Oona; J.C. Solem; L.R. Veeser, C.A. Ekdahl; P.J. Rodriquez; S.M. Younger; W. Lewis; W.D. Turley
1997-08-01
We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal.
NASA Astrophysics Data System (ADS)
Ohlsson, Henrik; Eldar, Yonina C.; Yang, Allen Y.; Sastry, S. Shankar
2014-08-01
The classical shift retrieval problem considers two signals in vector form that are related by a shift. The problem is of great importance in many applications and is typically solved by maximizing the cross-correlation between the two signals. Inspired by compressive sensing, in this paper, we seek to estimate the shift directly from compressed signals. We show that under certain conditions, the shift can be recovered using fewer samples and less computation compared to the classical setup. Of particular interest is shift estimation from Fourier coefficients. We show that under rather mild conditions only one Fourier coefficient suffices to recover the true shift.
Isentropic compression of argon
Veeser, L.R.; Ekdahl, C.A.; Oona, H.
1997-06-01
The compression was done in an MC-1 flux compression (explosive) generator, in order to study the transition from an insulator to a conductor. Since conductivity signals were observed in all the experiments (except when the probe is removed), both the Teflon and the argon are becoming conductive. The conductivity could not be determined (Teflon insulation properties unknown), but it could be bounded as being {sigma}=1/{rho}{le}8({Omega}cm){sub -1}, because when the Teflon breaks down, the dielectric constant is reduced. The Teflon insulator problem remains, and other ways to better insulate the probe or to measure the conductivity without a probe is being sought.
Orbiting dynamic compression laboratory
NASA Technical Reports Server (NTRS)
Ahrens, T. J.; Vreeland, T., Jr.; Kasiraj, P.; Frisch, B.
1984-01-01
In order to examine the feasibility of carrying out dynamic compression experiments on a space station, the possibility of using explosive gun launchers is studied. The question of whether powders of a refractory metal (molybdenum) and a metallic glass could be well considered by dynamic compression is examined. In both cases extremely good bonds are obtained between grains of metal and metallic glass at 180 and 80 kb, respectively. When the oxide surface is reduced and the dynamic consolidation is carried out in vacuum, in the case of molybdenum, tensile tests of the recovered samples demonstrated beneficial ultimate tensile strengths.
NASA Technical Reports Server (NTRS)
Kraemer, Steve; Downes, Ron; Katsanis, Rocio; Crenshaw, Mike; McGrath, Melissa; Robinson, Rich
1997-01-01
We describe the STIS autonomous target acquisition capabilities. We also present the results of dedicated tests executed as part of Cycle 7 calibration, following post-launch improvements to the Space Telescope Imaging Spectrograph (STIS) flight software. The residual pointing error from the acquisitions are < 0.5 CCD pixels, which is better than preflight estimates. Execution of peakups show clear improvement of target centering for slits of width 0.1 sec or smaller. These results may be used by Guest Observers in planning target acquisitions for their STIS programs.
Interactive knowledge acquisition tools
NASA Technical Reports Server (NTRS)
Dudziak, Martin J.; Feinstein, Jerald L.
1987-01-01
The problems of designing practical tools to aid the knowledge engineer and general applications used in performing knowledge acquisition tasks are discussed. A particular approach was developed for the class of knowledge acquisition problem characterized by situations where acquisition and transformation of domain expertise are often bottlenecks in systems development. An explanation is given on how the tool and underlying software engineering principles can be extended to provide a flexible set of tools that allow the application specialist to build highly customized knowledge-based applications.
