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Sample records for high-capacity steganography scheme

  1. A high capacity 3D steganography algorithm.

    Science.gov (United States)

    Chao, Min-Wen; Lin, Chao-hung; Yu, Cheng-Wei; Lee, Tong-Yee

    2009-01-01

    In this paper, we present a very high-capacity and low-distortion 3D steganography scheme. Our steganography approach is based on a novel multilayered embedding scheme to hide secret messages in the vertices of 3D polygon models. Experimental results show that the cover model distortion is very small as the number of hiding layers ranges from 7 to 13 layers. To the best of our knowledge, this novel approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography on 3D models.

  2. A high-capacity steganography scheme for JPEG2000 baseline system.

    Science.gov (United States)

    Zhang, Liang; Wang, Haili; Wu, Renbiao

    2009-08-01

    Hiding capacity is very important for efficient covert communications. For JPEG2000 compressed images, it is necessary to enlarge the hiding capacity because the available redundancy is very limited. In addition, the bitstream truncation makes it difficult to hide information. In this paper, a high-capacity steganography scheme is proposed for the JPEG2000 baseline system, which uses bit-plane encoding procedure twice to solve the problem due to bitstream truncation. Moreover, embedding points and their intensity are determined in a well defined quantitative manner via redundancy evaluation to increase hiding capacity. The redundancy is measured by bit, which is different from conventional methods which adjust the embedding intensity by multiplying a visual masking factor. High volumetric data is embedded into bit-planes as low as possible to keep message integrality, but at the cost of an extra bit-plane encoding procedure and slightly changed compression ratio. The proposed method can be easily integrated into the JPEG2000 image coder, and the produced stego-bitstream can be decoded normally. Simulation shows that the proposed method is feasible, effective, and secure.

  3. A high capacity text steganography scheme based on LZW compression and color coding

    Directory of Open Access Journals (Sweden)

    Aruna Malik

    2017-02-01

    Full Text Available In this paper, capacity and security issues of text steganography have been considered by employing LZW compression technique and color coding based approach. The proposed technique uses the forward mail platform to hide the secret data. This algorithm first compresses secret data and then hides the compressed secret data into the email addresses and also in the cover message of the email. The secret data bits are embedded in the message (or cover text by making it colored using a color coding table. Experimental results show that the proposed method not only produces a high embedding capacity but also reduces computational complexity. Moreover, the security of the proposed method is significantly improved by employing stego keys. The superiority of the proposed method has been experimentally verified by comparing with recently developed existing techniques.

  4. High Capacity and Resistance to Additive Noise Audio Steganography Algorithm

    Directory of Open Access Journals (Sweden)

    Haider Ismael Shahadi

    2011-09-01

    Full Text Available Steganography is the art of message hiding in a cover signal without attracting attention. The requirements of the good steganography algorithm are security, capacity, robustness and imperceptibility, all them are contradictory, therefore, satisfying all together is not easy especially in audio cover signal because human auditory system (HAS has high sensitivity to audio modification. In this paper, we proposed a high capacity audio steganography algorithm with good resistance to additive noise. The proposed algorithm is based on wavelet packet transform and blocks matching. It has capacity above 35% of the input audio file size with acceptable signal to noise ratio. Also, it is resistance to additive Gaussian noise to about 25 db. Furthermore, the reconstruction of actual secret messages does not require the original cover audio signal.

  5. High Capacity data hiding using LSB Steganography and Encryption

    Directory of Open Access Journals (Sweden)

    Shamim Ahmed Laskar

    2013-01-01

    Full Text Available The network provides a method of communication to distribute information to the masses. With the growthof data communication over computer network, the security of information has become a major issue.Steganography and cryptography are two different data hiding techniques. Steganography hides messagesinside some other digital media. Cryptography, on the other hand obscures the content of the message. Wepropose a high capacity data embedding approach by the combination of Steganography andcryptography. In the process a message is first encrypted using transposition cipher method and then theencrypted message is embedded inside an image using LSB insertion method. The combination of these twomethods will enhance the security of the data embedded. This combinational methodology will satisfy therequirements such as capacity, security and robustness for secure data transmission over an open channel.A comparative analysis is made to demonstrate the effectiveness of the proposed method by computingMean square error (MSE and Peak Signal to Noise Ratio (PSNR. We analyzed the data hiding techniqueusing the image performance parameters like Entropy, Mean and Standard Deviation. The stego imagesare tested by transmitting them and the embedded data are successfully extracted by the receiver. The mainobjective in this paper is to provide resistance against visual and statistical attacks as well as highcapacity.

  6. High capacity image steganography method based on framelet and compressive sensing

    Science.gov (United States)

    Xiao, Moyan; He, Zhibiao

    2015-12-01

    To improve the capacity and imperceptibility of image steganography, a novel high capacity and imperceptibility image steganography method based on a combination of framelet and compressive sensing (CS) is put forward. Firstly, SVD (Singular Value Decomposition) transform to measurement values obtained by compressive sensing technique to the secret data. Then the singular values in turn embed into the low frequency coarse subbands of framelet transform to the blocks of the cover image which is divided into non-overlapping blocks. Finally, use inverse framelet transforms and combine to obtain the stego image. The experimental results show that the proposed steganography method has a good performance in hiding capacity, security and imperceptibility.

  7. High Capacity Secure Image Steganography Based on Contourlet Transform

    Directory of Open Access Journals (Sweden)

    Kolsoom Shahryari

    2013-09-01

    Full Text Available In this paper we propose an image steganography technique which embeds secret data without making explicit modifications to the image. The proposed method simultaneously provides both imperceptibility and undetectability. We decompose image by contourlet transform and determine nonsmooth regions. Embedding data in these regions cause less degradation in image quality. Contourlet sub-bands are divided into 3×3 blocks. Central coefficient of each block is considered for embedding if they belong to edgy regions. Experiments show that this method can achieve high embedding capacity while remains undetectable by Farid's universal steganalysis technique.

  8. A Novel Information Security Scheme using Cryptic Steganography

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    K RAMA MOHANA RAO

    2010-12-01

    Full Text Available The demand for effective information security schemes is increasing day by day with the exponential growth of Internet. Cryptography and Steganography are the two popular techniques for secret communication. The contents of message are kept secret in cryptography, where as in steganography the message is embedded into the cover image (text, video and image (pay load. In this proposed system we developed a system in which cryptography and steganography are used as integrated part along with newly developed enhanced security model. In cryptography we are using MD-5 Algorithm to encrypt a message and a part of message is hidden in DCT of an image, remaining part of the message is used to generate three ( 3 secret keys which make the system highly secured. To avoid the problem of unauthorized data access steganography along with cryptography called as Cryptic-Steganography scheme is the right most solution.

  9. A Novel and High Capacity Audio Steganography Algorithm Based on Adaptive Data Embedding Positions

    Directory of Open Access Journals (Sweden)

    Haider Ismael Shahadi

    2014-03-01

    Full Text Available In this study, a novel and high embedding capacity audio steganography scheme based on Lifting Wavelet Transform (LWT and adaptive embedding positions is proposed. Specifically, the message data is inserted in the imperceptible positions that chosen from the coefficients of detail sub-bands taking advantage of our proposed Weighted Block Matching (WBM. The WBM is preceded by preparing the cover audio in order to select the bits-positions that can possibly be used for embedding from each detail coefficient based on coefficient amplitude then copy the contents of the selected bits-positions and arrange them in blocks of bits. Also, the message data is arranged in blocks of bits after preprocessed and encrypted. The WBM computes the matching between each message block and whole extracted cover blocks to find the similarity between them. This process help to provide optimal locations to hide the message blocks. These locations are considered as a stego-key that is ciphered and hided within the final detail sub-band which is specified for this purpose. The proposed approach attains higher security than other fixed embedding positions approaches because the random positions for the embedded message blocks based on adaptive selection for embedding positions. Experimental results show that the proposed technique is not only has very high embedding capacity (exceed 300 kbps with excellent transparency (above 35 dB for the cover to noise ratio, but also achieve lossless massage retrieved. Comparisons with the related audio steganography algorithms also show that our proposed scheme outperforms all the selected algorithms.

  10. Quantum watermarking scheme through Arnold scrambling and LSB steganography

    Science.gov (United States)

    Zhou, Ri-Gui; Hu, Wenwen; Fan, Ping

    2017-09-01

    Based on the NEQR of quantum images, a new quantum gray-scale image watermarking scheme is proposed through Arnold scrambling and least significant bit (LSB) steganography. The sizes of the carrier image and the watermark image are assumed to be 2n× 2n and n× n, respectively. Firstly, a classical n× n sized watermark image with 8-bit gray scale is expanded to a 2n× 2n sized image with 2-bit gray scale. Secondly, through the module of PA-MOD N, the expanded watermark image is scrambled to a meaningless image by the Arnold transform. Then, the expanded scrambled image is embedded into the carrier image by the steganography method of LSB. Finally, the time complexity analysis is given. The simulation experiment results show that our quantum circuit has lower time complexity, and the proposed watermarking scheme is superior to others.

  11. A Blind High-Capacity Wavelet-Based Steganography Technique for Hiding Images into other Images

    Directory of Open Access Journals (Sweden)

    HAMAD, S.

    2014-05-01

    Full Text Available The flourishing field of Steganography is providing effective techniques to hide data into different types of digital media. In this paper, a novel technique is proposed to hide large amounts of image data into true colored images. The proposed method employs wavelet transforms to decompose images in a way similar to the Human Visual System (HVS for more secure and effective data hiding. The designed model can blindly extract the embedded message without the need to refer to the original cover image. Experimental results showed that the proposed method outperformed all of the existing techniques not only imperceptibility but also in terms of capacity. In fact, the proposed technique showed an outstanding performance on hiding a secret image whose size equals 100% of the cover image while maintaining excellent visual quality of the resultant stego-images.

  12. A New Steganography Technique Based on Difference Scheme of RGB Channels and Text Using Histogram Analysis

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Sharma,

    2014-05-01

    Full Text Available Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. The motivation for this work includes provision of protection of information during transmission without any detection of information. We also propose a new technique namely „A New Steganography Technique Based on Difference Scheme of RGB Channels and Text Using Histogram Analysis‟. The proposed technique can encode any colored image files in order to protect confidential text data from unauthorized access. It can be applied to a very small images (24 × 24 as well as large images (1024 × 1024. We use Image quality parameters Peak Signal to Noise Ratio and Mean Square Error. The proposed method has higher PSNR value and lower MSE values. The PSNR value is greater than 50 and MSE value is in fractions.

  13. Effective Electrocardiogram Steganography Based on Coefficient Alignment.

    Science.gov (United States)

    Yang, Ching-Yu; Wang, Wen-Fong

    2016-03-01

    This study presents two types of data hiding methods based on coefficient alignment for electrocardiogram (ECG) signals, namely, lossy and reversible ECG steganographys. The lossy method is divided into high-quality and high-capacity ECG steganography, both of which are capable of hiding confidential patient data in ECG signals. The reversible data hiding method can not only hide secret messages but also completely restore the original ECG signal after bit extraction. Simulations confirmed that the perceived quality generated by the lossy ECG steganography methods was good, while hiding capacity was acceptable. In addition, these methods have a certain degree of robustness, which is rare in conventional ECG stegangraphy schemes. Moreover, the proposed reversible ECG steganography method can not only successfully extract hidden messages but also completely recover the original ECG data.

  14. A high capacity MP3 steganography based on Huffman coding%基于Huffman编码的大容量MP3隐写算法

    Institute of Scientific and Technical Information of China (English)

    严迪群; 王让定; 张力光

    2011-01-01

    A high capacity steganography method for mp3 audios is proposed in this paper. According to the characteristic of Huffman coding, the code words in Huffman tables are first classified to ensure that the embedding operation does not change the bitstream structure in MP3 standard. Then secret data are embedded by replacing the corresponding code words. The embedding strategy is based on multiple-base nation system. The structure of bit stream and the size of the cover audio can be kept unchanged after embedding. The results show that the proposed method can obtain higher hiding capacity and better effi ciency than that of the method under binary case. Furthermore, the imperceptibility can also be better maintained in our method.%本文针对MP3编码标准中哈夫曼码字对特点,提出了一种借助码字替换实现秘密信息隐写的新算法.该算法首先对哈夫曼码表中的码字进行分类,以保证替换操作不改变MP3码流的固定结构,再借鉴混合进制的概念,采用多进制方式隐藏秘密信息.给出了算法在二进制和多进制两种模式下的仿真结果,表明多进制隐写模式可以获得更高的隐写速率和效率,同时算法的感知透明性也能得到较好保持.

  15. Sensitive Patient Data Hiding using a ROI Reversible Steganography Scheme for DICOM Images.

    Science.gov (United States)

    Mantos, Petros L K; Maglogiannis, Ilias

    2016-06-01

    The exchange of medical images over the Internet has evoked significant interest over the past few years due to the introduction of web and cloud based medical information systems. The protection of sensitive data has always been a key indicator in the performance of such systems. In this context, this work presents an algorithm developed for Digital Imaging and Communications in Medicine (DICOM) medical images, which applies secret-sharing steganography methods for ensuring the integrity of sensitive patient data as well as the important parts of the image. In the proposed algorithm, images are divided into two parts: the region of interest (ROI) and the region of non interest (RONI). Patient data and integrity hashes are positioned inside the ROI while the information (map) needed to recover the ROI before insertion is positioned in the RONI. Security of the extraction process is assured through the use of cryptography. The experimental results prove that the original (cover) images and the stego images provide an excellent visual equality result in terms of PSNR. Furthermore, they prove that the proposed scheme can be efficiently used as a steganography scheme in DICOM images with limited smooth areas.

  16. Information Hiding in CSS : A Secure Scheme Text-Steganography using Public Key Cryptosystem

    CERN Document Server

    Kabetta, Herman; Suyoto,

    2012-01-01

    In many recent years, the programming world has been introduced about a new programming language for designing websites, it is CSS that can be be used together with HTML to develop a web interface. And now, these two programming languages as if inseparably from each other. As a client-side scripting, CSS is visible by all users as the original script, but it can not be granted changed. Website is a tool of information disseminator throughout the world, this is certainly can be used to a secret communication by using CSS as a message hider. This paper proposed a new scheme using web tools like CSS for hiding informations. This is a secret communication mechanism using text steganography techniques that is embedded messages on CSS files and is further encrypted using RSA as a public key cryptographic algorithm.

  17. BPCS steganography using EZW lossy compressed images

    OpenAIRE

    Spaulding, Jeremiah; Noda, Hideki; Shirazi, Mahdad N.; Kawaguchi, Eiji

    2002-01-01

    This paper presents a steganography method based on an embedded zerotree wavelet (EZW) compression scheme and bit-plane complexity segmentation (BPCS) steganography. The proposed steganography enables us to use lossy compressed images as dummy files in bit-plane-based steganographic algorithms. Large embedding rates of around 25% of the compressed image size were achieved with little noticeable degradation in image quality.

  18. A high capacity multiple watermarking scheme based on Fourier descriptor and Sudoku

    Science.gov (United States)

    Zhang, Li; Zheng, Huimin

    2015-12-01

    Digital watermark is a type of technology to hide some significant information which is mainly used to protect digital data. A high capacity multiple watermarking method is proposed, which adapts the Fourier descriptor to pre-process the watermarks, while a Sudoku puzzle is used as a reference matrix in embedding process and a key in extraction process. It can dramatically reduce the required capacity by applying Fourier descriptor. Meanwhile, the security of watermarks can be guaranteed due to the Sudoku puzzle. Unlike previous algorithms applying Sudoku puzzle in spatial domain, the proposed algorithm works in transformed domain by applying LWT2.In addition, the proposed algorithm can detect the temper location accurately. The experimental results demonstrated that the goals mentioned above have been achieved.

  19. A Steganography Based on CT-CDMA Communication Scheme Using Complete Complementary Codes

    CERN Document Server

    Kojima, Tetsuya

    2010-01-01

    It has been shown that complete complementary codes can be applied into some communication systems like approximately synchronized CDMA systems because of its good correlation properties. CT-CDMA is one of the communication systems based on complete complementary codes. In this system, the information data of the multiple users can be transmitted by using the same set of complementary codes through a single frequency band. In this paper, we propose to apply CT-CDMA systems into a kind of steganography. It is shown that a large amount of secret data can be embedded in the stego image by the proposed method through some numerical experiments using color images.

  20. A High-Capacity Image Data Hiding Scheme Using Adaptive LSB Substitution

    Directory of Open Access Journals (Sweden)

    H. Yang

    2009-12-01

    Full Text Available Many existing steganographic methods hide more secret data into edged areas than smooth areas in the host image, which does not differentiate textures from edges and causes serious degradation in actual edge areas. To avoid abrupt changes in image edge areas, as well as to achieve better quality of the stego-image, a novel image data hiding technique by adaptive Least Significant Bits (LSBs substitution is proposed in this paper. The scheme exploits the brightness, edges, and texture masking of the host image to estimate the number k of LSBs for data hiding. Pixels in the noise non-sensitive regions are embedded by a k-bit LSB substitution with a lager value of k than that of the pixels in noise sensitive regions. Moreover, an optimal pixel adjustment process is used to enhance stego-image visual quality obtained by simple LSB substitution method. To ensure that the adaptive number k of LSBs remains unchanged after pixel modification, the LSBs number is computed by the high-order bits rather than all the bits of the image pixel value. The theoretical analyses and experiment results show that the proposed method achieves higher embedding capacity and better stegoimage quality compared with some existing LSB methods.

  1. Spread spectrum image steganography.

    Science.gov (United States)

    Marvel, L M; Boncelet, C R; Retter, C T

    1999-01-01

    In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

  2. CRYPTOGRAPHIC STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    Vikas Yadav

    2014-08-01

    Full Text Available In the cryptographic steganography system, the message will first be converted into unreadable cipher and then this cipher will be embedded into an image file. Hence this type of system will provide more security by achieving both data encoding as well as data hiding. In this paper we propose an advanced steganocryptic system that combines the features of cryptography and steganography. In this proposed steganocryptic system we will encrypt the message into cipher1 by using Kunal Secure Astro-Encryption and we again encrypt this cipher to cipher2 by using grid cipher technique. Advantage of Kunal Secure Astro-Encryption is that it generates random useless points in between, thus fixed size messages can be generated providing more security compared to other cryptographic algorithms as the number of characters in original message cannot be found from encrypted message without the knowing the black holes. Now we will embed this cipher2 into image file by using visual steganography .In this proposed steganocryptic system we will use modified bit insertion technique to achieve visual steganography. This proposed system will be more secure than cryptography or steganography techniques[digital steganography] alone and also as compared to steganography and cryptography combined systems.

  3. Digital Steganography

    OpenAIRE

    KOCIÁNOVÁ, Helena

    2009-01-01

    Digital steganography is a technique for hiding data mostly into multimedia files (images, audio, video). With the development of information technology this technique has found its use in the field of copyright protection and secret data transfer, could be even applied in places where is limited possibility of using cryptography (e. g. by law). This thesis gives insight into digital steganography and contains an application using this technique.

  4. An RGB colour image steganography scheme using overlapping block-based pixel-value differencing.

    Science.gov (United States)

    Prasad, Shiv; Pal, Arup Kumar

    2017-04-01

    This paper presents a steganographic scheme based on the RGB colour cover image. The secret message bits are embedded into each colour pixel sequentially by the pixel-value differencing (PVD) technique. PVD basically works on two consecutive non-overlapping components; as a result, the straightforward conventional PVD technique is not applicable to embed the secret message bits into a colour pixel, since a colour pixel consists of three colour components, i.e. red, green and blue. Hence, in the proposed scheme, initially the three colour components are represented into two overlapping blocks like the combination of red and green colour components, while another one is the combination of green and blue colour components, respectively. Later, the PVD technique is employed on each block independently to embed the secret data. The two overlapping blocks are readjusted to attain the modified three colour components. The notion of overlapping blocks has improved the embedding capacity of the cover image. The scheme has been tested on a set of colour images and satisfactory results have been achieved in terms of embedding capacity and upholding the acceptable visual quality of the stego-image.

  5. SURVEY AND ANALYSIS OF 3D STEGANOGRAPHY

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    K .LAKSHMI

    2011-01-01

    Full Text Available Steganography is the science that involves communicating secret data in an appropriate multimedia carrier, eg., images, audio, and video files. The remarkable growth in computational power, increase in current security approaches and techniques are often used together to ensures security of the secret message. Steganography’s ultimate objectives, which are capacity and invisibility, are the main factors that separate it from related techniques. In this paper we focus on 3D models of steganography and conclude with some review analysis of high capacity data hiding and low-distortion 3D models.

  6. Steganography: Past, Present, Future

    Energy Technology Data Exchange (ETDEWEB)

    Judge, J C

    2001-12-01

    Steganography (a rough Greek translation of the term Steganography is secret writing) has been used in various forms for 2500 years. It has found use in variously in military, diplomatic, personal and intellectual property applications. Briefly stated, steganography is the term applied to any number of processes that will hide a message within an object, where the hidden message will not be apparent to an observer. This paper will explore steganography from its earliest instances through potential future application.

  7. Enhancement of LSB based Steganography for Hiding Image in Audio

    OpenAIRE

    Pradeep Kumar Singh; R.K.Aggrawal

    2010-01-01

    In this paper we will take an in-depth look on steganography by proposing a new method of Audio Steganography. Emphasize will be on the proposed scheme of image hiding in audio and its comparison with simple Least Significant Bit insertion method for data hiding in audio.

  8. Quantum Steganography

    CERN Document Server

    Shaw, Bilal A

    2010-01-01

    Steganography is the process of hiding secret information by embedding it in an "innocent" message. We present protocols for hiding quantum information in a codeword of a quantum error-correcting code passing through a channel. Using either a shared classical secret key or shared entanglement the sender (Alice) disguises her information as errors in the channel. The receiver (Bob) can retrieve the hidden information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for certain protocols.

  9. 基于JPEG图像的密写改进方案%The improved steganography scheme based on JPEG image

    Institute of Scientific and Technical Information of China (English)

    戴薇

    2013-01-01

    为了提高秘密信息的嵌入量,文中基于F4密写提出了一种增大嵌入量的密写改进方法.该方法通过让部分DCT系数中0系数携带秘密信息,从而提高秘密信息的嵌入量.实验表明,该方案在保持图像DCT系数直方图基础上,不但能抵抗直方图和分块特性密写分析,安全性也比较高,而且信息嵌入率也提高了8%左右.%In order to increase the embedding capacity of secret messages,a secure steganographic technique which based on the F4 steganography method is propose.The method allows partial DCT coefficients of the 0 coefficients to embed secret information,so as to increase the hiding capacity.This way,the histogram-based an d blockiness-based steganalyses are effectively resisted.Simulation results show that the proposed method is high secure for cover images,andand information embedding rate has increased by about 8%.

  10. Performance Improvement of Threshold based Audio Steganography using Parallel Computation

    Directory of Open Access Journals (Sweden)

    Muhammad Shoaib

    2016-10-01

    Full Text Available Audio steganography is used to hide secret information inside audio signal for the secure and reliable transfer of information. Various steganography techniques have been proposed and implemented to ensure adequate security level. The existing techniques either focus on the payload or security, but none of them has ensured both security and payload at same time. Data Dependency in existing solution was reluctant for the execution of steganography mechanism serially. The audio data and secret data pre-processing were done and existing techniques were experimentally tested in Matlab that ensured the existence of problem in efficient execution. The efficient least significant bit steganography scheme removed the pipelining hazard and calculated Steganography parallel on distributed memory systems. This scheme ensures security, focuses on payload along with provisioning of efficient solution. The result depicts that it not only ensures adequate security level but also provides better and efficient solution.

  11. Improved Adaptive LSB Steganography Based on Chaos and Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yu Lifang

    2010-01-01

    Full Text Available We propose a novel steganographic method in JPEG images with high performance. Firstly, we propose improved adaptive LSB steganography, which can achieve high capacity while preserving the first-order statistics. Secondly, in order to minimize visual degradation of the stego image, we shuffle bits-order of the message based on chaos whose parameters are selected by the genetic algorithm. Shuffling message's bits-order provides us with a new way to improve the performance of steganography. Experimental results show that our method outperforms classical steganographic methods in image quality, while preserving characteristics of histogram and providing high capacity.

  12. Investigator's guide to steganography

    CERN Document Server

    Kipper, Gregory

    2003-01-01

    The Investigator's Guide to Steganography provides a comprehensive look at this unique form of hidden communication from its earliest beginnings to its most modern uses. The book begins by exploring the past, providing valuable insight into how this method of communication began and evolved from ancient times to the present day. It continues with an in-depth look at the workings of digital steganography and watermarking methods, available tools on the Internet, and a review of companies who are providing cutting edge steganography and watermarking services. The third section builds on the first two by outlining and discussing real world uses of steganography from the business and entertainment to national security and terrorism. The book concludes by reviewing steganography detection methods and what can be expected in the future

  13. Steganography Based on Integer Wavelet Transform and Bicubic Interpolation

    Directory of Open Access Journals (Sweden)

    N. Ajeeshvali

    2012-11-01

    Full Text Available Steganography is the art and science of hiding information in unremarkable cover media so as not to observe any suspicion. It is an application under information security field, being classified under information security, Steganography will be characterized by having set of measures that rely on strengths and counter attacks that are caused by weaknesses and vulnerabilities. The aim of this paper is to propose a modified high capacity image steganography technique that depends on integer wavelet transform with acceptable levels of imperceptibility and distortion in the cover image as a medium file and high levels of security. Bicubic interpolation causes overshoot, which increases acutance (apparent sharpness. The Bicubic algorithm is frequently used for scaling images and video for display. The algorithm preserves fine details of the image better than the common bilinear algorithm.

  14. Quantum red-green-blue image steganography

    Science.gov (United States)

    Heidari, Shahrokh; Pourarian, Mohammad Rasoul; Gheibi, Reza; Naseri, Mosayeb; Houshmand, Monireh

    One of the most considering matters in the field of quantum information processing is quantum data hiding including quantum steganography and quantum watermarking. This field is an efficient tool for protecting any kind of digital data. In this paper, three quantum color images steganography algorithms are investigated based on Least Significant Bit (LSB). The first algorithm employs only one of the image’s channels to cover secret data. The second procedure is based on LSB XORing technique, and the last algorithm utilizes two channels to cover the color image for hiding secret quantum data. The performances of the proposed schemes are analyzed by using software simulations in MATLAB environment. The analysis of PSNR, BER and Histogram graphs indicate that the presented schemes exhibit acceptable performances and also theoretical analysis demonstrates that the networks complexity of the approaches scales squarely.

  15. Quantum steganography using prior entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, Takashi, E-mail: mihara@toyo.jp

    2015-06-05

    Steganography is the hiding of secret information within innocent-looking information (e.g., text, audio, image, video, etc.). A quantum version of steganography is a method based on quantum physics. In this paper, we propose quantum steganography by combining quantum error-correcting codes with prior entanglement. In many steganographic techniques, embedding secret messages in error-correcting codes may cause damage to them if the embedded part is corrupted. However, our proposed steganography can separately create secret messages and the content of cover messages. The intrinsic form of the cover message does not have to be modified for embedding secret messages. - Highlights: • Our steganography combines quantum error-correcting codes with prior entanglement. • Our steganography can separately create secret messages and the content of cover messages. • Errors in cover messages do not have affect the recovery of secret messages. • We embed a secret message in the Steane code as an example of our steganography.

  16. MP3 Steganography: Review

    Directory of Open Access Journals (Sweden)

    Mohammed Salem Atoum

    2012-11-01

    Full Text Available Steganography has existed as the science and art for hiding information in a way that the secret message cannot be deciphered by others, except the sender and receiver. All digital files such as audio, image and text files can be utilized for hiding secret information. Audio file can provide a good hiding medium because of its high data transmission rate and high degree of redundancy. Many formats such as MP3 have been utilized in audio information hiding, however to date there are limited review on the use of MP3 file as an audio file information hiding format. In this paper, we present a thorough analysis on the techniques used in audio files technologies, with more emphasis on MP3 steganography technique. This is to make available comprehensive information on the strengths and weaknesses of the MP3 file steganography techniques and detail comparison information for the research community on information protection.

  17. STEGANOGRAPHY: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    JAMMI ASHOK,

    2010-10-01

    Full Text Available Steganography is a technique of hiding information in digital media in such a way that no one apart from the intended recipient knows the existence of the information. Steganography can be viewed as akin tocryptography. Both have been used throughout recorded history as means to protect information. At times these two technologies seem to converge while the objectives of the two differ. Cryptographic techniques "scramble" messages so if intercepted, the messages cannot be understood. Steganography, in an essence, "camouflages" a message to hide its existence and make it seem "invisible" thus concealing the fact that a message is being sent altogether. An encrypted message may draw suspicion while an invisible message will not. Besides hiding data for confidentiality, this approach of information hiding can be extended to copyright protection for digital media like audio, video, and images.

  18. Retransmission Steganography Applied

    CERN Document Server

    Mazurczyk, Wojciech; Szczypiorski, Krzysztof

    2010-01-01

    This paper presents experimental results of the implementation of network steganography method called RSTEG (Retransmission Steganography). The main idea of RSTEG is to not acknowledge a successfully received packet to intentionally invoke retransmission. The retransmitted packet carries a steganogram instead of user data in the payload field. RSTEG can be applied to many network protocols that utilize retransmissions. We present experimental results for RSTEG applied to TCP (Transmission Control Protocol) as TCP is the most popular network protocol which ensures reliable data transfer. The main aim of the performed experiments was to estimate RSTEG steganographic bandwidth and detectability by observing its influence on the network retransmission level.

  19. Towards Statistically Undetectable Steganography

    Science.gov (United States)

    2011-06-30

    rate-distortion bound. This is because the local characteristics (6.24) ram WV-VIV -v \\« exp(-XD(y’ty^t)) lUi &i exp(-A£>(riy^)) do not...FA9550-08-1-0084 ENTITLED "TOWARDS STATISTICALLY UNDETECTABLE STEGANOGRAPHY" 66 [12] P. Comesana and F. Perez- Gonzales . On the capacity of

  20. Dynamic Pattern Based Image Steganography

    OpenAIRE

    Thiyagarajan, P.; G. Aghila; Venkatesan, V. Prasanna

    2012-01-01

    Steganography is the art of hiding secret information in media such as image, audio and video. The purpose of steganography is to conceal the existence of the secret information in any given medium. This work aims at strengthening the security in steganography algorithm by generating dynamic pattern in selection of indicator sequence. In addition to this dynamicity is also encompassed in number of bits embedded in data channel. This technique has been implemented and the results have been com...

  1. Developing a Video Steganography Toolkit

    OpenAIRE

    Ridgway, James; Stannett, Mike

    2014-01-01

    Although techniques for separate image and audio steganography are widely known, relatively little has been described concerning the hiding of information within video streams ("video steganography"). In this paper we review the current state of the art in this field, and describe the key issues we have encountered in developing a practical video steganography system. A supporting video is also available online at http://www.youtube.com/watch?v=YhnlHmZolRM

  2. Progressive Exponential Clustering-Based Steganography

    Directory of Open Access Journals (Sweden)

    Li Yue

    2010-01-01

    Full Text Available Cluster indexing-based steganography is an important branch of data-hiding techniques. Such schemes normally achieve good balance between high embedding capacity and low embedding distortion. However, most cluster indexing-based steganographic schemes utilise less efficient clustering algorithms for embedding data, which causes redundancy and leaves room for increasing the embedding capacity further. In this paper, a new clustering algorithm, called progressive exponential clustering (PEC, is applied to increase the embedding capacity by avoiding redundancy. Meanwhile, a cluster expansion algorithm is also developed in order to further increase the capacity without sacrificing imperceptibility.

  3. Steganography on multiple MP3 files using spread spectrum and Shamir's secret sharing

    Science.gov (United States)

    Yoeseph, N. M.; Purnomo, F. A.; Riasti, B. K.; Safiie, M. A.; Hidayat, T. N.

    2016-11-01

    The purpose of steganography is how to hide data into another media. In order to increase security of data, steganography technique is often combined with cryptography. The weakness of this combination technique is the data was centralized. Therefore, a steganography technique is develop by using combination of spread spectrum and secret sharing technique. In steganography with secret sharing, shares of data is created and hidden in several medium. Medium used to concealed shares were MP3 files. Hiding technique used was Spread Spectrum. Secret sharing scheme used was Shamir's Secret Sharing. The result showed that steganography with spread spectrum combined with Shamir's Secret Share using MP3 files as medium produce a technique that could hid data into several cover. To extract and reconstruct the data hidden in stego object, it is needed the amount of stego object which more or equal to its threshold. Furthermore, stego objects were imperceptible and robust.

  4. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    OpenAIRE

    Seyyedi, S. A.; R. Kh. Sadykhov

    2013-01-01

    Steganography is a method of hiding information in other information of different format (container). There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  5. Is image steganography natural?

    Science.gov (United States)

    Martín, Alvaro; Sapiro, Guillermo; Seroussi, Gadiel

    2005-12-01

    Steganography is the art of secret communication. Its purpose is to hide the presence of information, using, for example, images as covers. We experimentally investigate if stego-images, bearing a secret message, are statistically "natural." For this purpose, we use recent results on the statistics of natural images and investigate the effect of some popular steganography techniques. We found that these fundamental statistics of natural images are, in fact, generally altered by the hidden "nonnatural" information. Frequently, the change is consistently biased in a given direction. However, for the class of natural images considered, the change generally falls within the intrinsic variability of the statistics, and, thus, does not allow for reliable detection, unless knowledge of the data hiding process is taken into account. In the latter case, significant levels of detection are demonstrated.

  6. Adaptive Steganography: A survey of Recent Statistical Aware Steganography Techniques

    Directory of Open Access Journals (Sweden)

    Manish Mahajan

    2012-09-01

    Full Text Available Steganography is the science that deals with hiding of secret data in some carrier media which may be image, audio, formatted text or video. The main idea behind this is to conceal the very existence of data. We will be dealing here with image steganography. Many algorithms have been proposed for this purpose in spatial & frequency domain. But in almost all the algorithms it has been noticed that as we embed the secret data in the image the certain characteristics or statistics of the image get disturbed. Based on these disturbed statistics steganalysts can get the reflection about the existence of secret data which they further decode with the help of available steganalytic tools. Steganalysis is a science of attacking the hidden data to get an authorized access. Although steganalysis is not a part of this work but it may be sometimes discussed as a part of literature. Even in steganography we are not purely concerned with spatial or frequency domain rather our main emphasis is on adaptive steganography or model based steganography. Adaptive steganography is not entirely a new branch of steganography rather it is based upon spatial & frequency domain with an additional layer of mathematical model. So here we will be dealing with adaptive steganography which take care about the important characteristics & statistics of the cover image well in advance to the embedding of secret data so that the disturbance of image statistics as mentioned earlier, which attracts the forgery or unauthorized access, can be minimized. In this survey we will analyze the various steganography algorithms which are based upon certain mathematical model or in other words algorithms which come under the category of model based steganography.

  7. Cropping and noise resilient steganography algorithm using secret image sharing

    Science.gov (United States)

    Juarez-Sandoval, Oswaldo; Fierro-Radilla, Atoany; Espejel-Trujillo, Angelina; Nakano-Miyatake, Mariko; Perez-Meana, Hector

    2015-03-01

    This paper proposes an image steganography scheme, in which a secret image is hidden into a cover image using a secret image sharing (SIS) scheme. Taking advantage of the fault tolerant property of the (k,n)-threshold SIS, where using any k of n shares (k≤n), the secret data can be recovered without any ambiguity, the proposed steganography algorithm becomes resilient to cropping and impulsive noise contamination. Among many SIS schemes proposed until now, Lin and Chan's scheme is selected as SIS, due to its lossless recovery capability of a large amount of secret data. The proposed scheme is evaluated from several points of view, such as imperceptibility of the stegoimage respect to its original cover image, robustness of hidden data to cropping operation and impulsive noise contamination. The evaluation results show a high quality of the extracted secret image from the stegoimage when it suffered more than 20% cropping or high density noise contamination.

  8. Steganography and Steganalysis: Different Approaches

    CERN Document Server

    Das, Soumyendu; Bandyopadhyay, Bijoy; Sanyal, Sugata

    2011-01-01

    Steganography is the technique of hiding confidential information within any media. Steganography is often confused with cryptography because the two are similar in the way that they both are used to protect confidential information. The difference between the two is in the appearance in the processed output; the output of steganography operation is not apparently visible but in cryptography the output is scrambled so that it can draw attention. Steganlysis is process to detect of presence of steganography. In this article we have tried to elucidate the different approaches towards implementation of steganography using 'multimedia' file (text, static image, audio and video) and Network IP datagram as cover. Also some methods of steganalysis will be discussed.

  9. A New Image Steganography Based On First Component Alteration Technique

    Directory of Open Access Journals (Sweden)

    Amanpreet Kaur

    2009-12-01

    Full Text Available In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.Keywords—image; mean square error; Peak signal to noise ratio; steganography;

  10. Quantum Steganography via Greenberger-Horne-Zeilinger GHZ_4 State

    Institute of Scientific and Technical Information of China (English)

    A.El Allati; M.B.Ould Medeni; Y.Hassouni

    2012-01-01

    A quantum steganography communication scheme via Greenberger-Horne-Zeilinger GHZ 4 state is constructed to investigate the possibility of remotely transferred hidden information.Moreover,the multipartite entangled states are become a hectic topic due to its important applications and deep effects on aspects of quantum information.Then,the scheme consists of sharing the correlation of four particle GHZ4 states between the legitimate users.After insuring the security of the quantum channel,they begin to hide the secret information in the cover of message.Comparing the scheme with the previous quantum steganographies,capacity and imperceptibility of hidden message are good.The security of the present scheme against many attacks is also discussed.

  11. Multi-Party Quantum Steganography

    Science.gov (United States)

    Mihara, Takashi

    2017-02-01

    Steganography has been proposed as a data hiding technique. As a derivation, quantum steganography based on quantum physics has also been proposed. In this paper, we extend the results in presented (Mihara, Phys. Lett. 379, 952 2015) and propose a multi-party quantum steganography technique that combines quantum error-correcting codes with entanglement. The proposed protocol shares an entangled state among n +1 parties and sends n secret messages, corresponding to the n parties, to the other party. With no knowledge of the other secret messages, the n parties can construct a stego message by cooperating with each other. Finally, we propose a protocol for sending qubits using the same technique.

  12. Noiseless Steganography The Key to Covert Communications

    CERN Document Server

    Desoky, Abdelrahman

    2012-01-01

    Among the features that make Noiseless Steganography: The Key to Covert Communications a first of its kind: The first to comprehensively cover Linguistic Steganography The first to comprehensively cover Graph Steganography The first to comprehensively cover Game Steganography Although the goal of steganography is to prevent adversaries from suspecting the existence of covert communications, most books on the subject present outdated steganography approaches that are detectable by human and/or machine examinations. These approaches often fail because they camouflage data as a detectable noise b

  13. Efficient adaptive verifiable secret sharing with steganography and tamper resistance scheme%高效自适应可验证抗篡改秘密共享方案

    Institute of Scientific and Technical Information of China (English)

    李瑞林; 陈够喜; 武雪芹

    2015-01-01

    Greater distortion of image steganography was caused by applying the simple least significant bit (LSB) to embed se‐cret information directly in the traditional technology .Therefore ,an efficient verifiable secret sharing method was proposed .A bit sequence was taken as the input of secret sharing which was generated using differential Huffman lossless compression of se‐cret image .The polynomial interpolation and certified value formula were improved .As a result ,the quality of the stego image and the verifiability were enhanced using the technology .Theoretical analysis and experimental results show that high quality of stego image with efficient verifiability and security can be obtained through the scheme .%在传统方案中,直接采用简单最低有效位(LSB)嵌入秘密信息,导致隐写图像失真度较高,为此提出一种高效的可验证秘密共享方案。引入差分哈夫曼无损压缩思想,将产生的比特序列作为秘密共享的输入;通过改进插值多项式和认证值计算公式,增强隐写图像的质量并提高其可验证性。理论分析与实验结果表明,应用该方案可得到高质量的隐写图像,其具有高效可验证性和安全性。

  14. Colour Guided Colour Image Steganography

    CERN Document Server

    Amirtharajan, R; Swarup, Motamarri Abhilash; K, Mohamed Ashfaaq; Rayappan, John Bosco Balaguru

    2010-01-01

    Information security has become a cause of concern because of the electronic eavesdropping. Capacity, robustness and invisibility are important parameters in information hiding and are quite difficult to achieve in a single algorithm. This paper proposes a novel steganography technique for digital color image which achieves the purported targets. The professed methodology employs a complete random scheme for pixel selection and embedding of data. Of the three colour channels (Red, Green, Blue) in a given colour image, the least two significant bits of any one of the channels of the color image is used to channelize the embedding capacity of the remaining two channels. We have devised three approaches to achieve various levels of our desired targets. In the first approach, Red is the default guide but it results in localization of MSE in the remaining two channels, which makes it slightly vulnerable. In the second approach, user gets the liberty to select the guiding channel (Red, Green or Blue) to guide the r...

  15. Distortion-Free Steganography Mechanism with Compression to VQ Indices

    Directory of Open Access Journals (Sweden)

    Chin-Chen Chang

    2009-06-01

    Full Text Available Directly embedding the secret data into the VQ-compressed domain is practical for reducing storage and transmittal bandwidth. Many steganography techniques are currently exploited for the VQ index table. However, embedding strategies extend the amount ofcompression needed for embedding secret data and distort the original quality of the VQ decompressed image. To satisfy the essentials of increasing the secret payload, preserve theVQ index table without loss, and reduce the compression rate, the proposed scheme utilizes search order coding to find the correlation between the VQ indices and neighboring indices. Due to the similarity of adjacent indices, the new scheme can effectively embed the secret stream into the index table and encode the embedded index table with fewer bits. The experimental results indicate that the new scheme can achieve superior outcomes of the compression rate and embedding efficiency than related steganography techniques.

  16. A Survey on different techniques of steganography

    OpenAIRE

    Kaur Harpreet; Rani Jyoti

    2016-01-01

    Steganography is important due to the exponential development and secret communication of potential computer users over the internet. Steganography is the art of invisible communication to keep secret information inside other information. Steganalysis is the technology that attempts to ruin the Steganography by detecting the hidden information and extracting.Steganography is the process of Data embedding in the images, text/documented, audio and video files. The paper also highlights the secu...

  17. Code wars: steganography, signals intelligence, and terrorism

    OpenAIRE

    Conway, Maura

    2003-01-01

    This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null cipher...

  18. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    S. A. Seyyedi

    2013-01-01

    Full Text Available Steganography is a method of hiding information in other information of different format (container. There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  19. Code wars: steganography, signals intelligence, and terrorism

    OpenAIRE

    Conway, Maura

    2003-01-01

    This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null cipher...

  20. Digital watermarking and steganography fundamentals and techniques

    CERN Document Server

    Shih, Frank Y

    2007-01-01

    Introduction Digital Watermarking Digital Steganography Differences between Watermarking and Steganography A Brief History Appendix: Selected List of Books on Watermarking and Steganography Classification in Digital Watermarking Classification Based on Characteristics Classification Based on Applications Mathematical Preliminaries  Least-Significant-Bit Substitution Discrete Fourier Transform (DFT) Discrete Cosine Transform Discrete Wavelet Transform Random Sequence Generation  The Chaotic M

  1. A Survey on different techniques of steganography

    Directory of Open Access Journals (Sweden)

    Kaur Harpreet

    2016-01-01

    Full Text Available Steganography is important due to the exponential development and secret communication of potential computer users over the internet. Steganography is the art of invisible communication to keep secret information inside other information. Steganalysis is the technology that attempts to ruin the Steganography by detecting the hidden information and extracting.Steganography is the process of Data embedding in the images, text/documented, audio and video files. The paper also highlights the security improved by applying various techniques of video steganography.

  2. Steganalysis of stochastic modulation steganography

    Institute of Scientific and Technical Information of China (English)

    HE Junhui; HUANG Jiwu

    2006-01-01

    Stochastic modulation steganography embeds secret message within the cover image by adding stego-noise with a specific probabilistic distribution. No method is known to be applicable to the estimation of stochastic modulation steganography. By analyzing the distributions of the horizontal pixel difference of images before and after stochastic modulation embedding, we present a new steganalytic approach to accurately estimate the length of secret message in stochastic modulation steganography. The proposed method first establishes a model describing the statistical relationship among the differences of the cover image, stego-image and stego-noise. In the case of stego- image-only steganalysis, rough estimate of the distributional parameters of the cover image's pixel difference is obtained with the use of the provided stego-image. And grid search and Chi-square goodness of fit test are exploited to estimate the length of the secret message embedded with stochastic modulation steganography. The experimental results demonstrate that our new approach is effective for steganalyzing stochastic modulation steganography and accurately estimating the length of the secret message.

  3. Steganography in arrhythmic electrocardiogram signal.

    Science.gov (United States)

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  4. Enhanced Audio LSB Steganography for Secure Communication

    Directory of Open Access Journals (Sweden)

    Muhammad Junaid Hussain

    2016-01-01

    Full Text Available The ease with which data can be remitted across the globe via Internet has made it an obvious (as medium choice for on line data transmission and communication. This salient trait, however, is constraint with akin issues of privacy, veracity of the information being exchanged over it, and legitimacy of its sender together with its availability when needed. Although cryptography is being used to confront confidentiality concern yet for many is slightly limited in scope because of discernibility of encrypted information. Further, due to restrictions imposed on the use of cryptography by its citizens for personal doings, various Governments have also coxswained the research arena to explore another discipline of information hiding called steganography – whose sole purpose is to make the information being exchanged inaudible. This research is focused on evolution of model based secure LSB Steganographic scheme for digital audio wave file format to withstand passive attack by Warden Wendy.

  5. Pictographic steganography based on social networking websites

    Directory of Open Access Journals (Sweden)

    Feno Heriniaina RABEVOHITRA

    2016-01-01

    Full Text Available Steganography is the art of communication that does not let a third party know that the communication channel exists. It has always been influenced by the way people communicate and with the explosion of social networking websites, it is likely that these will be used as channels to cover the very existence of communication between different entities. In this paper, we present a new effective pictographic steganographic channel. We make use of the huge amount of photos available online as communication channels. We are exploiting the ubiquitousness of those social networking platforms to propel a powerful and pragmatic protocol. Our novel scheme exploiting social networking websites is robust against active and malicious.

  6. A New Robust Audio Signal Steganography Based On Multiple Chaotic Algorithms With Edge Detection Technique

    Directory of Open Access Journals (Sweden)

    Amir Houshang Arab Avval

    Full Text Available This paper proposes a novel robust blind steganography scheme for embedding audio signal into edge of color image based on a chaotic map and LSB method,which is different from some existing works. In this paper, we employed the LSB substitution technique ...

  7. Overview: Main Fundamentals for Steganography

    OpenAIRE

    AL-Ani, Zaidoon Kh.; Zaidan, A. A.; Zaidan, B. B.; Alanazi, Hamdan. O.

    2010-01-01

    The rapid development of multimedia and internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information .Besides that, digital documents are also easy to copy and distribute, therefore it will be faced by many threats. It is a big security and privacy issue, it become necessary to find appropriate protection because of the significance, accuracy and sensitivity of the information. Steganography considers one of the techniqu...

  8. Applying statistical methods to text steganography

    CERN Document Server

    Nechta, Ivan

    2011-01-01

    This paper presents a survey of text steganography methods used for hid- ing secret information inside some covertext. Widely known hiding techniques (such as translation based steganography, text generating and syntactic embed- ding) and detection are considered. It is shown that statistical analysis has an important role in text steganalysis.

  9. Genetic Algorithm Based Image Steganography for Enhancement of Concealing Capacity and Security

    Directory of Open Access Journals (Sweden)

    yoti

    2013-06-01

    Full Text Available This paper proposes a Genetic Algorithm based steganography for enhancement of embedding capacity and security. Steganography is a method to provide secret communication between sender and receiver by concealing message in cover image. LSB bit encoding method is that the simplest encoding method to cover secret message in color pictures and grayscale pictures. Steganalysis is a method of detecting secret message hidden in a cover image. RS steganalysis is one of the most reliable steganalysis which performs statistical analysis of the pixels to successfully detection of hidden message in an image. This paper presents a secured steganography method using genetic algorithm to protect against the RS attack in color images. The proposed steganography scheme embeds message in integer wavelet transform coefficients by using a mapping function. This mapping function based on GA in an 8x8 block on the input cover color image. After embedding the message optimal pixel adjustment process is applied. By applying the OPAP the error difference between the cover image and stego image is minimized. Frequency domain technique is used to increase the robustness of proposed method. Use of IWT prevents the floating point precision problems of the wavelet filter. GA is used to increase the hiding capacity of image and maintains the quality of image. Experimental results are shows that the proposed steganography method is more secured against RS attack as compared to existing methods. Result showed that Peak signal to noise ratio and image utilization, 49.65 db and 100% respectively.

  10. Audio Steganography with Embedded Text

    Science.gov (United States)

    Teck Jian, Chua; Chai Wen, Chuah; Rahman, Nurul Hidayah Binti Ab.; Hamid, Isredza Rahmi Binti A.

    2017-08-01

    Audio steganography is about hiding the secret message into the audio. It is a technique uses to secure the transmission of secret information or hide their existence. It also may provide confidentiality to secret message if the message is encrypted. To date most of the steganography software such as Mp3Stego and DeepSound use block cipher such as Advanced Encryption Standard or Data Encryption Standard to encrypt the secret message. It is a good practice for security. However, the encrypted message may become too long to embed in audio and cause distortion of cover audio if the secret message is too long. Hence, there is a need to encrypt the message with stream cipher before embedding the message into the audio. This is because stream cipher provides bit by bit encryption meanwhile block cipher provide a fixed length of bits encryption which result a longer output compare to stream cipher. Hence, an audio steganography with embedding text with Rivest Cipher 4 encryption cipher is design, develop and test in this project.

  11. Future High Capacity Backbone Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan

    This thesis - Future High Capacity Backbone Networks - deals with the energy efficiency problems associated with the development of future optical networks. In the first half of the thesis, novel approaches for using multiple/single alternative energy sources for improving energy efficiency...... the context of the integrated control plane structure. Results show improvements of energy efficiency over three types of traffic, while still keeping acceptable QoS levels for high priority traffic....

  12. A Novel Scheme for Image Authentication and Secret Data Sharing

    Directory of Open Access Journals (Sweden)

    Auqib Hamid Lone

    2016-09-01

    Full Text Available Privacy protection is of extreme importance especially in security sensitive environments. Neither cryptography nor steganography comes up with ultimate solution for privacy preservation in open systems. However, combination of steganography and cryptography can greatly increase the security of communication and is usually considered a good practice for securing security driven communication environments. In this paper we propose a novel scheme for image authentication and secret data sharing based on three level security model viz: Compression, steganography and cryptography. Compression optimizes the resource usage, steganography conceals the existence of message and cryptography is used to achieve confidentiality and authentication.

  13. A robust chaotic algorithm for digital image steganography

    Science.gov (United States)

    Ghebleh, M.; Kanso, A.

    2014-06-01

    This paper proposes a new robust chaotic algorithm for digital image steganography based on a 3-dimensional chaotic cat map and lifted discrete wavelet transforms. The irregular outputs of the cat map are used to embed a secret message in a digital cover image. Discrete wavelet transforms are used to provide robustness. Sweldens' lifting scheme is applied to ensure integer-to-integer transforms, thus improving the robustness of the algorithm. The suggested scheme is fast, efficient and flexible. Empirical results are presented to showcase the satisfactory performance of our proposed steganographic scheme in terms of its effectiveness (imperceptibility and security) and feasibility. Comparison with some existing transform domain steganographic schemes is also presented.

  14. A New Image Steganography Based On First Component Alteration Technique

    CERN Document Server

    Kaur, Amanpreet; Sikka, Geeta

    2010-01-01

    In this paper, A new image steganography scheme is proposed which is a kind of spatial domain technique. In order to hide secret data in cover-image, the first component alteration technique is used. Techniques used so far focuses only on the two or four bits of a pixel in a image (at the most five bits at the edge of an image) which results in less peak to signal noise ratio and high root mean square error. In this technique, 8 bits of blue components of pixels are replaced with secret data bits. Proposed scheme can embed more data than previous schemes and shows better image quality. To prove this scheme, several experiments are performed, and are compared the experimental results with the related previous works.

  15. Product Perfect Z2Z4-linear codes in Steganography

    CERN Document Server

    Rifa, J

    2010-01-01

    Product perfect codes have been proven to enhance the performance of the F5 steganographic method, whereas perfect Z2Z4-linear codes have been recently introduced as an efficient way to embed data, conforming to the +/-1-steganography. In this paper, we present two steganographic methods. On the one hand, a generalization of product perfect codes is made. On the other hand, this generalization is applied to perfect Z2Z4-linear codes. Finally, the performance of the proposed methods is evaluated and compared with those of the aforementioned schemes.

  16. Fourier Phase Domain Steganography: Phase Bin Encoding Via Interpolation

    Science.gov (United States)

    Rivas, Edward

    2007-04-01

    In recent years there has been an increased interest in audio steganography and watermarking. This is due primarily to two reasons. First, an acute need to improve our national security capabilities in light of terrorist and criminal activity has driven new ideas and experimentation. Secondly, the explosive proliferation of digital media has forced the music industry to rethink how they will protect their intellectual property. Various techniques have been implemented but the phase domain remains a fertile ground for improvement due to the relative robustness to many types of distortion and immunity to the Human Auditory System. A new method for embedding data in the phase domain of the Discrete Fourier Transform of an audio signal is proposed. Focus is given to robustness and low perceptibility, while maintaining a relatively high capacity rate of up to 172 bits/s.

  17. Forensic analysis of video steganography tools

    Directory of Open Access Journals (Sweden)

    Thomas Sloan

    2015-05-01

    Full Text Available Steganography is the art and science of concealing information in such a way that only the sender and intended recipient of a message should be aware of its presence. Digital steganography has been used in the past on a variety of media including executable files, audio, text, games and, notably, images. Additionally, there is increasing research interest towards the use of video as a media for steganography, due to its pervasive nature and diverse embedding capabilities. In this work, we examine the embedding algorithms and other security characteristics of several video steganography tools. We show how all feature basic and severe security weaknesses. This is potentially a very serious threat to the security, privacy and anonymity of their users. It is important to highlight that most steganography users have perfectly legal and ethical reasons to employ it. Some common scenarios would include citizens in oppressive regimes whose freedom of speech is compromised, people trying to avoid massive surveillance or censorship, political activists, whistle blowers, journalists, etc. As a result of our findings, we strongly recommend ceasing any use of these tools, and to remove any contents that may have been hidden, and any carriers stored, exchanged and/or uploaded online. For many of these tools, carrier files will be trivial to detect, potentially compromising any hidden data and the parties involved in the communication. We finish this work by presenting our steganalytic results, that highlight a very poor current state of the art in practical video steganography tools. There is unfortunately a complete lack of secure and publicly available tools, and even commercial tools offer very poor security. We therefore encourage the steganography community to work towards the development of more secure and accessible video steganography tools, and make them available for the general public. The results presented in this work can also be seen as a useful

  18. Random linear codes in steganography

    Directory of Open Access Journals (Sweden)

    Kamil Kaczyński

    2016-12-01

    Full Text Available Syndrome coding using linear codes is a technique that allows improvement in the steganographic algorithms parameters. The use of random linear codes gives a great flexibility in choosing the parameters of the linear code. In parallel, it offers easy generation of parity check matrix. In this paper, the modification of LSB algorithm is presented. A random linear code [8, 2] was used as a base for algorithm modification. The implementation of the proposed algorithm, along with practical evaluation of algorithms’ parameters based on the test images was made.[b]Keywords:[/b] steganography, random linear codes, RLC, LSB

  19. High capacity embedding with indexed data recovery using adjunctive numerical relations in multimedia signal covers

    Science.gov (United States)

    Collins, James C.; Agaian, Sos S.

    2013-05-01

    We introduce a technique for covertly embedding data throughout an audio file using redundant number system decomposition across non-standard digital bit-lines. This bit-line implementation integrates an index recoverable embedded algorithm with an extended bit level representation that achieves a high capacity data channel within an audio multimedia file. It will be shown this new steganography method has minimal aural distortive affects while preserving both first and second order cover statistics, making it less susceptible to most steganalysis attacks. Our research approach involves reviewing the common numerical methods used in common binary-based algorithms. We then describe basic concepts and challenges when attempting to implement complex embedding algorithms that are based on redundant number systems. Finally, we introduce a novel class of numerical based multiple bit-line decomposition systems, which we define as Adjunctive Numerical Representations. The system is primarily described using basic PCM techniques in uncompressed audio files however extended applications for alternate multimedia is addressed. This new embedding system will not only provide the statistical stability required for effective steganography but will also give us an improvement in the embedding capacity in this class of multimedia carrier files. This novelty of our approach is demonstrated by an ability to embed high capacity covert data while simultaneously providing a means for rapid, indexed data recovery.

  20. Audio Steganography Techniques-A Survey

    Directory of Open Access Journals (Sweden)

    Navneet Kaur

    2014-06-01

    Full Text Available we can communicate with each other by passing messages which is not secure, but we make a communication be kept secret by embedding the message into carrier or by special tools such as invisible ink, microdots etc. Steganography is the science that involves communicating secret data in an appropriate carrier which is used from hundreds of years. In digital age new techniques of hiding the data inside the carrier are invented which are known as digital steganography. Nowadays, the carrier of the message can be an image, audio, video or a text file. In this paper we have purposed a method to enhance the security level in audio steganography and also improve the quality by making 2-level steganography.

  1. Steganography An Art of Hiding Data

    CERN Document Server

    Channalli, Shashikala

    2009-01-01

    In today's world the art of sending & displaying the hidden information especially in public places, has received more attention and faced many challenges. Therefore, different methods have been proposed so far for hiding information in different cover media. In this paper a method for hiding of information on the billboard display is presented. It is well known that encryption provides secure channels for communicating entities. However, due to lack of covertness on these channels, an eavesdropper can identify encrypted streams through statistical tests and capture them for further cryptanalysis. In this paper we propose a new form of steganography, on-line hiding of information on the output screens of the instrument. This method can be used for announcing a secret message in public place. It can be extended to other means such as electronic advertising board around sports stadium, railway station or airport. This method of steganography is very similar to image steganography and video steganography. Pr...

  2. Wavelet based Non LSB Steganography

    Directory of Open Access Journals (Sweden)

    H S Manjunatha Reddy

    2011-11-01

    Full Text Available Steganography is the methods of communicating secrete information hidden in the cover object. The messages hidden in a host data are digital image, video or audio files, etc, and then transmitted secretly to the destination. In this paper we propose Wavelet based Non LSB Steganography (WNLS. The cover image is segmented into 4*4 cells and DWT/IWT is applied on each cell. The 2*2 cell of HH band of DWT/IWT are considered and manipulated with payload bit pairs using identity matrix to generate stego image. The key is used to extract payload bit pairs at the destination. It is observed that the PSNR values are better in the case of IWT compare to DWT for all image formats. The algorithm can’t be detected by existing steganalysis techniques such as chi-square and pair of values techniques. The PSNR values are high in the case of raw images compared to formatted images.

  3. DIGITAL DATA PROTECTION USING STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    R. Rejani

    2016-03-01

    Full Text Available In today’s digital world applications from a computer or a mobile device consistently used to get every kind of work done for professional as well as entertainment purpose. However, one of the major issue that a software publisher will face is the issue of piracy. Throughout the last couple of decades, almost all-major or minor software has been pirated and freely circulated across the internet. The impact of the rampant software piracy has been huge and runs into billions of dollars every year. For an independent developer or a programmer, the impact of piracy will be huge. Huge companies that make specialized software often employ complex hardware methods such as usage of dongles to avoid software piracy. However, this is not possible to do for a normal independent programmer of a small company. As part of the research, a new method of software protection that does not need proprietary hardware and other complex methods are proposed in this paper. This method uses a combination of inbuilt hardware features as well as steganography and encryption to protect the software against piracy. The properties or methods used include uniqueness of hardware, steganography, strong encryption like AES and geographic location. To avoid hacking the proposed framework also makes use of self-checks in a random manner. The process is quite simple to implement for any developer and is usable on both traditional PCs as well as mobile environments.

  4. Audio Steganography Techniques-A Survey

    OpenAIRE

    Navneet Kaur; Sunny Behal

    2014-01-01

    we can communicate with each other by passing messages which is not secure, but we make a communication be kept secret by embedding the message into carrier or by special tools such as invisible ink, microdots etc. Steganography is the science that involves communicating secret data in an appropriate carrier which is used from hundreds of years. In digital age new techniques of hiding the data inside the carrier are invented which are known as digital steganography. Nowadays, t...

  5. Comments on "Steganography Using Reversible Texture Synthesis".

    Science.gov (United States)

    Zhou, Hang; Chen, Kejiang; Zhang, Weiming; Yu, Nenghai

    2017-04-01

    Message hiding in texture image synthesis is a novel steganography approach by which we resample a smaller texture image and synthesize a new texture image with a similar local appearance and an arbitrary size. However, the mirror operation over the image boundary is flawed and is easy to attack. We propose an attacking method on this steganography, which can not only detect the stego-images but can also extract the hidden messages.

  6. Multimedia security watermarking, steganography, and forensics

    CERN Document Server

    Shih, Frank Y

    2012-01-01

    Multimedia Security: Watermarking, Steganography, and Forensics outlines essential principles, technical information, and expert insights on multimedia security technology used to prove that content is authentic and has not been altered. Illustrating the need for improved content security as the Internet and digital multimedia applications rapidly evolve, this book presents a wealth of everyday protection application examples in fields including multimedia mining and classification, digital watermarking, steganography, and digital forensics. Giving readers an in-depth overview of different asp

  7. Steganography: A Security Model for Open Communication

    Directory of Open Access Journals (Sweden)

    K. Chandra Sekhar

    2013-01-01

    Full Text Available Steganography is the art and science of hiding messages. Steganography is basically about embedding a secret message in an innocuous wrapper; to communicate privately in an open channel. Steganography is often combined with cryptography so that even if the message is discovered it cannot be read. The key difference between Cryptography and Steganography lies with the fact that when a message is encrypted, third party knows that the message exists and it is encrypted, whereas with Steganography third party might not even know (or observe that there does exists a message too, simply because its hidden behind an image, video or an audio etc which without keen observation might go without any suspicion. In the proposed system Steganography involves the method of acquiring insignificant bits in the audio file. After acquiring the insignificant bits in the audio header, replace them with significant bits (covert message of information hiding[6]. Video file consists of both audio and images so the above two methods can be combined implemented with this.

  8. MoveSteg: A Method of Network Steganography Detection

    OpenAIRE

    Szczypiorski, Krzysztof; Tyl, Tomasz

    2016-01-01

    This article presents a new method for detecting a source point of time based network steganography - MoveSteg. A steganography carrier could be an example of multimedia stream made with packets. These packets are then delayed intentionally to send hidden information using time based steganography methods. The presented analysis describes a method that allows finding the source of steganography stream in network that is under our management.

  9. An Analysis of Perturbed Quantization Steganography in the Spatial Domain

    Science.gov (United States)

    2005-03-01

    steganography is also common with audio [KaP00]. Figure 1 depicts this form of steganography . Figure 1. Least Significant Bit Substitution 6...QUANTIZATION STEGANOGRAPHY IN THE SPATIAL DOMAIN THESIS Matthew D. Spisak AFIT/GIA/ENG/05-04DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY ORCE...ANALYSIS OF PERTURBED QUANTIZATION STEGANOGRAPHY IN THE SPATIAL DOMAIN THESIS Presented to the Faculty Department of Electrical and

  10. A Quick review of Network Security and Steganography

    OpenAIRE

    Gandharba Swain; Saroj Kumar Lanka

    2012-01-01

    In this paper we present a classification of network security techniques such as: secrecy, authentication, non-repudiation and integrity control. The secrecy techniques are two categories: cryptography and steganography. Steganography like cryptography is a very useful technique to achieve secrecy in communication. If both cryptography and steganography are used then the communication becomes two fold secured. All the major techniques on image steganography proposed by different researcher...

  11. MoveSteg: A Method of Network Steganography Detection

    OpenAIRE

    Szczypiorski, Krzysztof; Tyl, Tomasz

    2016-01-01

    This article presents a new method for detecting a source point of time based network steganography - MoveSteg. A steganography carrier could be an example of multimedia stream made with packets. These packets are then delayed intentionally to send hidden information using time based steganography methods. The presented analysis describes a method that allows finding the source of steganography stream in network that is under our management.

  12. Information hiding techniques for steganography and digital watermarking

    CERN Document Server

    Katzenbeisser, Stefan

    2000-01-01

    Steganography, a means by which two or more parties may communicate using ""invisible"" or ""subliminal"" communication, and watermarking, a means of hiding copyright data in images, are becoming necessary components of commercial multimedia applications that are subject to illegal use. This new book is the first comprehensive survey of steganography and watermarking and their application to modern communications and multimedia.Handbook of Information Hiding: Steganography and Watermarking helps you understand steganography, the history of this previously neglected element of cryptography, the

  13. Breaking the Digital Video Steganography

    Directory of Open Access Journals (Sweden)

    Yueqiang LI

    2013-01-01

    Full Text Available In this paper we provide a new digital video steganalysis algorithm.  When frames of the cover video are embedded with secret messages, both number of connected component and number of holes will change dramatically, thus Euler number of the stego-frame will has pulsing increase. This proposed steganalysis algorithm is applied to stego-video, estimating steganographic algorithm for frames chosen and estimating steganographic capacity. Experimental results indicate that it’s much simpler and faster, more sensitive and robust, steganography rate as small as 0.0154% can be reliably detected. It’s effective and efficient to detect any format video, because this algorithm is only correlated with the connected components number and holes number of the frames.

  14. Application of Steganography for Anonymity through the Internet

    CERN Document Server

    Bahi, Jacques M; Friot, Nicolas; Guyeux, Christophe

    2012-01-01

    In this paper, a novel steganographic scheme based on chaotic iterations is proposed. This research work takes place into the information hiding security framework. The applications for anonymity and privacy through the Internet are regarded too. To guarantee such an anonymity, it should be possible to set up a secret communication channel into a web page, being both secure and robust. To achieve this goal, we propose an information hiding scheme being stego-secure, which is the highest level of security in a well defined and studied category of attacks called "watermark-only attack". This category of attacks is the best context to study steganography-based anonymity through the Internet. The steganalysis of our steganographic process is also studied in order to show it security in a real test framework.

  15. High capacity image watermarking scheme robust to geometric attacks based on local feature regions%基于LFRs的大容量抗几何攻击水印算法

    Institute of Scientific and Technical Information of China (English)

    赵文娴; 王玲; 王美珍

    2011-01-01

    如何有效抵抗几何攻击是目前水印技术研究的难点之一,且已有抗几何攻击水印算法的嵌入容量有限.提出了一种利用尺度不变特征变换(SIFT)特征点确定的局部特征区域(LFRs)嵌入水印的大容量抗几何攻击的水印算法.算法首先从图像的非抽样的Contourlet域(NSCT)低频分量中提取出SIFT中等尺度的稳定特征点,并通过最小生成树聚类算法的选择策略获得一组分布均匀且彼此独立的圆形特征区域;然后对每个圆形区域进行等角度的扇形分割和等面积的同心圆环分割,划分成等面积的子块;最后采用奇偶量化将经过混沌加密的水印嵌入到子块的NSCT低频分量中.水印检测时,利用SIFT匹配算法获得同步的水印嵌入区域,再进行水印的盲提取.仿真实验表明,该算法采用的圆形区域分割方法显著地提高了水印的嵌入容量,对于噪声、滤波、压缩以及各类几何攻击都具有较好的鲁棒性.%Image watermarking resistant to geometric attacks is the hotspot and challenging task in the state of the research on watermarking, and the capacity of these watermarking schemes existed usually is limited. This article presented an image watermarking scheme robust to geometric attacks based on local feature regions ( LFRs) , which were selected by scale-invariant feature transform (SIFT) keypoints. Firstly,it extracted the stable keypoints in medium scale from the non-subsampled Cont-ourlet transform ( NSCT) low-frequency of the host image by the SIFT algorithm, and got a set of widely-distributed and non-overlapped circle feature regions via selection criterion based on the minimum spanning tree clustering algorithm. Then every circle region was partitioned to sub-blocks with the same area in a sector pattern with the same angle and a homocentric cirque pattern with the same area. Finally, using odd-even quantization, the watermark, which had been encrypted by chaos system, could be

  16. A novel technique for image steganography based on Block-DCT and Huffman Encoding

    CERN Document Server

    Nag, A; Sarkar, D; Sarkar, P P; 10.5121/ijcsit.2010.2308

    2010-01-01

    Image steganography is the art of hiding information into a cover image. This paper presents a novel technique for Image steganography based on Block-DCT, where DCT is used to transform original image (cover image) blocks from spatial domain to frequency domain. Firstly a gray level image of size M x N is divided into no joint 8 x 8 blocks and a two dimensional Discrete Cosine Transform (2-d DCT) is performed on each of the P = MN / 64 blocks. Then Huffman encoding is also performed on the secret messages/images before embedding and each bit of Huffman code of secret message/image is embedded in the frequency domain by altering the least significant bit of each of the DCT coefficients of cover image blocks. The experimental results show that the algorithm has a high capacity and a good invisibility. Moreover PSNR of cover image with stego-image shows the better results in comparison with other existing steganography approaches. Furthermore, satisfactory security is maintained since the secret message/image ca...

  17. A novel technique for image steganography based on Block-DCT and Huffman Encoding

    Directory of Open Access Journals (Sweden)

    A.Nag

    2010-06-01

    Full Text Available Image steganography is the art of hiding information into a cover image. This paper presents anovel technique for Image steganography based on Block-DCT, where DCT is used to transform originalimage (cover image blocks from spatial domain to frequency domain. Firstly a gray level image of size M× N is divided into no joint 8 × 8 blocks and a two dimensional Discrete Cosine Transform(2-d DCT isperformed on each of the P = MN / 64 blocks. Then Huffman encoding is also performed on the secretmessages/images before embedding and each bit of Huffman code of secret message/image is embedded inthe frequency domain by altering the least significant bit of each of the DCT coefficients of cover imageblocks. The experimental results show that the algorithm has a high capacity and a good invisibility.Moreover PSNR of cover image with stego-image shows the better results in comparison with otherexisting steganography approaches. Furthermore, satisfactory security is maintained since the secretmessage/image cannot be extracted without knowing decoding rules and Huffman table.

  18. GRADIENT ENERGY DETECTION OF LSB STEGANOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    Li Zhi; Sui Aifen; Niu Xinxin; Yang Yixian

    2005-01-01

    The spatial Least Significant Bit (LSB) steganography results in the alteration of the smooth characteristics between adjoining pixels of the raw image. The relation between the length of embedded message and the gradient energy is theoretically analyzed, and then a steganalysis and detection method, named Gradient Energy-Flipping Rate (GEFR) detection is proposed. Based on the analysis of the variation of the gradient energy, which results from the LSB steganography in color and grayscale image, the secret message embedded in the target image is detected, and the length of the embedded message is estimated. The method is proved effective and accurate by simulation (detection rate reaches 0.01bit per pixel).

  19. Transform domain steganography with blind source separation

    Science.gov (United States)

    Jouny, Ismail

    2015-05-01

    This paper applies blind source separation or independent component analysis for images that may contain mixtures of text, audio, or other images for steganography purposes. The paper focuses on separating mixtures in the transform domain such as Fourier domain or the Wavelet domain. The study addresses the effectiveness of steganography when using linear mixtures of multimedia components and the ability of standard blind sources separation techniques to discern hidden multimedia messages. Mixing in the space, frequency, and wavelet (scale) domains is compared. Effectiveness is measured using mean square error rate between original and recovered images.

  20. Trellis-coded quantization for public-key steganography

    CERN Document Server

    Guelvouit, Gaëtan Le

    2008-01-01

    This paper deals with public-key steganography in the presence of a passive warden. The aim is to hide secret messages within cover-documents without making the warden suspicious, and without any preliminar secret key sharing. Whereas a practical attempt has been already done to provide a solution to this problem, it suffers of poor flexibility (since embedding and decoding steps highly depend on cover-signals statistics) and of little capacity compared to recent data hiding techniques. Using the same framework, this paper explores the use of trellis-coded quantization techniques (TCQ and turbo TCQ) to design a more efficient public-key scheme. Experiments on audio signals show great improvements considering Cachin's security criterion.

  1. Steganography by using Logistic Map Function and Cellular Automata

    Directory of Open Access Journals (Sweden)

    Mehdi Alirezanejad

    2012-12-01

    Full Text Available A tradeoff between the hiding capacity of a cover image and the quality of a stego-image in steganographic schemes is inevitable. In this study a hybrid model of cellular automata and chaotic function is proposed for steganography. In this method, N-bits mask is used for choosing a pixel position in main image which is suitable for hiding one bit of secret data. This mask is generated in each stage by cellular automat and logistic map function. Using cellular automata and logistic map function cause more security and safety in proposed method. Studying the obtained results of the performed experiments, high resistance of the proposed method against brute-force and statistical invasions is obviously illustrated.

  2. ENERGY EFFICIENT DISTRIBUTED STEGANOGRAPHY FOR SECURE COMMUNICATION IN WIRELESS MULTIMEDIA SENSOR NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Lin Qiaomin; Wang Ruchuan; Ye Ning; Wang Zhongqin

    2013-01-01

    A secure communication mechanism is necessary in the applications of Wireless Multimedia Sensor Networks (WMSNs),which is more vulnerable to security attacks due to the presence of multimedia data.Additionally,given the limited technological resources (in term of energy,computation,bandwidth,and storage) of sensor nodes,security and privacy policies have to be combined with energy-aware algorithms and distributed processing of multimedia contents in WMSNs.To solve these problems in this paper,an energy efficient distributed steganography scheme,which combines steganography technique with the concept of distributed computing,is proposed for secure communication in WMSNs.The simulation results show that the proposed method can achieve considerable energy efficiency while assuring the communication security simultaneously.

  3. Transparency benchmarking on audio watermarks and steganography

    Science.gov (United States)

    Kraetzer, Christian; Dittmann, Jana; Lang, Andreas

    2006-02-01

    The evaluation of transparency plays an important role in the context of watermarking and steganography algorithms. This paper introduces a general definition of the term transparency in the context of steganography, digital watermarking and attack based evaluation of digital watermarking algorithms. For this purpose the term transparency is first considered individually for each of the three application fields (steganography, digital watermarking and watermarking algorithm evaluation). From the three results a general definition for the overall context is derived in a second step. The relevance and applicability of the definition given is evaluated in practise using existing audio watermarking and steganography algorithms (which work in time, frequency and wavelet domain) as well as an attack based evaluation suite for audio watermarking benchmarking - StirMark for Audio (SMBA). For this purpose selected attacks from the SMBA suite are modified by adding transparency enhancing measures using a psychoacoustic model. The transparency and robustness of the evaluated audio watermarking algorithms by using the original and modifid attacks are compared. The results of this paper show hat transparency benchmarking will lead to new information regarding the algorithms under observation and their usage. This information can result in concrete recommendations for modification, like the ones resulting from the tests performed here.

  4. Performance Improvement of Threshold based Audio Steganography using Parallel Computation

    OpenAIRE

    Muhammad Shoaib; Zakir Khan; Danish Shehzad; Tamer Dag; Arif Iqbal Umar; Noor Ul Amin

    2016-01-01

    Audio steganography is used to hide secret information inside audio signal for the secure and reliable transfer of information. Various steganography techniques have been proposed and implemented to ensure adequate security level. The existing techniques either focus on the payload or security, but none of them has ensured both security and payload at same time. Data Dependency in existing solution was reluctant for the execution of steganography mechanism serially. The audio data and secret ...

  5. A Fractional Random Wavelet Transform Based Image Steganography

    OpenAIRE

    G.K. Rajini; RAMACHANDRA REDDY G.

    2015-01-01

    This study presents a novel technique for image steganography based on Fractional Random Wavelet Transform. This transform has all the features of wavelet transform with randomness and fractional order built into it. The randomness and fractional order in the algorithm brings in robustness and additional layers of security to steganography. The stegano image generated by this algorithm contains both cover image and hidden image and image degradation is not observed in it. The steganography st...

  6. Researcher’s Perspective of Substitution Method on Text Steganography

    Science.gov (United States)

    Zamir Mansor, Fawwaz; Mustapha, Aida; Azah Samsudin, Noor

    2017-08-01

    The linguistic steganography studies are still in the stage of development and empowerment practices. This paper will present several text steganography on substitution methods based on the researcher’s perspective, all scholar paper will analyse and compared. The objective of this paper is to give basic information in the substitution method of text domain steganography that has been applied by previous researchers. The typical ways of this method also will be identified in this paper to reveal the most effective method in text domain steganography. Finally, the advantage of the characteristic and drawback on these techniques in generally also presented in this paper.

  7. A Novel Steganography Technique for SDTV-H.264/AVC Encoded Video

    Directory of Open Access Journals (Sweden)

    Christian Di Laura

    2016-01-01

    Full Text Available Today, eavesdropping is becoming a common issue in the rapidly growing digital network and has foreseen the need for secret communication channels embedded in digital media. In this paper, a novel steganography technique designed for Standard Definition Digital Television (SDTV H.264/AVC encoded video sequences is presented. The algorithm introduced here makes use of the compression properties of the Context Adaptive Variable Length Coding (CAVLC entropy encoder to achieve a low complexity and real-time inserting method. The chosen scheme hides the private message directly in the H.264/AVC bit stream by modifying the AC frequency quantized residual luminance coefficients of intrapredicted I-frames. In order to avoid error propagation in adjacent blocks, an interlaced embedding strategy is applied. Likewise, the steganography technique proposed allows self-detection of the hidden message at the target destination. The code source was implemented by mixing MATLAB 2010 b and Java development environments. Finally, experimental results have been assessed through objective and subjective quality measures and reveal that less visible artifacts are produced with the technique proposed by reaching PSNR values above 40.0 dB and an embedding bit rate average per secret communication channel of 425 bits/sec. This exemplifies that steganography is affordable in digital television.

  8. Steganography and encrypting based on immunochemical systems.

    Science.gov (United States)

    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. Copyright © 2010 Wiley Periodicals, Inc.

  9. LSB Based Quantum Image Steganography Algorithm

    Science.gov (United States)

    Jiang, Nan; Zhao, Na; Wang, Luo

    2016-01-01

    Quantum steganography is the technique which hides a secret message into quantum covers such as quantum images. In this paper, two blind LSB steganography algorithms in the form of quantum circuits are proposed based on the novel enhanced quantum representation (NEQR) for quantum images. One algorithm is plain LSB which uses the message bits to substitute for the pixels' LSB directly. The other is block LSB which embeds a message bit into a number of pixels that belong to one image block. The extracting circuits can regain the secret message only according to the stego cover. Analysis and simulation-based experimental results demonstrate that the invisibility is good, and the balance between the capacity and the robustness can be adjusted according to the needs of applications.

  10. Review on Binary Image Steganography and Watermarking

    Directory of Open Access Journals (Sweden)

    Mrs. Gyankamal J. Chhaje

    2011-11-01

    Full Text Available In this paper we have reviewed and analyzed different watermarking and steganography techniques. This is based on image processing in spatial and transform domain. We have reviewed different techniques like data hiding by employing pairs of contour edge patterns, edge pixels, visual distortion tables, visual quality preserving rules, substitution, fixed partitioning of images, run lengths in spatial and using Discrete Cosine Transform, Discrete Wavelet Transform in transform domain. We have also represented analysis of these techniques in the form of table considering different factors ofwatermarking and steganography like visual quality, embedding capacity, security, robustness and computational complexity. It is concluded that spatial domain techniques are best with some factors like visual quality, while transform domain are best for some factors like robustness against attacks or other image processing operations and security. The data hiding capacity and computational complexity are common factors for both the domains.

  11. Attacks on lexical natural language steganography systems

    Science.gov (United States)

    Taskiran, Cuneyt M.; Topkara, Umut; Topkara, Mercan; Delp, Edward J.

    2006-02-01

    Text data forms the largest bulk of digital data that people encounter and exchange daily. For this reason the potential usage of text data as a covert channel for secret communication is an imminent concern. Even though information hiding into natural language text has started to attract great interest, there has been no study on attacks against these applications. In this paper we examine the robustness of lexical steganography systems.In this paper we used a universal steganalysis method based on language models and support vector machines to differentiate sentences modified by a lexical steganography algorithm from unmodified sentences. The experimental accuracy of our method on classification of steganographically modified sentences was 84.9%. On classification of isolated sentences we obtained a high recall rate whereas the precision was low.

  12. Embedded Zero -Tree Wavelet Based Image Steganography

    OpenAIRE

    Vijendra Rai; Jaishree Jain; Ajay Kr. Yadav; Sheshmani Yadav

    2012-01-01

    Image steganography using Discrete Wavelet Transform can attain very good results as compared to traditional methods, in this paper we discuss a method to embed digital watermark based on modifying frequency coefficient in discrete wavelet transform (DWT) domain. This method uses the embedded zero-tree (EZW) algorithm to insert a watermark in discrete wavelet transform domain. EZW is an effective image compression algorithm, having property that image in the bit stream are generated in order...

  13. Is Cloud Computing Steganography-proof?

    CERN Document Server

    Mazurczyk, Wojciech

    2011-01-01

    The paper focuses on characterisation of information hiding possibilities in Cloud Computing. After general introduction to cloud computing and its security we move to brief description of steganography. In particular we introduce classification of steganographic communication scenarios in cloud computing which is based on location of the steganograms receiver. These scenarios as well as the threats that steganographic methods can cause must be taken into account when designing secure cloud computing services.

  14. STEGANOGRAPHY USAGE TO CONTROL MULTIMEDIA STREAM

    Directory of Open Access Journals (Sweden)

    Grzegorz Koziel

    2014-03-01

    Full Text Available In the paper, a proposal of new application for steganography is presented. It is possible to use steganographic techniques to control multimedia stream playback. Special control markers can be included in the sound signal and the player can detect markers and modify the playback parameters according to the hidden instructions. This solution allows for remembering user preferences within the audio track as well as allowing for preparation of various versions of the same content at the production level.

  15. DWT Steganography with Usage of Scrambling

    Directory of Open Access Journals (Sweden)

    Jakub Oravec

    2016-07-01

    Full Text Available This article describes image steganography technique, which uses Discrete Wavelet Transform and Standard map for storage of secret data in form of binary image. Modifications, which are done on cover image depend on its scrambled and decomposed version. To avoid unnecessary amount of changes, proposed approach marks location of altered DWT coefficients. The paper ends with illustration of yielded results and presents some possible topics for future work.

  16. Pictographic steganography based on social networking websites

    OpenAIRE

    Feno Heriniaina RABEVOHITRA; Xiaofeng Liao

    2016-01-01

    Steganography is the art of communication that does not let a third party know that the communication channel exists. It has always been influenced by the way people communicate and with the explosion of social networking websites, it is likely that these will be used as channels to cover the very existence of communication between different entities. In this paper, we present a new effective pictographic steganographic channel. We make use of the huge amount of photos available online as com...

  17. Steganography and Steganalysis in Digital Images

    Science.gov (United States)

    2012-01-01

    Michigan examined over 2 million images from popular websites like Ebay auction images and USENET archives searching for Steganography traces. They have...been posting images on Ebay with hidden messages inside to send to different terrorist groups. Recent attempts to detect the presence of such...images on Ebay have not uncovered anything. You might have seen in old Chinese movies that monks used to safeguard secrets by hiding those secrets on

  18. Steganography and Cryptography Inspired Enhancement of Introductory Programming Courses

    Science.gov (United States)

    Kortsarts, Yana; Kempner, Yulia

    2015-01-01

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

  19. Multi-Class Classification for Identifying JPEG Steganography Embedding Methods

    Science.gov (United States)

    2008-09-01

    B.H. (2000). STEGANOGRAPHY: Hidden Images, A New Challenge in the Fight Against Child Porn . UPDATE, Volume 13, Number 2, pp. 1-4, Retrieved June 3...Other crimes involving the use of steganography include child pornography where the stego files are used to hide a predator’s location when posting

  20. Improved information security using robust Steganography system

    CERN Document Server

    Juneja, Mamta

    2010-01-01

    Steganography is an emerging area which is used for secured data transmission over any public media.Steganography is a process that involves hiding a message in an appropriate carrier like image or audio. It is of Greek origin and means "covered or hidden writing". The carrier can be sent to a receiver without any one except the authenticated receiver knowing the existence of this information. In this paper, a specific image based steganography technique for communicating information more securely between two locations is proposed. The author incorporated the idea of secret key and password security features for authentication at both ends in order to achieve high level of security. As a further improvement of security level, the information has been permuted, encoded and then finally embedded on an image to form the stego image. In addition segmented objects extraction and reassembly of the stego image through normalized cut method has been carried out at the sender side and receiver side respectively in ord...