A Data Encryption Solution for Mobile Health Apps in Cooperation Environments
Silva, Bruno M; Canelo, Fábio; Lopes, Ivo C; Zhou, Liang
2013-01-01
Background Mobile Health (mHealth) proposes health care delivering anytime and anywhere. It aims to answer several emerging problems in health services, including the increasing number of chronic diseases, high costs on national health services, and the need to provide direct access to health services, regardless of time and place. mHealth systems include the use of mobile devices and apps that interact with patients and caretakers. However, mobile devices present several constraints, such as processor, energy, and storage resource limitations. The constant mobility and often-required Internet connectivity also exposes and compromises the privacy and confidentiality of health information. Objective This paper presents a proposal, construction, performance evaluation, and validation of a data encryption solution for mobile health apps (DE4MHA), considering a novel and early-proposed cooperation strategy. The goal was to present a robust solution based on encryption algorithms that guarantee the best confidentiality, integrity, and authenticity of users health information. In this paper, we presented, explained, evaluated the performance, and discussed the cooperation mechanisms and the proposed encryption solution for mHealth apps. Methods First, we designed and deployed the DE4MHA. Then two studies were performed: (1) study and comparison of symmetric and asymmetric encryption/decryption algorithms in an mHealth app under a cooperation environment, and (2) performance evaluation of the DE4MHA. Its performance was evaluated through a prototype using an mHealth app for obesity prevention and cares, called SapoFit. We then conducted an evaluation study of the mHealth app with cooperation mechanisms and the DE4MHA using real users and a real cooperation scenario. In 5 days, 5 different groups of 7 students selected randomly agreed to use and experiment the SapoFit app using the 7 devices available for trials. Results There were 35 users of SapoFit that participated in
Nonlinear Frequency Compression
Scollie, Susan; Glista, Danielle; Seelisch, Andreas
2013-01-01
Frequency lowering technologies offer an alternative amplification solution for severe to profound high frequency hearing losses. While frequency lowering technologies may improve audibility of high frequency sounds, the very nature of this processing can affect the perceived sound quality. This article reports the results from two studies that investigated the impact of a nonlinear frequency compression (NFC) algorithm on perceived sound quality. In the first study, the cutoff frequency and compression ratio parameters of the NFC algorithm were varied, and their effect on the speech quality was measured subjectively with 12 normal hearing adults, 12 normal hearing children, 13 hearing impaired adults, and 9 hearing impaired children. In the second study, 12 normal hearing and 8 hearing impaired adult listeners rated the quality of speech in quiet, speech in noise, and music after processing with a different set of NFC parameters. Results showed that the cutoff frequency parameter had more impact on sound quality ratings than the compression ratio, and that the hearing impaired adults were more tolerant to increased frequency compression than normal hearing adults. No statistically significant differences were found in the sound quality ratings of speech-in-noise and music stimuli processed through various NFC settings by hearing impaired listeners. These findings suggest that there may be an acceptable range of NFC settings for hearing impaired individuals where sound quality is not adversely affected. These results may assist an Audiologist in clinical NFC hearing aid fittings for achieving a balance between high frequency audibility and sound quality. PMID:23539261
ERIC Educational Resources Information Center
Branzburg, Jeffrey
2005-01-01
File compression enables data to be squeezed together, greatly reducing file size. Why would someone want to do this? Reducing file size enables the sending and receiving of files over the Internet more quickly, the ability to store more files on the hard drive, and the ability pack many related files into one archive (for example, all files…
Cahill, C.
1997-07-01
Historically, the decision to purchase or rent compression has been set as a corporate philosophy. As companies decentralize, there seems to be a shift away from corporate philosophy toward individual profit centers. This has led the decision to rent versus purchase to be looked at on a regional or project-by-project basis.
The Compressed Video Experience.
ERIC Educational Resources Information Center
Weber, John
In the fall semester 1995, Southern Arkansas University- Magnolia (SAU-M) began a two semester trial delivering college classes via a compressed video link between SAU-M and its sister school Southern Arkansas University Tech (SAU-T) in Camden. As soon as the University began broadcasting and receiving classes, it was discovered that using the…
Acquisition signal transmitter
NASA Technical Reports Server (NTRS)
Friedman, Morton L. (Inventor)
1989-01-01
An encoded information transmitter which transmits a radio frequency carrier that is amplitude modulated by a constant frequency waveform and thereafter amplitude modulated by a predetermined encoded waveform, the constant frequency waveform modulated carrier constituting an acquisition signal and the encoded waveform modulated carrier constituting an information bearing signal, the acquisition signal providing enhanced signal acquisition and interference rejection favoring the information bearing signal. One specific application for this transmitter is as a distress transmitter where a conventional, legislated audio tone modulated signal is transmitted followed first by the acquisition signal and then the information bearing signal, the information bearing signal being encoded with, among other things, vehicle identification data. The acquistion signal enables a receiver to acquire the information bearing signal where the received signal is low and/or where the received signal has a low signal-to-noise ratio in an environment where there are multiple signals in the same frequency band as the information bearing signal.
Not Available
1990-06-01
The continuing instability in the overall defense budget and the recent changes in Eastern Europe are forcing DOD and the military services to reexamine the need, priority, and annual funding levels for many weapon system acquisition programs. GAO reviewed six weapon system acquisition programs that DOD was scheduled to make an acquisition milestone decision on during fiscal year 1991. Under milestone authorization, up to five years funding can be approved to cover the entire acquisition phase for either full-scale development or full-rate production. This report examines the Non-Line-of-Sight Missile, the Light Helicopter, the MK-50 Torpedo, the Sensor Fuzed Weapon, the Advanced Tactical Fighter, and the Joint Tactical Information Distribution System Class 2 Terminals.
Documentation and knowledge acquisition
NASA Technical Reports Server (NTRS)
Rochowiak, Daniel; Moseley, Warren
1990-01-01
Traditional approaches to knowledge acquisition have focused on interviews. An alternative focuses on the documentation associated with a domain. Adopting a documentation approach provides some advantages during familiarization. A knowledge management tool was constructed to gain these advantages.
Airborne data acquisition techniques
Arro, A.A.
1980-01-01
The introduction of standards on acceptable procedures for assessing building heat loss has created a dilemma for the contractor performing airborne thermographic surveys. These standards impose specifications on instrumentation, data acquisition, recording, interpretation, and presentation. Under the standard, the contractor has both the obligation of compliance and the requirement of offering his services at a reasonable price. This paper discusses the various aspects of data acquisition for airborne thermographic surveys and various techniques to reduce the costs of this operation. These techniques include the calculation of flight parameters for economical data acquisition, the selection and use of maps for mission planning, and the use of meteorological forecasts for flight scheduling and the actual execution of the mission. The proper consideration of these factors will result in a cost effective data acquisition and will place the contractor in a very competitive position in offering airborne thermographic survey services.
Shapiro, Stephen L.; Mani, Sudhindra; Atlas, Eugene L.; Cords, Dieter H. W.; Holbrook, Britt
1997-01-01
A data acquisition circuit for a particle detection system that allows for time tagging of particles detected by the system. The particle detection system screens out background noise and discriminate between hits from scattered and unscattered particles. The detection system can also be adapted to detect a wide variety of particle types. The detection system utilizes a particle detection pixel array, each pixel containing a back-biased PIN diode, and a data acquisition pixel array. Each pixel in the particle detection pixel array is in electrical contact with a pixel in the data acquisition pixel array. In response to a particle hit, the affected PIN diodes generate a current, which is detected by the corresponding data acquisition pixels. This current is integrated to produce a voltage across a capacitor, the voltage being related to the amount of energy deposited in the pixel by the particle. The current is also used to trigger a read of the pixel hit by the particle.
NASA Astrophysics Data System (ADS)
Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Molodtsov, Dmitriy Y.; Rodin, Vladislav G.; Shifrina, Anna V.
2016-04-01
The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution. This provides best encryption strength for fixed quantities of elements and phase levels in a mask. Downsides are holographic registration scheme used in order to register not only light intensity distribution but also its phase distribution and speckle noise occurring due to coherent illumination. That factors lead to very poor decryption quality when it comes from computer simulations to optical implementations. Method of optical encryption with spatially incoherent illumination does not have drawbacks inherent to coherent systems, however, as only light intensity distribution is considered, mean value of image to be encrypted is always above zero which leads to intensive zero spatial frequency peak in image spectrum. Therefore, in case of spatially incoherent illumination, image spectrum, as well as encryption key spectrum, cannot be white. If encryption is based on convolution operation, no matter coherent light used or not, Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Another factor affecting decrypted image quality is original image spectrum. Usually, most part of image energy is concentrated in area of low frequencies. Consequently, only this area in encrypted image contains information about original image, while other areas contain only noise. We propose to use additional encoding of input scene to increase size of the area containing useful information. This provides increase of signal-to-noise ratio in encrypted image and consequentially increases quality of decrypted images. Results of computer simulations of test images optical encryption with spatially incoherent illumination and additional input amplitude masks are presented.
Direct-Y: Fast Acquisition of the GPS PPS Signal
NASA Technical Reports Server (NTRS)
Namoos, Omar M.; DiEsposti, Raymond S.