  1. High capacity optical links for datacentre connectivity

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Usuga, Mario; Vegas Olmos, Juan José

    There is a timely and growing demand for high capacity optical data transport solutions to provide connectivity inside data centres and between data centres located at different geographical locations. The requirements for reach are in the order of 2 km for intra-datacentre and up to 100 km for i...

  2. Survey of the Use of Steganography over the Internet

    Directory of Open Access Journals (Sweden)

    Lavinia Mihaela DINCA

    2011-01-01

    Full Text Available This paper addressesthe use of Steganography over the Internet by terrorists. There were ru-mors in the newspapers that Steganography is being used to covert communication between terrorists, without presenting any scientific proof. Niels Provos and Peter Honeyman conducted an extensive Internet search where they analyzed over 2 million images and didn’t find a single hidden image. After this study the scientific community was divided: some believed that Niels Provos and Peter Honeyman was conclusive enough other did not. This paper describes what Steganography is and what can be used for, various Steganography techniques and also presents the studies made regarding the use of Steganography on the Internet.

  3. A Procedure of Text Steganography Using Indian Regional Language

    Directory of Open Access Journals (Sweden)

    Indradip Banerjee

    2012-08-01

    Full Text Available In this paper we present a work of text steganography. Now a days, maintain the security of the secret information has been a great challenge. Sender can send messages habitually through a communication channel like Internet, draws the attention of third parties, hackers and crackers, perhaps causing attempts to break and expose the unusual messages. Steganography is a promising region which is used for secured data transmission over any public media. Substantial amount of research work has been accepted by different researchers on steganography. In this paper, a text steganography procedure has been planned with the help of an Indian regional language i.e. Oriya language. Text steganography together with quantum approach based on the use of two specific characters and two special characters like invited comas (opening and closing in Oriya language and mapping technique of quantum gate truth table have been used.

  4. IMPROVED PROTECTION IN VIDEO STEGANOGRAPHY USED COMPRESSED VIDEO BITSTREAMS

    Directory of Open Access Journals (Sweden)

    S. Suma Christal Mary M.E

    2010-05-01

    Full Text Available In this paper propose a new method for the real-time hiding of information used in compressed video bitstreams. This method is based on the real-time hiding of information in audio steganography. This method of steganography is very similar to the two discussions ofimage steganography and video steganography. A new compressed video secure steganography(CVSS algorithm is proposed. In this algorithm, embedding and detection operations are both executed entirely in the compressed domain, with no need for the decompression process. Thenew criteria employing statistical invisibility of contiguous frames is used to adjust the embedding strategy and capacity, which increases the security of proposed algorithm. Therefore, the collusion resistant properties are obtained. Video steganalysis with closed loop feedback manner is design as a checker to find out obvious bugs.

  5. System for non-disruptive high-capacity indexed data embedding and recovery using multimedia signal covers

    Science.gov (United States)

    Collins, James C.; Agaian, Sos S.

    2011-06-01

    Over the past several years there has been an apparent shift in research focus in the area of digital steganography and steganalysis - a shift from primarily image based methods to a new focus on broader multimedia techniques. More specifically the area of digital audio steganography is of prime interest. We introduce a new high capacity, covert channel data embedding and recovery system for digital audio carrier files using a key based encoding and decoding method. It will be shown that the added information file is interleaved within the carrier file and is fully indexed allowing for segmented extraction and recovery of data at chosen start and stop points in the sampled stream. The original audio quality is not affected by the addition of this covert data. The embedded information can also be secured by a binary key string or cryptographic algorithm and resists statistical analytic detection attempts. We will also describe how this new method can be used for data compression and expansion applications in the transfer and storage of digital multimedia to increase the overall data capacity and security.

  6. SECURE STEGANOGRAPHY BASED ON BINARY PARTICLE SWARM OPTIMIZATION

    Institute of Scientific and Technical Information of China (English)

    Guo Yanqing; Kong Xiangwei; You Xingang

    2009-01-01

    The objective of steganography is to hide message securely in cover objects for secret communication. How to design a secure steganographic algorithm is still major challenge in this research field. In this letter, developing secure steganography is formulated as solving a constrained IP (Integer Programming) problem, which takes the relative entropy of cover and stego distributions as the objective function. Furthermore, a novel method is introduced based on BPSO (Binary Particle Swarm Optimization) for achieving the optimal solution of this programming problem. Experimental results show that the proposed method can achieve excellent performance on preserving neighboring co-occurrence features for JPEG steganography.

  7. On Steganography in Lost Audio Packets

    CERN Document Server

    Mazurczyk, Wojciech; Szczypiorski, Krzysztof

    2011-01-01

    The paper presents a new hidden data insertion procedure based on estimated probability of the remaining time of the call for steganographic method called LACK (Lost Audio PaCKets steganography). LACK provides hidden communication for real-time services like Voice over IP. The analytical results presented in this paper concern the influence of LACK's hidden data insertion procedures on the method's impact on quality of voice transmission and its resistance to steganalysis. The proposed hidden data insertion procedure is also compared to previous steganogram insertion approach based on estimated remaining average call duration.

  8. Information Security using Audio Steganography -A Survey

    Directory of Open Access Journals (Sweden)

    B. Santhi

    2012-07-01

    Full Text Available The most important application of internet is data transmission. Unfortunately this is less secured because of advanced hacking technologies. So, for secured data transmission we make use of steganography. This is the art of hiding information where the existence of data is unknown. Any medium like music, video, text, speech, etc can be used. In this study, the selected medium is audio. This study discusses about the existing audio steganographic techniques along with their advantages and limitations. Also an algorithm implementing parity and LSB methods is proposed. This mitigates the limitations of the existing methods discussed, thus increasing security and reducing computational load and code complexity.

  9. Secured Data Transmission Using Video Steganographic Scheme

    Directory of Open Access Journals (Sweden)

    B.suneetha

    2014-07-01

    Full Text Available Steganography is the art of hiding information in ways that avert the revealing of hiding messages. Video Steganography is focused on spatial and transform domain. Spatial domain algorithm directly embedded information in the cover image with no visual changes. This kind of algorithms has the advantage in Steganography capacity, but the disadvantage is weak robustness. Transform domain algorithm is embedding the secret information in the transform space. This kind of algorithms has the advantage of good stability, but the disadvantage of small capacity. These kinds of algorithms are vulnerable to steganalysis. This paper proposes a new Compressed Video Steganographic scheme. The data is hidden in the horizontal and the vertical components of the motion vectors. The PSNR value is calculated so that the quality of the video after the data hiding is evaluated.

  10. Quantum steganography with a large payload based on dense coding and entanglement swapping of Greenberger-Horne-Zeilinger states

    Institute of Scientific and Technical Information of China (English)

    Ye Tian-Yu; Jiang Li-Zhen

    2013-01-01

    A quantum steganography protocol with a large payload is proposed based on the dense coding and the entanglement swapping of the Greenberger-Home-Zeilinger (GHZ) states.Its super quantum channel is formed by building up a hidden channel within the original quantum secure direct communication (QSDC) scheme.Based on the original QSDC,secret messages are transmitted by integrating the dense coding and the entanglement swapping of the GHZ states.The capacity of the super quantum channel achieves six bits per round covert communication,much higher than the previous quantum steganography protocols.Its imperceptibility is good,since the information and the secret messages can be regarded to be random or pseudo-random.Moreover,its security is proved to be reliable.

  11. Quantum steganography with a large payload based on dense coding and entanglement swapping of Greenberger—Horne—Zeilinger states

    Science.gov (United States)

    Ye, Tian-Yu; Jiang, Li-Zhen

    2013-05-01

    A quantum steganography protocol with a large payload is proposed based on the dense coding and the entanglement swapping of the Greenberger—Horne—Zeilinger (GHZ) states. Its super quantum channel is formed by building up a hidden channel within the original quantum secure direct communication (QSDC) scheme. Based on the original QSDC, secret messages are transmitted by integrating the dense coding and the entanglement swapping of the GHZ states. The capacity of the super quantum channel achieves six bits per round covert communication, much higher than the previous quantum steganography protocols. Its imperceptibility is good, since the information and the secret messages can be regarded to be random or pseudo-random. Moreover, its security is proved to be reliable.

  12. Secure Steganography for Digital Images

    Directory of Open Access Journals (Sweden)

    Khan Farhan Rafat

    2016-06-01

    Full Text Available The degree of imperceptibility of hidden image in the ‘Digital Image Steganography’ is mostly defined in relation to the limitation of Human Visual System (HVS, its chances of detection using statistical methods and its capacity to hide maximum information inside its body. Whereas, a tradeoff does exist between data hiding capacity of the cover image and robustness of underlying information hiding scheme. This paper is an exertion to underline the technique to embed information inside the cover at Stego key dependent locations, which are hard to detect, to achieve optimal security. Hence, it is secure under worst case scenario where Wendy is in possession of the original image (cover agreed upon by Alice and Bob for their secret communication. Reliability of our proposed solution can be appreciated by observing the differences between cover, preprocessed cover and Stego object. Proposed scheme is equally good for color as well as gray scaled images. Another interesting aspect of this research is that it implicitly presents fusion of cover and information to be hidden in it while taking care of passive attacks on it.

  13. A Unique Wavelet Steganography Based Voice Biometric Protection Scheme

    Directory of Open Access Journals (Sweden)

    Sanjaypande M. B

    2013-03-01

    Full Text Available Voice biometric is an easy and cost effective biometric technique which requires minimalistic hardware and software complexity. General voice biometric needs a voice phrase by user which is processed with Mel Filter and Vector Quantized features are extracted. Vector quantization reduces the codebook size but decreases the accuracy of recognition. Therefore we propose a voice biometric system where voice file's non quantized code books are matched with spoken phrase. In order to ensure security to such direct voice sample we embed the voice file in a randomly selected image using DWT technique. Imposters are exposed to only images and are unaware of the voice files. We show that the technique produces better efficiency in comparison to VQ based technique.

  14. Applied public-key steganography

    Science.gov (United States)

    Guillon, Pierre; Furon, Teddy; Duhamel, Pierre

    2002-04-01

    We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.

  15. A New Information Hiding Method Based on Improved BPCS Steganography

    OpenAIRE

    Shuliang Sun

    2015-01-01

    Bit-plane complexity segmentation (BPCS) steganography is advantageous in its capacity and imperceptibility. The important step of BPCS steganography is how to locate noisy regions in a cover image exactly. The regular method, black-and-white border complexity, is a simple and easy way, but it is not always useful, especially for periodical patterns. Run-length irregularity and border noisiness are introduced in this paper to work out this problem. Canonical Cray coding (CGC) is also used to ...

  16. A New Information Hiding Method Based on Improved BPCS Steganography

    OpenAIRE

    Shuliang Sun

    2015-01-01

    Bit-plane complexity segmentation (BPCS) steganography is advantageous in its capacity and imperceptibility. The important step of BPCS steganography is how to locate noisy regions in a cover image exactly. The regular method, black-and-white border complexity, is a simple and easy way, but it is not always useful, especially for periodical patterns. Run-length irregularity and border noisiness are introduced in this paper to work out this problem. Canonical Cray coding (CGC) is also used to ...

  17. Image Steganography using Hybrid Edge Detector and Ridgelet Transform

    OpenAIRE

    S.UMA MAHESWARI; D. Jude Hemanth

    2015-01-01

    Steganography is the art of hiding high sensitive information in digital image, text, video, and audio. In this paper, authors have proposed a frequency domain steganography method operating in the Ridgelet transform. Authors engage the advantage of ridgelet transform, which represents the digital image with straight edges. In the embedding phase, the proposed hybrid edge detector acts as a preprocessing step to obtain the edge image from the cover image, then the edge image is partitioned in...

  18. Pixastic: Steganography based Anti-Phihsing Browser Plug-in

    OpenAIRE

    P.Thiyagarajan; G.Aghila; Venkatesan, V. Prasanna

    2012-01-01

    In spite of existence of many standard security mechanisms for ensuring secure e-Commerce business, users still fall prey for online attacks. One such simple but powerful attack is 'Phishing'. Phishing is the most alarming threat in the e-Commerce world and effective anti-phishing technique is the need of the hour. This paper focuses on a novel anti-phishing browser plug-in which uses information hiding technique - Steganography. A Robust Message based Image Steganography (RMIS) algorithm has...

  19. High Capacity Radio over Fiber Transmission Links

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio

    . This achievement has satisfied the requirements on transmission robustness and high capacity of next generation hybrid optical fibre-wireless networks. One important contribution of this thesis is the novel concept of photonic downconversion with free-running pulsed laser source for phase modulated Radio...... confirmed that this configuration provides high linear end-to-end transmission links and is capable of transparent transport of high spectral efficient modulation formats. Furthermore, this thesis introduces a novel approach for the generation and detection of high speed wireless signals in mm...... of the writing of this thesis. In conclusion, the results presented in this thesis demonstrate the feasibility of photonic technologies for the generation, distribution and detection of high speed wireless signals. Furthermore, it opens the prospects for next generation hybrid wireless-wired access networks...

  20. Android-Stego: A Novel Service Provider Imperceptible MMS Steganography Technique Robust to Message Loss

    OpenAIRE

    Avinash Srinivasan; Jie Wu; Justin Shi

    2015-01-01

    Information hiding techniques, especially steganography, have been extensively researched for over two decades. Nonetheless, steganography on smartphones over cellular carrier networks is yet to be fully explored. Today, smartphones, which are at the epitome of ubiquitous and pervasive computing, make steganography an easily accessible covert communication channel. In this paper, we propose Android-Stego - a framework for steganography employing smart-phones. Android-Stego has been evaluated ...

  1. Steganography based on modified matrix encoding and iterative random blocking%基于MME和IRB的信息隐写算法

    Institute of Scientific and Technical Information of China (English)

    刘九芬; 王勇; 张卫明

    2011-01-01

    为提高隐写算法的安全性,提出一种基于MME(modified matrix encoding)和IRB(iterative random blocking)的信息隐写算法.通过分析基于IRB的隐写算法流程,找到了其栽密图像质量下降的主要原因,使用MME改进了该算法.实验结果表明,相比于IRB隐写算法,改进算法提高了载密图像质量,同时提高了抵抗盲检测的能力.改进算法表明了使用隐写编码可提高嵌入效率,从而提高隐写算法的安全性.%To improve the security of the steganography method, a kind of steganography based on IRB (iterative random blocking)and MME (modified matrix encoding) is presented. The process of the IRB steganography is analyzed to figure out the main reason why secret message embedding would make the image quality descending is analyzed, and the scheme with MME further is improved.Experimental results show that the proposed method would bring less distortion when embedding the secret message. Moreover, the proposed method also improve the capability resisting the recent blind steganalysis scheme. The proposed method show that steganography coding could achieve high embedding efficiency to improve the security of the steganography method.

  2. The Advent of Steganography in Computing Environments

    CERN Document Server

    Zielinska, Elzbieta; Szczypiorski, Krzysztof

    2012-01-01

    Steganography is a general term referring to all methods for the embedding of additional content into some form of carrier, with the aim of concealment of the introduced alterations. The choice of the carrier is nearly unlimited, it may be an ancient piece of parchment, as well as a network protocol header. Inspired by biological phenomena, adopted by man in the ancient times, it has been developed over the ages. Present day steganographic methods are far more sophisticated than their ancient predecessors, but the main principles had remained unchanged. They typically rely on the utilization of digital media files or network protocols as a carrier, in which secret data is embedded. This paper presents the evolution of the hidden data carrier from the ancient times till the present day and pinpoints the observed development trends.

  3. Steganography of VoIP streams

    CERN Document Server

    Mazurczyk, Wojciech

    2008-01-01

    In this paper, we circumscribe available steganographic techniques that can be used for creating covert channels for VoIP (Voice over Internet Protocol) streams. Apart from characterizing existing steganographic methods we provide new insights by presenting two new techniques. First one is network steganography solution and exploits free/unused fields of the RTCP (Real-Time Control Protocol) and RTP (Real-Time Transport Protocol) protocols. The second method provides hybrid storage-timing covert channel by utilizing delayed audio packets. The results of the experiment, that was performed, regardless of steganalysis, to estimate a total amount of data that can be covertly transferred in VoIP RTP stream during the typical call, are also included in this article.

  4. Hybrid distortion function for JPEG steganography

    Science.gov (United States)

    Wang, Zichi; Zhang, Xinpeng; Yin, Zhaoxia

    2016-09-01

    A hybrid distortion function for JPEG steganography exploiting block fluctuation and quantization steps is proposed. To resist multidomain steganalysis, both spatial domain and discrete cosine transformation (DCT) domain are involved in the proposed distortion function. In spatial domain, a distortion value is allotted for each 8×8 block according to block fluctuation. In DCT domain, quantization steps are employed to allot distortion values for DCT coefficients in a block. The two elements, block distortion and quantization steps, are combined together to measure the embedding risk. By employing the syndrome trellis coding to embed secret data, the embedding changes are constrained in complex regions, where modifications are hard to be detected. When compared to current state-of-the-art steganographic methods for JPEG images, the proposed method presents less detectable artifacts.

  5. Building the UPPA high capacity tensiometer

    Directory of Open Access Journals (Sweden)

    Mendes Joao

    2016-01-01

    Full Text Available High capacity tensiometers (HCTs are sensors capable of directly measuring tensile pore water pressure (suction in soils. HCTs are typically composed of a casing that encapsulates a high air entry value ceramic filter, a water reservoir and a pressure sensing element. Since the creation of the first HCT by Ridley and Burland in 1993 at Imperial College London, HCTs have been almost exclusively built and used in academic research. The limited use in industrial applications can be explained by a lack of unsaturated soil mechanics knowledge among engineering practitioners but also by the technical difficulties associated to the direct measurement of tensile water pressures beyond the cavitation limit of -100kPa. In this paper, we present the recent design and manufacture of a new HCT at the Université de Pau et des Pays de l’Adour (UPPA in France. Different prototypes were tried by changing the main components of the device including the type of ceramic filter, pressure transducer and geometry of the external casing. In particular, two ceramic filters of distinct porosity, three pressure transducers with distinct materials/geometries and four casing designs were tested.

  6. Towards green high capacity optical networks

    Science.gov (United States)

    Glesk, I.; Mohd Warip, M. N.; Idris, S. K.; Osadola, T. B.; Andonovic, I.

    2012-02-01

    The demand for fast, secure, energy efficient high capacity networks is growing. It is fuelled by transmission bandwidth needs which will support among other things the rapid penetration of multimedia applications empowering smart consumer electronics and E-businesses. All the above trigger unparallel needs for networking solutions which must offer not only high-speed low-cost "on demand" mobile connectivity but should be ecologically friendly and have low carbon footprint. The first answer to address the bandwidth needs was deployment of fibre optic technologies into transport networks. After this it became quickly obvious that the inferior electronic bandwidth (if compared to optical fiber) will further keep its upper hand on maximum implementable serial data rates. A new solution was found by introducing parallelism into data transport in the form of Wavelength Division Multiplexing (WDM) which has helped dramatically to improve aggregate throughput of optical networks. However with these advancements a new bottleneck has emerged at fibre endpoints where data routers must process the incoming and outgoing traffic. Here, even with the massive and power hungry electronic parallelism routers today (still relying upon bandwidth limiting electronics) do not offer needed processing speeds networks demands. In this paper we will discuss some novel unconventional approaches to address network scalability leading to energy savings via advance optical signal processing. We will also investigate energy savings based on advanced network management through nodes hibernation proposed for Optical IP networks. The hibernation reduces the network overall power consumption by forming virtual network reconfigurations through selective nodes groupings and by links segmentations and partitionings.

  7. High-capacity three-party quantum secret sharing with superdense coding

    Institute of Scientific and Technical Information of China (English)

    Gu Bin; Li Chuan-Qi; Xu Fei; Chen Yu-Lin

    2009-01-01

    This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liu et al (2002 Phys. Rev. A 65 022304) and the quantum secret sharing scheme by Deng et al (2008 Phys. Left. A 372 1957). Instead of using two sets of nonorthogonal states, the boss Alice needs only to prepare a sequence of Einstein-Podolsky-Rosen pairs in d-dimension. The two agents Bob and Charlie encode their information with dense coding unitary operations, and security is checked by inserting decoy photons. The scheme has a high capacity and intrinsic efficiency as each pair can carry 21bd bits of information, and almost all the pairs can be used for carrying useful information.

  8. Hash Based Least Significant Bit Technique For Video Steganography

    Directory of Open Access Journals (Sweden)

    Prof. Dr. P. R. Deshmukh ,

    2014-01-01

    Full Text Available The Hash Based Least Significant Bit Technique For Video Steganography deals with hiding secret message or information within a video.Steganography is nothing but the covered writing it includes process that conceals information within other data and also conceals the fact that a secret message is being sent.Steganography is the art of secret communication or the science of invisible communication. In this paper a Hash based least significant bit technique for video steganography has been proposed whose main goal is to embed a secret information in a particular video file and then extract it using a stego key or password. In this Least Significant Bit insertion method is used for steganography so as to embed data in cover video with change in the lower bit.This LSB insertion is not visible.Data hidding is the process of embedding information in a video without changing its perceptual quality. The proposed method involve with two terms that are Peak Signal to Noise Ratio (PSNR and the Mean Square Error (MSE .This two terms measured between the original video files and steganographic video files from all video frames where a distortion is measured using PSNR. A hash function is used to select the particular position for insertion of bits of secret message in LSB bits.

  9. Secure Image Steganography Algorithm Based on DCT with OTP Encryption

    Directory of Open Access Journals (Sweden)

    De Rosal Ignatius Moses Setiadi

    2017-04-01

    Full Text Available Rapid development of Internet makes transactions message even easier and faster. The main problem in the transactions message is security, especially if the message is private and secret. To secure these messages is usually done with steganography or cryptography. Steganography is a way to hide messages into other digital content such as images, video or audio so it does not seem nondescript from the outside. While cryptography is a technique to encrypt messages so that messages can not be read directly. In this paper have proposed combination of steganography using discrete cosine transform (DCT and cryptography using the one-time pad or vernam cipher implemented on a digital image. The measurement method used to determine the quality of stego image is the peak signal to noise ratio (PSNR and ormalize cross Correlation (NCC to measure the quality of the extraction of the decrypted message. Of steganography and encryption methods proposed obtained satisfactory results with PSNR and NCC high and resistant to JPEG compression and median filter. Keywords—Image Steganography, Discrete Cosine Transform (DCT, One Time Pad, Vernam, Chiper, Image Cryptography

  10. Steganography Algorithm to Hide Secret Message inside an Image

    CERN Document Server

    Ibrahim, Rosziati

    2011-01-01

    In this paper, the authors propose a new algorithm to hide data inside image using steganography technique. The proposed algorithm uses binary codes and pixels inside an image. The zipped file is used before it is converted to binary codes to maximize the storage of data inside the image. By applying the proposed algorithm, a system called Steganography Imaging System (SIS) is developed. The system is then tested to see the viability of the proposed algorithm. Various sizes of data are stored inside the images and the PSNR (Peak signal-to-noise ratio) is also captured for each of the images tested. Based on the PSNR value of each images, the stego image has a higher PSNR value. Hence this new steganography algorithm is very efficient to hide the data inside the image.

  11. Text Steganography using LSB insertion method along with Chaos Theory

    CERN Document Server

    S., Bhavana

    2012-01-01

    The art of information hiding has been around nearly as long as the need for covert communication. Steganography, the concealing of information, arose early on as an extremely useful method for covert information transmission. Steganography is the art of hiding secret message within a larger image or message such that the hidden message or an image is undetectable; this is in contrast to cryptography, where the existence of the message itself is not disguised, but the content is obscure. The goal of a steganographic method is to minimize the visually apparent and statistical differences between the cover data and a steganogram while maximizing the size of the payload. Current digital image steganography presents the challenge of hiding message in a digital image in a way that is robust to image manipulation and attack. This paper explains about how a secret message can be hidden into an image using least significant bit insertion method along with chaos.

  12. Large payload quantum steganography based on cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Ye Tian-Yu; Jiang Li-Zhen

    2013-01-01

    A large payload quantum steganography protocol based on cavity quantum electrodynamics (QED) is presented in this paper,which effectively uses the evolutionary law of atoms in cavity QED.The protocol builds up a hidden channel to transmit secret messages using entanglement swapping between one GHZ state and one Bell state in cavity QED together with the Hadamard operation.The quantum steganography protocol is insensitive to cavity decay and the thermal field.The capacity,imperceptibility and security against eavesdropping are analyzed in detail in the protocol.It turns out that the protocol not only has good imperceptibility but also possesses good security against eavesdropping.In addition,its capacity for a hidden channel achieves five bits,larger than most of the previous quantum steganography protocols.

  13. Amplifier Noise Based Optical Steganography with Coherent Detection

    Science.gov (United States)

    Wu, Ben; Chang, Matthew P.; Caldwell, Naomi R.; Caldwell, Myles E.; Prucnal, Paul R.

    2014-12-01

    We summarize the principle and experimental setup of optical steganography based on amplified spontaneous emission (ASE) noise. Using ASE noise as the signal carrier, optical steganography effectively hides a stealth channel in both the time domain and the frequency domain. Coherent detection is used at the receiver of the stealth channel. Because ASE noise has short coherence length and random phase, it only interferes with itself within a very short range. Coherent detection requires the stealth transmitter and stealth receiver to precisely match the optical delay,which generates a large key space for the stealth channel. Several methods to further improve optical steganography, signal to noise ratio, compatibility with the public channel, and applications of the stealth channel are also summarized in this review paper.

  14. A Fractional Random Wavelet Transform Based Image Steganography

    Directory of Open Access Journals (Sweden)

    G.K. Rajini

    2015-04-01

    Full Text Available This study presents a novel technique for image steganography based on Fractional Random Wavelet Transform. This transform has all the features of wavelet transform with randomness and fractional order built into it. The randomness and fractional order in the algorithm brings in robustness and additional layers of security to steganography. The stegano image generated by this algorithm contains both cover image and hidden image and image degradation is not observed in it. The steganography strives for security and pay load capacity. The performance measures like PeakSignal to Noise Ratio (PSNR, Mean Square Error (MSE, Structural Similarity Index Measure (SSIM and Universal Image Quality Index (UIQI are computed. In this proposed algorithm, imperceptibility and robustness are verified and it can sustain geometric transformations like rotation, scaling and translation and is compared with some of the existing algorithms. The numerical results show the effectiveness of the proposed algorithm.

  15. Spatial Domain Image Steganography based on Security and Randomization

    Directory of Open Access Journals (Sweden)

    Namita Tiwari

    2014-01-01

    Full Text Available In the present digital scenario secure communication is the prime requirement. Commonly, cryptography used for the said purpose. Another method related to cryptography is used for the above objective is Steganography. Steganography is the art of hiding information in some medium. Here we are using image as a means for covering information. Spatial domain image Steganography has been used for the work because of its compatibility to images. Objective of the paper is to increase the capacity of hidden data in a way that security could be maintained. In the current work MSB of the randomly selected pixel have been used as indicator. Result analysis has been performed on the basis of different parameters like PSNR, MSE and capacity.

  16. An Improved Retransmission-based Network Steganography: Design and Detection

    Directory of Open Access Journals (Sweden)

    Jiangtao Zhai

    2013-01-01

    Full Text Available Network steganography is a covert communication technique that uses redundancies in network protocols to transfer secret information. The retransmission-based steganography (RSTEG embeds covert messages into the payload field of the intentionally retransmission packets. So its capacity is higher than most of the existing methods. Because TCP checksum field of the original packet is different from that of the retransmitted packet, RSTEG is not stealthy in fact. An improved method named IRSTEG is presented to resolve the flaw by introducing the payload compensation. Further, a method is proposed to detect IRSTEG based the payload segment comparison. Experiments show that the method can detect IRSTEG well.

  17. VoIP Steganography and Its Detection - A Survey

    CERN Document Server

    Mazurczyk, Wojciech

    2012-01-01

    Steganography is an ancient art that encompasses various techniques of information hiding, the aim of which is to secret information into a carrier message. Steganographic methods are usually aimed at hiding the very existence of the communication. Due to the rise in popularity of IP telephony, together with the large volume of data and variety of protocols involved, it is currently attracting the attention of the research community as a perfect carrier for steganographic purposes. This paper is a survey of the existing VoIP steganography (steganophony) methods and their countermeasures.

  18. SPEED-UP IMPROVEMENT USING PARALLEL APPROACH IN IMAGE STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    JyothiUpadhya K

    2013-12-01

    Full Text Available This paper presents a parallel approach to improve the time complexity problem associated with sequential algorithms. An image steganography algorithm in transform domain is considered for implementation. Image steganography is a technique to hide secret message in an image. With the parallel implementation, large message can be hidden in large image since it does not take much processing time. It is implemented on GPU systems. Parallel programming is done using OpenCL in CUDA cores from NVIDIA. The speed-up improvement obtained is very good with reasonably good output signal quality, when large amount of data is processed

  19. BIT LENGTH REPLACEMENT STEGANOGRAPHY BASED ON DCT COEFFICIENTS

    Directory of Open Access Journals (Sweden)

    K B Shiva Kumar

    2010-08-01

    Full Text Available Steganography is a means of establishing secret communication through public channel in an artistic manner. In this paper, we propose Bit Length Replacement Steganography Based on DCT Coefficients (BLSDCT . The cover image is segmented into 8*8 blocks and DCT is applied on each block. The numbers of payload MSB bits are embedded into DCT coefficients of the cover image based on the values of DCT oefficients. It is observed that the proposed algorithm has better PSNR, Security and capacity compared to the existing algorithm.

  20. An FPGA Implementation of Secured Steganography Communication System

    Directory of Open Access Journals (Sweden)

    Ahlam Mahmood

    2014-04-01

    Full Text Available Steganography is the idea of hiding secret message in multimedia cover which will be transmitted through the Internet. The cover carriers can be image, video, sound or text data. This paper presents an implementation of color image steganographic system on Field Programmable Gate Array and the information hiding/extracting techniques in various images. The proposed algorithm is based on merge between the idea from the random pixel manipulation methods and the Least Significant Bit (LSB matching of Steganography embedding and extracting method.  In a proposed steganography hardware approach, Linear Feedback Shift Register (LFSR method has been used in stego architecture to hide the information in the image. The LFSRs are utilized in this approach as address generators. Different LFSR arrangements using different connection unit have been implemented at the hardware level for hiding/extracting the secret data. Multilayer embedding is implemented in parallel manner with a three-stage pipeline on FPGA.  This work showed attractive results especially in the high throughputs, better stego-image quality, requires little calculation and less utilization of FPGA area. The imperceptibility of the technique combined with high payload, robustness of embedded data and accurate data retrieval renders the proposed Steganography system is suitable for covert communication and secure data transmission applications

  1. A Detailed look of Audio Steganography Techniques using LSB and Genetic Algorithm Approach

    Directory of Open Access Journals (Sweden)

    Gunjan Nehru

    2012-01-01

    Full Text Available This paper is the study of various techniques of audio steganography using different algorithmis like genetic algorithm approach and LSB approach. We have tried some approaches that helps in audio steganography. As we know it is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. In steganography, the message used to hide secret message is called host message or cover message. Once the contents of the host message or cover message are modified, the resultant message is known as stego message. In other words, stego message is combination of host message and secret message. Audio steganography requires a text or audio secret message to be embedded within a cover audio message. Due to availability of redundancy, the cover audio message before steganography, stego message after steganography remains same. for information hiding.

  2. Novel Steganography System using Lucas Sequence

    Directory of Open Access Journals (Sweden)

    Fahd Alharbi

    2013-05-01

    Full Text Available Steganography is the process of embedding data into a media form such as image, voice, and video. The major methods used for data hiding are the frequency domain and the spatial domain. In the frequency domain, the secret data bits are inserted into the coefficients of the image pixel's frequency representation such as Discrete Cosine Transform (DCT , Discrete Fourier Transform (DFT and Discrete Wavelet Transform (DWT . On the other hand, in the spatial domain method, the secret data bits are inserted directly into the images' pixels value decomposition. The Lest Significant Bit (LSB is consider as the most widely spatial domain method used for data hiding. LSB embeds the secret message's bits into the least significant bit plane( Binary decomposition of the image in a sequentially manner . The LSB is simple, but it poses some critical issues. The secret message is easily detected and attacked duo to the sequential embedding process. Moreover, embedding using a higher bit plane would degrade the image quality. In this paper, we are proposing a novel data hiding method based on Lucas number system. We use Lucas number system to decompose the images' pixels values to allow using higher bit plane for embedding without degrading the image's quality. The experimental results show that the proposed method achieves better Peak Signal to Noise Ratio ( PSNR than the LSB method for both gray scale and color images. Moreover, the security of the hidden data is enhanced by using Pseudo Random Number Generators(PRNG for selecting the secret data bits to be embedded and the image's pixels used for embedding.

  3. A Detailed look of Audio Steganography Techniques using LSB and Genetic Algorithm Approach

    OpenAIRE

    Gunjan Nehru; Puja Dhar

    2012-01-01

    This paper is the study of various techniques of audio steganography using different algorithmis like genetic algorithm approach and LSB approach. We have tried some approaches that helps in audio steganography. As we know it is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. In steganography, the message used to hide secret message is called hos...

  4. Steganography: Applying and Evaluating Two Algorithms for Embedding Audio Data in an Image

    OpenAIRE

    Khaled Nasser ElSayed

    2015-01-01

    Information transmission is increasing with grow of using WEB. So, information security has become very important. Security of data and information is the major task for scientists and political and military people. One of the most secure methods is embedding data (steganography) in different media like text, audio, digital images. this paper present two experiments in steganography of digital audio data file. It applies empirically, two algorithms in steganography in images through random in...

  5. Proposed System for data hiding using Cryptography and Steganography Proposed System for data hiding using Cryptography and Steganography

    CERN Document Server

    Sarmah, Dipti Kapoor

    2010-01-01

    Steganography and Cryptography are two popular ways of sending vital information in a secret way. One hides the existence of the message and the other distorts the message itself. There are many cryptography techniques available; among them AES is one of the most powerful techniques. In Steganography we have various techniques in different domains like spatial domain, frequency domain etc. to hide the message. It is very difficult to detect hidden message in frequency domain and for this domain we use various transformations like DCT, FFT and Wavelets etc. In this project we are developing a system where we develop a new technique in which Cryptography and Steganography are used as integrated part along with newly developed enhanced security module. In Cryptography we are using AES algorithm to encrypt a message and a part of the message is hidden in DCT of an image; remaining part of the message is used to generate two secret keys which make this system highly secured. Keyword: Cryptography, Steganography, S...

  6. Radiation Tolerant, High Capacity Non-Volatile Memory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for reliable, high capacity, radiation tolerant nonvolatile memory exists in many Human space flight applications. Most projects rely on COTS hardware for a...

  7. 一种三路像素差值的视频隐写算法设计及实现%Design and implementation of a video steganography methods using TPVD

    Institute of Scientific and Technical Information of China (English)

    张海龙; 徐伯庆

    2011-01-01

    In order to improve the concealment and hiding capacity of the video steganography, a new video steganography scheme is introduced and implemented in platform of VC++6. 0. In this algorithm, data are embedded in the macro blocks of I frame with maximum scene change, perceived not easily, so as to increase the concealment of the video steganography. To enlarge the hiding capacity of the secret information, a novel steganography approach called tri-way pixel-value differencing (TPVD) is used for embedding. Experimental results demonstrate that the proposed algorithm has high concealment and hiding capacity.%为了提高视频隐写的隐蔽性和隐藏量,介绍一种新的视频隐写方法并在VC++6.0下得以实现.在这种算法中,数据嵌在场景变化最大的I帧宏块中,人眼不易察觉,从而提高了视频隐写的隐蔽性.为了扩大秘密信息的隐藏量,现使用一种新的方法三路像素差值(TPVD)算法完成信息隐写.实验结果表明该方法具有较高的隐蔽性和隐藏量.

  8. An Image Steganography Algorithm Combined with Integer Programming and YASS%一种结合整数规划和YASS的图像隐写算法

    Institute of Scientific and Technical Information of China (English)

    忻佳琳; 王士林

    2013-01-01

    In order to increase the steganography rate, this paper proposes a new scheme of steganography which is based on YASS algorithm. After discussing the inherent relationship between Discrete Cosine Transform(DCT) coefficients in different blocks, a method of iterative programming is proposed which is referenced to integer programming, and the carrier which has steganography has been corrected. In aspect of anti-detection, 98 degree’s Markov steganalysis method is used to detect the stego images. Experimental result shows that this optimization algorithm is proved to effectively decrease the errors caused by JPEG compression during YASS steganography. In this way, steganographic rate is increased to a great extent. This method is also proved to get the same outstanding performance in common anti-detection.%为提高图像隐写率,在 YASS 算法的基础上,提出一种改进的图像隐写算法。分析不同图像分块离散余弦变换系数之间的固有联系,借鉴整数规划的思想设计迭代算法,对已隐写的载体进行数据校正。使用98维马尔科夫通用图像检测方法进行实验,结果表明,该算法能减少YASS隐写过程中由JPEG图像压缩引入的误码,提高隐写率,同时可有效抵抗通用隐写检测。

  9. A Robust Image Steganography using DWT Difference Modulation (DWTDM

    Directory of Open Access Journals (Sweden)

    Souvik Bhattacharyya

    2012-07-01

    Full Text Available Maintaining the secrecy of information is of great concern today.Steganography is the art and science that hides the information in an appropriate cover carrier like image, text, audio and video media. Considerable amount of work has been carried out by different researchers on steganography. In this work a new transform domain image stenographic technique DWTDM is presented where secret data is embedded in adjacent DWT coefficient differences. The dynamic range of the DWT difference considered while extraction of data which results an efficient and robust stenographic technique which can avoid various image attacks and works perfectly well for both uncompressed and compressed domain. Experimental results demonstrate the effectiveness and accuracy of the proposed technique in terms of security of hidden data and various image similarity metrics.

  10. PadSteg: Introducing Inter-Protocol Steganography

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2011-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents inter-protocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  11. Influence of Speech Codecs Selection on Transcoding Steganography

    CERN Document Server

    Janicki, Artur; Szczypiorski, Krzysztof

    2012-01-01

    The typical approach to steganography is to compress the covert data in order to limit its size, which is reasonable in the context of a limited steganographic bandwidth. TranSteg (Trancoding Steganography) is a new IP telephony steganographic method that was recently proposed that offers high steganographic bandwidth while retaining good voice quality. In TranSteg, compression of the overt data is used to make space for the steganogram. In this paper we focus on analyzing the influence of the selection of speech codecs on hidden transmission performance, that is, which codecs would be the most advantageous ones for TranSteg. Therefore, by considering the codecs which are currently most popular for IP telephony we aim to find out which codecs should be chosen for transcoding to minimize the negative influence on voice quality while maximizing the obtained steganographic bandwidth.

  12. An efficient steganography method for hiding patient confidential information.

    Science.gov (United States)

    Al-Dmour, Hayat; Al-Ani, Ahmed; Nguyen, Hung

    2014-01-01

    This paper deals with the important issue of security and confidentiality of patient information when exchanging or storing medical images. Steganography has recently been viewed as an alternative or complement to cryptography, as existing cryptographic systems are not perfect due to their vulnerability to certain types of attack. We propose in this paper a new steganography algorithm for hiding patient confidential information. It utilizes Pixel Value Differencing (PVD) to identify contrast regions in the image and a Hamming code that embeds 3 secret message bits into 4 bits of the cover image. In order to preserve the content of the region of interest (ROI), the embedding is only performed using the Region of Non-Interest (RONI).

  13. Perfect Z2Z4-linear codes in Steganography

    CERN Document Server

    Rifà, H; Ronquillo, L

    2010-01-01

    Steganography is an information hiding application which aims to hide secret data imperceptibly into a commonly used media. Unfortunately, the theoretical hiding asymptotical capacity of steganographic systems is not attained by algorithms developed so far. In this paper, we describe a novel coding method based on Z2Z4-linear codes that conforms to +/-1-steganography, that is secret data is embedded into a cover message by distorting each symbol by one unit at most. This method solves some problems encountered by the most efficient methods known today, based on ternary Hamming codes. Finally, the performance of this new technique is compared with that of the mentioned methods and with the well-known theoretical upper bound.

  14. Quantum Steganography for Multi-party Covert Communication

    Science.gov (United States)

    Liu, Lin; Tang, Guang-Ming; Sun, Yi-Feng; Yan, Shu-Fan

    2016-01-01

    A novel multi-party quantum steganography protocol based on quantum secret sharing is proposed in this paper. Hidden channels are built in HBB and improved HBB quantum secret sharing protocols for secret messages transmitting, via the entanglement swapping of GHZ states and Bell measurement. Compared with the original protocol, there are only a few different GHZ sates transmitted in the proposed protocol, making the hidden channel with good imperceptibility. Moreover, the secret messages keep secure even when the hidden channel is under the attack from the dishonest participators, for the sub-secretmessages distributed randomly to different participators. With good imperceptibility and security, the capacity of proposed protocol is higher than previous multi-party quantum steganography protocol.

  15. Comparison of Video Steganography Methods for Watermark Embedding

    Directory of Open Access Journals (Sweden)

    Griberman David

    2016-05-01

    Full Text Available The paper focuses on the comparison of video steganography methods for the purpose of digital watermarking in the context of copyright protection. Four embedding methods that use Discrete Cosine and Discrete Wavelet Transforms have been researched and compared based on their embedding efficiency and fidelity. A video steganography program has been developed in the Java programming language with all of the researched methods implemented for experiments. The experiments used 3 video containers with different amounts of movement. The impact of the movement has been addressed in the paper as well as the ways of potential improvement of embedding efficiency using adaptive embedding based on the movement amount. Results of the research have been verified using a survey with 17 participants.