1996-01-01
The NAVSTAR Global Positioning System (GPS) provides positioning and time information to military users via the Precise Positioning Service (PPS) which typically allows users a significant margin of precision over the commercially available Standard Positioning Service (SPS), Military sets that rely on first acquiring the SPS Coarse Acquisition (C/A) code, read from the data message the handover word (HOW) that provides the time-of-signal transmission needed to acquire and lock onto the PPS Y-code. Under extreme battlefield conditions, the use of GPS would be denied to the warfighter who cannot pick up the un-encrypted C/A code. Studies are underway at the GPS Joint Program Office (JPO) at the Space and Missile Center, Los Angeles Air Force Base that are aimed at developing the capability to directly acquire Y-code without first acquiring C/A code. This paper briefly outlines efforts to develop 'direct-Y' acquisition, and various approaches to solving this problem. The potential ramifications of direct-Y to military users are also discussed.
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.
NASA Astrophysics Data System (ADS)
Lang, Jun
2012-07-01
In recent years, a number of methods have been proposed in the literature for the encryption of two-dimensional information by use of the fractional Fourier transform, but most of their encryptions are complex value and need digital hologram technique to record their encrypted information, which is inconvenience for digital transmission. In this paper, we first propose a novel reality-preserving multiple-parameter fractional Fourier transform which share real-valuedness outputs as well as most of the properties required for a fractional transform. Then we propose a new approach for image encryption based on the real-valuedness of the reality-preserving multiple-parameter fractional Fourier transform and the decorrelation property of chaotic maps in order to meet the requirements of the secure image transmission. In the proposed scheme, the image is encrypted by juxtaposition of sections of the image in the reality-preserving multiple-parameter fractional Fourier domains and the alignment of sections is determined by chaotic logistic maps. Numerical simulations are performed to demonstrate that the proposed method is reliable and more robust to blind decryption than several existing methods.
Coded aperture compressive temporal imaging.
Llull, Patrick; Liao, Xuejun; Yuan, Xin; Yang, Jianbo; Kittle, David; Carin, Lawrence; Sapiro, Guillermo; Brady, David J
2013-05-01
We use mechanical translation of a coded aperture for code division multiple access compression of video. We discuss the compressed video's temporal resolution and present experimental results for reconstructions of > 10 frames of temporal data per coded snapshot.
Acceleration of multi-dimensional propagator measurements with compressed sensing.
Paulsen, Jeffrey L; Cho, HyungJoon; Cho, Gyunggoo; Song, Yi-Qiao
2011-12-01
NMR can probe the microstructures of anisotropic materials such as liquid crystals, stretched polymers and biological tissues through measurement of the diffusion propagator, where internal structures are indicated by restricted diffusion. Multi-dimensional measurements can probe the microscopic anisotropy, but full sampling can then quickly become prohibitively time consuming. However, for incompletely sampled data, compressed sensing is an effective reconstruction technique to enable accelerated acquisition. We demonstrate that with a compressed sensing scheme, one can greatly reduce the sampling and the experimental time with minimal effect on the reconstruction of the diffusion propagator with an example of anisotropic diffusion. We compare full sampling down to 64× sub-sampling for the 2D propagator measurement and reduce the acquisition time for the 3D experiment by a factor of 32 from ∼80 days to ∼2.5 days. PMID:21924932
The STOne Transform: Multi-Resolution Image Enhancement and Compressive Video.
Goldstein, Tom; Xu, Lina; Kelly, Kevin F; Baraniuk, Richard
2015-12-01
Compressive sensing enables the reconstruction of high-resolution signals from under-sampled data. While the compressive methods simplify data acquisition, they require the solution of difficult recovery problems to make use of the resulting measurements. This paper presents a new sensing framework that combines the advantages of both the conventional and the compressive sensing. Using the proposed sum-to-one transform, the measurements can be reconstructed instantly at the Nyquist rates at any power-of-two resolution. The same data can then be enhanced to higher resolutions using the compressive methods that leverage sparsity to beat the Nyquist limit. The availability of a fast direct reconstruction enables the compressive measurements to be processed on small embedded devices. We demonstrate this by constructing a real-time compressive video camera.
Space-time compressive imaging.
Treeaporn, Vicha; Ashok, Amit; Neifeld, Mark A
2012-02-01
Compressive imaging systems typically exploit the spatial correlation of the scene to facilitate a lower dimensional measurement relative to a conventional imaging system. In natural time-varying scenes there is a high degree of temporal correlation that may also be exploited to further reduce the number of measurements. In this work we analyze space-time compressive imaging using Karhunen-Loève (KL) projections for the read-noise-limited measurement case. Based on a comprehensive simulation study, we show that a KL-based space-time compressive imager offers higher compression relative to space-only compressive imaging. For a relative noise strength of 10% and reconstruction error of 10%, we find that space-time compressive imaging with 8×8×16 spatiotemporal blocks yields about 292× compression compared to a conventional imager, while space-only compressive imaging provides only 32× compression. Additionally, under high read-noise conditions, a space-time compressive imaging system yields lower reconstruction error than a conventional imaging system due to the multiplexing advantage. We also discuss three electro-optic space-time compressive imaging architecture classes, including charge-domain processing by a smart focal plane array (FPA). Space-time compressive imaging using a smart FPA provides an alternative method to capture the nonredundant portions of time-varying scenes.
SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) 2013
Gordon Rueff; Lyle Roybal; Denis Vollmer
2013-01-01
There is a significant need to protect the nation’s energy infrastructures from malicious actors using cyber methods. Supervisory, Control, and Data Acquisition (SCADA) systems may be vulnerable due to the insufficient security implemented during the design and deployment of these control systems. This is particularly true in older legacy SCADA systems that are still commonly in use. The purpose of INL’s research on the SCADA Protocol Anomaly Detection Utilizing Compression (SPADUC) project was to determine if and how data compression techniques could be used to identify and protect SCADA systems from cyber attacks. Initially, the concept was centered on how to train a compression algorithm to recognize normal control system traffic versus hostile network traffic. Because large portions of the TCP/IP message traffic (called packets) are repetitive, the concept of using compression techniques to differentiate “non-normal” traffic was proposed. In this manner, malicious SCADA traffic could be identified at the packet level prior to completing its payload. Previous research has shown that SCADA network traffic has traits desirable for compression analysis. This work investigated three different approaches to identify malicious SCADA network traffic using compression techniques. The preliminary analyses and results presented herein are clearly able to differentiate normal from malicious network traffic at the packet level at a very high confidence level for the conditions tested. Additionally, the master dictionary approach used in this research appears to initially provide a meaningful way to categorize and compare packets within a communication channel.
Layered compression for high-precision depth data.
Miao, Dan; Fu, Jingjing; Lu, Yan; Li, Shipeng; Chen, Chang Wen
2015-12-01
With the development of depth data acquisition technologies, access to high-precision depth with more than 8-b depths has become much easier and determining how to efficiently represent and compress high-precision depth is essential for practical depth storage and transmission systems. In this paper, we propose a layered high-precision depth compression framework based on an 8-b image/video encoder to achieve efficient compression with low complexity. Within this framework, considering the characteristics of the high-precision depth, a depth map is partitioned into two layers: 1) the most significant bits (MSBs) layer and 2) the least significant bits (LSBs) layer. The MSBs layer provides rough depth value distribution, while the LSBs layer records the details of the depth value variation. For the MSBs layer, an error-controllable pixel domain encoding scheme is proposed to exploit the data correlation of the general depth information with sharp edges and to guarantee the data format of LSBs layer is 8 b after taking the quantization error from MSBs layer. For the LSBs layer, standard 8-b image/video codec is leveraged to perform the compression. The experimental results demonstrate that the proposed coding scheme can achieve real-time depth compression with satisfactory reconstruction quality. Moreover, the compressed depth data generated from this scheme can achieve better performance in view synthesis and gesture recognition applications compared with the conventional coding schemes because of the error control algorithm. PMID:26415171
Digital cinema video compression
NASA Astrophysics Data System (ADS)
Husak, Walter
2003-05-01
The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.
The UCR gamma ray telescope data acquisition system
NASA Technical Reports Server (NTRS)
O'Neill, T. J.; Sweeney, W. E.; Tumer, O. T.; Zych, A. D.; White, R. S.
1988-01-01
A description is given of an electronics system based on the DEC Falcon SBC-11/23+, which has been designed and built to support a balloon-borne double Compton gamma-ray telescope. The system provides support for commands, data acquisition, data routing and compression, and photomultiplier tube gain control. The software consists of a number of interrupt-driven routines of differing priorities to handle each system task. This includes two circular buffers for onboard processing and bit encoding before transmission of the information to the ground computer. Acquisition of gamma-ray events at rates above the 200-Hz telemetry constraint is easily achieved.