  16. RSA Based Secured Image Steganography Using DWT Approach

    Directory of Open Access Journals (Sweden)

    E. Yuva Kumar

    2014-08-01

    Full Text Available The need for keeping safe secrecy of secret and sensitive data has been ever increasing with the new developments in digital system. In this paper, we present an increased way for getting embedding encrypted secret facts in gray scale images to give high level safety of facts for news over unsecured narrow channels Cryptography and Steganography are two closely related techniques are used in proposed system. Cryptography gets into making one of religion the secret note into a non-recognizable chipper. Steganography is then sent in name for using Double-Stegging to fix this encrypted data into a cover thing by which something is done and keeps secret its existence.

  17. A Security Enhanced Robust Steganography Algorithm for Data Hiding

    OpenAIRE

    Siddharth Singh; Tanveer J. Siddiqui

    2012-01-01

    In this paper, a new robust steganography algorithm based on discrete cosine transform (DCT), Arnold transform and chaotic system is proposed. The chaotic system is used to generate a random sequence to be used for spreading data in the middle frequency band DCT coefficient of the cover image. The security is further enhanced by scrambling the secret data using Arnold Cat map before embedding. The recovery process is blind. A series of experiments is conducted to prove the security and robust...

  18. EFFICIENT ADAPTIVE STEGANOGRAPHY FOR COLOR IMAGESBASED ON LSBMR ALGORITHM

    Directory of Open Access Journals (Sweden)

    B. Sharmila

    2012-02-01

    Full Text Available Steganography is the art of hiding the fact that communication is taking place, by hiding information in other medium. Many different carrier file formats can be used, but digital images are the most popular because of their frequent use on the Internet. For hiding secret information in images, there exists a large variety of steganographic techniques. The Least Significant Bit (LSB based approach is a simplest type of steganographic algorithm. In all the existing approaches, the decision of choosing the region within a cover image is performed without considering the relationship between image content and the size of secret message. Thus, the plain regions in the cover will be ruin after data hiding even at a low data rate. Hence choosing the edge region for data hiding will be a solution. Many algorithms are deal with edges in images for data hiding. The Paper 'Edge adaptive image steganography based on LSBMR algorithm' is a LSB steganography presented the results of algorithms on gray-scale images only. This paper presents the results of analyzing the performance of edge adaptive steganography for colored images (JPEG. The algorithms have been slightly modified for colored image implementation and are compared on the basis of evaluation parameters like peak signal noise ratio (PSNR and mean square error (MSE. This method can select the edge region depending on the length of secret message and difference between two consecutive bits in the cover image. For length of message is short, only small edge regions are utilized while on leaving other region as such. When the data rate increases, more regions can be used adaptively for data hiding by adjusting the parameters. Besides this, the message is encrypted using efficient cryptographic algorithm which further increases the security.

  19. PIXASTIC: STEGANOGRAPHY BASED ANTI-PHISHING BROWSER PLUG-IN

    OpenAIRE

    P.Thiyagarajan; G.Aghila; V. Prasanna Venkatesan

    2012-01-01

    In spite of existence of many standard security mechanisms for ensuring secure e- Commerce business, users still fall prey for onlin e attacks. One such simple but powerful attack is ‘Phishing’. Phishing is the most alarming threat in the e-Commerce world and effective anti-phishing technique is the need of the hour. This paper focuses on a novel anti-phishing browser plug-in which uses information hiding technique - Steganography. A Robust Message based Im...

  20. Design of high-capacity fiber-optic transport systems

    Science.gov (United States)

    Liao, Zhi Ming

    2001-08-01

    We study the design of fiber-optic transport systems and the behavior of fiber amplifiers/lasers with the aim of achieving higher capacities with larger amplifier spacing. Solitons are natural candidates for transmitting short pulses for high-capacity fiber-optic networks because of its innate ability to use two of fiber's main defects, fiber dispersion and fiber nonlinearity to balance each other. In order for solitons to retain its dynamic nature, amplifiers must be placed periodically to restore powers to compensate for fiber loss. Variational analysis is used to study the long-term stability of a periodical- amplifier system. A new regime of operation is identified which allows the use of a much longer amplifier spacing. If optical fibers are the blood vessels of an optical communication system, then the optical amplifier based on erbium-doped fiber is the heart. Optical communication systems can avoid the use of costly electrical regenerators to maintain system performance by being able to optically amplify the weakened signals. The length of amplifier spacing is largely determined by the gain excursion experienced by the solitons. We propose, model, and demonstrate a distributed erbium-doped fiber amplifier which can drastically reduce the amount of gain excursion experienced by the solitons, therefore allowing a much longer amplifier spacing and superior stability. Dispersion management techniques have become extremely valuable tools in the design of fiber-optic communication systems. We have studied in depth the advantage of different arnplification schemes (lumped and distributed) for various dispersion compensation techniques. We measure the system performance through the Q factor to evaluate the added advantage of effective noise figure and smaller gain excursion. An erbium-doped fiber laser has been constructed and characterized in an effort to develop a test bed to study transmission systems. The presence of mode-partition noise in an erbium

  1. The Quantum Steganography Protocol via Quantum Noisy Channels

    Science.gov (United States)

    Wei, Zhan-Hong; Chen, Xiu-Bo; Niu, Xin-Xin; Yang, Yi-Xian

    2015-08-01

    As a promising branch of quantum information hiding, Quantum steganography aims to transmit secret messages covertly in public quantum channels. But due to environment noise and decoherence, quantum states easily decay and change. Therefore, it is very meaningful to make a quantum information hiding protocol apply to quantum noisy channels. In this paper, we make the further research on a quantum steganography protocol for quantum noisy channels. The paper proved that the protocol can apply to transmit secret message covertly in quantum noisy channels, and explicity showed quantum steganography protocol. In the protocol, without publishing the cover data, legal receivers can extract the secret message with a certain probability, which make the protocol have a good secrecy. Moreover, our protocol owns the independent security, and can be used in general quantum communications. The communication, which happen in our protocol, do not need entangled states, so our protocol can be used without the limitation of entanglement resource. More importantly, the protocol apply to quantum noisy channels, and can be used widely in the future quantum communication.

  2. Medical Image Steganography: Study of Medical Image Quality Degradation when Embedding Data in the Frequency Domain

    Directory of Open Access Journals (Sweden)

    M.I.Khalil

    2017-02-01

    Full Text Available Steganography is the discipline of invisible communication by hiding the exchanged secret information (message in another digital information media (image, video or audio. The existence of the message is kept indiscernible in sense that no one, other than the intended recipient, suspects the existence of the message. The majority of steganography techniques are implemented either in spatial domain or in frequency domain of the digital images while the embedded information can be in the form of plain or cipher message. Medical image steganography is classified as a distinctive case of image steganography in such a way that both the image and the embedded information have special requirements such as achieving utmost clarity reading of the medical images and the embedded messages. There is a contention between the amount of hidden information and the caused detectable distortion of image. The current paper studies the degradation of the medical image when undergoes the steganography process in the frequency domain.

  3. Genetic Algorithm to Make Persistent Security and Quality of Image in Steganography from RS Analysis

    CERN Document Server

    Nair, T R Gopalakrishnan; S, Manas

    2012-01-01

    Retention of secrecy is one of the significant features during communication activity. Steganography is one of the popular methods to achieve secret communication between sender and receiver by hiding message in any form of cover media such as an audio, video, text, images etc. Least significant bit encoding is the simplest encoding method used by many steganography programs to hide secret message in 24bit, 8bit colour images and grayscale images. Steganalysis is a method of detecting secret message hidden in a cover media using steganography. RS steganalysis is one of the most reliable steganalysis which performs statistical analysis of the pixels to successfully detect the hidden message in an image. However, existing steganography method protects the information against RS steganalysis in grey scale images. This paper presents a steganography method using genetic algorithm to protect against the RS attack in colour images. Stego image is divided into number of blocks. Subsequently, with the implementation ...

  4. Detection of Steganography-Producing Software Artifacts on Crime-Related Seized Computers

    Directory of Open Access Journals (Sweden)

    Asawaree Kulkarni

    2009-06-01

    Full Text Available Steganography is the art and science of hiding information within information so that an observer does not know that communication is taking place. Bad actors passing information using steganography are of concern to the national security establishment and law enforcement. An attempt was made to determine if steganography was being used by criminals to communicate information. Web crawling technology was used and images were downloaded from Web sites that were considered as likely candidates for containing information hidden using steganographic techniques. A detection tool was used to analyze these images. The research failed to demonstrate that steganography was prevalent on the public Internet. The probable reasons included the growth and availability of large number of steganography-producing tools and the limited capacity of the detection tools to cope with them. Thus, a redirection was introduced in the methodology and the detection focus was shifted from the analysis of the ‘product’ of the steganography-producing software; viz. the images, to the 'artifacts’ left by the steganography-producing software while it is being used to generate steganographic images. This approach was based on the concept of ‘Stego-Usage Timeline’. As a proof of concept, a sample set of criminal computers was scanned for the remnants of steganography-producing software. The results demonstrated that the problem of ‘the detection of the usage of steganography’ could be addressed by the approach adopted after the research redirection and that certain steganographic software was popular among the criminals. Thus, the contribution of the research was in demonstrating that the limitations of the tools based on the signature detection of steganographically altered images can be overcome by focusing the detection effort on detecting the artifacts of the steganography-producing tools.

  5. High capacity anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Herman A.; Anguchamy, Yogesh Kumar; Deng, Haixia; Han, Yongbon; Masarapu, Charan; Venkatachalam, Subramanian; Kumar, Suject

    2015-11-19

    High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.

  6. Steganalysis of content-adaptive JPEG steganography based on Gauss partial derivative filter bank

    Science.gov (United States)

    Zhang, Yi; Liu, Fenlin; Yang, Chunfang; Luo, Xiangyang; Song, Xiaofeng; Lu, Jicang

    2017-01-01

    A steganalysis feature extraction method based on Gauss partial derivative filter bank is proposed in this paper to improve the detection performance for content-adaptive JPEG steganography. Considering that the embedding changes of content-adaptive steganographic schemes are performed in the texture and edge regions, the proposed method generates filtered images comprising rich texture and edge information using Gauss partial derivative filter bank, and histograms of absolute values of filtered subimages are extracted as steganalysis features. Gauss partial derivative filter bank can represent texture and edge information in multiple orientations with less computation load than conventional methods and prevent redundancy in different filtered images. These two properties are beneficial in the extraction of low-complexity sensitive features. The results of experiments conducted on three selected modern JPEG steganographic schemes-uniform embedding distortion, JPEG universal wavelet relative distortion, and side-informed UNIWARD-indicate that the proposed feature set is superior to the prior art feature sets-discrete cosine transform residual, phase aware rich model, and Gabor filter residual.

  7. Micro-machined high capacity silicon load cells

    NARCIS (Netherlands)

    Zwijze, A.F.

    2000-01-01

    The aim of the research presented in this thesis is to improve the performance of high capacity conventional load cells or force sensors by using silicon as the base material. Silicon is used because it offers the possibility of realising small, light, low cost and high performance mechanical sensor

  8. Steganography Using Adaptive Pixel Value Differencing(APVD) of Gray Images Through Exclusion of Overflow/Underflow

    CERN Document Server

    Mandal, J K

    2012-01-01

    In a gray scale image the pixel value ranges from 0 to 255. But when we use pixel-value differencing (pvd) method as image steganographic scheme, the pixel values in the stego-image may exceed gray scale range. An adaptive steganography based on modified pixel-value differencing through management of pixel values within the range of gray scale has been proposed in this paper. PVD method is used and check whether the pixel value exceeds the range on embedding. Positions where the pixel exceeds boundary has been marked and a delicate handle is used to keep the value within the range. From the experimental it is seen that the results obtained in proposed method provides with identical payload and visual fidelity of stego-image compared to the pvd method.

  9. Steganography: Applying and Evaluating Two Algorithms for Embedding Audio Data in an Image

    Directory of Open Access Journals (Sweden)

    Khaled Nasser ElSayed

    2015-03-01

    Full Text Available Information transmission is increasing with grow of using WEB. So, information security has become very important. Security of data and information is the major task for scientists and political and military people. One of the most secure methods is embedding data (steganography in different media like text, audio, digital images. this paper present two experiments in steganography of digital audio data file. It applies empirically, two algorithms in steganography in images through random insertion of digital audio data using bytes and pixels in image files. Finally, it evaluates both experiments, in order to enhance security of transmitted data.

  10. Blind Detection of LSB Steganography in Grayscale Images

    Institute of Scientific and Technical Information of China (English)

    HU Ling-na; JIANG Ling-ge; HE Chen

    2007-01-01

    There are many detectors for the least significant bit (LSB) steganography which is broadly used in hiding information in the digital images. The length of the hidden information is one of the most important parameters in detecting steganographic information. Using 2-D gradient of a pixel and the distance between variables the proposed method gives the length of hidden information in natural grayscale images without original image. Extensive experimental results show good performance even at low embedding rate compared with other methods. Furthermore, the proposed method also works well disregarding the status of the embedded information.

  11. Lost Audio Packets Steganography: The First Practical Evaluation

    CERN Document Server

    Mazurczyk, Wojciech

    2011-01-01

    This paper presents first experimental results for an IP telephony-based steganographic method called LACK (Lost Audio PaCKets steganography). This method utilizes the fact that in typical multimedia communication protocols like RTP (Real-Time Transport Protocol), excessively delayed packets are not used for the reconstruction of transmitted data at the receiver, i.e. these packets are considered useless and discarded. The results presented in this paper were obtained basing on a functional LACK prototype and show the method's impact on the quality of voice transmission. Achievable steganographic bandwidth for the different IP telephony codecs is also calculated.

  12. Modified 8×8 quantization table and Huffman encoding steganography

    Science.gov (United States)

    Guo, Yongning; Sun, Shuliang

    2014-10-01

    A new secure steganography, which is based on Huffman encoding and modified quantized discrete cosine transform (DCT) coefficients, is provided in this paper. Firstly, the cover image is segmented into 8×8 blocks and modified DCT transformation is applied on each block. Huffman encoding is applied to code the secret image before embedding. DCT coefficients are quantized by modified quantization table. Inverse DCT(IDCT) is conducted on each block. All the blocks are combined together and the steg image is finally achieved. The experiment shows that the proposed method is better than DCT and Mahender Singh's in PSNR and Capacity.

  13. Secured Data Transmission Using Wavelet Based Steganography and cryptography

    Directory of Open Access Journals (Sweden)

    K.Ravindra Reddy

    2014-02-01

    Full Text Available Steganography and cryptographic methods are used together with wavelets to increase the security of the data while transmitting through networks. Another technology, the digital watermarking is the process of embedding information into a digital (image signal. Before embedding the plain text into the image, the plain text is encrypted by using Data Encryption Standard (DES algorithm. The encrypted text is embedded into the LL sub band of the wavelet decomposed image using Least Significant Bit (LSB method. Then the inverse wavelet transform is applied and the resultant image is transmitted to the receiver. The receiver will perform the same operations in reverse order

  14. 基于GMM模型的自适应扩频隐写安全性分析%Security Analysis of Adaptive Spread Spectrum Image Steganography Based on Gaussian Mixture Model

    Institute of Scientific and Technical Information of China (English)

    奚玲; 平西建; 张昊

    2012-01-01

    Aiming at the security problem of adaptive steganography, the analysis method based on Gaussian mixture model(GMM) of real image is proposed. Compared the stego random characteristic function of probability density function between the adaptive Spread Spectrum Image Steganography(SSIS) and the general non adaptive one under the condition that the total embedding intensity is equal, it demonstrates that the security of adaptive SSIS is higher than that of non-adaptive schemes. Analysis result shows that the method provides theoretical evidence for using adaptive scheme to improve statistical imperceptibility of steganography.%对自适应隐写的安全性问题进行分析,提出一种基于自然图像的高斯混合模型分析方法.在总嵌入强度相同的条件下,比较自适应和非自适应扩频隐写载密随机变量概率密度函数的特征函数,验证自适应扩频隐写的统计安全性高于等嵌入强度下非自适应扩频隐写.分析结果表明,该方法能为提升信息隐藏系统的抗统计分析性能提供理论依据.

  15. Recycling rice husks for high-capacity lithium battery anodes.

    Science.gov (United States)

    Jung, Dae Soo; Ryou, Myung-Hyun; Sung, Yong Joo; Park, Seung Bin; Choi, Jang Wook

    2013-07-23

    The rice husk is the outer covering of a rice kernel and protects the inner ingredients from external attack by insects and bacteria. To perform this function while ventilating air and moisture, rice plants have developed unique nanoporous silica layers in their husks through years of natural evolution. Despite the massive amount of annual production near 10(8) tons worldwide, so far rice husks have been recycled only for low-value agricultural items. In an effort to recycle rice husks for high-value applications, we convert the silica to silicon and use it for high-capacity lithium battery anodes. Taking advantage of the interconnected nanoporous structure naturally existing in rice husks, the converted silicon exhibits excellent electrochemical performance as a lithium battery anode, suggesting that rice husks can be a massive resource for use in high-capacity lithium battery negative electrodes.

  16. 一种透明健壮大容量的音频密写算法%A TRANSPARENT ROBUST AND HIGH CAPACITY AUDIO STEGANOGRAPHY ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    李跃强; 丁超; 孙星明

    2010-01-01

    提出一种新的基于离散余弦变换的大容量数字音频密写算法.音频的低频DCT系数集中了音频的重要信息,而高频DCT系数只包含少量信息.根据这一特性,采取不改变、缩小及增加高频DCT系数的方法,在高频DCT系数中嵌入秘密信息.实验证明,该算法具有较大的嵌入量、较强的健壮性、较好的透明性,提取属盲提取,能经受重采样、重新量化、添加噪声、低通滤波、音频格式转换等常见信号处理及攻击.

  17. Robust and High Capacity Steganography in Audio%鲁棒的高容量音频信息隐藏算法

    Institute of Scientific and Technical Information of China (English)

    柴毅; 刘一均; 郭茂耘; 刘宇

    2008-01-01

    提出一种音频信息隐藏算法,该算法利用CDMA扩谱方法对秘密信息进行预处理,使用离散小波变换获得掩护声音的近似系数,将秘密信息嵌入到近似系数的离散余弦变换中频部分.实验结果表明该算法具有较高的信息隐藏容量和较强的鲁棒性,能抵抗幅值规范化、滤波、失真、消噪及其部分组合攻击.

  18. High Capacity Audio Steganography in MP3 Bitstreams%大容量 MP3 比特流音频隐写算法

    Institute of Scientific and Technical Information of China (English)

    刘秀娟; 郭立

    2007-01-01

    通过对MP3编解码算法原理的研究,提出了一种基于小值区哈夫曼编码特点的信息嵌入方法--码字映射替换规则,进而实现了一种能在MP3压缩文件的比特流中隐藏大量信息的盲检测隐写算法.算法先对载体mp3文件部分解码,搜索出适合嵌入的小值区码字,然后按规则修改比特流中的相应码字来嵌入秘密信息.实验结果表明,算法的容量高于MP3Stego,计算复杂度低,同时可保证不可感知性,并具有一定的不可检测性,能抵抗针对MP3Stego的隐写分析算法.

  19. A graph theory practice on transformed image: a random image steganography.

    Science.gov (United States)

    Thanikaiselvan, V; Arulmozhivarman, P; Subashanthini, S; Amirtharajan, Rengarajan

    2013-01-01

    Modern day information age is enriched with the advanced network communication expertise but unfortunately at the same time encounters infinite security issues when dealing with secret and/or private information. The storage and transmission of the secret information become highly essential and have led to a deluge of research in this field. In this paper, an optimistic effort has been taken to combine graceful graph along with integer wavelet transform (IWT) to implement random image steganography for secure communication. The implementation part begins with the conversion of cover image into wavelet coefficients through IWT and is followed by embedding secret image in the randomly selected coefficients through graph theory. Finally stegoimage is obtained by applying inverse IWT. This method provides a maximum of 44 dB peak signal to noise ratio (PSNR) for 266646 bits. Thus, the proposed method gives high imperceptibility through high PSNR value and high embedding capacity in the cover image due to adaptive embedding scheme and high robustness against blind attack through graph theoretic random selection of coefficients.

  20. A Survey on Steganography Techniques in Real Time Audio Signals and Evaluation

    Directory of Open Access Journals (Sweden)

    Abdulaleem Z. Al-Othmani

    2012-01-01

    Full Text Available Steganography has proven to be one of the practical ways of securing data. It is a new kind of secret communication used mainly to hide secret data inside other innocent digital mediums. Most of existing steganographic techniques use digital multimedia files as cover mediums to hide secret data. Audio files and signals make appropriate mediums for steganography due to the high data transmission rate and the high level of redundancy. Hiding data in real time communication audio signals is not a simple mission. Steganography requirements as well as real time communication requirements are supposed to be met in order to construct a useful and useful data hiding application. In this paper we will survey the general principles of hiding secret information using audio technology, and provide an overview of current functions and techniques. These techniques will be evaluated across both, steganography and real time communication requirements.

  1. A NEW APPROACH TO TELUGU TEXT STEGANOGRAPHY BY SHIFTING INHERENT VOWEL SIGNS

    Directory of Open Access Journals (Sweden)

    SRAVANI ALAMETI. ANKAM,

    2010-12-01

    Full Text Available Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. The advantage of steganography, over cryptography alone, is that messages do not attract attention to themselves. Cryptography protects the contents of a message, steganography can be said to protect both messages and communicating parties. Wide ranges of algorithms have been introduced using text, audio, video and imagesfiles as covering media. This paper presents a new approach for steganography in Telugu texts. Taking the typical structure of Telugu alphabets into consideration, in this approach, by shifting inherent vowel signs either left or right, we hide the secret message. The approach shows good result on the sample collected from differentTelugu newspaper.

  2. PIXASTIC: STEGANOGRAPHY BASED ANTI-PHISHING BROWSER PLUG-IN

    Directory of Open Access Journals (Sweden)

    P.Thiyagarajan

    2012-04-01

    Full Text Available In spite of existence of many standard security mechanisms for ensuring secure e- Commerce business, users still fall prey for onlin e attacks. One such simple but powerful attack is ‘Phishing’. Phishing is the most alarming threat in the e-Commerce world and effective anti-phishing technique is the need of the hour. This paper focuses on a novel anti-phishing browser plug-in which uses information hiding technique - Steganography. A Robust Message based Image Steganography (RMIS algorithm has been proposed. The same has been incorporated in the form of a browser plug-in (safari called Pixastic. Pixastic is tested in an online banking scenario and it is compared with other well-known anti-phishing plug-in methods in practice. Various parameters such as robustness, usability and its behavior on various attacks have been analysed. From experimental results, it is ev ident that our method Pixastic performs well compared to other anti-phishing plug-ins.

  3. Mel-cepstrum-based steganalysis for VoIP steganography

    Science.gov (United States)

    Kraetzer, Christian; Dittmann, Jana

    2007-02-01

    Steganography and steganalysis in VoIP applications are important research topics as speech data is an appropriate cover to hide messages or comprehensive documents. In our paper we introduce a Mel-cepstrum based analysis known from speaker and speech recognition to perform a detection of embedded hidden messages. In particular we combine known and established audio steganalysis features with the features derived from Melcepstrum based analysis for an investigation on the improvement of the detection performance. Our main focus considers the application environment of VoIP-steganography scenarios. The evaluation of the enhanced feature space is performed for classical steganographic as well as for watermarking algorithms. With this strategy we show how general forensic approaches can detect information hiding techniques in the field of hidden communication as well as for DRM applications. For the later the detection of the presence of a potential watermark in a specific feature space can lead to new attacks or to a better design of the watermarking pattern. Following that the usefulness of Mel-cepstrum domain based features for detection is discussed in detail.

  4. Image Steganography using Hybrid Edge Detector and Ridgelet Transform

    Directory of Open Access Journals (Sweden)

    S. Uma Maheswari

    2015-05-01

    Full Text Available Steganography is the art of hiding high sensitive information in digital image, text, video, and audio. In this paper, authors have proposed a frequency domain steganography method operating in the Ridgelet transform. Authors engage the advantage of ridgelet transform, which represents the digital image with straight edges. In the embedding phase, the proposed hybrid edge detector acts as a preprocessing step to obtain the edge image from the cover image, then the edge image is partitioned into several blocks to operate with straight edges and Ridgelet transform is applied to each block. Then, the most significant gradient vectors (or significant edges are selected to embed the secret data. The proposed method has shown the advantages of imperceptibility of the stego image is increased because the secret data is hidden in the significant gradient vector. Authors employed the hybrid edge detector to obtain the edge image, which increases the embedding capacity. Experimental results demonstrates that peak signal-to-noise (PSNR ratio of stego image generated by this method versus the cover image is guaranteed to be above 49 dB. PSNR is much higher than that of all data hiding techniques reported in the literature.Defence Science Journal, Vol. 65, No. 3, May 2015, pp.214-219, DOI: http://dx.doi.org/10.14429/dsj.65.7871

  5. Video Steganography: Text Hiding In Video By LSB Substitution

    Directory of Open Access Journals (Sweden)

    Kamred Udham Singh

    2014-05-01

    Full Text Available The development of high speed computer networks and Internet has increased the easiness of Information Communication. In contrast with Analog media and Digital media provide several different advantages such as high quality, simple editing, high loyalty copying and authenticity. But in the field of data communication this type of development has increased the fear of sneaking the data while sending data from the sender to the receiver. Due to this reason Information Security is main problem of Data Communication. Steganography plays an important role in field of Information Security. Video and images are very common choice for hiding data. It is very important for effective and successful embedding process to select appropriate pixels in the video frames, which are used to store the secret data. We use video based Steganography because of large size and memory requirements. Hiding information in a carrier file we use least significant bit (LSB insertion technique. In Least significant bit (LSB insertion technique, for hiding information we change LSB of video file with the information bits .This paper will focus on hiding information in specific frames of the video and in specific position of the frame by LSB substitution.

  6. Text steganography in digital images by chaos-based mapping

    Directory of Open Access Journals (Sweden)

    Elnaz Ghasemi

    2016-06-01

    Full Text Available The purpose of steganography is protecting hidden information from attackers. When a secret feature transfers in obvious form in the communication canal, it is clear that it would be attacked. Purpose of this study is safe transfer of secret data. In order to have a strong steganography, chaos mapping has been used, because in contrary with classic methods, chaos-based algorithms provide simple and low-cost solutions for solving security problem. Results of simulation showed that ratio of noise to signal for images is 13/42 and 42/66 which had better results than compared method. Embedding capacity was 1024 bit. TAF parameter returned 0 that indicated QR code retrieval without any change. Image entropy returned values between 7/12 and 7/64 that was very near to ideal value 8. Qualitative studies indicated that in proposed method, quality of carrying media was preserved in acceptable level. Security test showed that proposed method has high security due to using QR code and chaosbased method.

  7. Throughput increase of the covert communication channel organized by the stable steganography algorithm using spatial domain of the image

    Directory of Open Access Journals (Sweden)

    O.V. Kostyrka

    2016-09-01

    Full Text Available At the organization of a covert communication channel a number of requirements are imposed on used steganography algorithms among which one of the main are: resistance to attacks against the built-in message, reliability of perception of formed steganography message, significant throughput of a steganography communication channel. Aim: The aim of this research is to modify the steganography method, developed by the author earlier, which will allow to increase the throughput of the corresponding covert communication channel when saving resistance to attacks against the built-in message and perception reliability of the created steganography message, inherent to developed method. Materials and Methods: Modifications of a steganography method that is steady against attacks against the built-in message which is carrying out the inclusion and decoding of the sent (additional information in spatial domain of the image allowing to increase the throughput of the organized communication channel are offered. Use of spatial domain of the image allows to avoid accumulation of an additional computational error during the inclusion/decoding of additional information due to “transitions” from spatial domain of the image to the area of conversion and back that positively affects the efficiency of decoding. Such methods are considered as attacks against the built-in message: imposing of different noise on a steganography message, filtering, lossy compression of a ste-ganography message where the JPEG and JPEG2000 formats with different quality coefficients for saving of a steganography message are used. Results: It is shown that algorithmic implementations of the offered methods modifications remain steady against the perturbing influences, including considerable, provide reliability of perception of the created steganography message, increase the throughput of the created steganography communication channel in comparison with the algorithm implementing

  8. Ensuring message embedding in wet paper steganography

    CERN Document Server

    Augot, Daniel; Fontaine, Caroline

    2011-01-01

    Syndrome coding has been proposed by Crandall in 1998 as a method to stealthily embed a message in a cover-medium through the use of bounded decoding. In 2005, Fridrich et al. introduced wet paper codes to improve the undetectability of the embedding by nabling the sender to lock some components of the cover-data, according to the nature of the cover-medium and the message. Unfortunately, almost all existing methods solving the bounded decoding syndrome problem with or without locked components have a non-zero probability to fail. In this paper, we introduce a randomized syndrome coding, which guarantees the embedding success with probability one. We analyze the parameters of this new scheme in the case of perfect codes.

  9. An Approach for Message Hiding using Substitution Techniques and Audio Hiding in Steganography

    CERN Document Server

    Mukhopadhyay, Debajyoti; Ghosh, Surjya; Biswas, Sudipto; Chakraborty, Poulami

    2011-01-01

    A crypto system can be used to encrypt messages sent between two communicating parties so that an eavesdropper who overhears the encrypted messages will not be able to decode them. The paper mainly concentrates on the method in which the substitution technique of steganography can been used to hide data in a 24-bit bitmap file. Popular audio hiding techniques based on methods of steganography is also discussed here.

  10. IMAGE STEGANOGRAPHY BASED ON TRANSFORM DOMAIN, BLOWFISH AND AES FOR SECOND LEVEL SECURITY

    Directory of Open Access Journals (Sweden)

    Janki Gajjar

    2015-10-01

    Full Text Available Steganography is technique for secret communication. It hides the existence of the communication between parties. So viewer cannot detect the existence of the message and also not detect the communication channel. So attacker cannot modify and see the secret information. In image steganography, secrecy is accomplished by hide the secret message in cover image using steganography techniques. There are different types of steganography techniques each have their merits and demerits. Using Steganography techniques on cover image we can improve the security and robustness. For improving second level security we are using cryptography. Cryptography is used to convert the secret message in cipher text means unreadable form of message. Cryptography introduces many algorithms. This algorithm converts the secret message in cipher text. In our proposed method we are using Blowfish and AES algorithm for converting the message in cipher text and then hide this cipher text in cover image using DCT steganography technique. Using this combine technique we can get the stego-image. Here using this proposed method we can get the security and robustness in terms of message when we retrieve the message from the stego-image.

  11. High-capacity nanocarbon anodes for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Haitao; Sun, Xianzhong; Zhang, Xiong; Lin, He; Wang, Kai; Ma, Yanwei, E-mail: ywma@mail.iee.ac.cn

    2015-02-15

    Highlights: • The nanocarbon anodes in lithium-ion batteries deliver a high capacity of ∼1100 mA h g{sup −1}. • The nanocarbon anodes exhibit excellent cyclic stability. • A novel structure of carbon materials, hollow carbon nanoboxes, has potential application in lithium-ion batteries. - Abstract: High energy and power density of secondary cells like lithium-ion batteries become much more important in today’s society. However, lithium-ion battery anodes based on graphite material have theoretical capacity of 372 mA h g{sup −1} and low charging-discharging rate. Here, we report that nanocarbons including mesoporous graphene (MPG), carbon tubular nanostructures (CTN), and hollow carbon nanoboxes (HCB) are good candidate for lithium-ion battery anodes. The nanocarbon anodes have high capacity of ∼1100, ∼600, and ∼500 mA h g{sup −1} at 0.1 A g{sup −1} for MPG, CTN, and HCB, respectively. The capacity of 181, 141, and 139 mA h g{sup −1} at 4 A g{sup −1} for MPG, CTN, and HCB anodes is retained. Besides, nanocarbon anodes show high cycling stability during 1000 cycles, indicating formation of a passivating layer—solid electrolyte interphase, which support long-term cycling. Nanocarbons, constructed with graphene layers which fulfill lithiation/delithiation process, high ratio of graphite edge structure, and high surface area which facilitates capacitive behavior, deliver high capacity and improved rate-capability.

  12. Cycloaddition in peptides for high-capacity optical storage

    DEFF Research Database (Denmark)

    Lohse, Brian; Berg, Rolf Henrik; Hvilsted, Søren

    2006-01-01

    Photodimerization of chromophores attached to a short peptide chain is investigated for high-capacity optical digital storage with UV lasers. The length and rigidity of the peptide chain assure an optimal distance and orientation of the chromophores for effective photodimerization. Using a theory...... developed by Tomlinson, the absorption cross section for the dimerization process in a uracil-ornithine-based hexamer is determined to be 9 x 10(-20) cm(2). A large change in the transmission due to irradiation in the UV area may make it possible to realize multilevel storage in a thin film of the peptides....

  13. 整数小波域湿纸码自适应信息隐藏算法%Wet Paper Code Based Adaptive Steganography in IWT Domain

    Institute of Scientific and Technical Information of China (English)

    奚玲; 平西建; 张涛

    2011-01-01

    By analyzing the security of some nowadays adaptive steganographies, a new wet paper code ( WPC) based adaptive steganography in IWT domain is proposed in order to enhance the security. The scheme calculates the threshold according to the quantity of the secrete message and the cover element's characteristic, then adaptively chooses the complex texture region as embedding position, embedding secrete data by two layer WPC steganography, and adopt a new histogram adjustment strategy to prevent distortion. By such way, the capability of resisting steganalysis is improved. Quantities of experiments show that under average embedding rate of 100% , the new algorithm behaves better in visual and statistical imperceptibility.%通过对一些已有的自适应隐写算法进行分析,提出一种旨在提高安全性的整数小波域自适应信息隐藏算法.根据隐藏的数据量和载体单元特性确定阈值,自适应地在图像整数小波高频子带系数中选择合适的隐藏位置;利用湿纸码双层嵌入法嵌入秘密数据,并采用直方图调整策略保持小波高频子带系数直方图特性,由此从多方面提高了信息隐藏算法的安全性.大量与同类算法的对比实验表明,在嵌入率小于100%的条件下,该算法具有较强的视觉隐蔽性和抗统计检测的能力.

  14. High capacity 30 K remote helium cooling loop

    Science.gov (United States)

    Trollier, T.; Tanchon, J.; Icart, Y.; Ravex, A.

    2014-01-01

    Absolut System has built several 50 K remote helium cooling loops used as high capacity and very low vibration cooling source into large wavelength IR detectors electro-optical characterization test benches. MgB2 based superconducting electro-technical equipment's under development require also distributed high cooling power in the 20-30 K temperature range. Absolut System has designed, manufactured and tested a high capacity 30 K remote helium cooling loop. The equipment consists of a CRYOMECH AL325 type cooler, a CP830 type compressor package used as room temperature circulator and an intermediate LN2 bath cooling used between two recuperator heat exchangers (300 K-77 K and 77 K-20 K). A cooling capacity of 30 W @ 20 K or 80 W @ 30 K has been demonstrated on the application heat exchanger, with a 4-meter remote distance ensured by a specifically designed gas circulation flexible line. The design and the performance will be reported in this paper.

  15. High-capacity hydrogen storage in Al-adsorbed graphene

    Science.gov (United States)

    Ao, Z. M.; Peeters, F. M.

    2010-05-01

    A high-capacity hydrogen storage medium—Al-adsorbed graphene—is proposed based on density-functional theory calculations. We find that a graphene layer with Al adsorbed on both sides can store hydrogen up to 13.79wt% with average adsorption energy -0.193eV/H2 . Its hydrogen storage capacity is in excess of 6wt% , surpassing U. S. Department of Energy (DOE’s) target. Based on the binding-energy criterion and molecular-dynamics calculations, we find that hydrogen storage can be recycled at near ambient conditions. This high-capacity hydrogen storage is due to the adsorbed Al atoms that act as bridges to link the electron clouds of the H2 molecules and the graphene layer. As a consequence, a two-layer arrangement of H2 molecules is formed on each side of the Al-adsorbed graphene layer. The H2 concentration in the hydrogen storage medium can be measured by the change in the conductivity of the graphene layer.

  16. JPEG versus GIF Images in forms of LSB Steganography

    Directory of Open Access Journals (Sweden)

    ELTYEB E. ABED ELGABAR

    2013-12-01

    Full Text Available Steganography (from Greek steganos, or "covered,"and graphie, or "writing" is the hiding of undisclosed message(such as text, image, audio and video within an ordinarymessage (such as text, image, audio and video and theextraction of it at its target (receiver. Steganographytakes cryptography a step farther by hiding an encryptedmessage so that no one suspects it exists. This paper comparesand analyses Least Significant Bit (LSB algorithm using thecover object as an image with a focus on two types: JPEG andGIF. The comparison and analysis are done with deferencenumber of criteria (Robustness against statistical attacks,Invisibility, Steganalysis detection, Robustness against imagemanipulation, Efficient when amount of data reasonable,Payload capacity, Unsuspicious files and Amount of embeddeddata to understand their strengths and weaknesses.

  17. Steganography based on wavelet transform and modulus function

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to provide larger capacity of the hidden secret data while maintaining a good visual quality of stego-image,in accordance with the visual property that human eyes are less sensitive to strong texture,a novel steganographic method based on wavelet and modulus function is presented.First,an image is divided into blocks of prescribed size,and every block is decomposed into one-level wavelet.Then,the capacity of the hidden secret data is decided with the number of wavelet coefficients of larger magnitude.Finall,secret information is embedded by steganography based on modulus function. From the experimental results,the proposed method hides much more information and maintains a good visual quality of stego-image.Besides,the embedded data can be extracted from the stego-image without referencing the original image.

  18. Message Segmentation to Enhance the Security of LSB Image Steganography

    Directory of Open Access Journals (Sweden)

    Dr. Mohammed Abbas Fadhil Al-Husainy

    2012-03-01

    Full Text Available Classic Least Significant Bit (LSB steganography technique is the most used technique to hide secret information in the least significant bit of the pixels in the stego-image. This paper proposed a technique by splitting the secret message into set of segments, that have same length (number of characters, and find the best LSBs of pixels in the stego-image that are matched to each segment. The main goal of this technique is to minimize the number of LSBs that are changed when substituting them with the bits of characters in the secret message. This will lead to decrease the distortion (noise that is occurred in the pixels of the stego-image and as result increase the immunity of the stego-image against the visual attack. The experiment shows that the proposed technique gives good enhancement to the Classic Least Significant Bit (LSB technique

  19. An Alternative Approach of Steganography using Reference Image

    CERN Document Server

    Bandyopadhyay, Samir Kumar

    2010-01-01

    This paper is to create a practical steganographic implementation for 4-bit images.The proposed technique converts 4 bit image into 4 shaded Gray Scale image. This image will be act as reference image to hide the text. Using this grey scale reference image any text can be hidden. Single character of a text can be represented by 8-bit. The 8-bit character can be split into 4X2 bit information. If the reference image and the data file are transmitted through network separately, we can achieve the effect of Steganography. Here the image is not at all distorted because said image is only used for referencing. Any huge mount of text material can be hidden using a very small image. Decipher the text is not possible intercepting the image or data file separately. So, it is more secure.

  20. Bio-Authentication based Secure Transmission System using Steganography

    CERN Document Server

    Zehra, Najme; Ahuja, Somya; Bansal, Shubha

    2010-01-01

    Biometrics deals with identity verification of an individual by using certain physiological or behavioral features associated with a person. Biometric identification systems using fingerprints patterns are called AFIS (Automatic Fingerprint Identification System). In this paper a composite method for Fingerprint recognition is considered using a combination of Fast Fourier Transform (FFT) and Sobel Filters for improvement of a poor quality fingerprint image. Steganography hides messages inside other messages in such a way that an "adversary" would not even know a secret message were present. The objective of our paper is to make a bio-secure system. In this paper bio-authentication has been implemented in terms of finger print recognition and the second part of the paper is an interactive steganographic system hides the user's data by two options- creating a songs list or hiding the data in an image.

  1. A 3-Level Secure Histogram Based Image Steganography Technique

    Directory of Open Access Journals (Sweden)

    G V Chaitanya

    2013-04-01

    Full Text Available Steganography is an art that involves communication of secret data in an appropriate carrier, eg. images, audio, video, etc. with a goal to hide the very existence of embedded data so as not to arouse an eavesdropper’s suspicion. In this paper, a steganographic technique with high level of security and having a data hiding capacity close to 20% of cover image data has been developed. An adaptive and matched bit replacement method is used based on the sensitivity of Human Visual System (HVS at different intensities. The proposed algorithm ensures that the generated stego image has a PSNR greater than 38.5 and is also resistant to visual attack. A three level security is infused into the algorithm which makes data retrieval from the stego image possible only in case of having all the right keys.

  2. Proposed Arabic Text Steganography Method Based on New Coding Technique

    Directory of Open Access Journals (Sweden)

    Assist. prof. Dr. Suhad M. Kadhem

    2016-09-01

    Full Text Available Steganography is one of the important fields of information security that depend on hiding secret information in a cover media (video, image, audio, text such that un authorized person fails to realize its existence. One of the lossless data compression techniques which are used for a given file that contains many redundant data is run length encoding (RLE. Sometimes the RLE output will be expanded rather than compressed, and this is the main problem of RLE. In this paper we will use a new coding method such that its output will be contains sequence of ones with few zeros, so modified RLE that we proposed in this paper will be suitable for compression, finally we employ the modified RLE output for stenography purpose that based on Unicode and non-printed characters to hide the secret information in an Arabic text.

  3. Image steganography using layered pixel-value differencing

    Science.gov (United States)

    Kim, Jaeyoung; Park, Hanhoon

    2017-02-01

    This paper proposes a layered approach to improve the embedding capacity of the existing pixel-value differencing (PVD) methods for image steganography. Specifically, one of the PVD methods is applied to embed a secret information into a cover image and the resulting image, called stego-image, is used to embed additional secret information by the same or another PVD method. This results in a double-layered stego-image. Then, another PVD method can be applied to the double-layered stego-image, resulting in a triple-layered stego-image. Likewise, multi-layered stego-images can be obtained. To successfully recover the secret information hidden in each layer, the embedding process is carefully designed. In the experiment, the proposed layered PVD method proved to be effective.