NASA Technical Reports Server (NTRS)
Vinet, P.; Ferrante, J.; Rose, J. H.; Smith, J. R.
1987-01-01
A universal form is proposed for the equation of state (EOS) of solids. Good agreement is found for a variety of test data. The form of the EOS is used to suggest a method of data analysis, which is applied to materials of geophysical interest. The isothermal bulk modulus is discussed as a function of the volume and of the pressure. The isothermal compression curves for materials of geophysical interest are examined.
Basic cluster compression algorithm
NASA Technical Reports Server (NTRS)
Hilbert, E. E.; Lee, J.
1980-01-01
Feature extraction and data compression of LANDSAT data is accomplished by BCCA program which reduces costs associated with transmitting, storing, distributing, and interpreting multispectral image data. Algorithm uses spatially local clustering to extract features from image data to describe spectral characteristics of data set. Approach requires only simple repetitive computations, and parallel processing can be used for very high data rates. Program is written in FORTRAN IV for batch execution and has been implemented on SEL 32/55.
NASA Astrophysics Data System (ADS)
Qin, Yi; Jiang, Hualong; Gong, Qiong
2014-11-01
We propose a novel interference-based method for multiple-image encryption by phase-only mask (POM) multiplexing. The information of multiple images can be encrypted into two POMs (i.e. ciphertexts) without any iterative process. For correct decryption, one should hold the ciphertexts as well as the private keys, which are also POMs obtained analytically. Moreover, the bothersome silhouette problem can also be thoroughly resolved during the generation procedure of these POMs. The retrieved images by this method are totally free from the cross-talk noise that puzzles previous interference-based multiple-image encryption methods. Numerical results are presented to verify the validity of the proposed approach.
NASA Astrophysics Data System (ADS)
Nason, Sarah; Houghton, Brittany; Renfro, Timothy
2012-03-01
The fall university physics class, at McMurry University, created a compression modulus experiment that even high school students could do. The class came up with this idea after a Young's modulus experiment which involved stretching wire. A question was raised of what would happen if we compressed something else? We created our own Young's modulus experiment, but in a more entertaining way. The experiment involves measuring the height of a cake both before and after a weight has been applied to the cake. We worked to derive the compression modulus by applying weight to a cake. In the end, we had our experimental cake and, ate it too! To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.TSS.B1.1
Scale adaptive compressive tracking.
Zhao, Pengpeng; Cui, Shaohui; Gao, Min; Fang, Dan
2016-01-01
Recently, the compressive tracking (CT) method (Zhang et al. in Proceedings of European conference on computer vision, pp 864-877, 2012) has attracted much attention due to its high efficiency, but it cannot well deal with the scale changing objects due to its constant tracking box. To address this issue, in this paper we propose a scale adaptive CT approach, which adaptively adjusts the scale of tracking box with the size variation of the objects. Our method significantly improves CT in three aspects: Firstly, the scale of tracking box is adaptively adjusted according to the size of the objects. Secondly, in the CT method, all the compressive features are supposed independent and equal contribution to the classifier. Actually, different compressive features have different confidence coefficients. In our proposed method, the confidence coefficients of features are computed and used to achieve different contribution to the classifier. Finally, in the CT method, the learning parameter λ is constant, which will result in large tracking drift on the occasion of object occlusion or large scale appearance variation. In our proposed method, a variable learning parameter λ is adopted, which can be adjusted according to the object appearance variation rate. Extensive experiments on the CVPR2013 tracking benchmark demonstrate the superior performance of the proposed method compared to state-of-the-art tracking algorithms. PMID:27386298
Compression of multiwall microbubbles
NASA Astrophysics Data System (ADS)
Lebedeva, Natalia; Moore, Sam; Dobrynin, Andrey; Rubinstein, Michael; Sheiko, Sergei
2012-02-01
Optical monitoring of structural transformations and transport processes is prohibited if the objects to be studied are bulky and/or non-transparent. This paper is focused on the development of a microbbuble platform for acoustic imaging of heterogeneous media under harsh environmental conditions including high pressure (<500 atm), temperature (<100 C), and salinity (<10 wt%). We have studied the compression behavior of gas-filled microbubbles composed of multiple layers of surfactants and stabilizers. Upon hydrostatic compression, these bubbles undergo significant (up to 100x) changes in volume, which are completely reversible. Under repeated compression/expansion cycles, the pressure-volume P(V) characteristic of these microbubbles deviate from ideal-gas-law predictions. A theoretical model was developed to explain the observed deviations through contributions of shell elasticity and gas effusion. In addition, some of the microbubbles undergo peculiar buckling/smoothing transitions exhibiting intermittent formation of facetted structures, which suggest a solid-like nature of the pressurized shell. Preliminary studies illustrate that these pressure-resistant microbubbles maintain their mechanical stability and acoustic response at pressures greater than 1000 psi.
Pessione, Enrica; Cirrincione, Simona
2016-01-01
Lactic acid bacteria (LAB) can produce a huge amount of bioactive compounds. Since their elective habitat is food, especially dairy but also vegetal food, it is frequent to find bioactive molecules in fermented products. Sometimes these compounds can have adverse effects on human health such as biogenic amines (tyramine and histamine), causing allergies, hypertensive crises, and headache. However, some LAB products also display benefits for the consumers. In the present review article, the main nitrogen compounds produced by LAB are considered. Besides biogenic amines derived from the amino acids tyrosine, histidine, phenylalanine, lysine, ornithine, and glutamate by decarboxylation, interesting peptides can be decrypted by the proteolytic activity of LAB. LAB proteolytic system is very efficient in releasing encrypted molecules from several proteins present in different food matrices. Alpha and beta-caseins, albumin and globulin from milk and dairy products, rubisco from spinach, beta-conglycinin from soy and gluten from cereals constitute a good source of important bioactive compounds. These encrypted peptides are able to control nutrition (mineral absorption and oxidative stress protection), metabolism (blood glucose and cholesterol lowering) cardiovascular function (antithrombotic and hypotensive action), infection (microbial inhibition and immunomodulation) and gut-brain axis (opioids and anti-opioids controlling mood and food intake). Very recent results underline the role of food-encrypted peptides in protein folding (chaperone-like molecules) as well as in cell cycle and apoptosis control, suggesting new and positive aspects of fermented food, still unexplored. In this context, the detailed (transcriptomic, proteomic, and metabolomic) characterization of LAB of food interest (as starters, biocontrol agents, nutraceuticals, and probiotics) can supply a solid evidence-based science to support beneficial effects and it is a promising approach as well to obtain
Bioactive Molecules Released in Food by Lactic Acid Bacteria: Encrypted Peptides and Biogenic Amines
Pessione, Enrica; Cirrincione, Simona
2016-01-01
Lactic acid bacteria (LAB) can produce a huge amount of bioactive compounds. Since their elective habitat is food, especially dairy but also vegetal food, it is frequent to find bioactive molecules in fermented products. Sometimes these compounds can have adverse effects on human health such as biogenic amines (tyramine and histamine), causing allergies, hypertensive crises, and headache. However, some LAB products also display benefits for the consumers. In the present review article, the main nitrogen compounds produced by LAB are considered. Besides biogenic amines derived from the amino acids tyrosine, histidine, phenylalanine, lysine, ornithine, and glutamate by decarboxylation, interesting peptides can be decrypted by the proteolytic activity of LAB. LAB proteolytic system is very efficient in releasing encrypted molecules from several proteins present in different food matrices. Alpha and beta-caseins, albumin and globulin from milk and dairy products, rubisco from spinach, beta-conglycinin from soy and gluten from cereals constitute a good source of important bioactive compounds. These encrypted peptides are able to control nutrition (mineral absorption and oxidative stress protection), metabolism (blood glucose and cholesterol lowering) cardiovascular function (antithrombotic and hypotensive action), infection (microbial inhibition and immunomodulation) and gut-brain axis (opioids and anti-opioids controlling mood and food intake). Very recent results underline the role of food-encrypted peptides in protein folding (chaperone-like molecules) as well as in cell cycle and apoptosis control, suggesting new and positive aspects of fermented food, still unexplored. In this context, the detailed (transcriptomic, proteomic, and metabolomic) characterization of LAB of food interest (as starters, biocontrol agents, nutraceuticals, and probiotics) can supply a solid evidence-based science to support beneficial effects and it is a promising approach as well to obtain