  4. Improving the privacy of optical steganography with temporal phase masks.

    Science.gov (United States)

    Wang, Z; Fok, M P; Xu, L; Chang, J; Prucnal, P R

    2010-03-15

    Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

  5. Optical steganography based on amplified spontaneous emission noise.

    Science.gov (United States)

    Wu, Ben; Wang, Zhenxing; Tian, Yue; Fok, Mable P; Shastri, Bhavin J; Kanoff, Daniel R; Prucnal, Paul R

    2013-01-28

    We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver.

  6. A Security Enhanced Robust Steganography Algorithm for Data Hiding

    Directory of Open Access Journals (Sweden)

    Siddharth Singh

    2012-05-01

    Full Text Available In this paper, a new robust steganography algorithm based on discrete cosine transform (DCT, Arnold transform and chaotic system is proposed. The chaotic system is used to generate a random sequence to be used for spreading data in the middle frequency band DCT coefficient of the cover image. The security is further enhanced by scrambling the secret data using Arnold Cat map before embedding. The recovery process is blind. A series of experiments is conducted to prove the security and robustness of the proposed algorithm. The experimental results demonstrate that the proposed algorithm achieves higher security and robustness against JPEG compression, addition of noise, low pass filtering and cropping attacks as compared to other existing algorithms for data hiding in the DCT domain.

  7. HISTOGRAM TECHNIQUE WITH PIXEL INDICATOR FOR HIGH FIDELITY STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    V.Meiamai

    2013-06-01

    Full Text Available In this current world of increasing technology trends and the “internet age”, the security of our personal information has become more important than it has ever been there are media reports ofidentity theft and fraud and the numbers of innocent victims are increasing exponentially. Steganography plays an important role in preventing such information destruction by implementing a principle ofimperceptible secret sharing. By this security can be established by clearly embedding data in such a way that the quality of the image is not affected. The existing methodology prevailing now is based on pixel indicator and number of data to be embedded is by pixel value differencing technique. A limitation in this methodology is that the pixel indicator channel is manually selected. The proposed methodology uses pixel indicator channel which is decided using histogram technique and the secret message file has to be embedded in the plane which has the highest color intensity.

  8. A secure steganography for privacy protection in healthcare system.

    Science.gov (United States)

    Liu, Jing; Tang, Guangming; Sun, Yifeng

    2013-04-01

    Private data in healthcare system require confidentiality protection while transmitting. Steganography is the art of concealing data into a cover media for conveying messages confidentially. In this paper, we propose a steganographic method which can provide private data in medical system with very secure protection. In our method, a cover image is first mapped into a 1D pixels sequence by Hilbert filling curve and then divided into non-overlapping embedding units with three consecutive pixels. We use adaptive pixel pair match (APPM) method to embed digits in the pixel value differences (PVD) of the three pixels and the base of embedded digits is dependent on the differences among the three pixels. By solving an optimization problem, minimal distortion of the pixel ternaries caused by data embedding can be obtained. The experimental results show our method is more suitable to privacy protection of healthcare system than prior steganographic works.

  9. SECURITY SYSTEM FOR DATA USING STEGANOGRAPHY AND CRYPTOGRAPHY (SSDSC

    Directory of Open Access Journals (Sweden)

    Ayman Wazwaz1

    2016-08-01

    Full Text Available Security System for Data using Steganography and Cryptography (SSDSC is a set of hardware and software components that will be used to send secured documents through the internet. Some of the software will be loaded into a microcontrollers in order to increase the complexity and security. The data will be encrypted using the Advanced Encryption Standard (AES algorithm with a key from the Raspberry PI microcontroller and hide it inside an image using Least Significant Bit (LSB algorithm, the data will be invisible. The image will be transmitted and received through the internet, the receivers will extract the hidden data from the image and decrypt it to have the original data with the image. Complicating the steps of hiding and encryption will reduce the possiblity of intrusin of secured documents, and the process will be trasparent to the user to increase security without affecting the normal steps and the behavior in secured documents exchange.

  10. Diagonal queue medical image steganography with Rabin cryptosystem.

    Science.gov (United States)

    Jain, Mamta; Lenka, Saroj Kumar

    2016-03-01

    The main purpose of this work is to provide a novel and efficient method to the image steganography area of research in the field of biomedical, so that the security can be given to the very precious and confidential sensitive data of the patient and at the same time with the implication of the highly reliable algorithms will explode the high security to the precious brain information from the intruders. The patient information such as patient medical records with personal identification information of patients can be stored in both storage and transmission. This paper describes a novel methodology for hiding medical records like HIV reports, baby girl fetus, and patient's identity information inside their Brain disease medical image files viz. scan image or MRI image using the notion of obscurity with respect to a diagonal queue least significant bit substitution. Data structure queue plays a dynamic role in resource sharing between multiple communication parties and when secret medical data are transferred asynchronously (secret medical data not necessarily received at the same rate they were sent). Rabin cryptosystem is used for secret medical data writing, since it is computationally secure against a chosen-plaintext attack and shows the difficulty of integer factoring. The outcome of the cryptosystem is organized in various blocks and equally distributed sub-blocks. In steganography process, various Brain disease cover images are organized into various blocks of diagonal queues. The secret cipher blocks and sub-blocks are assigned dynamically to selected diagonal queues for embedding. The receiver gets four values of medical data plaintext corresponding to one ciphertext, so only authorized receiver can identify the correct medical data. Performance analysis was conducted using MSE, PSNR, maximum embedding capacity as well as by histogram analysis between various Brain disease stego and cover images.

  11. Hydrophilic carbon clusters as therapeutic, high capacity antioxidants

    Science.gov (United States)

    Samuel, Errol L. G.; Duong, MyLinh T.; Bitner, Brittany R.; Marcano, Daniela C.; Tour, James M.; Kent, Thomas A.

    2014-01-01

    Oxidative stress reflects an excessive accumulation of reactive oxygen species (ROS) and is a hallmark of several acute and chronic human pathologies. While many antioxidants have been investigated, the majority have demonstrated poor efficacy in clinical trials. Here, we discuss limitations of current antioxidants and describe a new class of nanoparticle antioxidants, poly(ethylene glycol)-functionalized hydrophilic carbon clusters (PEG-HCCs). PEG-HCCs show high capacity to annihilate ROS such as superoxide and hydroxyl radicals, show no reactivity toward nitric oxide, and can be functionalized with targeting moieties without loss of activity. Given these properties, we propose that PEG-HCCs offer an exciting new area of study for treatment of numerous ROS-induced human pathologies. PMID:25175886

  12. Holographic memory module with ultra-high capacity and throughput

    Energy Technology Data Exchange (ETDEWEB)

    Vladimir A. Markov, Ph.D.

    2000-06-04

    High capacity, high transfer rate, random access memory systems are needed to archive and distribute the tremendous volume of digital information being generated, for example, the human genome mapping and online libraries. The development of multi-gigabit per second networks underscores the need for next-generation archival memory systems. During Phase I we conducted the theoretical analysis and accomplished experimental tests that validated the key aspects of the ultra-high density holographic data storage module with high transfer rate. We also inspected the secure nature of the encoding method and estimated the performance of full-scale system. Two basic architectures were considered, allowing for reversible compact solid-state configuration with limited capacity, and very large capacity write once read many memory system.

  13. Tracking inhomogeneity in high-capacity lithium iron phosphate batteries

    Science.gov (United States)

    Paxton, William A.; Zhong, Zhong; Tsakalakos, Thomas

    2015-02-01

    Energy-dispersive x-ray diffraction (EDXRD) is one of the few techniques that can internally probe a sealed battery under operating conditions. In this paper, we use EDXRD with ultrahigh energy synchrotron radiation to track inhomogeneity in a cycled high-capacity lithium iron phosphate cell under in-situ and operando conditions. A sequence of depth-profile x-ray diffraction spectra are collected with 40 μm resolution as the cell is discharged. Additionally, nine different locations of the cell are tracked independently throughout a second discharge process. In each case, a two-peak reference intensity ratio analysis (RIR) was used on the LiFePO4 311 and the FePO4 020 reflections to estimate the relative phase abundance of the lithiated and non-lithiated phases. The data provide a first-time look at the dynamics of electrochemical inhomogeneity in a real-world battery. We observe a strong correlation between inhomogeneity and overpotential in the galvanic response of the cell. Additionally, the data closely follow the behavior that is predicted by the resistive-reactant model originally proposed by Thomas-Alyea. Despite a non-linear response in the independently measured locations, the behavior of the ensemble is strikingly linear. This suggests that effects of inhomogeneity can be elusive and highlights the power of the EDXRD technique.

  14. Space qualification of high capacity grooved heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, M.; Mullender, B.; Druart, J. [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W.; Beddows, A. [ESTEC-The (Netherlands)

    1996-12-31

    Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

  15. High-Capacity, High-Voltage Composite Oxide Cathode Materials

    Science.gov (United States)

    Hagh, Nader M.

    2015-01-01

    This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

  16. High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

    2015-01-01

    Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and multifunctional operation. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flight-like, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station.

  17. High-capacity quantum Fibonacci coding for key distribution

    Science.gov (United States)

    Simon, David S.; Lawrence, Nate; Trevino, Jacob; Dal Negro, Luca; Sergienko, Alexander V.

    2013-03-01

    Quantum cryptography and quantum key distribution (QKD) have been the most successful applications of quantum information processing, highlighting the unique capability of quantum mechanics, through the no-cloning theorem, to securely share encryption keys between two parties. Here, we present an approach to high-capacity, high-efficiency QKD by exploiting cross-disciplinary ideas from quantum information theory and the theory of light scattering of aperiodic photonic media. We propose a unique type of entangled-photon source, as well as a physical mechanism for efficiently sharing keys. The key-sharing protocol combines entanglement with the mathematical properties of a recursive sequence to allow a realization of the physical conditions necessary for implementation of the no-cloning principle for QKD, while the source produces entangled photons whose orbital angular momenta (OAM) are in a superposition of Fibonacci numbers. The source is used to implement a particular physical realization of the protocol by randomly encoding the Fibonacci sequence onto entangled OAM states, allowing secure generation of long keys from few photons. Unlike in polarization-based protocols, reference frame alignment is unnecessary, while the required experimental setup is simpler than other OAM-based protocols capable of achieving the same capacity and its complexity grows less rapidly with increasing range of OAM used.

  18. AUDIO CRYPTANALYSIS- AN APPLICATION OF SYMMETRIC KEY CRYPTOGRAPHY AND AUDIO STEGANOGRAPHY

    Directory of Open Access Journals (Sweden)

    Smita Paira

    2016-09-01

    Full Text Available In the recent trend of network and technology, “Cryptography” and “Steganography” have emerged out as the essential elements of providing network security. Although Cryptography plays a major role in the fabrication and modification of the secret message into an encrypted version yet it has certain drawbacks. Steganography is the art that meets one of the basic limitations of Cryptography. In this paper, a new algorithm has been proposed based on both Symmetric Key Cryptography and Audio Steganography. The combination of a randomly generated Symmetric Key along with LSB technique of Audio Steganography sends a secret message unrecognizable through an insecure medium. The Stego File generated is almost lossless giving a 100 percent recovery of the original message. This paper also presents a detailed experimental analysis of the algorithm with a brief comparison with other existing algorithms and a future scope. The experimental verification and security issues are promising.

  19. A novel approach for implementing Steganography with computing power obtained by combining Cuda and Matlab

    CERN Document Server

    Patel, Samir B; Ambegaokar, Saumitra U

    2009-01-01

    With the current development of multiprocessor systems, strive for computing data on such processor have also increased exponentially. If the multi core processors are not fully utilized, then even though we have the computing power the speed is not available to the end users for their respective applications. In accordance to this, the users or application designers also have to design newer applications taking care of the computing infrastructure available within. Our approach is to use the CUDA (Compute Unified Device Architecture) as backend and MATLAB as the front end to design an application for implementing steganography. Steganography is the term used for hiding information in the cover object like Image, Audio or Video data. As the computing required for multimedia data is much more than the text information, we have been successful in implementing image Steganography with the help of technology for the next generation.

  20. A Novel Strategy for Quantum Image Steganography Based on Moiré Pattern

    Science.gov (United States)

    Jiang, Nan; Wang, Luo

    2015-03-01

    Image steganography technique is widely used to realize the secrecy transmission. Although its strategies on classical computers have been extensively researched, there are few studies on such strategies on quantum computers. Therefore, in this paper, a novel, secure and keyless steganography approach for images on quantum computers is proposed based on Moiré pattern. Algorithms based on the Moiré pattern are proposed for binary image embedding and extraction. Based on the novel enhanced quantum representation of digital images (NEQR), recursive and progressively layered quantum circuits for embedding and extraction operations are designed. In the end, experiments are done to verify the validity and robustness of proposed methods, which confirms that the approach in this paper is effective in quantum image steganography strategy.

  1. A novel JPEG steganography method based on modulus function with histogram analysis

    Directory of Open Access Journals (Sweden)

    V. Banoci

    2012-06-01

    Full Text Available In this paper, we present a novel steganographic method for embedding of secret data in still grayscale JPEG image. In order to provide large capacity of the proposed method while maintaining good visual quality of stego-image, the embedding process is performed in quantized transform coefficients of Discrete Cosine transform (DCT by modifying coefficients according to modulo function, what gives to the steganography system blind extraction predisposition. After-embedding histogram of proposed Modulo Histogram Fitting (MHF method is analyzed to secure steganography system against steganalysis attacks. In addition, AES ciphering was implemented to increase security and improve histogram after-embedding characteristics of proposed steganography system as experimental results show.

  2. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    Directory of Open Access Journals (Sweden)

    Jude Hemanth Duraisamy

    2016-01-01

    Full Text Available Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA and Particle Swarm Optimization (PSO have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT and Finite Ridgelet Transform (FRIT are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  3. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    Science.gov (United States)

    Jude Hemanth, Duraisamy; Umamaheswari, Subramaniyan; Popescu, Daniela Elena; Naaji, Antoanela

    2016-01-01

    Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT) and Finite Ridgelet Transform (FRIT) are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  4. A NEW TECHNIQUE BASED ON CHAOTIC STEGANOGRAPHY AND ENCRYPTION TEXT IN DCT DOMAIN FOR COLOR IMAGE

    Directory of Open Access Journals (Sweden)

    MELAD J. SAEED

    2013-10-01

    Full Text Available Image steganography is the art of hiding information into a cover image. This paper presents a new technique based on chaotic steganography and encryption text in DCT domain for color image, where DCT is used to transform original image (cover image from spatial domain to frequency domain. This technique used chaotic function in two phases; firstly; for encryption secret message, second; for embedding in DCT cover image. With this new technique, good results are obtained through satisfying the important properties of steganography such as: imperceptibility; improved by having mean square error (MSE, peak signal to noise ratio (PSNR and normalized correlation (NC, to phase and capacity; improved by encoding the secret message characters with variable length codes and embedding the secret message in one level of color image only.

  5. High capacity implantable data recorders: system design and experience in canines and Denning black bears.

    Science.gov (United States)

    Laske, Timothy G; Harlow, Henry J; Werder, Jon C; Marshall, Mark T; Iaizzo, Paul A

    2005-11-01

    Implantable medical devices have increasingly large capacities for storing patient data as a diagnostic aid and to allow patient monitoring. Although these devices can store a significant amount of data, an increased ability for data storage was required for chronic monitoring in recent physiological studies. Novel high capacity implantable data recorders were designed for use in advanced physiological studies of canines and free-ranging black bears. These hermitically sealed titanium encased recorders were chronically implanted and programmed to record intrabody broadband electrical activity to monitor electrocardiograms and electromyograms, and single-axis acceleration to document relative activities. Changes in cardiac T-wave morphology were characterized in the canines over a 6 month period, providing new physiological data for the design of algorithms and filtering schemes that could be employed to avoid inappropriate implantable defibrillator shocks. Unique characteristics of bear hibernation physiology were successfully identified in the black bears, including: heart rate, respiratory rate, gross body movement, and shiver An unanticipated high rejection rate of these devices occurred in the bears, with five of six being externalized during the overwintering period, including two devices implanted in the peritoneal cavity. High capacity implantable data recorders were designed and utilized for the collection of long-term physiological data in both laboratory and extreme field environments. The devices described were programmable to accommodate the diverse research protocols. Additionally, we have described substantial differences in the response of two species to a common device. Variations in the foreign body response of different mammals must be identified and taken into consideration when choosing tissue-contacting materials in the application of biomedical technology to physiologic research.

  6. CRYPTO-STEG: A Hybrid Cryptology - Steganography Approach for Improved Data Security

    Directory of Open Access Journals (Sweden)

    Atif Bin Mansoor

    2012-04-01

    Full Text Available Internet is a widely used medium for transfer of information due to its reach and ease of availability. However, internet is an insecure medium and any information might be easily intercepted and viewed during its transfer. Different mechanisms like cryptology and steganography are adopted to secure the data communication over an inherently insecure medium like internet. Cryptology scrambles the information in a manner that an unintended recipient cannot easily extract the information, while steganography hides the information in a cover object so that it is transferred unnoticed in the cover. Encrypted data may not be extracted easily but causes a direct suspicion to any observer, while data hidden using steganographic techniques go inconspicuous. Cryptanalysis is the process of attacking the encrypted text to extract the information, while steganalysis is the process of detecting the disguised messages. In literature, both cryptology and steganography are treated separately. In this paper, we present our research on an improved data security paradigm, where data is first encrypted using AES (Advanced Encryption Standard and DES (Data Encryption Standard cryptology algorithms. Both plain and encrypted data is hidden in the images using Model Based and F5 steganographic techniques. Features are extracted in DWT (Discrete Wavelet Transform and DCT (Discrete Cosine Transform domains using higher order statistics for steganalysis, and subsequently used to train a FLD (Fisher Linear Discriminant classifier which is employed to categorize a separate set of images as clean or stego (containing hidden messages. Experimental results demonstrate improved data security using proposed CRYPTO-STEG approach compared to plain text steganography. Results also demonstrate that the Model Based steganography is more secure than the F5 steganography.

  7. Demonstration of optical steganography transmission using temporal phase coded optical signals with spectral notch filtering.

    Science.gov (United States)

    Hong, Xuezhi; Wang, Dawei; Xu, Lei; He, Sailing

    2010-06-07

    A novel approach is proposed and experimentally demonstrated for optical steganography transmission in WDM networks using temporal phase coded optical signals with spectral notch filtering. A temporal phase coded stealth channel is temporally and spectrally overlaid onto a public WDM channel. Direct detection of the public channel is achieved in the presence of the stealth channel. The interference from the public channel is suppressed by spectral notching before the detection of the optical stealth signal. The approach is shown to have good compatibility and robustness to the existing WDM network for optical steganography transmission.

  8. Application of T-Code, Turbo Codes and Pseudo-Random Sequence for Steganography

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2006-01-01

    Full Text Available In this study, we propose new technique that will address the problem of robustness and data safety in steganography. The steganography consists of techniques to allow the communication between two persons, hiding not only the contents but also the very existence of the communication in the eyes of any observer. T-Codes used with Turbo Codes generates cryptic and error-coded data stream, which is hidden in the stego-object using Pseudo-Random sequence. This technique makes our processed data stream non-vulnerable to the attack of an active intruder, or due to noise in the transmission link.

  9. Multi-Level Steganography: Improving Hidden Communication in Networks

    CERN Document Server

    Fraczek, Wojciech; Szczypiorski, Krzysztof

    2011-01-01

    The paper presents Multi-Level Steganography (MLS), which defines a new concept for hidden communication. In MLS, at least two steganographic methods are utilised simultaneously, in such a way that one method (called the upper-level) serves as a carrier for the second one (called the lower-level). Such a relationship between two (or more) information hiding solutions has several potential benefits. The most important is that the lower-level method steganographic bandwidth can be utilised to make the steganogram unreadable even after the detection of the upper-level method: e.g., it can carry a cryptographic key that deciphers the steganogram carried by the upper-level one. It can also be used to provide the steganogram with integrity. Another important benefit is that the lower-layer method may be used as a signalling channel in which to exchange information that affects the way that the upper-level method functions, thus possibly making the steganographic communication harder to detect. MLS is presented in t...

  10. A Frequency Domain Steganography using Z Transform (FDSZT)

    CERN Document Server

    Mandal, J K

    2012-01-01

    Image steganography is art of hiding information onto the cover image. In this proposal a transformed domain based gray scale image authentication/data hiding technique using Z transform (ZT) termed as FDSZT, has been proposed. ZTransform is applied on 2x2 masks of the source image in row major order to transform original sub image (cover image) block to its corresponding frequency domain. One bit of the hidden image is embedded in each mask of the source image onto the fourth LSB of transformed coefficient based on median value of the mask. A delicate handle has also been performed as post embedding operation for proper decoding. Stego sub image is obtained through a reverse transform as final step of embedding in a mask. During the process of embedding, dimension of the hidden image followed by the content of the message/hidden image are embedded. Reverse process is followed during decoding. High PSNR obtained for various images conform the quality of invisible watermark of FDSZT.

  11. Steganography forensics method for detecting least significant bit replacement attack

    Science.gov (United States)

    Wang, Xiaofeng; Wei, Chengcheng; Han, Xiao

    2015-01-01

    We present an image forensics method to detect least significant bit replacement steganography attack. The proposed method provides fine-grained forensics features by using the hierarchical structure that combines pixels correlation and bit-planes correlation. This is achieved via bit-plane decomposition and difference matrices between the least significant bit-plane and each one of the others. Generated forensics features provide the susceptibility (changeability) that will be drastically altered when the cover image is embedded with data to form a stego image. We developed a statistical model based on the forensics features and used least square support vector machine as a classifier to distinguish stego images from cover images. Experimental results show that the proposed method provides the following advantages. (1) The detection rate is noticeably higher than that of some existing methods. (2) It has the expected stability. (3) It is robust for content-preserving manipulations, such as JPEG compression, adding noise, filtering, etc. (4) The proposed method provides satisfactory generalization capability.

  12. The Impact of Hard Disk Firmware Steganography on Computer Forensics

    Directory of Open Access Journals (Sweden)

    Iain Sutherland

    2009-06-01

    Full Text Available The hard disk drive is probably the predominant form of storage media and is a primary data source in a forensic investigation. The majority of available software tools and literature relating to the investigation of the structure and content contained within a hard disk drive concerns the extraction and analysis of evidence from the various file systems which can reside in the user accessible area of the disk. It is known that there are other areas of the hard disk drive which could be used to conceal information, such as the Host Protected Area and the Device Configuration Overlay. There are recommended methods for the detection and forensic analysis of these areas using appropriate tools and techniques. However, there are additional areas of a disk that have currently been overlooked.  The Service Area or Platter Resident Firmware Area is used to store code and control structures responsible for the functionality of the drive and for logging failing or failed sectors.This paper provides an introduction into initial research into the investigation and identification of issues relating to the analysis of the Platter Resident Firmware Area. In particular, the possibility that the Platter Resident Firmware Area could be manipulated and exploited to facilitate a form of steganography, enabling information to be concealed by a user and potentially from a digital forensic investigator.

  13. Multimodal Biometric-based Secured Authentication System using Steganography

    Directory of Open Access Journals (Sweden)

    S. Swamynathan

    2012-01-01

    Full Text Available Problem statement: The main challenge in the design of a security system for high security mobile ad OC network is how to prevent the attacks against data modification and authentication. Approach: In this novel proposed system the messages communicated between the users are encrypted by the cancellable cryptographic key generated from fingerprint features of the receiver by applying genetic operators and are embedded inside the scrambled face biometrics of the sender using steganography method. Results: The receiver first unscrambles the facial image of the sender and separates the facial image and the encrypted data. Then he verifies the sender by using an Eigen face recognition algorithm and if he is a genuine sender he decrypts the cipher text with the key generated using the receiver’s fingerprint biometric. Conclusion/Recommendations: By this way, the receiver ensures the genuineness of the sender and data confidentiality. Revocability is also guaranteed since we apply genetic operator to randomize the cryptographic key whenever it is necessary. By simulation results, we also show that the proposed method is more efficient mechanism for authentication and security.

  14. Design of DPSS based fiber bragg gratings and their application in all-optical encryption, OCDMA, optical steganography, and orthogonal-division multiplexing.

    Science.gov (United States)

    Djordjevic, Ivan B; Saleh, Alaa H; Küppers, Franko

    2014-05-05

    The future information infrastructure will be affected by limited bandwidth of optical networks, high energy consumption, heterogeneity of network segments, and security issues. As a solution to all problems, we advocate the use of both electrical basis functions (orthogonal prolate spheroidal basis functions) and optical basis functions, implemented as FBGs with orthogonal impulse response in addition to spatial modes. We design the Bragg gratings with orthogonal impulse responses by means of discrete layer peeling algorithm. The target impulse responses belong to the class of discrete prolate spheroidal sequences, which are mutually orthogonal regardless of the sequence order, while occupying the fixed bandwidth. We then design the corresponding encoders and decoders suitable for all-optical encryption, optical CDMA, optical steganography, and orthogonal-division multiplexing (ODM). Finally, we propose the spectral multiplexing-ODM-spatial multiplexing scheme enabling beyond 10 Pb/s serial optical transport networks.

  15. Android-Stego: A Novel Service Provider Imperceptible MMS Steganography Technique Robust to Message Loss

    Directory of Open Access Journals (Sweden)

    Avinash Srinivasan

    2015-08-01

    Full Text Available Information hiding techniques, especially steganography, have been extensively researched for over two decades. Nonetheless, steganography on smartphones over cellular carrier networks is yet to be fully explored. Today, smartphones, which are at the epitome of ubiquitous and pervasive computing, make steganography an easily accessible covert communication channel. In this paper, we propose Android-Stego - a framework for steganography employing smart-phones. Android-Stego has been evaluated and confirmed to achieve covert communication over real world cellular service providers' communication networks such as Verizon and Sprint. A key contribution of our research presented in this paper is the benchmark results we have provided by analyzing real world cellular carriers network restrictions on MMS message size. We have also analyzed the actions the carriers take - such as compression and/or format conversion - on MMS messages that fall outside the established MMS communication norm, which varies for each service provider. Finally, We have used these benchmark results in implementing Android-Stego such that it is sensitive to carrier restrictions and robust to message loss.

  16. AES Inspired Hex Symbols Steganography for Anti-Forensic Artifacts on Android Devices

    Directory of Open Access Journals (Sweden)

    Somyia M. Abu Asbeh

    2016-05-01

    Full Text Available Mobile phones technology has become one of the most common and important technologies that started as a communication tool and then evolved into key reservoirs of personal information and smart applications. With this increased level of complications, increased dangers and increased levels of countermeasures and opposing countermeasures have emerged, such as Mobile Forensics and anti-forensics. One of these anti-forensics tools is steganography, which introduced higher levels of complexity and security against hackers’ attacks but simultaneously create obstacles to forensic investigations. In this paper we proposed a new data hiding approach, the AES Inspired Steganography (AIS, which utilizes some AES data encryption concepts while hiding the data using the concept of hex symbols steganography. As the approach is based on the use of multiple encryption steps, the resulting carrier files would be unfathomable without the use of the cipher key agreed upon by the communicating parties. These carrier files can be exchanged amongst android devices and/or computers. Assessments of the proposed approach have proven it to be advantageous over the currently existing steganography approaches in terms of character frequency, security, robustness, length of key, and Compatibility.

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

    Science.gov (United States)

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

    2017-04-01

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

  18. Design And Implementation Of Multilevel Access Control In Medical Image Transmission Using Symmetric Polynomial Based Audio Steganography

    CERN Document Server

    Begum, J Nafeesa; Sumathy, V

    2010-01-01

    ...The steganography scheme makes it possible to hide the medical image in different bit locations of host media without inviting suspicion. The Secret file is embedded in a cover media with a key. At the receiving end the key can be derived by all the classes which are higher in the hierarchy using symmetric polynomial and the medical image file can be retrieved. The system is implemented and found to be secure, fast and scalable. Simulation results show that the system is dynamic in nature and allows any type of hierarchy. The proposed approach performs better even during frequent member joins and leaves. The computation cost is reduced as the same algorithm is used for key computation and descendant key derivation. Steganographic technique used in this paper does not use the conventional LSB's and uses two bit positions and the hidden data occurs only from a frame which is dictated by the key that is used. Hence the quality of stego data is improved.

  19. A Novel Approach for Arabic Text Steganography Based on the “BloodGroup” Text Hiding Method

    Directory of Open Access Journals (Sweden)

    S. Malalla,

    2017-04-01

    Full Text Available Steganography is the science of hiding certain messages (data in groups of irrelevant data possibly of other form. The purpose of steganography is covert communication to hide the existence of a message from an intermediary. Text Steganography is the process of embedding secret message (text in another text (cover text so that the existence of secret message cannot be detected by a third party. This paper presents a novel approach for text steganography using the Blood Group (BG method based on the behavior of blood group. Experimentally it is found that the proposed method got good results in capacity, hiding capacity, time complexity, robustness, visibility, and similarity which shows its superiority as compared to most several existing methods.

  20. High-Capacity Transmission Using High-Density Multicore Fiber

    DEFF Research Database (Denmark)

    Morioka, Toshio

    2017-01-01

    There have been intense research activities on SDM technologies including SDM fibers, MC-, MM-amplifiers, DEMUXs/DEMUXs with record-breaking transmission demonstrations up to 2 Pbit/s. 100 (20 dB) SDM gain, i.e. 10 Pbit/s per fiber will be a short-term goal in order for the new fibers to be consi......There have been intense research activities on SDM technologies including SDM fibers, MC-, MM-amplifiers, DEMUXs/DEMUXs with record-breaking transmission demonstrations up to 2 Pbit/s. 100 (20 dB) SDM gain, i.e. 10 Pbit/s per fiber will be a short-term goal in order for the new fibers...... to be considered for installation in the future systems although the far long term demand should be transporting 1 Ebit/s per fiber over 1000 km meaning Zbit/s-km. Cost effective network capability such as ADM and XC should also be investigated based on the new SDM schemes. In the 10-20 years time frame, we need...

  1. 基于双层湿纸嵌入的自适应图像隐写算法%Double-layered embedding based wet-paper-code adaptive steganography

    Institute of Scientific and Technical Information of China (English)

    奚玲; 平西建; 张涛

    2011-01-01

    In order to enhance the statistical security of a data hiding system, the factors that influenced the security of a steganography were analyzed. Three ways to reduce the statistical distortion of the stego-image were found: Increasing embedding efficiency, controlling modifying amplitude and choosing embedding position adaptively. According to the three ways, a new adaptive steganography based on double-layered embedding method was proposed. The new scheme chose pixels under strong noise background as message carrier and embedded secrets in their least significant and second least significant bit-planes. The experimental results on uncompressed images show that the proposed steganography outpedorms the prior algorithm for resisting blind steganalysis.%为了提高隐写系统抗统计检测的能力,对影响隐写算法统计安全性的因素进行了分析,得出减小载密图像统计失真的3条途径.以此为基础,提出一种基于双层湿纸嵌入的图像自适应隐写算法.该算法根据邻域相关性,选取局部环境噪声强的像素作为嵌入对象,利用"湿纸码(WPC)"在其最低有效位及次低有效位嵌入秘密信息.对未压缩图像库的实验表明,该方法比现有算法具有更好的抗统计检测性能.

  2. A Novel Approach of Text Steganography using Nonlinear Character Positions (NCP

    Directory of Open Access Journals (Sweden)

    Sabyasachi Samanta

    2013-11-01

    Full Text Available Usually, the steganographic algorithms employ images, audio, video or text files as the medium to ensure hidden exchange of information between multiple contenders and to protect the data from the prying eyes. This paper presents a survey of text steganography method used for hiding secret information inside some cover text. Here the text steganography algorithms based on modification of font format, font style et cetera, has advantages of great capacity, good imperceptibility and wide application range. The nonlinear character positions of different pages are targeted through out the cover with insignificant modification. As compared to other methods, we believe that the approaches proposed convey superior randomness and thus support higher security.

  3. Improved diagonal queue medical image steganography using Chaos theory, LFSR, and Rabin cryptosystem.

    Science.gov (United States)

    Jain, Mamta; Kumar, Anil; Choudhary, Rishabh Charan

    2016-09-09

    In this article, we have proposed an improved diagonal queue medical image steganography for patient secret medical data transmission using chaotic standard map, linear feedback shift register, and Rabin cryptosystem, for improvement of previous technique (Jain and Lenka in Springer Brain Inform 3:39-51, 2016). The proposed algorithm comprises four stages, generation of pseudo-random sequences (pseudo-random sequences are generated by linear feedback shift register and standard chaotic map), permutation and XORing using pseudo-random sequences, encryption using Rabin cryptosystem, and steganography using the improved diagonal queues. Security analysis has been carried out. Performance analysis is observed using MSE, PSNR, maximum embedding capacity, as well as by histogram analysis between various Brain disease stego and cover images.

  4. Medical Image Protection using steganography by crypto-image as cover Image

    Directory of Open Access Journals (Sweden)

    Vinay Pandey

    2012-09-01

    Full Text Available This paper presents securing the transmission of medical images. The presented algorithms will be applied to images. This work presents a new method that combines image cryptography, data hiding and Steganography technique for denoised and safe image transmission purpose. In This method we encrypt the original image with two shares mechanism encryption algorithm then embed the encrypted image with patient information by using lossless data embedding technique with data hiding method after that for more security. We apply steganography by encrypted image of any other medical image as cover image and embedded images as secrete image with the private key. In receiver side when the message is arrived then we apply the inverse methods in reverse order to get the original image and patient information and to remove noise we extract the image before the decryption of message. We have applied and showed the results of our method to medical images.

  5. A novel quantum LSB-based steganography method using the Gray code for colored quantum images

    Science.gov (United States)

    Heidari, Shahrokh; Farzadnia, Ehsan

    2017-10-01

    As one of the prevalent data-hiding techniques, steganography is defined as the act of concealing secret information in a cover multimedia encompassing text, image, video and audio, imperceptibly, in order to perform interaction between the sender and the receiver in which nobody except the receiver can figure out the secret data. In this approach a quantum LSB-based steganography method utilizing the Gray code for quantum RGB images is investigated. This method uses the Gray code to accommodate two secret qubits in 3 LSBs of each pixel simultaneously according to reference tables. Experimental consequences which are analyzed in MATLAB environment, exhibit that the present schema shows good performance and also it is more secure and applicable than the previous one currently found in the literature.

  6. Frequency Assignment for Joint Aerial Layer Network High-Capacity Backbone

    Science.gov (United States)

    2017-08-11

    ARL-TR-8093•AUG 2017 US Army Research Laboratory Frequency Assignment for Joint Aerial Layer Network High-Capacity Backbone by Peng Wang and Brian...2017 US Army Research Laboratory Frequency Assignment for Joint Aerial Layer Network High-Capacity Backbone by Peng Wang and Brian Henz Computational...Rev. 8/98)    Prescribed by ANSI Std. Z39.18 August 2017 Technical Report Frequency Assignment for Joint Aerial Layer Network High-Capacity Backbone

  7. Steganography algorithm multi pixel value differencing (MPVD) to increase message capacity and data security

    Science.gov (United States)

    Rojali, Siahaan, Ida Sri Rejeki; Soewito, Benfano

    2017-08-01

    Steganography is the art and science of hiding the secret messages so the existence of the message cannot be detected by human senses. The data concealment is using the Multi Pixel Value Differencing (MPVD) algorithm, utilizing the difference from each pixel. The development was done by using six interval tables. The objective of this algorithm is to enhance the message capacity and to maintain the data security.

  8. MB隐写分析算法%A Steganalysis Algorithm on MB Steganography

    Institute of Scientific and Technical Information of China (English)

    董秀则; 张茹; 钮心忻

    2012-01-01

    对图像的高阶统计量进行研究,首先利用离散余弦变换(DCT)域共生矩阵、空域边界梯度能量和空域图像子块的虚特征值分解等对基于模型(MB)隐写带来的变化进行描述,然后利用支持向量机( SVM)设计了MB隐写分析算法.实验结果表明,算法在保持低虚警率的同时具有较高的检出率.%A new steganalysis algorithm on model-based (MB) steganography is proposed after researching the high order statistics of images. The difference, imported fay MB steganography is described by the co-occurrence discrete cosine transform(DCT) matrix, the boundary gradient energy in airspace and the imaginary eigenvalue decomposition. The MB steganography is detected using all of the features and support vector machine. Experiments show that this algorithm has a high accuracy rate of detection with a low false detection rate.

  9. 批量隐写容量研究%Research of capacity for batch steganography

    Institute of Scientific and Technical Information of China (English)

    陈够喜; 陈俊杰

    2011-01-01

    通过对批量隐写的定性分析,提出了增大批量隐写容量的方法.对大容量图像的位平面进行等分分块,采用矩阵编码技术,证明了至多修改像素的1 LSB位能够嵌入2 bit隐秘信息的结论,提升了批量隐写容量,并给出了安全性分析.最后结合隐秘信息的嵌入和提取算法,以航拍图为隐写载体进行实验,验证了算法的有效性.%According to the definition of batch steganography and the properties of security,this paper presented a method to increase capacity for batch steganography. By dividing up bit-plane of large images and matrix coding,it proved that,a given image block could embed 2 bit by changing at most 1 bit in pixel,and enlarging embedding capacity. Besides analyed security of algorithm and gave embedding and extracting algorithm. The result of experiments shows that the new method of batch steganography for capacity increasing is reasonable.

  10. Extreme learning machine based optimal embedding location finder for image steganography.

    Science.gov (United States)

    Atee, Hayfaa Abdulzahra; Ahmad, Robiah; Noor, Norliza Mohd; Rahma, Abdul Monem S; Aljeroudi, Yazan

    2017-01-01

    In image steganography, determining the optimum location for embedding the secret message precisely with minimum distortion of the host medium remains a challenging issue. Yet, an effective approach for the selection of the best embedding location with least deformation is far from being achieved. To attain this goal, we propose a novel approach for image steganography with high-performance, where extreme learning machine (ELM) algorithm is modified to create a supervised mathematical model. This ELM is first trained on a part of an image or any host medium before being tested in the regression mode. This allowed us to choose the optimal location for embedding the message with best values of the predicted evaluation metrics. Contrast, homogeneity, and other texture features are used for training on a new metric. Furthermore, the developed ELM is exploited for counter over-fitting while training. The performance of the proposed steganography approach is evaluated by computing the correlation, structural similarity (SSIM) index, fusion matrices, and mean square error (MSE). The modified ELM is found to outperform the existing approaches in terms of imperceptibility. Excellent features of the experimental results demonstrate that the proposed steganographic approach is greatly proficient for preserving the visual information of an image. An improvement in the imperceptibility as much as 28% is achieved compared to the existing state of the art methods.

  11. Extreme learning machine based optimal embedding location finder for image steganography

    Science.gov (United States)

    Aljeroudi, Yazan

    2017-01-01

    In image steganography, determining the optimum location for embedding the secret message precisely with minimum distortion of the host medium remains a challenging issue. Yet, an effective approach for the selection of the best embedding location with least deformation is far from being achieved. To attain this goal, we propose a novel approach for image steganography with high-performance, where extreme learning machine (ELM) algorithm is modified to create a supervised mathematical model. This ELM is first trained on a part of an image or any host medium before being tested in the regression mode. This allowed us to choose the optimal location for embedding the message with best values of the predicted evaluation metrics. Contrast, homogeneity, and other texture features are used for training on a new metric. Furthermore, the developed ELM is exploited for counter over-fitting while training. The performance of the proposed steganography approach is evaluated by computing the correlation, structural similarity (SSIM) index, fusion matrices, and mean square error (MSE). The modified ELM is found to outperform the existing approaches in terms of imperceptibility. Excellent features of the experimental results demonstrate that the proposed steganographic approach is greatly proficient for preserving the visual information of an image. An improvement in the imperceptibility as much as 28% is achieved compared to the existing state of the art methods. PMID:28196080

  12. Frame-bitrate-change based steganography for voice-over-IP

    Institute of Scientific and Technical Information of China (English)

    刘进; 田晖; 周可

    2014-01-01

    Steganography based on bits-modification of speech frames is a kind of commonly used method, which targets at RTP payloads and offers covert communications over voice-over-IP (VoIP). However, direct modification on frames is often independent of the inherent speech features, which may lead to great degradation of speech quality. A novel frame-bitrate-change based steganography is proposed in this work, which discovers a novel covert channel for VoIP and introduces less distortion. This method exploits the feature of multi-rate speech codecs that the practical bitrate of speech frame is identified only by speech decoder at receiving end. Based on this characteristic, two steganography strategies called bitrate downgrading (BD) and bitrate switching (BS) are provided. The first strategy substitutes high bit-rate speech frames with lower ones to embed secret message, which introduces very low distortion in practice, and much less than other bits-modification based methods with the same embedding capacity. The second one encodes secret message bits into different types of speech frames, which is an alternative choice for supplement. The two strategies are implemented and tested on our covert communication system StegVoIP. The experiment results show that our proposed method is effective and fulfills the real-time requirement of VoIP communication.

  13. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, the active...

  14. Mesoporous Silicon-Based Anodes for High Capacity, High Performance Li-ion Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new high capacity anode composite based on mesoporous silicon is proposed. By virtue of a structure that resembles a pseudo one-dimensional phase, the active anode...

  15. Multi-core Fibers in Submarine Networks for High-Capacity Undersea Transmission Systems

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Morioka, Toshio

    2017-01-01

    Application of multi-core fibers in undersea networks for high-capacity submarine transmission systems is studied. It is demonstrated how different architectures of submerged branching unit affect network component counts in long-haul undersea transmission systems......Application of multi-core fibers in undersea networks for high-capacity submarine transmission systems is studied. It is demonstrated how different architectures of submerged branching unit affect network component counts in long-haul undersea transmission systems...

  16. High-capacity electrode materials for electrochemical energy storage: Role of nanoscale effects

    Indian Academy of Sciences (India)

    Jagjit Nanda; Surendra K Martha; Ramki Kalyanaraman

    2015-06-01

    This review summarizes the current state-of-the art electrode materials used for high-capacity lithium-ion-based batteries and their significant role towards revolutionizing the electrochemical energy storage landscape in the area of consumer electronics, transportation and grid storage application. We discuss the role of nanoscale effects on the electrochemical performance of high-capacity battery electrode materials. Decrease in the particle size of the primary electrode materials from micron to nanometre size improves the ionic and electronic diffusion rates significantly. Nanometre-thick solid electrolyte (such as lithium phosphorous oxynitride) and oxides (such as Al2O3, ZnO, TiO2 etc.) material coatings also improve the interfacial stability and rate capability of a number of battery chemistries. We elucidate these effects in terms of different high-capacity battery chemistries based on intercalation and conversion mechanism.

  17. State-of-the-art soft computing techniques in image steganography domain

    Science.gov (United States)

    Hussain, Hanizan Shaker; Din, Roshidi; Samad, Hafiza Abdul; Yaacub, Mohd Hanafizah; Murad, Roslinda; Rukhiyah, A.; Sabdri, Noor Maizatulshima

    2016-08-01

    This paper reviews major works of soft computing (SC) techniques in image steganography and watermarking in the last ten years, focusing on three main SC techniques, which are neural network, genetic algorithm, and fuzzy logic. The findings suggests that all these works applied SC techniques either during pre-processing, embedding or extracting stages or more than one of these stages. Therefore, the presence of SC techniques with their diverse approaches and strengths can help researchers in future work to attain excellent quality of image information hiding that comprises both imperceptibility and robustness.

  18. Steganography-based access control to medical data hidden in electrocardiogram.

    Science.gov (United States)

    Mai, Vu; Khalil, Ibrahim; Ibaida, Ayman

    2013-01-01

    Steganographic techniques allow secret data to be embedded inside another host data such as an image or a text file without significant changes to the quality of the host data. In this research, we demonstrate how steganography can be used as the main mechanism to build an access control model that gives data owners complete control to their sensitive cardiac health information hidden in their own Electrocardiograms. Our access control model is able to protect the privacy of users, the confidentiality of medical data, reduce storage space and make it more efficient to upload and download large amount of data.

  19. High-Capacity Photorefractive Neural Network Implementing a Kohonen Topological Map

    Science.gov (United States)

    Frauel, Yann; Pauliat, Gilles; Villing, André; Roosen, Gérald

    2001-10-01

    We designed and built a high-capacity neural network based on volume holographic interconnections in a photorefractive crystal. We used this system to implement a Kohonen topological map. We describe and justify our optical setup and present some experimental results of self-organization in the learning database.

  20. High-powered conveyor systems: long distance, downhill, open-pit, and high capacity conveyors

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, H.K.

    1978-01-01

    Paper indicates the conditions under which belt conveyors are superior to other forms of transport, the limitations of these conveyors. Long distance, downhill, open-pit and high capacity conveyor installations are described, including a 60-mile long conveyor in the Sahara.

  1. Building a Steganography Program Including How to Load, Process, and Save JPEG and PNG Files in Java

    Science.gov (United States)

    Courtney, Mary F.; Stix, Allen

    2006-01-01

    Instructors teaching beginning programming classes are often interested in exercises that involve processing photographs (i.e., files stored as .jpeg). They may wish to offer activities such as color inversion, the color manipulation effects archived with pixel thresholding, or steganography, all of which Stevenson et al. [4] assert are sought by…

  2. An Efficient Method to Audio Steganography based on Modification of Least Significant Bit Technique using Random Keys

    Directory of Open Access Journals (Sweden)

    Ali M. Meligy

    2015-06-01

    Full Text Available Steganography is the art of amalgamating the secret message into another public message which may be text, audio or video file in a way that no one can know or imperceptible the existence of message. So, the secret message can send in a secret and obscure way using steganography techniques. In this paper, we use the audio steganography where the secret message conceal in audio file. We use audio rather than image because the human auditory system (HAS is more sensitive than human visual system (HVS. We propose an audio steganography algorithm, for embedding text, audio or image based on Lifting Wavelet Transform (LWT transform with modification of Least Significant Bit (LSB technique and three random keys where these key is used to increase the robustness of the LSB technique and without it no one can know the sort of secret message type, the length of the secret message and the initial position of the embedded secret message in LSB. The performance of our algorithm is calculated using SNR and we compare the values of our proposed method with some known algorithms.

  3. Building a Steganography Program Including How to Load, Process, and Save JPEG and PNG Files in Java

    Science.gov (United States)

    Courtney, Mary F.; Stix, Allen

    2006-01-01

    Instructors teaching beginning programming classes are often interested in exercises that involve processing photographs (i.e., files stored as .jpeg). They may wish to offer activities such as color inversion, the color manipulation effects archived with pixel thresholding, or steganography, all of which Stevenson et al. [4] assert are sought by…

  4. Direct Sequence Spread Spectrum Steganographic Scheme for IEEE 802.15.4

    CERN Document Server

    Zielinska, Elzbieta

    2011-01-01

    This work addresses the issues related to network steganography in IEEE 802.15.4 Wireless Personal Area Networks (WPAN). The proposed communication scheme employs illicit Direct Sequence Spread Spectrum code sequences for the transmission of steganographic data. The presented approach is a compromise between minimising the probability of covert channel disclosure and providing robustness against random errors and a high steganographic data rate. The conducted analyses show that it is possible to create a covert channel with a data rate comparable to the raw data rate of IEEE 802.15.4 without much impact on the perceived receiver sensitivity, the Chip Error Rate and the Bit Error Rate.

  5. An Improved Image Steganography Method Based on LSB Technique with Random Pixel Selection

    Directory of Open Access Journals (Sweden)

    Marwa M. Emam

    2016-03-01

    Full Text Available with the rapid advance in digital network, information technology, digital libraries, and particularly World Wide Web services, many kinds of information could be retrieved any time. Thus, the security issue has become one of the most significant problems for distributing new information. It is necessary to protect this information while passing over insecure channels. Steganography introduces a strongly approach to hide the secret data in an appropriate media carriers such as images, audio files, text files, and video files. In this paper, a new image steganography method based on spatial domain is proposed. According to the proposed method, the secret message is embedded randomly in the pixel location of the cover image using Pseudo Random Number Generator (PRNG of each pixel value of the cover image instead of embedding sequentially in the pixels of the cover image. This randomization is expected to increase the security of the system. The proposed method works with two layers (Blue and Green, as (2-1-2 layer, and the byte of the message will be embedded in three pixels only in this form (3-2-3. From the experimental results, it has found that the proposed method achieves a very high Maximum Hiding Capacity (MHC, and higher visual quality as indicated by the Peak Signal-to- Noise Ratio (PSNR.

  6. Steganalysis and improvement of a quantum steganography protocol via a GHZ4 state

    Institute of Scientific and Technical Information of China (English)

    Xu Shu-Jiang; Chen Xiu-Bo; Niu Xin-Xin; Yang Yi-Xian

    2013-01-01

    Quantum steganography that utilizes the quantum mechanical effect to achieve the purpose of information hiding is a popular topic of quantum information.Recently,El Allati et al.proposed a new quantum steganography using the GHZ4 state.Since all of the 8 groups of unitary transformations used in the secret message encoding rule change the GHZ4 state into 6 instead of 8 different quantum states when the global phase is not considered,we point out that a 2-bit instead of a 3-bit secret message can be encoded by one group of the given unitary transformations.To encode a 3-bit secret message by performing a group of unitary transformations on the GHZ4 state,we give another 8 groups of unitary transformations that can change the GHZ4 state into 8 different quantum states.Due to the symmetry of the GHZ4 state,all the possible 16 groups of unitary transformations change the GHZ4 state into 8 different quantum states,so the improved protocol achieves a high efficiency.

  7. Implementation and Analysis Audio Steganography Used Parity Coding for Symmetric Cryptography Key Delivery

    Directory of Open Access Journals (Sweden)

    Afany Zeinata Firdaus

    2013-12-01

    Full Text Available In today's era of communication, online data transactions is increasing. Various information even more accessible, both upload and download. Because it takes a capable security system. Blowfish cryptographic equipped with Audio Steganography is one way to secure the data so that the data can not be accessed by unauthorized parties. In this study Audio Steganography technique is implemented using parity coding method that is used to send the key cryptography blowfish in e-commerce applications based on Android. The results obtained for the average computation time on stage insertion (embedding the secret message is shorter than the average computation time making phase (extracting the secret message. From the test results can also be seen that the more the number of characters pasted the greater the noise received, where the highest SNR is obtained when a character is inserted as many as 506 characters is equal to 11.9905 dB, while the lowest SNR obtained when a character is inserted as many as 2006 characters at 5,6897 dB . Keywords: audio steganograph, parity coding, embedding, extractin, cryptography blowfih.

  8. COMPARATIVE STUDY OF EDGE BASED LSB MATCHING STEGANOGRAPHY FOR COLOR IMAGES

    Directory of Open Access Journals (Sweden)

    A.J. Umbarkar

    2016-02-01

    Full Text Available Steganography is a very pivotal technique mainly used for covert transfer of information over a covert communication channel. This paper proposes a significant comparative study of the spatial LSB domain technique that focuses on sharper edges of the color as well as gray scale images for the purpose of data hiding and hides secret message first in sharper edge regions and then in smooth regions of the image. Message embedding depends on content of the image and message size. The experimental results illustrate that, for low embedding rate the method hides the message in sharp edges of cover image to get better stego image visualization quality. For high embedding rate, smooth regions and edges of the cover image are used for the purpose of data hiding. In this steganography method, color image and textured kind of image preserves better visual quality of stego image. The novelty of the comparative study is that, it helps to analyze the efficiency and performance of the method as it gives better results because it directly works on color images instead of converting to gray scale image.

  9. Quantum Image Steganography and Steganalysis Based On LSQu-Blocks Image Information Concealing Algorithm

    Science.gov (United States)

    A. AL-Salhi, Yahya E.; Lu, Songfeng

    2016-08-01

    Quantum steganography can solve some problems that are considered inefficient in image information concealing. It researches on Quantum image information concealing to have been widely exploited in recent years. Quantum image information concealing can be categorized into quantum image digital blocking, quantum image stereography, anonymity and other branches. Least significant bit (LSB) information concealing plays vital roles in the classical world because many image information concealing algorithms are designed based on it. Firstly, based on the novel enhanced quantum representation (NEQR), image uniform blocks clustering around the concrete the least significant Qu-block (LSQB) information concealing algorithm for quantum image steganography is presented. Secondly, a clustering algorithm is proposed to optimize the concealment of important data. Finally, we used Con-Steg algorithm to conceal the clustered image blocks. Information concealing located on the Fourier domain of an image can achieve the security of image information, thus we further discuss the Fourier domain LSQu-block information concealing algorithm for quantum image based on Quantum Fourier Transforms. In our algorithms, the corresponding unitary Transformations are designed to realize the aim of concealing the secret information to the least significant Qu-block representing color of the quantum cover image. Finally, the procedures of extracting the secret information are illustrated. Quantum image LSQu-block image information concealing algorithm can be applied in many fields according to different needs.

  10. Two New Approaches for Secured Image Steganography Using Cryptographic Techniques and Type Conversions

    Directory of Open Access Journals (Sweden)

    Sujay Narayana

    2011-02-01

    Full Text Available The science of securing a data by encryption is Cryptography whereas the method of hiding secretmessages in other messages is Steganography, so that the secret’s very existence is concealed. The term‘Steganography’ describes the method of hiding cognitive content in another medium to avoid detectionby the intruders. This paper introduces two new methods wherein cryptography and steganography arecombined to encrypt the data as well as to hide the encrypted data in another medium so the fact that amessage being sent is concealed. One of the methods shows how to secure the image by converting it intocipher text by S-DES algorithm using a secret key and conceal this text in another image bysteganographic method. Another method shows a new way of hiding an image in another image byencrypting the image directly by S-DES algorithm using a key image and the data obtained is concealedin another image. The proposed method prevents the possibilities of steganalysis also.

  11. A Modified Multi-resolutional LSB Insertion Algorithm for High Capacity Audio Steganography%改进的大容量多分辨率LSB音频隐写算法

    Institute of Scientific and Technical Information of China (English)

    刘秀娟; 郭立; 邱天

    2006-01-01

    算法将载体音频信号用可完全重构的滤波器组进行小波包分解,根据各子带的边际信号失真敏感度将其分组,然后用改进的LSB算法以不同的分辨率将秘密信息嵌入到选定子带的小波系数中.实验结果表明,在信噪比相同的情况下,该算法的隐写容量比传统时域LSB算法高160kbps~200kbps,同时可很好地保持不可感知性,并具有一定的不可检测性,能抵抗一类针对时域LSB算法的隐写分析算法.

  12. Estimation of Parameters Obtained by Electrochemical Impedance Spectroscopy on Systems Containing High Capacities

    Directory of Open Access Journals (Sweden)

    Mirjana Rajčić Vujasinović

    2009-09-01

    Full Text Available Electrochemical systems with high capacities demand devices for electrochemical impedance spectroscopy (EIS with ultra-low frequencies (in order of mHz, that are almost impossible to accomplish with analogue techniques, but this becomes possible by using a computer technique and accompanying digital equipment. Recently, an original software and hardware for electrochemical measurements, intended for electrochemical systems exhibiting high capacities, such as supercapacitors, has been developed. One of the included methods is EIS. In this paper, the method of calculation of circuit parameters from an EIS curve is described. The results of testing on a physical model of an electrochemical system, constructed of known elements (including a 1.6 F capacitor in a defined arrangement, proved the validity of the system and the method.

  13. High-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding

    Science.gov (United States)

    Lai, Hong; Orgun, Mehmet A.; Pieprzyk, Josef; Li, Jing; Luo, Mingxing; Xiao, Jinghua; Xiao, Fuyuan

    2016-08-01

    We propose an approach that achieves high-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding. In particular, we encode a key with the Chebyshev-map values corresponding to Lucas numbers and then use k-Chebyshev maps to achieve consecutive and flexible key expansion and apply the pre-shared classical information between Alice and Bob and fountain codes for privacy amplification to solve the security of the exchange of classical information via the classical channel. Consequently, our high-capacity protocol does not have the limitations imposed by orbital angular momentum and down-conversion bandwidths, and it meets the requirements for longer distances and lower error rates simultaneously.

  14. High-Capacity Hydrogen-Based Green-Energy Storage Solutions For The Grid Balancing

    Science.gov (United States)

    D'Errico, F.; Screnci, A.

    One of the current main challenges in green-power storage and smart grids is the lack of effective solutions for accommodating the unbalance between renewable energy sources, that offer intermittent electricity supply, and a variable electricity demand. Energy management systems have to be foreseen for the near future, while they still represent a major challenge. Integrating intermittent renewable energy sources, by safe and cost-effective energy storage systems based on solid state hydrogen is today achievable thanks to recently some technology breakthroughs. Optimized solid storage method made of magnesium-based hydrides guarantees a very rapid absorption and desorption kinetics. Coupled with electrolyzer technology, high-capacity storage of green-hydrogen is therefore practicable. Besides these aspects, magnesium has been emerging as environmentally friend energy storage method to sustain integration, monitoring and control of large quantity of GWh from high capacity renewable generation in the EU.

  15. Radiation and temperature effects on electronic components investigated under the CSTI high capacity power project

    Science.gov (United States)

    Schwarze, Gene E.; Niedra, Janis M.; Frasca, Albert J.; Wieserman, William R.

    1993-01-01

    The effects of nuclear radiation and high temperature environments must be fully known and understood for the electronic components and materials used in both the Power Conditioning and Control subsystem and the reactor Instrumentation and Control subsystem of future high capacity nuclear space power systems. This knowledge is required by the designer of these subsystems in order to develop highly reliable, long-life power systems for future NASA missions. A review and summary of the experimental results obtained for the electronic components and materials investigated under the power management element of the Civilian Space Technology Initiative (CSTI) high capacity power project are presented: (1) neutron, gamma ray, and temperature effects on power semiconductor switches, (2) temperature and frequency effects on soft magnetic materials; and (3) temperature effects on rare earth permanent magnets.

  16. High-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding

    Science.gov (United States)

    Lai, Hong; Orgun, Mehmet A.; Pieprzyk, Josef; Li, Jing; Luo, Mingxing; Xiao, Jinghua; Xiao, Fuyuan

    2016-11-01

    We propose an approach that achieves high-capacity quantum key distribution using Chebyshev-map values corresponding to Lucas numbers coding. In particular, we encode a key with the Chebyshev-map values corresponding to Lucas numbers and then use k-Chebyshev maps to achieve consecutive and flexible key expansion and apply the pre-shared classical information between Alice and Bob and fountain codes for privacy amplification to solve the security of the exchange of classical information via the classical channel. Consequently, our high-capacity protocol does not have the limitations imposed by orbital angular momentum and down-conversion bandwidths, and it meets the requirements for longer distances and lower error rates simultaneously.

  17. Estimation of parameters obtained by electrochemical impedance spectroscopy on systems containing high capacities.

    Science.gov (United States)

    Stević, Zoran; Vujasinović, Mirjana Rajčić; Radunović, Milan

    2009-01-01

    Electrochemical systems with high capacities demand devices for electrochemical impedance spectroscopy (EIS) with ultra-low frequencies (in order of mHz), that are almost impossible to accomplish with analogue techniques, but this becomes possible by using a computer technique and accompanying digital equipment. Recently, an original software and hardware for electrochemical measurements, intended for electrochemical systems exhibiting high capacities, such as supercapacitors, has been developed. One of the included methods is EIS. In this paper, the method of calculation of circuit parameters from an EIS curve is described. The results of testing on a physical model of an electrochemical system, constructed of known elements (including a 1.6 F capacitor) in a defined arrangement, proved the validity of the system and the method.

  18. Estimation of Parameters Obtained by Electrochemical Impedance Spectroscopy on Systems Containing High Capacities

    Science.gov (United States)

    Stević, Zoran; Vujasinović, Mirjana Rajčić; Radunović, Milan

    2009-01-01

    Electrochemical systems with high capacities demand devices for electrochemical impedance spectroscopy (EIS) with ultra-low frequencies (in order of mHz), that are almost impossible to accomplish with analogue techniques, but this becomes possible by using a computer technique and accompanying digital equipment. Recently, an original software and hardware for electrochemical measurements, intended for electrochemical systems exhibiting high capacities, such as supercapacitors, has been developed. One of the included methods is EIS. In this paper, the method of calculation of circuit parameters from an EIS curve is described. The results of testing on a physical model of an electrochemical system, constructed of known elements (including a 1.6 F capacitor) in a defined arrangement, proved the validity of the system and the method. PMID:22400000

  19. Overview of space power electronic's technology under the CSTI High Capacity Power Program

    Science.gov (United States)

    Schwarze, Gene E.

    The Civilian Space Technology Initiative (CSTI) is a NASA Program targeted at the development of specific technologies in the areas of transportation, operations and science. Each of these three areas consists of major elements and one of the operation's elements is the High Capacity Power element. The goal of this element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA initiatives. The High Capacity Power element is broken down into several subelements that includes energy conversion in the areas of the free piston Stirling power converter and thermoelectrics, thermal management, power management, system diagnostics, and environmental compatibility and system's lifetime. A recent overview of the CSTI High capacity Power element and a description of each of the program's subelements is given by Winter (1989). The goals of the Power Management subelement are twofold. The first is to develop, test, and demonstrate high temperature, radiation-resistant power and control components and circuits that will be needed in the Power Conditioning, Control and Transmission (PCCT) subsystem of a space nuclear power system. The results obtained under this goal will also be applicable to the instrumentation and control subsystem of a space nuclear reactor. These components and circuits must perform reliably for lifetimes of 7-10 years. The second goal is to develop analytical models for use in computer simulations of candidate PCCT subsystems. Circuits which will be required for a specific PCCT subsystem will be designed and built to demonstrate their performance and, also, to validate the analytical models and simulations. The tasks under the Power Management subelement will now be described in terms of objectives, approach and present status of work.

  20. Topology Management Algorithms for Large Scale Aerial High Capacity Directional Networks

    Science.gov (United States)

    2016-11-01

    Introduction of classes of topology management algo- rithms and example implementations of each • Performance evaluation of the algorithms in 2 example relevant...Topology Management Algorithms for Large-Scale Aerial High Capacity Directional Networks Joy Wang, Thomas Shake, Patricia Deutsch, Andrea Coyle, Bow...airborne backbone network is large- scale topology management of directional links in a dynamic environment. In this paper, we present several

  1. Overview of space power electronic's technology under the CSTI High Capacity Power Program

    Science.gov (United States)

    Schwarze, Gene E.

    1994-01-01

    The Civilian Space Technology Initiative (CSTI) is a NASA Program targeted at the development of specific technologies in the areas of transportation, operations and science. Each of these three areas consists of major elements and one of the operation's elements is the High Capacity Power element. The goal of this element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA initiatives. The High Capacity Power element is broken down into several subelements that includes energy conversion in the areas of the free piston Stirling power converter and thermoelectrics, thermal management, power management, system diagnostics, and environmental compatibility and system's lifetime. A recent overview of the CSTI High capacity Power element and a description of each of the program's subelements is given by Winter (1989). The goals of the Power Management subelement are twofold. The first is to develop, test, and demonstrate high temperature, radiation-resistant power and control components and circuits that will be needed in the Power Conditioning, Control and Transmission (PCCT) subsystem of a space nuclear power system. The results obtained under this goal will also be applicable to the instrumentation and control subsystem of a space nuclear reactor. These components and circuits must perform reliably for lifetimes of 7-10 years. The second goal is to develop analytical models for use in computer simulations of candidate PCCT subsystems. Circuits which will be required for a specific PCCT subsystem will be designed and built to demonstrate their performance and, also, to validate the analytical models and simulations. The tasks under the Power Management subelement will now be described in terms of objectives, approach and present status of work.

  2. Silicon oxide based high capacity anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Haixia; Han, Yongbong; Masarapu, Charan; Anguchamy, Yogesh Kumar; Lopez, Herman A.; Kumar, Sujeet

    2017-03-21

    Silicon oxide based materials, including composites with various electrical conductive compositions, are formulated into desirable anodes. The anodes can be effectively combined into lithium ion batteries with high capacity cathode materials. In some formulations, supplemental lithium can be used to stabilize cycling as well as to reduce effects of first cycle irreversible capacity loss. Batteries are described with surprisingly good cycling properties with good specific capacities with respect to both cathode active weights and anode active weights.

  3. Robo-line storage: Low latency, high capacity storage systems over geographically distributed networks

    Science.gov (United States)

    Katz, Randy H.; Anderson, Thomas E.; Ousterhout, John K.; Patterson, David A.

    1991-01-01

    Rapid advances in high performance computing are making possible more complete and accurate computer-based modeling of complex physical phenomena, such as weather front interactions, dynamics of chemical reactions, numerical aerodynamic analysis of airframes, and ocean-land-atmosphere interactions. Many of these 'grand challenge' applications are as demanding of the underlying storage system, in terms of their capacity and bandwidth requirements, as they are on the computational power of the processor. A global view of the Earth's ocean chlorophyll and land vegetation requires over 2 terabytes of raw satellite image data. In this paper, we describe our planned research program in high capacity, high bandwidth storage systems. The project has four overall goals. First, we will examine new methods for high capacity storage systems, made possible by low cost, small form factor magnetic and optical tape systems. Second, access to the storage system will be low latency and high bandwidth. To achieve this, we must interleave data transfer at all levels of the storage system, including devices, controllers, servers, and communications links. Latency will be reduced by extensive caching throughout the storage hierarchy. Third, we will provide effective management of a storage hierarchy, extending the techniques already developed for the Log Structured File System. Finally, we will construct a protototype high capacity file server, suitable for use on the National Research and Education Network (NREN). Such research must be a Cornerstone of any coherent program in high performance computing and communications.

  4. Double Layer Image Security System using Encryption and Steganography

    Directory of Open Access Journals (Sweden)

    Samreen Sekhon Brar

    2016-03-01

    Full Text Available The image security on internet transfers is the concern of the hour as the breaching attacks into the image databases are rising every year. The hackers take advantage of the stolen personal and important images to fulfill their dangerous and unethical intentions. The image data theft can be used to defame a person on the internet by posting the illegal and unacceptable images of that person (internet user. Hence the images transfers have to be secure to ensure the privacy of the user's image data. In this research, a number of image security systems have been studied to evaluate the research gap. Majority of the existing image security systems are not up to date to protect against the latest breaching attacks. So, we have proposed an effective and robust image security framework particularly designed for the images. The proposed has been designed and implemented using MATLAB. In this research, a hybrid image security framework has been proposed to overcome the problem stated earlier, which will be implemented by combining various techniques together to achieve the image security goal. The techniques included in the combination would beimage compression, cryptography andsteganography. DWT compression has been used, because it is a stronger compression algorithm. The steganographed image would be compressed to reduce its size. Blowfish encryption algorithm would be used for the encryption purposes. It offers maximum throughput (faster and also energy efficient. Compressed image would be encrypted to enhance the image security. Real image will be hidden into another image. A cluster based steganographic technique will be used. Real image and face image would be analyzed, and the real image would be embedded in those areas of face image, where color schemes of the real image and face image would be most similar. Kmeans or Hierarchical clustering would be used as a clustering technique. An all new comparative analysis technique would be applied to

  5. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  6. An Efficient Method for Image and Audio Steganography using Least Significant Bit (LSB) Substitution

    Science.gov (United States)

    Chadha, Ankit; Satam, Neha; Sood, Rakshak; Bade, Dattatray

    2013-09-01

    In order to improve the data hiding in all types of multimedia data formats such as image and audio and to make hidden message imperceptible, a novel method for steganography is introduced in this paper. It is based on Least Significant Bit (LSB) manipulation and inclusion of redundant noise as secret key in the message. This method is applied to data hiding in images. For data hiding in audio, Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) both are used. All the results displayed prove to be time-efficient and effective. Also the algorithm is tested for various numbers of bits. For those values of bits, Mean Square Error (MSE) and Peak-Signal-to-Noise-Ratio (PSNR) are calculated and plotted. Experimental results show that the stego-image is visually indistinguishable from the original cover-image when nsteganography process does not reveal presence of any hidden message, thus qualifying the criteria of imperceptible message.

  7. Temporal phase mask encrypted optical steganography carried by amplified spontaneous emission noise.

    Science.gov (United States)

    Wu, Ben; Wang, Zhenxing; Shastri, Bhavin J; Chang, Matthew P; Frost, Nicholas A; Prucnal, Paul R

    2014-01-13

    A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

  8. Parallel steganography framework for hiding a color image inside stereo images

    Science.gov (United States)

    Munoz-Ramirez, David O.; Ponomaryov, Volodymyr I.; Reyes-Reyes, Rogelio; Cruz-Ramos, Clara

    2017-05-01

    In this work, a robust steganography framework to hide a color image into a stereo images is proposed. The embedding algorithm is performed via Discrete Cosine Transform (DCT) and Quantization Index Modulation-Dither Modulation (QIM-DM) hiding the secret data. Additionally, the Arnold's Cat Map Transform is applied in order to scramble the secret color image, guaranteeing better security and robustness of the proposed system. Novel framework has demonstrated better performance against JPEG compression attacks among other existing approaches. Besides, the proposed algorithm is developed taking into account the parallel paradigm in order to be implemented in multi-core CPU increasing the processing speed. The results obtained by the proposed framework show high values of PSNR and SSIM, which demonstrate imperceptibility and sufficient robustness against JPEG compression attacks.

  9. Public key Steganography Using Discrete Cross-Coupled One-Dimensional Chaotic Maps

    Directory of Open Access Journals (Sweden)

    Mahdiyeh Majidpour

    2013-07-01

    Full Text Available By cross-coupling two one-dimensional chaotic maps a novel method is proposed for the public key steganography in JPEG image. Chaotic maps entail high complexity in the used algorithm for embedding secret data in a medium. In this paper, discrete cross-coupled chaotic maps are used to specifying the location of the different parts of the secret data in the image. Modifying JPEG format during compressing and decompressing, and also using public key enhanced difficulty of the algorithm. Simulation results show that in addition to excessive capacity, this method has high robustness and resistance against hackers and can be applicable in secret communication. Also the PSNR value is high compared to the other works.

  10. Cyclic Combination Method For Digital Image Steganography With Uniform Distribution Of Message

    Directory of Open Access Journals (Sweden)

    Rajkumar Yadav

    2011-12-01

    Full Text Available In this paper, a new image steganography technique for embedding messages into Gray Level Images isproposed. This new technique distributes the message uniformly throughout the image. The image isdivided into blocks of equal sizes and the message is then embedded into the central pixel of the blockusing cyclic combination of 6th, 7th & 8th bit. The blocks of the image are chosen randomly using thePseudo Random Generator seeded with a secret key. In proposed method, cyclic combination of last threebits of pixel value provide 100% chances of message insertion at the pixel value and division of imageinto blocks distribute the message uniformly into the image. This method also provides minimumdegradation in image quality that cannot be perceived by human eye.

  11. Study on Strengthening Plan of Safety Network CCTV Monitoring by Steganography and User Authentication

    Directory of Open Access Journals (Sweden)

    Jung-oh Park

    2015-01-01

    Full Text Available Recently, as the utilization of CCTV (closed circuit television is emerging as an issue, the studies on CCTV are receiving much attention. Accordingly, due to the development of CCTV, CCTV has IP addresses and is connected to network; it is exposed to many threats on the existing web environment. In this paper, steganography is utilized to confirm the Data Masquerading and Data Modification and, in addition, to strengthen the security; the user information is protected based on PKI (public key infrastructure, SN (serial number, and R value (random number attributed at the time of login and the user authentication protocol to block nonauthorized access of malicious user in network CCTV environment was proposed. This paper should be appropriate for utilization of user infringement-related CCTV where user information protection-related technology is not applied for CCTV in the future.

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

    Science.gov (United States)

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

    2017-08-01

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

  13. DNS ID Covert Channel based on Lower Bound Steganography for Normal DNS ID Distribution

    Directory of Open Access Journals (Sweden)

    Abdulrahman H. Altalhi

    2011-11-01

    Full Text Available The covert channel is a method used to send secret data within a communication channel in unauthorized ways. This is performed by exploiting the weaknesses in packet or network communications with the intention to hide the existence of a covert communication. The DNS identification (DNS ID method has been exploited by Thyer. However, the major problem in Thyers implementation is that the encrypted cipher was directly inserted as a DNS ID value, which is abnormal, compared to the normal DNS ID distribution. We have overcome this problem through the application of Steganography to insert the cipher value into the DNS ID. The data set test for normal DNS ID is taken from MAWI. We tested four different message lengths and plotted the distribution graph. We found that the proposed result is normal compared to normal distribution of the DNS ID. Therefore, this method produces a normal distribution for DNS ID covert channel.

  14. Blind steganalysis method for JPEG steganography combined with the semisupervised learning and soft margin support vector machine

    Science.gov (United States)

    Dong, Yu; Zhang, Tao; Xi, Ling

    2015-01-01

    Stego images embedded by unknown steganographic algorithms currently may not be detected by using steganalysis detectors based on binary classifier. However, it is difficult to obtain high detection accuracy by using universal steganalysis based on one-class classifier. For solving this problem, a blind detection method for JPEG steganography was proposed from the perspective of information theory. The proposed method combined the semisupervised learning and soft margin support vector machine with steganalysis detector based on one-class classifier to utilize the information in test data for improving detection performance. Reliable blind detection for JPEG steganography was realized only using cover images for training. The experimental results show that the proposed method can contribute to improving the detection accuracy of steganalysis detector based on one-class classifier and has good robustness under different source mismatch conditions.

  15. Development and Testing of a High Capacity Plasma Chemical Reactor in the Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, Raymond W.

    2012-07-30

    This project, Development and Testing of a High Capacity Plasma Chemical Reactor in the Ukraine was established at the Kharkiv Institute of Physics and Technology (KIPT). The associated CRADA was established with Campbell Applied Physics (CAP) located in El Dorado Hills, California. This project extends an earlier project involving both CAP and KIPT conducted under a separate CRADA. The initial project developed the basic Plasma Chemical Reactor (PCR) for generation of ozone gas. This project built upon the technology developed in the first project, greatly enhancing the output of the PCR while also improving reliability and system control.

  16. Advanced Steganography Algorithm Using Randomized Intermediate QR Host Embedded With Any Encrypted Secret Message: ASA_QR Algorithm

    Directory of Open Access Journals (Sweden)

    Somdip Dey

    2012-06-01

    Full Text Available Due to tremendous growth in communication technology, now it is a real problem / challenge to send some confidential data / information through communication network. For this reason, Nath et al. developed several information security systems, combining cryptography and steganography together, and the present method, ASA_QR, is also one of them. In the present paper, the authors present a new steganography algorithm to hide any small encrypted secret message inside QR CodeTM , which is then randomized and then, finally embed that randomized QR Code inside some common image. Quick Response Codes (or QR Codes are a type of two-dimensional matrix barcodes used for encoding information. It has become very popular recently for its high storage capacity. The present method is ASA_QR is a combination of strong encryption algorithm and data hiding in two stages to make the entire process extremely hard to break. Here, the secret message is encrypted first and hide it in a QR CodeTM and then again that QR CodeTM is embed in a cover file (picture file in random manner, using the standard method of steganography. In this way the data, which is secured, is almost impossible to be retrieved without knowing the cryptography key, steganography password and the exact unhide method. For encrypting data The authors used a method developed by Nath et al i.e. TTJSA, which is based on generalized modified Vernam Cipher, MSA and NJJSA method; and from the cryptanalysis it is seen that TTJSA is free from any standard cryptographic attacks, like differential attack, plain-text attack or any brute force attack. After encrypting the data using TTJSA,the authors have used standard steganographic method To hide data inside some host file. The present method may be used for sharing secret key, password, digital signature etc.

  17. 多载体信息隐藏安全性研究%Research Security for Batch Steganography

    Institute of Scientific and Technical Information of China (English)

    陈够喜; 陈俊杰

    2011-01-01

    分析单载体信息隐藏技术的的特点和局限性,针对单载体信息隐藏的不足,提出一种多载体信息隐藏的理论模型.给出了其工作原理和实现过程,得到了载体的最大有效载荷与载体容量的关系.从信息论的角度对单载体信息隐藏和多载体信息隐藏的安全性进行了分析,并给出了形式化的证明,最后给出了完备多载体信息隐藏系统安全性的约束条件.%This paper,analyzed features and limitations with single cover steganography,proposed a theoretical model of batch steg-anography for lack of single cover steganography. It expresses working principle and implementation process,and derives a closed form expression for maximal payload and capacity of covers. In this paper,it analyses steganographic security of single cover and batch covers by information theory, and gives formal proof . Finally, it obtains the security constraints of perfect batch steganosystem.

  18. Charge Modulation in Graphitic Carbon Nitride as a Switchable Approach to High-Capacity Hydrogen Storage.

    Science.gov (United States)

    Tan, Xin; Kou, Liangzhi; Tahini, Hassan A; Smith, Sean C

    2015-11-01

    Electrical charging of graphitic carbon nitride nanosheets (g-C4 N3 and g-C3 N4 ) is proposed as a strategy for high-capacity and electrocatalytically switchable hydrogen storage. Using first-principle calculations, we found that the adsorption energy of H2 molecules on graphitic carbon nitride nanosheets is dramatically enhanced by injecting extra electrons into the adsorbent. At full hydrogen coverage, the negatively charged graphitic carbon nitride achieves storage capacities up to 6-7 wt %. In contrast to other hydrogen storage approaches, the storage/release occurs spontaneously once extra electrons are introduced or removed, and these processes can be simply controlled by switching on/off the charging voltage. Therefore, this approach promises both facile reversibility and tunable kinetics without the need of specific catalysts. Importantly, g-C4 N3 has good electrical conductivity and high electron mobility, which can be a very good candidate for electron injection/release. These predictions may prove to be instrumental in searching for a new class of high-capacity hydrogen storage materials.

  19. Programmatic status of NASA's CSTI high capacity power Stirling space power converter program

    Science.gov (United States)

    Dudenhoefer, James E.

    1990-01-01

    An overview is presented of the NASA Lewis Research Center Free-Piston Stirling Space Power Converter Technology Development Program. This work is being conducted under NASA's Civil Space Technology Initiative (CSTI). The goal of the CSTI High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space initiatives. Efforts are focused upon increasing system thermal and electric energy conversion efficiency at least fivefold over current SP-100 technology, and on achieving systems that are compatible with space nuclear reactors. The status of test activities with the Space Power Research Engine (SPRE) is discussed. Design deficiencies are gradually being corrected and the power converter is now outputting 11.5 kWe at a temperature ratio of 2 (design output is 12.5 kWe). Detail designs were completed for the 1050 K Component Test Power Converter (CTPC). The success of these and future designs is dependent upon supporting research and technology efforts including heat pipes, gas bearings, superalloy joining technologies and high efficiency alternators. An update of progress in these technologies is provided.

  20. E- and W-band high-capacity hybrid fiber-wireless link

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Pang, Xiaodan; Tafur Monroy, Idelfonso

    2014-01-01

    In this paper we summarize the work conducted in our group in the area of E- and W-band optical high-capacity fiber-wireless links. We present performance evaluations of E- and W-band mm-wave signal generation using photonic frequency upconversion employing both VCSELs and ECLs, along with transm......In this paper we summarize the work conducted in our group in the area of E- and W-band optical high-capacity fiber-wireless links. We present performance evaluations of E- and W-band mm-wave signal generation using photonic frequency upconversion employing both VCSELs and ECLs, along...... with transmission over different type of optical fibers and for a number of values for the wireless link distance. Hybrid wireless-optical links can be composed of mature and resilient technology available off-the-shelf, and provide functionalities that can add value to optical access networks, specifically...... in mobile backhaul/fronthaul applications, dense distributed antenna systems and fiber-over-radio scenarios....

  1. Review on anionic redox for high-capacity lithium- and sodium-ion batteries

    Science.gov (United States)

    Zhao, Chenglong; Wang, Qidi; Lu, Yaxiang; Hu, Yong-Sheng; Li, Baohua; Chen, Liquan

    2017-05-01

    Rechargeable batteries, especially lithium-ion batteries, are now widely used as power sources for portable electronics and electric vehicles, but material innovations are still needed to satisfy the increasing demand for larger energy density. Recently, lithium- and sodium-rich electrode materials, including the A2MO3-family layered compounds (A  =  Li, Na; M  =  Mn4+, Ru4+, etc), have been extensively studied as potential high-capacity electrode materials for a cumulative cationic and anionic redox activity. Negatively charged oxide ions can potentially donate electrons to compensate for the absence of oxidable transition metals as a redox center to further increase the reversible capacity. Understanding and controlling the state-of-the-art anionic redox processes is pivotal for the design of advanced energy materials, highlighted in rechargeable batteries. Hence, experimental and theoretical approaches have been developed to consecutively study the diverting processes, states, and structures involved. In this review, we attempt to present a literature overview and provide insight into the reaction mechanism with respect to the anionic redox processes, proposing some opinions as target oriented. It is hoped that, through this discussion, the search for anionic redox electrode materials with high-capacity rechargeable batteries can be advanced, and practical applications realized as soon as possible.

  2. High capacity fiber optic sensor networks using hybrid multiplexing techniques and their applications

    Science.gov (United States)

    Sun, Qizhen; Li, Xiaolei; Zhang, Manliang; Liu, Qi; Liu, Hai; Liu, Deming

    2013-12-01

    Fiber optic sensor network is the development trend of fiber senor technologies and industries. In this paper, I will discuss recent research progress on high capacity fiber sensor networks with hybrid multiplexing techniques and their applications in the fields of security monitoring, environment monitoring, Smart eHome, etc. Firstly, I will present the architecture of hybrid multiplexing sensor passive optical network (HSPON), and the key technologies for integrated access and intelligent management of massive fiber sensor units. Two typical hybrid WDM/TDM fiber sensor networks for perimeter intrusion monitor and cultural relics security are introduced. Secondly, we propose the concept of "Microstructure-Optical X Domin Refecltor (M-OXDR)" for fiber sensor network expansion. By fabricating smart micro-structures with the ability of multidimensional encoded and low insertion loss along the fiber, the fiber sensor network of simple structure and huge capacity more than one thousand could be achieved. Assisted by the WDM/TDM and WDM/FDM decoding methods respectively, we built the verification systems for long-haul and real-time temperature sensing. Finally, I will show the high capacity and flexible fiber sensor network with IPv6 protocol based hybrid fiber/wireless access. By developing the fiber optic sensor with embedded IPv6 protocol conversion module and IPv6 router, huge amounts of fiber optic sensor nodes can be uniquely addressed. Meanwhile, various sensing information could be integrated and accessed to the Next Generation Internet.

  3. Crack-resistant polyimide coating for high-capacity battery anodes

    Science.gov (United States)

    Li, Yingshun; Wang, Shuo; Lee, Pui-Kit; He, Jieqing; Yu, Denis Y. W.

    2017-10-01

    Electrode cracking is a serious problem that hinders the application of many next-generation high-capacity anode materials for lithium-ion batteries. Even though nano-sizing the material can reduce fracturing of individual particles, capacity fading is still observed due to large volume change and loss of contact in the electrode during lithium insertion and extraction. In this study, we design a crack-resistant high-modulus polyimide coating with high compressive strength which can hold multiple particles together during charge and discharge to maintain contact. The effectiveness of the coating is demonstrated on tin dioxide, a high-capacity large-volume-change material that undergoes both alloy and conversion reactions. The polyimide coating improves capacity retention of SnO2 from 80% to 100% after 80 cycles at 250 mA g-1. Stable capacity of 585 mAh g-1 can be obtained even at 500 mA g-1 after 300 cycles. Scanning electron microscopy and in-situ dilatometry confirm that electrode cracking is suppressed and thickness change is reduced with the coating. In addition, the chemically-stable polyimide film can separate the surface from direct contact with electrolyte, improving coulombic efficiency to ∼100%. We expect the novel strategy of suppressing electrode degradation with a crack-resistant coating can also be used for other alloy and conversion-based anodes.

  4. A micro-structured Si-based electrodes for high capacity electrical double layer capacitors

    Science.gov (United States)

    Krikscikas, Valdas; Oguchi, Hiroyuki; Yanazawa, Hiroshi; Hara, Motoaki; Kuwano, Hiroki

    2014-11-01

    We challenged to make basis for Si electrodes of electric double layer capacitors (EDLC) used as a power source of micro-sensor nodes. Mcroelectromechanical systems (MEMS) processes were successfully introduced to fabricate micro-structured Si-based electrodes to obtain high surface area which leads to high capacity of EDLCs. Study of fundamental properties revealed that the microstructured electrodes benefit from good wettability to electrolytes, but suffer from electric resistance. We found that this problem can be solved by metal-coating of the electrode surface. Finally we build an EDLC consisting of Au-coated micro-structured Si electrodes. This EDLC showed capacity of 14.3 mF/cm2, which is about 530 times larger than that of an EDLC consisting of flat Au electrodes.

  5. Synthesization of high-capacity auto-associative memories using complex-valued neural networks

    Science.gov (United States)

    Huang, Yu-Jiao; Wang, Xiao-Yan; Long, Hai-Xia; Yang, Xu-Hua

    2016-12-01

    In this paper, a novel design procedure is proposed for synthesizing high-capacity auto-associative memories based on complex-valued neural networks with real-imaginary-type activation functions and constant delays. Stability criteria dependent on external inputs of neural networks are derived. The designed networks can retrieve the stored patterns by external inputs rather than initial conditions. The derivation can memorize the desired patterns with lower-dimensional neural networks than real-valued neural networks, and eliminate spurious equilibria of complex-valued neural networks. One numerical example is provided to show the effectiveness and superiority of the presented results. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503338, 61573316, 61374152, and 11302195) and the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ15F030005).

  6. Hierarchical network architectures of carbon fiber paper supported cobalt oxide nanonet for high-capacity pseudocapacitors.

    Science.gov (United States)

    Yang, Lei; Cheng, Shuang; Ding, Yong; Zhu, Xingbao; Wang, Zhong Lin; Liu, Meilin

    2012-01-11

    We present a high-capacity pseudocapacitor based on a hierarchical network architecture consisting of Co(3)O(4) nanowire network (nanonet) coated on a carbon fiber paper. With this tailored architecture, the electrode shows ideal capacitive behavior (rectangular shape of cyclic voltammograms) and large specific capacitance (1124 F/g) at high charge/discharge rate (25.34 A/g), still retaining ~94% of the capacitance at a much lower rate of 0.25 A/g. The much-improved capacity, rate capability, and cycling stability may be attributed to the unique hierarchical network structures, which improves electron/ion transport, enhances the kinetics of redox reactions, and facilitates facile stress relaxation during cycling.

  7. Mono-layer BC2 a high capacity anode material for Li-ion batteries

    Science.gov (United States)

    Hardikar, Rahul; Samanta, Atanu; Han, Sang Soo; Lee, Kwang-Ryeol; Singh, Abhishek

    2015-04-01

    Mono-layer of graphene with high surface area compared to the bulk graphite phase, shows less Li uptake. The Li activity or kinetics can be modified via defects and/or substitutional doping. Boron and Nitrogen are the best known dopants for carbonaceous anode materials. In particular, boron doped graphene shows higher capacity and better Li adsorption compared to Nitrogen doped graphene. Here, using first principles density functional theory calculations, we study the spectrum of boron carbide (BCx) mono-layer phases in order to estimate the maximum gravimetric capacity that can be achieved by substitutional doping in graphene. Our results show that uniformly boron doped BC2 phase shows a high capacity of? 1400 mAh/g, much higher than previously reported capacity of BC3. Supported by Korea Institute of Science and Technology.

  8. High-Capacity Hybrid Optical Fiber-Wireless Communications Links in Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan

    techniques with both coherent and incoherent optical sources are studied and demonstrated. Employments of advanced modulation formats including phase-shift keying (PSK), M-quadrature amplitude modulation (QAM) and orthogonal frequency-division multiplexing (OFDM) for high speed photonic-wireless transmission......Integration between fiber-optic and wireless communications systems in the "last mile" access networks is currently considered as a promising solution for both service providers and users, in terms of minimizing deployment cost, shortening upgrading period and increasing mobility and flexibility...... techniques. In conclusion, the results presented in the thesis show the feasibility of employing mm-wave signals, advanced modulation formats and spatial multiplexing technologies in next generation high capacity hybrid optical fiber-wireless access systems....

  9. High-capacity thick cathode with a porous aluminum current collector for lithium secondary batteries

    Science.gov (United States)

    Abe, Hidetoshi; Kubota, Masaaki; Nemoto, Miyu; Masuda, Yosuke; Tanaka, Yuichi; Munakata, Hirokazu; Kanamura, Kiyoshi

    2016-12-01

    A high-capacity thick cathode has been studied as one of ways to improve the energy density of lithium secondary batteries. In this study, the LiFePO4 cathode with a capacity per unit area of 8.4 m Ah cm-2 corresponding to four times the capacity of conventional cathodes has been developed using a three-dimensional porous aluminum current collector called "FUSPOROUS". This unique current collector enables the smooth transfer of electrons and Li+-ions through the thick cathode, resulting in a good rate capability (discharge capacity ratio of 1.0 C/0.2 C = 0.980) and a high charge-discharge cycle performance (80% of the initial capacity at 2000th cycle) even though the electrode thickness is 400 μm. To take practical advantage of the developed thick cathode, conceptual designs for a 10-Ah class cell were also carried out using graphite and lithium-metal anodes.

  10. OTDM Networking for Short Range High-Capacity Highly Dynamic Networks

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros

    This PhD thesis aims at investigating the possibility of designing energy-efficient high-capacity (up to Tbit/s) optical network scenarios, leveraging on the effect of collective switching of many bits simultaneously, as is inherent in high bit rate serial optical data signals. The focus...... is on short range highly dynamic networks, catering to data center needs. The investigation concerns optical network scenarios, and experimental implementations of high bit rate serial data packet generation and reception, scalable optical packet labeling, simple optical label extraction and stable ultra......-fast optical packet switching, with the constraint that there must be potential energy savings, which is also evaluated. A survey of the current trends in data centers is given and state-of-the-art research approaches are mentioned. Optical time-division multiplexing is proposed and demonstrated to generate...

  11. A new method for high-capacity information hiding in video robust against temporal desynchronization

    Science.gov (United States)

    Mitekin, Vitaly; Fedoseev, Victor A.

    2015-02-01

    This paper presents a new method for high-capacity information hiding in digital video and algorithms of embedding and extraction of hidden information based on this method. These algorithms do not require temporal synchronization to provide robustness against both malicious and non-malicious frame dropping (temporal desynchronization). At the same time, due to randomized distribution of hidden information bits across the video frames, the proposed method allows to increase the hiding capacity proportionally to the number of frames used for information embedding. The proposed method is also robust against "watermark estimation" attack aimed at estimation of hidden information without knowing the embedding key or non-watermarked video. Presented experimental results demonstrate declared features of this method.

  12. Lamprey parasitism of sharks and teleosts: high capacity urea excretion in an extant vertebrate relic.

    Science.gov (United States)

    Wilkie, Michael P; Turnbull, Steven; Bird, Jonathan; Wang, Yuxiang S; Claude, Jaime F; Youson, John H

    2004-08-01

    We observed 10 sea lampreys (Petromyzon marinus) parasitizing basking sharks (Cetorhinus maximus), the world's second largest fish, in the Bay of Fundy. Due to the high concentrations of urea in the blood and tissues of ureosmotic elasmobranchs, we hypothesized that sea lampreys would have mechanisms to eliminate co-ingested urea while feeding on basking sharks. Post-removal urea excretion rates (J(Urea)) in two lampreys, removed from separate sharks by divers, were initially 450 ( approximately 9000 micromol N kg-1 h-1) and 75 times ( approximately 1500 micromol N kg-1 h-1) greater than basal (non-feeding) rates ( approximately 20 micromol N kg-1 h-1). In contrast, J(Urea) increased by 15-fold after parasitic lampreys were removed from non-ureosmotic rainbow trout (Oncorhynchus mykiss). Since activities of the ornithine urea cycle (OUC) enzymes, carbamoyl phosphate synthetase III (CPSase III) and ornithine carbamoyl transferase (OCT) were relatively low in liver and below detection in intestine and muscle, it is unlikely that the excreted urea arose from de novo urea synthesis. Measurements of arginase activity suggested that hydrolysis of dietary arginine made a minor contribution to J(Urea.). Post-feeding ammonia excretion rates (J(Amm)) were 15- to 25-fold greater than basal rates in lampreys removed from both basking sharks and rainbow trout, suggesting that parasitic lampreys have a high capacity to deaminate amino acids. We conclude that the sea lamprey's ability to penetrate the dermal denticle armor of sharks, to rapidly excrete large volumes of urea and a high capacity to deaminate amino acids, represent adaptations that have contributed to the evolutionary success of these phylogenetically ancient vertebrates.

  13. Facile fabrication of Si mesoporous nanowires for high-capacity and long-life lithium storage

    Science.gov (United States)

    Chen, Jizhang; Yang, Li; Rousidan, Saibihai; Fang, Shaohua; Zhang, Zhengxi; Hirano, Shin-Ichi

    2013-10-01

    Si has the second highest theoretical capacity among all the known anode materials for lithium ion batteries, whereas it is vulnerable to pulverization and crumbling upon lithiation/delithiation. Herein, Si mesoporous nanowires prepared by a scalable and cost-effective procedure are reported for the first time. Such nanowire morphology and mesoporous structure can effectively buffer the huge lithiation-induced volume expansion of Si, therefore contributing to excellent cycling stability and high-rate capability. Reversible capacities of 1826.8 and 737.4 mA h g-1 can be obtained at 500 mA g-1 and a very high current density of 10 A g-1, respectively. After 1000 cycles at 2500 mA g-1, this product still maintains a high capacity of 643.5 mA h g-1.Si has the second highest theoretical capacity among all the known anode materials for lithium ion batteries, whereas it is vulnerable to pulverization and crumbling upon lithiation/delithiation. Herein, Si mesoporous nanowires prepared by a scalable and cost-effective procedure are reported for the first time. Such nanowire morphology and mesoporous structure can effectively buffer the huge lithiation-induced volume expansion of Si, therefore contributing to excellent cycling stability and high-rate capability. Reversible capacities of 1826.8 and 737.4 mA h g-1 can be obtained at 500 mA g-1 and a very high current density of 10 A g-1, respectively. After 1000 cycles at 2500 mA g-1, this product still maintains a high capacity of 643.5 mA h g-1. Electronic supplementary information (ESI) available: SEM images; N2 adsorption/desorption isotherm; long-term cycling performance at 500 mA g-1 comparison with other literature. See DOI: 10.1039/c3nr03955b

  14. High Capacity Reversible Watermarking for Audio by Histogram Shifting and Predicted Error Expansion

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2014-01-01

    Full Text Available Being reversible, the watermarking information embedded in audio signals can be extracted while the original audio data can achieve lossless recovery. Currently, the few reversible audio watermarking algorithms are confronted with following problems: relatively low SNR (signal-to-noise of embedded audio; a large amount of auxiliary embedded location information; and the absence of accurate capacity control capability. In this paper, we present a novel reversible audio watermarking scheme based on improved prediction error expansion and histogram shifting. First, we use differential evolution algorithm to optimize prediction coefficients and then apply prediction error expansion to output stego data. Second, in order to reduce location map bits length, we introduced histogram shifting scheme. Meanwhile, the prediction error modification threshold according to a given embedding capacity can be computed by our proposed scheme. Experiments show that this algorithm improves the SNR of embedded audio signals and embedding capacity, drastically reduces location map bits length, and enhances capacity control capability.

  15. High capacity reversible watermarking for audio by histogram shifting and predicted error expansion.

    Science.gov (United States)

    Wang, Fei; Xie, Zhaoxin; Chen, Zuo

    2014-01-01

    Being reversible, the watermarking information embedded in audio signals can be extracted while the original audio data can achieve lossless recovery. Currently, the few reversible audio watermarking algorithms are confronted with following problems: relatively low SNR (signal-to-noise) of embedded audio; a large amount of auxiliary embedded location information; and the absence of accurate capacity control capability. In this paper, we present a novel reversible audio watermarking scheme based on improved prediction error expansion and histogram shifting. First, we use differential evolution algorithm to optimize prediction coefficients and then apply prediction error expansion to output stego data. Second, in order to reduce location map bits length, we introduced histogram shifting scheme. Meanwhile, the prediction error modification threshold according to a given embedding capacity can be computed by our proposed scheme. Experiments show that this algorithm improves the SNR of embedded audio signals and embedding capacity, drastically reduces location map bits length, and enhances capacity control capability.

  16. Steganography and Hiding Data with Indicators-based LSB Using a Secret Key

    Directory of Open Access Journals (Sweden)

    W. Saqer

    2016-06-01

    Full Text Available Steganography is the field of science concerned with hiding secret data inside other innocent-looking data, called the container, carrier or cover, in a way that no one apart from the meant parties can suspect the existence of the secret data. There are many algorithms and techniques of concealing data. Each of which has its own way of hiding and its own advantages and limitations. In our research we introduce a new algorithm of hiding data. The algorithm uses the same technique used by the Least Significant Bit (LSB algorithm which is embedding secret data in the least significant bit(s of the bytes of the carrier. It differs from the LSB algorithm in that it does not embed the bytes of the cover data sequentially but it embeds into one bit or two bits at once. Actually it depends on indicators to determine where and how many bits to embed at a time. These indicators are two bits of each cover byte after the least two significant bits. The advantage of this algorithm over the LSB algorithm is the randomness used to confuse intruders as it does not use fixed sequential bytes and it does not always embed one bit at a time. This aims to increase the security of the technique. Also, the amount of cover data consumed is less because it sometimes embeds two bits at once.

  17. Discrete wavelet transform and singular value decomposition based ECG steganography for secured patient information transmission.

    Science.gov (United States)

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2014-10-01

    ECG Steganography provides secured transmission of secret information such as patient personal information through ECG signals. This paper proposes an approach that uses discrete wavelet transform to decompose signals and singular value decomposition (SVD) to embed the secret information into the decomposed ECG signal. The novelty of the proposed method is to embed the watermark using SVD into the two dimensional (2D) ECG image. The embedding of secret information in a selected sub band of the decomposed ECG is achieved by replacing the singular values of the decomposed cover image by the singular values of the secret data. The performance assessment of the proposed approach allows understanding the suitable sub-band to hide secret data and the signal degradation that will affect diagnosability. Performance is measured using metrics like Kullback-Leibler divergence (KL), percentage residual difference (PRD), peak signal to noise ratio (PSNR) and bit error rate (BER). A dynamic location selection approach for embedding the singular values is also discussed. The proposed approach is demonstrated on a MIT-BIH database and the observations validate that HH is the ideal sub-band to hide data. It is also observed that the signal degradation (less than 0.6%) is very less in the proposed approach even with the secret data being as large as the sub band size. So, it does not affect the diagnosability and is reliable to transmit patient information.

  18. A novel fuzzy logic-based image steganography method to ensure medical data security.

    Science.gov (United States)

    Karakış, R; Güler, I; Çapraz, I; Bilir, E

    2015-12-01

    This study aims to secure medical data by combining them into one file format using steganographic methods. The electroencephalogram (EEG) is selected as hidden data, and magnetic resonance (MR) images are also used as the cover image. In addition to the EEG, the message is composed of the doctor׳s comments and patient information in the file header of images. Two new image steganography methods that are based on fuzzy-logic and similarity are proposed to select the non-sequential least significant bits (LSB) of image pixels. The similarity values of the gray levels in the pixels are used to hide the message. The message is secured to prevent attacks by using lossless compression and symmetric encryption algorithms. The performance of stego image quality is measured by mean square of error (MSE), peak signal-to-noise ratio (PSNR), structural similarity measure (SSIM), universal quality index (UQI), and correlation coefficient (R). According to the obtained result, the proposed method ensures the confidentiality of the patient information, and increases data repository and transmission capacity of both MR images and EEG signals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Wavelet-Based ECG Steganography for Protecting Patient Confidential Information in Point-of-Care Systems.

    Science.gov (United States)

    Ibaida, Ayman; Khalil, Ibrahim

    2013-12-01

    With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as point-of-care (PoC) applications in hospitals around the world. Therefore, huge amount of ECG signal collected by body sensor networks from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level, etc., and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data are being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this paper, a wavelet-based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest. To evaluate the effectiveness of the proposed technique on the ECG signal, two distortion measurement metrics have been used: the percentage residual difference and the wavelet weighted PRD. It is found that the proposed technique provides high-security protection for patients data with low (less than 1%) distortion and ECG data remain diagnosable after watermarking (i.e., hiding patient confidential data) and as well as after watermarks (i.e., hidden data) are removed from the watermarked data.

  20. A Skin Tone Detection Algorithm for an Adaptive DWT Based Approach to Steganography using Biometrics

    Directory of Open Access Journals (Sweden)

    Mr. Patil Samadhan T.

    2014-03-01

    Full Text Available Challenges face biometrics researchers and particularly those who are dealing with skin tone detection include select a colour space, generating the particular skin model and processing the obtained regions. The majority of obtainable methods have in common the de-correlation of luminance from the considered colour channels. Luminance is the miscalculate since it is seen as the least causal colour component to skin colour detection. This type of work ques-tions this claim by showing that luminance can be useful in the segregation of skin and non-skin clusters. To this end, here we use a new colour space which contains error signals derived from differentiate the grayscale map and the non-red encoded grayscale version. The advantages of the approach are the reduction of space dimensionality from 3D, RGB, to 1D space advocating its candor and the construction of a rapid classifier necessary for real time applications. The fu-ture method generates a 1D space map without prior know-ledge of the host image. A complete experimental test was conducted and initial results are presented. This paper also discusses an application of the method to image steganogra-phy where it is used to orient the embedding process since skin information is deemed to be psycho visually redundant

  1. Study on a high capacity two-stage free piston Stirling cryocooler working around 30 K

    Science.gov (United States)

    Wang, Xiaotao; Zhu, Jian; Chen, Shuai; Dai, Wei; Li, Ke; Pang, Xiaomin; Yu, Guoyao; Luo, Ercang

    2016-12-01

    This paper presents a two-stage high-capacity free-piston Stirling cryocooler driven by a linear compressor to meet the requirement of the high temperature superconductor (HTS) motor applications. The cryocooler system comprises a single piston linear compressor, a two-stage free piston Stirling cryocooler and a passive oscillator. A single stepped displacer configuration was adopted. A numerical model based on the thermoacoustic theory was used to optimize the system operating and structure parameters. Distributions of pressure wave, phase differences between the pressure wave and the volume flow rate and different energy flows are presented for a better understanding of the system. Some characterizing experimental results are presented. Thus far, the cryocooler has reached a lowest cold-head temperature of 27.6 K and achieved a cooling power of 78 W at 40 K with an input electric power of 3.2 kW, which indicates a relative Carnot efficiency of 14.8%. When the cold-head temperature increased to 77 K, the cooling power reached 284 W with a relative Carnot efficiency of 25.9%. The influences of different parameters such as mean pressure, input electric power and cold-head temperature are also investigated.

  2. MEO based secured, robust, high capacity and perceptual quality image watermarking in DWT-SVD domain.

    Science.gov (United States)

    Gunjal, Baisa L; Mali, Suresh N

    2015-01-01

    The aim of this paper is to present multiobjective evolutionary optimizer (MEO) based highly secured and strongly robust image watermarking technique using discrete wavelet transform (DWT) and singular value decomposition (SVD). Many researchers have failed to achieve optimization of perceptual quality and robustness with high capacity watermark embedding. Here, we achieved optimized peak signal to noise ratio (PSNR) and normalized correlation (NC) using MEO. Strong security is implemented through eight different security levels including watermark scrambling by Fibonacci-Lucas transformation (FLT). Haar wavelet is selected for DWT decomposition to compare practical performance of wavelets from different wavelet families. The technique is non-blind and tested with cover images of size 512x512 and grey scale watermark of size 256x256. The achieved perceptual quality in terms of PSNR is 79.8611dBs for Lena, 87.8446 dBs for peppers and 93.2853 dBs for lake images by varying scale factor K1 from 1 to 5. All candidate images used for testing namely Lena, peppers and lake images show exact recovery of watermark giving NC equals to 1. The robustness is tested against variety of attacks on watermarked image. The experimental demonstration proved that proposed method gives NC more than 0.96 for majority of attacks under consideration. The performance evaluation of this technique is found superior to all existing hybrid image watermarking techniques under consideration.

  3. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment.

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-17

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems.

  4. Incorporating magnesium and calcium cations in porous organic frameworks for high-capacity hydrogen storage.

    Science.gov (United States)

    Wang, Lin; Sun, Yingxin; Sun, Huai

    2011-01-01

    We propose incorporating a bi-functional group consisting of magnesium or calcium cations and a 1,2,4,5-benzenetetroxide anion (C6H2O4(4-)) in porous materials to enhance the hydrogen storage capacity. The C6H2O4M2 bifunctional group is highly stable and polarized, and each group provides 18 (M = Mg) or 22 (M = Ca) binding sites for hydrogen molecules with an average binding energy of ca. 10 kJ mol(-1) per hydrogen molecule based on RIMP2/ TZVPP calculations. Two porous materials (PAF-Mg or PAF-Ca) constructed with the bi-functional groups show remarkable improvement in hydrogen uptakes at normal ambient conditions. At 233 K and 10 MPa, the predicted gravimetric uptakes are 6.8 and 6.4 wt% for PAF-Mg and PAF-Ca respectively. This work reveals that fabricating materials with large numbers of binding sites and relatively low binding energies is a promising approach to achieve high capacity for on-board storage of hydrogen.

  5. High capacity for extracellular acid-base regulation in the air-breathing fish Pangasianodon hypophthalmus.

    Science.gov (United States)

    Damsgaard, Christian; Gam, Le Thi Hong; Tuong, Dang Diem; Thinh, Phan Vinh; Huong Thanh, Do Thi; Wang, Tobias; Bayley, Mark

    2015-05-01

    The evolution of accessory air-breathing structures is typically associated with reduction of the gills, although branchial ion transport remains pivotal for acid-base and ion regulation. Therefore, air-breathing fishes are believed to have a low capacity for extracellular pH regulation during a respiratory acidosis. In the present study, we investigated acid-base regulation during hypercapnia in the air-breathing fish Pangasianodon hypophthalmus in normoxic and hypoxic water at 28-30°C. Contrary to previous studies, we show that this air-breathing fish has a pronounced ability to regulate extracellular pH (pHe) during hypercapnia, with complete metabolic compensation of pHe within 72 h of exposure to hypoxic hypercapnia with CO2 levels above 34 mmHg. The high capacity for pHe regulation relies on a pronounced ability to increase levels of HCO3(-) in the plasma. Our study illustrates the diversity in the physiology of air-breathing fishes, such that generalizations across phylogenies may be difficult.

  6. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-01

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems. PMID:28049820

  7. Multiresidue analysis of pesticides in vegetables and fruits using a high capacity absorbent polymer for water.

    Science.gov (United States)

    Obana, H; Akutsu, K; Okihashi, M; Kakimoto, S; Hori, S

    1999-08-01

    A single extraction and a single clean-up procedure was developed for multi-residue analysis of pesticides in non-fatty vegetables and fruits. The method involves the use of a high capacity absorbent polymer for water as a drying agent in extraction from wet food samples and of a graphitized carbon column for clean-up. A homogeneously chopped food sample (20 g) and polymer (3 g) were mixed to absorb water from the sample and then 10 min later the mixture was vigorously extracted with ethyl acetate (100 ml). The extract (50 ml), separated by filtration, was loaded on a graphitized carbon column without concentration. Additional ethyl acetate (50 ml) was also eluted and both eluates were concentrated to 5 ml for analysis. The procedure for sample preparation was completed within 2 h. In a recovery test, 107 pesticides were spiked and average recoveries were more than 80% from asparagus, orange, potato and strawberry. Most pesticides were recovered in the range 70-120% with usually less than a 10% RSD for six experiments. The results indicated that a single extraction with ethyl acetate in the presence of polymer can be applied to the monitoring of pesticide residues in foods.

  8. Li2C2, a High-Capacity Cathode Material for Lithium Ion Batteries.

    Science.gov (United States)

    Tian, Na; Gao, Yurui; Li, Yurong; Wang, Zhaoxiang; Song, Xiaoyan; Chen, Liquan

    2016-01-11

    As a typical alkaline earth metal carbide, lithium carbide (Li2C2) has the highest theoretical specific capacity (1400 mA h g(-1)) among all the reported lithium-containing cathode materials for lithium ion batteries. Herein, the feasibility of using Li2C2 as a cathode material was studied. The results show that at least half of the lithium can be extracted from Li2C2 and the reversible specific capacity reaches 700 mA h g(-1). The C≡C bond tends to rotate to form C4 (C≡C⋅⋅⋅C≡C) chains during lithium extraction, as indicated with the first-principles molecular dynamics (FPMD) simulation. The low electronic and ionic conductivity are believed to be responsible for the potential gap between charge and discharge, as is supported with density functional theory (DFT) calculations and Arrhenius fitting results. These findings illustrate the feasibility to use the alkali and alkaline earth metal carbides as high-capacity electrode materials for secondary batteries.

  9. State Violence and Oppositional Protest in High-Capacity Authoritarian Regimes

    Directory of Open Access Journals (Sweden)

    Hank Johnston

    2012-05-01

    Full Text Available This examination of the mobilization-repression nexus in high-capacity authoritarian regimes draws on examples from China, Russia, Iran, and several Middle Eastern states to develop a framework for analyzing state violence and how political oppositions are organized. The study examines middle and low levels of state violence, the provincial and municipal organization of party and regime, and the police, private militias, and thugs as low-level enforcers, and focuses on: (1 the complexity of the state’s apparatus of repression and control and how different levels exercise different forms of violence against activists; (2 the creativity of the opposition’s actions to voice its demands and avoid repression and surveillance; and (3 the recursive relationship between the two, a dark dance between state and opposition with high stakes for both. Hierarchical analysis at national, provincial, and local levels, and lateral analysis across these levels, where elite interests frequently diverge, show that intersections and gaps on both axes can create lapses in social control and openings the opposition. These free spaces of speech and innovative action give rise to novel ways to keep oppositional sentiments in the public forum. The article offers several propositions for analyzing repression and state violence at various levels, and, similarly, the various ways that these free spaces occur.

  10. An Aqueous Redox-Flow Battery with High Capacity and Power: The TEMPTMA/MV System.

    Science.gov (United States)

    Janoschka, Tobias; Martin, Norbert; Hager, Martin D; Schubert, Ulrich S

    2016-11-07

    Redox-flow batteries (RFB) can easily store large amounts of electric energy and thereby mitigate the fluctuating output of renewable power plants. They are widely discussed as energy-storage solutions for wind and solar farms to improve the stability of the electrical grid. Most common RFB concepts are based on strongly acidic metal-salt solutions or poorly performing organics. Herein we present a battery which employs the highly soluble N,N,N-2,2,6,6-heptamethylpiperidinyl oxy-4-ammonium chloride (TEMPTMA) and the viologen derivative N,N'-dimethyl-4,4-bipyridinium dichloride (MV) in a simple and safe aqueous solution as redox-active materials. The resulting battery using these electrolyte solutions has capacities of 54 Ah L(-1) , giving a total energy density of 38 Wh L(-1) at a cell voltage of 1.4 V. With peak current densities of up to 200 mA cm(-2) the TEMPTMA/MV system is a suitable candidate for compact high-capacity and high-power applications.

  11. 基于DCT域的数字图像隐写术分析%DCT-based Digital Image Steganography Analysis

    Institute of Scientific and Technical Information of China (English)

    潘洋; 郑紫微; 杨任尔

    2014-01-01

    Steganography plays a vital role in the security of multimedia communication. For digital image steganography based on DCT domain,the steganographic effects of secret information in mother and Lena image are simulated,the impact on image quality is studied with different embedded positions of the secret information in the DCT domain of an image, as well as with different carrier images. Studies show that: embedding the information in the low frequency part of the image and selecting the image with rich distribution pixel value can help improve the steganography effects of the information in the image and enhance the concealment of the secret information.%在多媒体通信的安全问题上,隐写术起着至关重要的作用。针对隐写术中常用的 DCT 域数字图像隐写方法,对秘密信息在mother和Lena图像中的隐写效果进行了仿真,研究了秘密信息在图像DCT域中的不同嵌入位置、不同的载体图像进行隐写时,对图像质量所产生的影响。研究表明:将信息嵌入图像的低频部分、选取像素值分布较丰富的图像,有利于提高信息在图像中的隐写效果,增强秘密信息的隐蔽性。

  12. Research on payload adaptive batch steganography%负载自适应的批量隐写研究

    Institute of Scientific and Technical Information of China (English)

    高瞻瞻; 汤光明; 代家铭

    2013-01-01

    In order to improve the security of batch steganography,this paper proposed a novel adaptive batch steganography system.First,it estimated embedding capacity of images under current steganalysis techniques by bringing ensemble classifier based on random forest into steganalysis,then distributed message bits to the images according to their embedding capacities.The new system could make full use of the images and improve batch steganography security further by dividing the message into groups.Experimental results show that the new security definition decreases the total detection error and running time,having a good balance between missed detection rate and false alarm rate.%为了进一步提高批量隐写的安全性,针对以往自适应批量隐写方案的不足设计了一种简单可靠的新方案.首先借助基于随机森林的集成分类器确定当前隐写分析技术下图像的隐写容量,在此基础上确定各个图像嵌入的信息量,方案最大程度地利用了载体资源,并通过对秘密信息进行分割分组进一步增强了安全性.实验结果表明,隐写容量计算中的安全判定方法准确性高,在保证低漏检率的同时避免了较高的虚警率,且运行时间更短.

  13. High-capacity thermo-responsive magnetic molecularly imprinted polymers for selective extraction of curcuminoids.

    Science.gov (United States)

    You, Qingping; Zhang, Yuping; Zhang, Qingwen; Guo, Junfang; Huang, Weihua; Shi, Shuyun; Chen, Xiaoqin

    2014-08-08

    Thermo-responsive magnetic molecularly imprinted polymers (TMMIPs) for selective recognition of curcuminoids with high capacity and selectivity have firstly been developed. The resulting TMMIPs were characterized by TEM, FT-IR, TGA, VSM and UV, which indicated that TMMIPs showed thermo-responsiveness [lower critical solution temperature (LCST) at 33.71°C] and rapid magnetic separation (5s). The polymerization, adsorption and release conditions were optimized in detail to obtain the highest binding capacity, selectivity and release ratio. We found that the adopted thermo-responsive monomer [N-isopropylacrylamide (NIPAm)] could be considered not only as inert polymer backbone for thermo-responsiveness but also as functional co-monomers combination with basic monomer (4-VP) for more specific binding sites when ethanol was added in binding solution. The maximum adsorption capacity with highest selectivity of curcumin was 440.3μg/g (1.93 times that on MMIPs with no thermosensitivity) at 45°C (above LCST) in 20% (v/v) ethanol solution on shrunk TMMIPs, and the maximum release proportion was about 98% at 20°C (below LCST) in methanol-acetic acid (9/1, v/v) solution on swelled TMMIPs. The adsorption process between curcumin and TMMIPs followed Langumuir adsorption isotherm and pseudo-first-order reaction kinetics. The prepared TMMIPs also showed high reproducibility (RSD<6% for batch-to-batch evaluation) and stability (only 7% decrease after five cycles). Subsequently, the TMMIPs were successfully applied for selective extraction of curcuminoids from complex natural product, Curcuma longa.

  14. Spherical polystyrene-supported chitosan thin film of fast kinetics and high capacity for copper removal

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Wei, E-mail: jiangwei@nju.edu.cn; Chen, Xubin; Pan, Bingcai; Zhang, Quanxing; Teng, Long; Chen, Yufan; Liu, Lu

    2014-07-15

    Graphical abstract: - Highlights: • Sub-micron-sized polystyrene supported chitosan thin-film was synthesized. • Absorbents exhibited fast kinetics and high capacity for Cu(II) removal from water. • Absorbents could be employed for repeated use for Cu(II) removal after regeneration. - Abstract: In order to accelerate the kinetics and improve the utilization of the surface active groups of chitosan (CS) for heavy metal ion removal, sub-micron-sized polystyrene supported chitosan thin-film was synthesized by the electrostatic assembly method. Glutaraldehyde was used as cross-linking agent. Chitosan thin-film was well coated onto the surface of the polystyrene (PS) beads characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). Their adsorption toward Cu(II) ions was investigated as a function of solution pH, degree of cross-linking, equilibrium Cu(II) ions concentration and contact time. The maximum adsorptive capacity of PS–CS was 99.8 mg/g in the adsorption isotherm study. More attractively, the adsorption equilibrium was achieved in 10 min, which showed superior properties among similar adsorbents. Continuous adsorption–desorption cyclic results demonstrated that Cu(II)-loaded PS–CS can be effectively regenerated by a hydrochloric acid solution (HCl), and the regenerated composite beads could be employed for repeated use without significant capacity loss, indicating the good stability of the adsorbents. The XPS analysis confirmed that the adsorption process was due to surface complexes with atoms of chitosan. Generally, PS beads could be employed as a promising host to fabricate efficient composites that originated from chitosan or other bio-sorbents for environmental remediation.

  15. A Low Cost, High Capacity Regenerable Sorbent for Pre-combustion CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan

    2012-09-30

    The overall objective of the proposed research is to develop a low cost, high capacity CO{sub 2} sorbent and demonstrate its technical and economic viability for pre-combustion CO{sub 2} capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for over 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO{sub 2} partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the performance of the sorbent). To support the field demonstration work, TDA collaborated with Phillips 66 and Southern Company to carry out two separate field tests using actual coal-derived synthesis gas at the Wabash River IGCC Power Plant in Terre Haute, IN and the National Carbon Capture Center (NCCC) in Wilsonville, AL. In collaboration with the University of California, Irvine (UCI), a detailed engineering and economic analysis for the new CO{sub 2} capture system was also proposed to be carried out using Aspen PlusTM simulation software, and estimate its effect on the plant efficiency.

  16. Secured Data Encoding Technique in High Capacity Color Barcodes for M-Ticket Application

    Directory of Open Access Journals (Sweden)

    B. Akila

    2013-01-01

    Full Text Available This research aim is to increase the capacity of barcode (i.e. Number of data bits embedded inside barcode will be increased by encoding data through orientation modulation in elliptical dot array. BARCODES that encode digital data on physical media are commonly utilized in commercial applications for tracing/tracking of trade items, in security applications for linking personal documents with a user, or in other applications as an auxiliary channel to encode additional information on a physical medium. which are fundamentally analog, these methods can add security and functionality and features that are associated with digital techniques at the expense of consuming space on the media. For instance, in personal IDs, driving licenses and passports, high capacity can enable the encoding of a sample speech signal, a picture, or other identifying personal information which in turn may be used to establish authenticity of the user. Care must, however, be exercised in designing color barcodes to ensure that they are robust to variations in the color printing and scanning processes, which have a greater impact when considering color rather than black/white reproduction and capture.2D bar codes are being considered for new emerging applications such as M-ticketing, where they carry selected information of a ticket that is received via a mobile phone; reliable and secure personal identification, where they store personal biometric data on the identification document; and visual communications with side information, where they can be used as an auxiliary channel conveying additional data for improving visual communications.

  17. High-Capacity Layered-Spinel Cathodes for Li-Ion Batteries.

    Science.gov (United States)

    Nayak, Prasant Kumar; Levi, Elena; Grinblat, Judith; Levi, Mikhael; Markovsky, Boris; Munichandraiah, N; Sun, Yang Kook; Aurbach, Doron

    2016-09-08

    Li and Mn-rich layered oxides with the general structure x Li2 MnO3 ⋅(1-x) LiMO2 (M=Ni, Mn, Co) are promising cathode materials for Li-ion batteries because of their high specific capacity, which may be greater than 250 mA h g(-1) . However, these materials suffer from high first-cycle irreversible capacity, gradual capacity fading, limited rate capability and discharge voltage decay upon cycling, which prevent their commercialization. The decrease in average discharge voltage is a major issue, which is ascribed to a structural layered-to-spinel transformation upon cycling of these oxide cathodes in wide potential ranges with an upper limit higher than 4.5 V and a lower limit below 3 V versus Li. By using four elements systems (Li, Mn, Ni, O) with appropriate stoichiometry, it is possible to prepare high capacity composite cathode materials that contain LiMn1.5 Ni0.5 O4 and Lix Mny Niz O2 components. The Li and Mn-rich layered-spinel cathode materials studied herein exhibit a high specific capacity (≥200 mA h g(-1) ) with good capacity retention upon cycling in a wide potential domain (2.4-4.9 V). The effect of constituent phases on their electrochemical performance, such as specific capacity, cycling stability, average discharge voltage, and rate capability, are explored here. This family of materials can provide high specific capacity, high rate capability, and promising cycle life. Using Co-free cathode materials is also an obvious advantage of these systems.

  18. Binders and Hosts for High-Capacity Lithium-ion Battery Anodes

    Science.gov (United States)

    Dufficy, Martin Kyle

    Lithium-ion batteries (LIBs) are universal electrochemical energy storage devices that have revolutionized our mobile society. Nonetheless, societal and technological advances drive consumer demand for LIBs with enhanced electrochemical performance, such as higher charge capacity and longer life, compared to conventional LIBs. One method to enhance LIB performance is to replace graphite, the industry standard anode since commercialization of LIBs in 1991, with high-charge capacity materials. Implementing high-capacity anode materials such as tin, silicon, and manganese vanadates, to LIBs presents challenges; Li-insertion is destructive to anode framework, and increasing capacity increases structural strains that pulverize anode materials and results in a short-cycle life. This thesis reports on various methods to extended the cycle life of high-capacity materials. Most of the work is conducted on nano-sized anode materials to reduce Li and electron transport pathway length (facilitating charge-transfer) and reduce strains from volume expansions (preserving anode structure). The first method involves encapsulating tin particles into a graphene-containing carbon nanofiber (CNF) matrix. The composite-CNF matrix houses tin particles to assume strains from tin-volume expansions and produces favorable surface-electrolyte chemistries for stable charge-discharge cycling. Before tin addition, graphene-containing CNFs are produced and assessed as anode materials for LIBs. Graphene addition to CNFs improves electronic and mechanical properties of CNFs. Furthermore, the 2-D nature of graphene provides Li-binding sites to enhance composite-CNF both first-cycle and high-rate capacities > 150% when compared to CNFs in the absence of graphene. With addition of Sn, we vary loadings and thermal production temperature to elucidate structure-composition relationships of tin and graphene-containing CNF electrodes that lead to increased capacity retention. Of note, electrodes containing

  19. 基于音频密写的载密移动通信系统的设计与实现%Design and implementation of the stego audio steganography based on mobile communication system

    Institute of Scientific and Technical Information of China (English)

    王莉; 康凯; 杨百龙; 赵文强; 时磊

    2016-01-01

    For in the public mobile communication system to embed secret information is hidden transmitting design implementation issues,this paper based on audio steganography of stego mobile communication system hardware and software design of the scheme for detailed analysis of the proposed based on DSP energy ratio adjusted the secret number according to the embedding/extraction algorithm. Experimental tests were carried out on the auditory similarity and robustness of the whole system. The results show that the system is able to realize the hidden and reliable transmission of the secret information in the mobile communication network.%针对在公共移动通信系统中嵌入秘密信息进行隐匿传输的设计实现问题,本文对基于音频密写的载密移动通信系统的软硬件设计方案进行详尽的分析,提出了基于DSP的能量比调整秘密数据嵌入/提取算法。对于整个系统的听觉相似性和健壮性进行了实验测试。结果表明系统能够很好地实现以语音为载体的秘密信息在移动通信网络中的隐蔽、可靠传递。

  20. Performance analysis of steganography transmission with temporal phase optical code-division multiple access%时域相位光码分多址隐藏通信性能分析

    Institute of Scientific and Technical Information of China (English)

    孟楠; 王荣; 蒲涛; 叶振兴

    2012-01-01

    In this paper, an optical steganography communication system of single wavelength public channel based on temporal phase OCDMA is proposed and demonstrated. By analysis the stimulating results of the proposed system, discussed the hiding and usability of steganography channel, the balance of power ratio between steganography channel and public channel, and the power penalty of public channel resulting from the steganography channel.%提出并建立了基于时域相位光码分多址的单波长宿主信道光隐藏通信系统.通过对系统仿真结果分析,论证了隐藏信道的隐藏性及可用性、隐藏信道与宿主信道功率比平衡点,以及隐藏信道的加入对宿主信道的功率代价.

  1. 基于直方图统计分类隐写检测算法设计%THE STEGANOGRAPHY DETECTION ALGORITHM DESIGN BASED ON HISTOGRAM STATISTICAL CLASSIFICATION

    Institute of Scientific and Technical Information of China (English)

    邱志宏

    2013-01-01

    In order to improve the detection performance of steganography detection algorithm,in this paper we put forward a steganography detection algorithm which is based on histogram statistical classification.Through extracting the histogram characteristic parameters of the image information and using the classification mode which is constructed based on artificial neural networks,this algorithm achieves accurate judgement on images embedded with steganography information.We analyse in detail the design,principle and process of this steganography algorithm,and at last construct the experimental test environment.Test results indicate that the detection success rate and the false alarm rate of the steganography detection algorithm designed in the paper are better than those of Ezstego detection tool.%为了提高隐写检测算法的检测性能,提出基于直方图统计分类的隐写检测算法.通过对图片信息的直方图特征参数的提取,使用构建基于人工神经网络的分类模式,实现对嵌入隐写信息的图片准确判定.详细分析基于直方图统计分类隐写算法的设计原理和过程,最后构建实验测试环境.测试结果表明,该隐写检测算法的检测成功率和误检率均优于Ezstego检测工具.

  2. Effect of using different cover image quality to obtain robust selective embedding in steganography

    Science.gov (United States)

    Abdullah, Karwan Asaad; Al-Jawad, Naseer; Abdulla, Alan Anwer

    2014-05-01

    One of the common types of steganography is to conceal an image as a secret message in another image which normally called a cover image; the resulting image is called a stego image. The aim of this paper is to investigate the effect of using different cover image quality, and also analyse the use of different bit-plane in term of robustness against well-known active attacks such as gamma, statistical filters, and linear spatial filters. The secret messages are embedded in higher bit-plane, i.e. in other than Least Significant Bit (LSB), in order to resist active attacks. The embedding process is performed in three major steps: First, the embedding algorithm is selectively identifying useful areas (blocks) for embedding based on its lighting condition. Second, is to nominate the most useful blocks for embedding based on their entropy and average. Third, is to select the right bit-plane for embedding. This kind of block selection made the embedding process scatters the secret message(s) randomly around the cover image. Different tests have been performed for selecting a proper block size and this is related to the nature of the used cover image. Our proposed method suggests a suitable embedding bit-plane as well as the right blocks for the embedding. Experimental results demonstrate that different image quality used for the cover images will have an effect when the stego image is attacked by different active attacks. Although the secret messages are embedded in higher bit-plane, but they cannot be recognised visually within the stegos image.

  3. Steganography and steganalysis in voice-over IP scenarios: operational aspects and first experiences with a new steganalysis tool set

    Science.gov (United States)

    Dittmann, Jana; Hesse, Danny; Hillert, Reyk

    2005-03-01

    Based on the knowledge and experiences from existing image steganalysis techniques, the overall objective of the paper is to evaluate existing audio steganography with a special focus on attacks in ad-hoc end-to-end media communications on the example of Voice over IP (VoIP) scenarios. One aspect is to understand operational requirements of recent steganographic techniques for VoIP applications. The other aspect is to elaborate possible steganalysis approaches applied to speech data. In particular we have examined existing VoIP applications with respect to their extensibility to steganographic algorithms. We have also paid attention to the part of steganalysis in PCM audio data which allows us to detect hidden communication while a running VoIP communication with the usage of the PCM codec. In our impelementation we use Jori's Voice over IP library by Jori Liesenborgs (JVOIPLIB) that provides primitives for a voice over IP communication. Finally we show first results of our prototypic implementation which extents the common VoIP scenario by the new feature of steganography. We also show the results for our PCM steganalyzer framework that is able to detect this kind of hidden communication by using a set of 13 first and second order statistics.

  4. Technology Assessment of High Capacity Data Storage Systems: Can We Avoid a Data Survivability Crisis?

    Science.gov (United States)

    Halem, M.; Shaffer, F.; Palm, N.; Salmon, E.; Raghavan, S.; Kempster, L.

    1998-01-01

    This technology assessment of long-term high capacity data storage systems identifies an emerging crisis of severe proportions related to preserving important historical data in science, healthcare, manufacturing, finance and other fields. For the last 50 years, the information revolution, which has engulfed all major institutions of modem society, centered itself on data-their collection, storage, retrieval, transmission, analysis and presentation. The transformation of long term historical data records into information concepts, according to Drucker, is the next stage in this revolution towards building the new information based scientific and business foundations. For this to occur, data survivability, reliability and evolvability of long term storage media and systems pose formidable technological challenges. Unlike the Y2K problem, where the clock is ticking and a crisis is set to go off at a specific time, large capacity data storage repositories face a crisis similar to the social security system in that the seriousness of the problem emerges after a decade or two. The essence of the storage crisis is as follows: since it could take a decade to migrate a peta-byte of data to a new media for preservation, and the life expectancy of the storage media itself is only a decade, then it may not be possible to complete the transfer before an irrecoverable data loss occurs. Over the last two decades, a number of anecdotal crises have occurred where vital scientific and business data were lost or would have been lost if not for major expenditures of resources and funds to save this data, much like what is happening today to solve the Y2K problem. A pr-ime example was the joint NASA/NSF/NOAA effort to rescue eight years worth of TOVS/AVHRR data from an obsolete system, which otherwise would have not resulted in the valuable 20-year long satellite record of global warming. Current storage systems solutions to long-term data survivability rest on scalable architectures

  5. The catalytic reactions in the Cu-Li-Mg-H high capacity hydrogen storage system.

    Science.gov (United States)

    Braga, M H; El-Azab, A

    2014-11-14

    A family of hydrides, including the high capacity MgH2 and LiH, is reported. The disadvantages these hydrides normally display (high absorption/desorption temperatures and poor kinetics) are mitigated by Cu-hydride catalysis. This paper reports on the synthesis of novel CuLi0.08Mg1.42H4 and CuLi0.08Mg1.92H5 hydrides, which are structurally and thermodynamically characterized for the first time. The CuLi0.08Mg1.42H4 hydride structure in nanotubes is able to hold molecular H2, increasing the gravimetric and volumetric capacity of this compound. The catalytic effect these compounds show on hydride formation and decomposition of CuMg2 and Cu2Mg/MgH2, Li and LiH, Mg and MgH2 is analyzed. The Gibbs energy, decomposition temperature, and gravimetric capacity of the reactions occurring within the Cu-Li-Mg-H system are presented for the first time. First principles and phonon calculations are compared with experiments, including neutron spectroscopy. It is demonstrated that the most advantageous sample contains CuLi0.08Mg1.92 and (Li) ∼ Li2Mg3; it desorbs/absorbs hydrogen according to the reaction, 2CuLi0.08Mg1.42H4 + 2Li + 4MgH2 ↔ 2CuLi0.08Mg1.92 + Li2Mg3 + 8H2 at 114 °C (5.0 wt%) - 1 atm, falling within the proton exchange membrane fuel cell applications window. Finally the reaction 2CuLi0.08Mg1.42H4 + MgH2 ↔ 2CuLi0.08Mg1.92 + 5H2 at 15 °C (4.4 wt%) - 1 atm is found to be the main reaction of the samples containing CuLi0.08Mg1.92 that were analyzed in this study.

  6. Robust Increased Capacity Image Steganographic Scheme

    Directory of Open Access Journals (Sweden)

    M. Khurrum Rahim Rashid

    2014-11-01

    Full Text Available with the rising tempo of unconventional right to use and hit protection of secret information is of extreme value. With the rising tempo of unconventional right to use and hit, protection of secret information is of extreme value. Steganography is the vital matter in information hiding. Steganography refers to the technology of hiding data into digital media without depiction of any misgiving. Lot of techniques has been projected during past years. In this paper, a new steganography approach for hiding data in digital images is presented with a special feature that it increases the capacity of hiding data in digital images with the least change in images perceptual appearance and statistical properties at too much less level which will be very difficult to detect.

  7. High-Capacity Multi-Core Fibers for Space-Division Multiplexing

    DEFF Research Database (Denmark)

    Ye, Feihong

    trench-assisted MCFs (TAMCFs). The traditional approach for TA-MCFs design has relied on numerical simulations, which make deriving relationships between XT and fiber structural parameters difficult and non-intuitive. As it is important to be able to understand the effects of various fiber structural...... of the present SMF-based systems. Among the proposed SDM schemes, the one based on uncoupled multi-core fibers (MCFs) having multiple cores in a mutual cladding has proven effective in substantially increasing the transmission capacity per fiber with least system complexity as demonstrated in several state...... the same refractive index profiles. Based on the model, the XT values in TA-MCFs as well as XT properties, including wavelength-dependent XT, XT reduction amount versus trench width, trench depth and XT dependence on core pitch are easily analyzed. It has also been shown that the XT in MCFs depends...

  8. High-capacity quantum secure direct communication using hyper-entanglement of photonic qubits

    Science.gov (United States)

    Cai, Jiarui; Pan, Ziwen; Wang, Tie-Jun; Wang, Sihai; Wang, Chuan

    2016-11-01

    Hyper-entanglement is a system constituted by photons entangled in multiple degrees of freedom (DOF), being considered as a promising way of increasing channel capacity and guaranteeing powerful eavesdropping safeguard. In this work, we propose a coding scheme based on a 3-particle hyper-entanglement of polarization and orbital angular momentum (OAM) system and its application as a quantum secure direct communication (QSDC) protocol. The OAM values are specially encoded by Fibonacci sequence and the polarization carries information by defined unitary operations. The internal relations of the secret message enhances security due to principle of quantum mechanics and Fibonacci sequence. We also discuss the coding capacity and security property along with some simulation results to show its superiority and extensibility.

  9. 基于LWE的密文域可逆信息隐藏%Reversible Steganography in Encrypted Domain Based on LWE

    Institute of Scientific and Technical Information of China (English)

    张敏情; 柯彦; 苏婷婷

    2016-01-01

    This paper proposes a novel scheme of reversible steganography in encrypted domain based on Learning With Errors (LWE). The original data is encrypted by the cryptographic algorithms with LWE. Then additional data could be embedded into the cipher text. With embedded cipher text, the additional data can be extracted by using data-hiding key, and the original data can be recovered by using encryption key, and the processes of extraction and decryption are separable. By deducing the error probability of the scheme, the standard deviation of noise sequence which directly related to the scheme’s correctness is mainly discussed, and reasonable range of the standard deviation is obtained by experiments. The probability distribution function of the embedded cipher text is deduced, that proves the embedded cipher text is not detective. The proposed scheme based on encrypted domain can apply to different kinds of media vehicle such as text, image or audio. Experimental results demonstrate that the proposed scheme can not only achieve statistical security without degrading the quality of encryption or data embedding, but realize that 1 bit original data can maximally load 1 bit additional data in encrypted domain.%该文提出了一种基于LWE(Learning With Errors)算法的密文域可逆隐写方案,利用LWE公钥密码算法对数据加密,用户在密文中嵌入隐藏信息,对于嵌入信息后的密文,用户使用隐写密钥可以有效提取隐藏信息,使用解密密钥可以无差错恢复出加密前数据实现了提取过程与解密过程的可分离。通过推导方案在解密与提取信息过程中出错的概率,得到直接影响方案正确性的参数为所选噪声的标准差,实验获得并验证了标准差的合理取值区间;通过推导嵌入后密文的分布函数,分析密文统计特征的变化情况,论证了嵌入密文的隐藏信息的不可感知性。该方案是在密文域进行的可逆隐写,与原始

  10. SLC2A9 is a high-capacity urate transporter in humans.

    Directory of Open Access Journals (Sweden)

    Mark J Caulfield

    2008-10-01

    0.98, 95% confidence interval [CI] 0.9 to 1.05, p > 0.33 by meta-analysis of an SLC2A9 variant in six case-control studies including 11,897 participants. In a separate meta-analysis of four population studies including 11,629 participants we found no association of SLC2A9 with systolic (effect size -0.12 mm Hg, 95% CI -0.68 to 0.43, p = 0.664 or diastolic blood pressure (effect size -0.03 mm Hg, 95% CI -0.39 to 0.31, p = 0.82. CONCLUSIONS: This study provides evidence that SLC2A9 splice variants act as high-capacity urate transporters and is one of the first functional characterisations of findings from genome-wide association scans. We did not find an association of the SLC2A9 gene with blood pressure in this study. Our findings suggest potential pathogenic mechanisms that could offer a new drug target for gout.

  11. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

  12. MMTD在隐写术检测率上的应用%Application of MMTD in Steganography Detection Rate

    Institute of Scientific and Technical Information of China (English)

    朱俚治

    2014-01-01

    数字水印是一种信息隐藏技术,同样隐写术也是一种信息隐藏技术。这两种隐藏技术的原理十分相似。由于数字水印存在透明性与鲁棒性之间的矛盾,所以隐写术也存在同样的矛盾。但如果隐写者将信息嵌入载体时具有一定的鲁棒性,这对抗拒外来攻击是有利的。当攻击者对载体进行攻击之后,人们在检测载体中是否藏有秘密信息时,容易产生漏警和虚警。因此为了减少漏警和虚警的发生,在本文将 MMTD 智能算法在检测载体中秘密内容方面进行有效的应用,以此来降低虚警率和漏警率。%Digital watermarking is a technology of information hiding, steganography is also a kind of information hiding technology.the two hidden technology principle is very similar.Because of the contradiction between the digital watermark transparency and robustness, so the steganography have the same contradictions. But if steganography wil be robust information into the carrier, which is beneficial to resist external at ack. When an at acker to carrier, whether people in possession of secret information in the detection of carriers, prone to leakage alarm and false alarm. Therefore, in order to reduce the false alarm and false alarm occurs, in this paper the MMTD intel igent algorithm for ef ective application of secret content in the detection of carriers, in order to reduce the false alarm rate and false alarm rate.

  13. Integration of high capacity materials into interdigitated mesostructured electrodes for high energy and high power density primary microbatteries

    Science.gov (United States)

    Pikul, James H.; Liu, Jinyun; Braun, Paul V.; King, William P.

    2016-05-01

    Microbatteries are increasingly important for powering electronic systems, however, the volumetric energy density of microbatteries lags behind that of conventional format batteries. This paper reports a primary microbattery with energy density 45.5 μWh cm-2 μm-1 and peak power 5300 μW cm-2 μm-1, enabled by the integration of large volume fractions of high capacity anode and cathode chemistry into porous micro-architectures. The interdigitated battery electrodes consist of a lithium metal anode and a mesoporous manganese oxide cathode. The key enabler of the high energy and power density is the integration of the high capacity manganese oxide conversion chemistry into a mesostructured high power interdigitated bicontinuous cathode architecture and an electrodeposited dense lithium metal anode. The resultant energy density is greater than previously reported three-dimensional microbatteries and is comparable to commercial conventional format lithium-based batteries.

  14. High Capacity Downlink Transmission with MIMO Interference Subspace Rejection in Multicellular CDMA Networks

    Directory of Open Access Journals (Sweden)

    Henrik Hansen

    2004-05-01

    Full Text Available We proposed recently a new technique for multiuser detection in CDMA networks, denoted by interference subspace rejection (ISR, and evaluated its performance on the uplink. This paper extends its application to the downlink (DL. On the DL, the information about the interference is sparse, for example, spreading factor (SF and modulation of interferers may not be known, which makes the task much more challenging. We present three new ISR variants which require no prior knowledge of interfering users. The new solutions are applicable to MIMO systems and can accommodate any modulation, coding, SF, and connection type. We propose a new code allocation scheme denoted by DACCA which significantly reduces the complexity of our solution at the receiving mobile. We present estimates of user capacities and data rates attainable under practically reasonable conditions regarding interferences identified and suppressed in a multicellular interference-limited system. We show that the system capacity increases linearly with the number of antennas despite the existence of interference. Our new DL multiuser receiver consistently provides an Erlang capacity gain of at least 3 db over the single-user detector.

  15. Current Trends of High capacity Optical Interconnection Data Link in High Performance Optical Communication Systems

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2013-02-01

    Full Text Available Optical technologies are ubiquitous in telecommunications networks and systems, providing multiple wavelength channels of transport at 2.5 Gbit/sec to 40 Gbit/sec data rates over single fiber optic cables. Market pressures continue to drive the number of wavelength channels per fiber and the data rate per channel. This trend will continue for many years to come as electronic commerce grows and enterprises demand higher and reliable bandwidth over long distances. Electronic commerce, in turn, is driving the growth curves for single processor and multiprocessor performance in data base transaction and Web based servers. Ironically, the insatiable taste for enterprise network bandwidth, which has driven up the volume and pushed down the price of optical components for telecommunications, is simultaneously stressing computer system bandwidth increasing the need for new interconnection schemes and providing for the first time commercial opportunities for optical components in computer systems. The evolution of integrated circuit technology is causing system designs to move towards communication based architectures. We have presented the current tends of high performance system capacity of optical interconnection data transmission link in high performance optical communication and computing systems over wide range of the affecting parameters.

  16. Lithographically encoded polymer microtaggant using high-capacity and error-correctable QR code for anti-counterfeiting of drugs.

    Science.gov (United States)

    Han, Sangkwon; Bae, Hyung Jong; Kim, Junhoi; Shin, Sunghwan; Choi, Sung-Eun; Lee, Sung Hoon; Kwon, Sunghoon; Park, Wook

    2012-11-20

    A QR-coded microtaggant for the anti-counterfeiting of drugs is proposed that can provide high capacity and error-correction capability. It is fabricated lithographically in a microfluidic channel with special consideration of the island patterns in the QR Code. The microtaggant is incorporated in the drug capsule ("on-dose authentication") and can be read by a simple smartphone QR Code reader application when removed from the capsule and washed free of drug.

  17. Morphology control of ordered mesoporous carbons for high capacity lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Joerg David

    2011-06-07

    The focus of this thesis concerns the morphology control of ordered mesoporous carbon (OMC) materials. Ordered mesoporous carbons with diverse morphologies, that are thin films, fibers - embedded in anodic alumina membranes and free-standing - or spherical nanoparticles, have been successfully prepared by soft-templating procedures. The mechanisms of structure formation and processing were investigated with in-situ SAXS measurements and their application in high capacity lithium-sulfur batteries was successfully tested in cooperation with Guang He and Linda Nazar from the University of Waterloo in Canada. The Li-S batteries receive increasing attention due to their high theoretical energy density which is 3 to 5 times higher than from lithium-ion batteries. For this type of battery the specific pore volume is crucial for the content of the active component (sulfur) in the cathode and therefore correlates with the capacity and gravimetric energy density of the battery. At first, mesoporous thin films with 2D-hexagonal structure were obtained through organic-organic self-assembly of a preformed oligomeric resol precursor and the triblock copolymer template Pluronic P123. The formation of a condensed-wall material through thermopolymerization of the precursor oligomers resulted in mesostructured phenolic resin films. Subsequent decomposition of the surfactant and partial carbonization were achieved through thermal treatment in inert atmosphere. The films were crack-free with tunable homogenous thicknesses, and showed either 2D-hexagonal or lamellar mesostructure. An additional, yet unknown 3D-mesostructure was also found. In the second part, cubic and circular hexagonal mesoporous carbon phases in the confined environment of tubular anodic alumina membrane (AAM) pores were obtained by self-assembly of the mentioned resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent-evaporation were also followed by

  18. A High-Capacity Adenoviral Hybrid Vector System Utilizing the Hyperactive Sleeping Beauty Transposase SB100X for Enhanced Integration.

    Science.gov (United States)

    Boehme, Philip; Zhang, Wenli; Solanki, Manish; Ehrke-Schulz, Eric; Ehrhardt, Anja

    2016-07-19

    For efficient delivery of required genetic elements we utilized high-capacity adenoviral vectors in the past allowing high transgene capacities of up to 36 kb. Previously we explored the hyperactive Sleeping Beauty (SB) transposase (HSB5) for somatic integration from the high-capacity adenoviral vectors genome. To further improve this hybrid vector system we hypothesized that the previously described hyperactive SB transposase SB100X will result in significantly improved efficacies after transduction of target cells. Plasmid based delivery of the SB100X system revealed significantly increased integration efficiencies compared with the previously published hyperactive SB transposase HSB5. After optimizing experimental setups for high-capacity adenoviral vectors-based delivery of the SB100X system we observed up to eightfold and 100-fold increased integration efficiencies compared with the previously published hyperactive SB transposase HSB5 and the inactive transposase mSB, respectively. Furthermore, transposon copy numbers per cell were doubled with SB100X compared with HSB5 when using the identical multiplicity of infection. We believe that this improved hybrid vector system represents a valuable tool for achieving stabilized transgene expression in cycling cells and for treatment of numerous genetic disorders. Especially for in vivo approaches this improved adenoviral hybrid vector system will be advantageous because it may potentially allow reduction of the applied viral dose.

  19. Dual-Size Silicon Nanocrystal-Embedded SiO(x) Nanocomposite as a High-Capacity Lithium Storage Material.

    Science.gov (United States)

    Park, Eunjun; Yoo, Hyundong; Lee, Jaewoo; Park, Min-Sik; Kim, Young-Jun; Kim, Hansu

    2015-07-28

    SiOx-based materials attracted a great deal of attention as high-capacity Li(+) storage materials for lithium-ion batteries due to their high reversible capacity and good cycle performance. However, these materials still suffer from low initial Coulombic efficiency as well as high production cost, which are associated with the complicated synthesis process. Here, we propose a dual-size Si nanocrystal-embedded SiOx nanocomposite as a high-capacity Li(+) storage material prepared via cost-effective sol-gel reaction of triethoxysilane with commercially available Si nanoparticles. In the proposed nanocomposite, dual-size Si nanocrystals are incorporated into the amorphous SiOx matrix, providing a high capacity (1914 mAh g(-1)) with a notably improved initial efficiency (73.6%) and stable cycle performance over 100 cycles. The highly robust electrochemical and mechanical properties of the dual-size Si nanocrystal-embedded SiOx nanocomposite presented here are mainly attributed to its peculiar nanoarchitecture. This study represents one of the most promising routes for advancing SiOx-based Li(+) storage materials for practical use.

  20. Laser Modified ZnO/CdSSe Core-Shell Nanowire Arrays for Micro-Steganography and Improved Photoconduction

    Science.gov (United States)

    Lu, Junpeng; Liu, Hongwei; Zheng, Minrui; Zhang, Hongji; Lim, Sharon Xiaodai; Tok, Eng Soon; Sow, Chorng Haur

    2014-09-01

    Arrays of ZnO/CdSSe core/shell nanowires with shells of tunable band gaps represent a class of interesting hybrid nanomaterials with unique optical and photoelectrical properties due to their type II heterojunctions and chemical compositions. In this work, we demonstrate that direct focused laser beam irradiation is able to achieve localized modification of the hybrid structure and chemical composition of the nanowire arrays. As a result, the photoresponsivity of the laser modified hybrid is improved by a factor of ~3. A 3D photodetector with improved performance is demonstrated using laser modified nanowire arrays overlaid with monolayer graphene as the top electrode. Finally, by controlling the power of the scanning focused laser beam, micropatterns with different fluorescence emissions are created on a substrate covered with nanowire arrays. Such a pattern is not apparent when imaged under normal optical microscopy but the pattern becomes readily revealed under fluorescence microscopy i.e. a form of Micro-Steganography is achieved.

  1. Audre's daughter: Black lesbian steganography in Dee Rees' Pariah and Audre Lorde's Zami: A New Spelling of My Name.

    Science.gov (United States)

    Kang, Nancy

    2016-01-01

    This article argues that African-American director Dee Rees' critically acclaimed debut Pariah (2011) is a rewriting of lesbian poet-activist Audre Lorde's iconic "bio-mythography" Zami: A New Spelling of My Name (1982). The article examines how Rees' work creatively and subtly re-envisions Lorde's Zami by way of deeply rooted and often cleverly camouflaged patterns, resonances, and contrasts. Shared topics include naming, mother-daughter bonds, the role of clothing in identity formation, domestic abuse, queer time, and lesbian, gay, bisexual, and transgender legacy discourse construction. What emerges between the visual and written texts is a hidden language of connection--what may be termed Black lesbian steganography--which proves thought-provoking to viewers and readers alike.

  2. A New Image Steganography Method Based on Pixel Neighbors and 6 Most Significant Bit(MSB Compare

    Directory of Open Access Journals (Sweden)

    Mashallah Abbasi Dezfouli

    2013-11-01

    Full Text Available Today, steganography is known as an effective way to convey secret data. A wide range of techniques has been developed in this context, each seeking to improve certain problems of their own. The current paper presents a method by which, when comparing three color values at each pixel to the corresponding ones from all its eight neighbors, it is attempted to embed message bits into the two least significant bits of a color component of an image that an acceptable color difference has happened in. Due to the mechanism proposed, this method makes the message difficult to be discovered. However, since message detection does not need to insert additional data to identify the colors containing message bits, changes in image is less and the imperceptibility is higher.

  3. LSB Steganography Technology and Its Performance Analysis%LSB隐写技术及其性能分析*

    Institute of Scientific and Technical Information of China (English)

    张春玉; 姚七栋

    2013-01-01

    在隐写与反隐写的对抗中,LSB隐写技术不断发展并被广泛应用。详细介绍LSB替换算法和LSB匹配算法各自的嵌入、提取原理,指出匹配算法虽有改进之处但并未改变LSB直方图异常、统计不对称性等弱点的原因,并用大量实验证明两种算法在相同嵌入率下各项性能指标基本相当,验证LSB隐写技术透明性好、算法简单、速度快、隐藏量大、鲁棒性差等特点,为相关邻域的研究提供较可靠的实验数据。%With the confrontation of steganography and steganalysis, LSB steganography is developing and widely applied. Introduces the principle of embedding and extraction of LSB replacement algo-rithm and LSB matching algorithm in great detail. Explains that the matching algorithm has im-proved a little, but can not do better than LSB replacement algorithm in the aspects of his-togram abnormality and statistical asymmetry. A large number of experiments show that the properties of the two algorithms are almost same, and they are good at transparency, simple, fast, the big hiding capacity and the bad robustness. Provides more reliable experimental data for related research.

  4. Klasifikasi Bit-Plane Noise untuk Penyisipan Pesan pada Teknik Steganography BPCS Menggunakan Fuzzy Inference Sistem Mamdani

    Directory of Open Access Journals (Sweden)

    Rahmad Hidayat

    2015-04-01

    Full Text Available Bit-Plane Complexity Segmentation (BPCS is a fairly new steganography technique. The most important process in BPCS is the calculation of complexity value of a bit-plane. The bit-plane complexity is calculated by looking at the amount of bit changes contained in a bit-plane. If a bit-plane has a high complexity, the bi-plane is categorized as a noise bit-plane that does not contain valuable information on the image. Classification of the bit-plane using the set cripst set (noise/not is not fair, where a little difference of the value will significantly change the status of the bit-plane. The purpose of this study is to apply the principles of fuzzy sets to classify the bit-plane into three sets that are informative, partly informative, and the noise region. Classification of the bit-plane into a fuzzy set is expected to classify the bit-plane in a more objective approach and ultimately message capacity of the images can be improved by using the Mamdani fuzzy inference to take decisions which bit-plane will be replaced with a message based on the classification of bit-plane and the size of the message that will be inserted. This research is able to increase the capability of BPCS steganography techniques to insert a message in bit-pane with more precise so that the container image quality would be better. It can be seen that the PSNR value of original image and stego-image is only slightly different.

  5. Steganography and steganalysis base on JPEG format%针对JPEG格式的数字隐写与隐写分析

    Institute of Scientific and Technical Information of China (English)

    张毅; 梅挺

    2012-01-01

    数字隐写和隐写分析是信息隐藏技术的重要分支。JPEG图像是隐写术最常见的载体,因而研究以JPEG图像为载体的隐写和隐写分析具有重要意义。剖析了JPEG文件结构,提出了基于JPEG格式的隐写方案;并针对该方案提出了相应的隐写分析方案;然后通过大量统计,建立了两个数据库,并最终构建了一个准实时隐藏信息提取系统。该系统从5万幅互联网上的JPEG图像提出了信息,并有效攻击了11种互联网上的隐写软件。%Digital steganography and steganalysis are significant parts of information hiding technology.It is important to study the steganography and steganalysis on JPEG format,which is the most popular image using in steganography.Firstly,by analyzing the structure of JPEG standard deeply,a algorithm of hiding communication based on JPEG format is proposed;secondly,a relevant algorithm of extracting attack is provided;finally,an approximate real time system for extracting hiding information is constructed.The system distilled much information from 50 thousands network images successfully and attacked 11 kinds of steganography software efficiently.

  6. Chaotic iterations for steganography: Stego-security and topological-security

    CERN Document Server

    Friot, Nicolas; Bahi, Jacques M

    2011-01-01

    In this paper is proposed a novel steganographic scheme based on chaotic iterations. This research work takes place into the information hiding security fields. We show that the proposed scheme is stego-secure, which is the highest level of security in a well defined and studied category of attack called "watermark-only attack". Additionally, we prove that this scheme presents topological properties so that it is one of the firsts able to face, at least partially, an adversary when considering the others categories of attacks defined in the literature.

  7. Efficient high payload and Randomly selected sub-blocks image Steganography%一种高效的随机分块图像隐写算法

    Institute of Scientific and Technical Information of China (English)

    唐明伟; 胡节; 范明钰; 郑秀林

    2012-01-01

    It has been a hot area of research in information and network security in which steganography has an efficient high payload and can hide much information. ERS(an Efficient high payload and Randomly selected sub-blocks image Steganography) is proposed. The experiment results show that the method can not only reduce change of cover image, but also improve the efficient high payload. ERS is simple. Its performance is better than others in the efficiency and security of information hiding.%嵌入效率高和隐藏信息量大的信息隐藏算法,已成为信息安全领域研究的一个热点.通过对该类信息隐藏算法的分析,提出了一种高效率的随机分块信息隐藏算法ERS (an Efficient high payload and Randomly selected sub-blocks image Steganography).实验与分析结果表明:该算法不仅能够减小对载体的修改,提高嵌入效率,而且其算法实现简单、计算量小,性能优于其他算法.

  8. High capacity MnOx:ZrO2 sorbent for elementary mercury capture: preparation, characterization and comparison to other sorbents

    Science.gov (United States)

    Lakatos, J.; Snape, C. E.

    2017-02-01

    Manganese oxide-zirconia type (MnOx:ZrO2) sorbents were prepared using the sol-gel technique by co precipitation ZrO(NO3)2.xH2O and Mn(NO3)2 xH2O. The heat treatment below 500°C resulted a high surface area solid structure which consists of amorphous Mn2O3 (Bixbyite) and amorphous ZrO2 phases. This material was found a high capacity oxidative sorbent for mercury removal from gas streams.

  9. piggyBac as a high-capacity transgenesis and gene-therapy vector in human cells and mice

    Directory of Open Access Journals (Sweden)

    Rongbo Li

    2013-05-01

    The stable genomic integration and expression of a large transgene is a major hurdle in gene therapy. We show that the modified piggyBac (PB transposon system can be used to introduce a 207 kb genomic DNA fragment containing the RORγ/γt locus into human cells and mice. PB-mediated transgenesis results in a single copy of a stably inherited and expressed transgene. These results indicate that PB could serve as an effective high-capacity vector for functional analysis of the mammalian genome and for gene therapy in human cells.

  10. piggyBac as a high-capacity transgenesis and gene-therapy vector in human cells and mice

    OpenAIRE

    Rongbo Li; Yuan Zhuang; Min Han; Tian Xu; Xiaohui Wu

    2013-01-01

    SUMMARY The stable genomic integration and expression of a large transgene is a major hurdle in gene therapy. We show that the modified piggyBac (PB) transposon system can be used to introduce a 207 kb genomic DNA fragment containing the RORγ/γt locus into human cells and mice. PB-mediated transgenesis results in a single copy of a stably inherited and expressed transgene. These results indicate that PB could serve as an effective high-capacity vector for functional analysis of the mammalian ...

  11. Development of a new biofertilizer with a high capacity for N2 fixation, phosphate and potassium solubilization and auxin production.

    Science.gov (United States)

    Leaungvutiviroj, Chaveevan; Ruangphisarn, Pimtida; Hansanimitkul, Pikul; Shinkawa, Hidenori; Sasaki, Ken

    2010-01-01

    Biofertilizers that possess a high capacity for N(2) fixation (Azotobacter tropicalis), and consist of phosphate solubilizing bacteria (Burkhoderia unamae), and potassium solubilizing bacteria (Bacillus subtilis) and produce auxin (KJB9/2 strain), have a high potential for growth and yield enhancement of corn and vegetables (Chinese kale). For vegetables, the addition of biofertilizer alone enhanced growth 4 times. Moreover, an enhancement of growth by 7 times was observed due to the addition of rock phosphate and K-feldspar, natural mineral fertilizers, in combination with the biofertilizer.

  12. A Multi-Source Steganography for Stereo Audio%面向立体声的多源音频信息隐写

    Institute of Scientific and Technical Information of China (English)

    常迪; 张霞; 吴越

    2013-01-01

    We proposed a steganography algorithm for stereo multi-source audio by studying sound source separation technique based on spatial clues and using it in information steganography technology.In this algorithm,the binary spectrum mask technology which is used in sound source separation technology is introduced in steganography algorithm.Regard the separated sound sources as carriers,and embed the stereo sound,by modifying part of the coefficients in odd windows in time-frequency domain,to achieve steganography information embedding,which replaces the traditional single source embedding steganography algorithms.Experimental results show that this algorithm has large embedding capacity,and it is able to resist the attacks of StriMark Benchmark for Audio and other common attacks effectively.The average bit error rate is smaller than 2.80 %,which provides good robustness.%针对多音源的音频信号,提出面向立体声的多源音频信息隐写算法.该算法将音源分离技术中的二进制时频掩码技术引入到信息隐写算法中,以各分离音源为载体,采用立体声混合嵌入的方式,通过修改时频域中奇数窗的部分系数,实现隐写信息的嵌入,该算法代替了传统信息隐写算法的单源嵌入方式.实验结果显示,该算法嵌入容量较大,并能有效抵抗常见信号处理攻击、StriMark Benchmark for Audio等攻击,平均误码率小于2.80%,算法具有很好的鲁棒性.

  13. Evaluation of high-capacity cation exchange chromatography for direct capture of monoclonal antibodies from high-titer cell culture processes.

    Science.gov (United States)

    Tao, Yinying; Ibraheem, Aladein; Conley, Lynn; Cecchini, Douglas; Ghose, Sanchayita

    2014-07-01

    Advances in molecular biology and cell culture technology have led to monoclonal antibody titers in excess of 10 g/L. Such an increase can pose concern to traditional antibody purification processes due to limitations in column hardware and binding capacity of Protein A resins. Recent development of high capacity cation exchangers can make cation exchange chromatography (CEX) a promising and economic alternative to Protein A capture. This work investigates the feasibility of using CEX for direct capture of monoclonal antibodies from high titer cell culture fluids. Two resin candidates were selected from seven newer generation cation exchangers for their higher binding capacity and selectivity. Two monoclonal antibodies with widely differing pI values were used to evaluate the capability of CEX as a platform capture step. Screening of loading pH and conductivity showed both resins to be capable of directly capturing both antibodies from undiluted cell culture fluid. At appropriate acidic pH range, product loading of over 65 g/L resin was achieved for both antibodies. A systematic design of experiment (DOE) approach was used to optimize the elution conditions for the CEX step. Elution pH showed the most significant impact on clearance of host cell proteins (HCPs). Under optimal conditions, HCP reduction factors in the range of 9-44 were achieved on the CEX step based on the pI of the antibody. Apart from comparing CEX directly to Protein A as the capture method, material from either modality was also processed through the subsequent polishing steps to compare product quality at the drug substance level. Process performance and product quality was found to be acceptable using the non-affinity based process scheme. The results shown here present a cheaper and higher capacity generic capture method for high-titer antibody processes. © 2014 Wiley Periodicals, Inc.

  14. When high-capacity readers slow down and low-capacity readers speed up: Working memory and locality effects

    Directory of Open Access Journals (Sweden)

    Bruno eNicenboim

    2016-03-01

    Full Text Available We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German, while taking into account readers’ working memory capacity and controlling for expectation (Levy, 2008 and other factors. We predicted only locality effects, that is, a slow-down produced by increased dependency distance (Gibson, 2000; Lewis & Vasishth, 2005. Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions.

  15. Life cycle environmental impact of high-capacity lithium ion battery with silicon nanowires anode for electric vehicles.

    Science.gov (United States)

    Li, Bingbing; Gao, Xianfeng; Li, Jianyang; Yuan, Chris

    2014-01-01

    Although silicon nanowires (SiNW) have been widely studied as an ideal material for developing high-capacity lithium ion batteries (LIBs) for electric vehicles (EVs), little is known about the environmental impacts of such a new EV battery pack during its whole life cycle. This paper reports a life cycle assessment (LCA) of a high-capacity LIB pack using SiNW prepared via metal-assisted chemical etching as anode material. The LCA study is conducted based on the average U.S. driving and electricity supply conditions. Nanowastes and nanoparticle emissions from the SiNW synthesis are also characterized and reported. The LCA results show that over 50% of most characterized impacts are generated from the battery operations, while the battery anode with SiNW material contributes to around 15% of global warming potential and 10% of human toxicity potential. Overall the life cycle impacts of this new battery pack are moderately higher than those of conventional LIBs but could be actually comparable when considering the uncertainties and scale-up potential of the technology. These results are encouraging because they not only provide a solid base for sustainable development of next generation LIBs but also confirm that appropriate nanomanufacturing technologies could be used in sustainable product development.

  16. Generalized Group Signature Scheme

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The concept of generalized group signature scheme will bepresent. Based on the generalized secret sharing scheme proposed by Lin and Ha rn, a non-interactive approach is designed for realizing such generalized group signature scheme. Using the new scheme, the authorized subsets of the group in w hich the group member can cooperate to produce the valid signature for any messa ge can be randomly specified

  17. Finite Boltzmann schemes

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2006-01-01

    In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

  18. MIDI Programming in Scheme

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2010-01-01

    A Scheme representation of Standard MIDI Files is proposed. The Scheme expressions are defined and constrained by an XML-language, which in the starting point is inspired by a MIDI XML event language made by the MIDI Manufactures Association. The representation of Standard MIDI Files in Scheme ma...

  19. MIDI Programming in Scheme

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2010-01-01

    A Scheme representation of Standard MIDI Files is proposed. The Scheme expressions are defined and constrained by an XML-language, which in the starting point is inspired by a MIDI XML event language made by the MIDI Manufactures Association. The representation of Standard MIDI Files in Scheme ma...

  20. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    This paper describes and discusses two different Scheme documentation tools. The first is SchemeDoc, which is intended for documentation of the interfaces of Scheme libraries (APIs). The second is the Scheme Elucidator, which is for internal documentation of Scheme programs. Although the tools...... are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...

  1. Spongelike Nanosized Mn 3 O 4 as a High-Capacity Anode Material for Rechargeable Lithium Batteries

    KAUST Repository

    Gao, Jie

    2011-07-12

    Mn3O4 has been investigated as a high-capacity anode material for rechargeable lithium ion batteries. Spongelike nanosized Mn 3O4 was synthesized by a simple precipitation method and characterized by powder X-ray diffraction, Raman scattering and scanning electron microscopy. Its electrochemical performance, as an anode material, was evaluated by galvanostatic discharge-charge tests. The results indicate that this novel type of nanosized Mn3O4 exhibits a high initial reversible capacity (869 mA h/g) and significantly enhanced first Coulomb efficiency with a stabilized reversible capacity of around 800 mA h/g after over 40 charge/discharge cycles. © 2011 American Chemical Society.

  2. Strong dependency of lithium diffusion on mechanical constraints in high-capacity Li-ion battery electrodes

    Institute of Scientific and Technical Information of China (English)

    Yi-Fan Gao; Min Zhou

    2012-01-01

    The effect of external constraints on Li diffusion in high-capacity Li-ion battery electrodes is investigated using a coupled finite deformation theory.It is found that thinfilm electrodes on rigid substrates experience much slower diffusion rates compared with free-standing films with the same material properties and geometric dimensions.More importantly,the study reveals that mechanical driving forces tend to retard diffusion in highly-constrained thin films when lithiation-induced softening is considered,in contrast to the fact that mechanical driving forces always enhance diffusion when deformation is fully elastic.The results provide further proof that nano-particles are a better design option for nextgeneration alloy-based electrodes compared with thin films.

  3. High-Capacity and Self-Stabilized Manganese Carbonate Microspheres as Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Xiao, Liang; Wang, Shiyao; Wang, Yafei; Meng, Wen; Deng, Bohua; Qu, Deyu; Xie, Zhizhong; Liu, Jinping

    2016-09-28

    Manganese carbonate (MnCO3) is an attractive anode material with high capacity based on conversion reaction for lithium-ion batteries (LIBs), but its application is mainly hindered by poor cycling performance. Building nanostructures/porous structures and nanocomposites has been demonstrated as an effective strategy to buffer the volume changes and maintain the electrode integrity for long-term cycling. It is widely believed that microsized MnCO3 is not suitable for use as anode material for LIBs because of its poor conductivity and the absence of nanostructure. Herein, different from previous reports, spherical MnCO3 with the mean diameters of 6.9 μm (MnCO3-B), 4.0 μm (MnCO3-M), and 2.6 μm (MnCO3-S) were prepared via controllable precipitation and utilized as anode materials for LIBs. It is interesting that the as-prepared MnCO3 microspheres demonstrate both high capacity and excellent cycling performance comparable to their reported nanosized counterparts. MnCO3-B, MnCO3-M, and MnCO3-S deliver reversible specific capacities of 487.3, 573.9, and 656.8 mA h g(-1) after 100 cycles, respectively. All the MnCO3 microspheres show capacity retention more than 90% after the initial stage. The advantages of MnCO3 microspheres were investigated via constant-current charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that there should be substantial structure transformation from microsized particle to self-stabilized nanostructured matrix for MnCO3 at the initial charge/discharge stage. The evolution of EIS during charge/discharge clearly indicates the formation and stabilization of the nanostructured matrix. The self-stabilized porous matrix maintains the electrode structure to deliver excellent cycling performance, and contributes extra capacity beyond conversion reaction.

  4. Topology of genetic associations between regional gray matter volume and intellectual ability: Evidence for a high capacity network.

    Science.gov (United States)

    Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Hedman, Anna M; van den Heuvel, Martijn P; van Haren, Neeltje E M; Kahn, René S; Pol, Hilleke E Hulshoff

    2016-01-01

    Intelligence is associated with a network of distributed gray matter areas including the frontal and parietal higher association cortices and primary processing areas of the temporal and occipital lobes. Efficient information transfer between gray matter regions implicated in intelligence is thought to be critical for this trait to emerge. Genetic factors implicated in intelligence and gray matter may promote a high capacity for information transfer. Whether these genetic factors act globally or on local gray matter areas separately is not known. Brain maps of phenotypic and genetic associations between gray matter volume and intelligence were made using structural equation modeling of 3T MRI T1-weighted scans acquired in 167 adult twins of the newly acquired U-TWIN cohort. Subsequently, structural connectivity analyses (DTI) were performed to test the hypothesis that gray matter regions associated with intellectual ability form a densely connected core. Gray matter regions associated with intellectual ability were situated in the right prefrontal, bilateral temporal, bilateral parietal, right occipital and subcortical regions. Regions implicated in intelligence had high structural connectivity density compared to 10,000 reference networks (p=0.031). The genetic association with intelligence was for 39% explained by a genetic source unique to these regions (independent of total brain volume), this source specifically implicated the right supramarginal gyrus. Using a twin design, we show that intelligence is genetically represented in a spatially distributed and densely connected network of gray matter regions providing a high capacity infrastructure. Although genes for intelligence have overlap with those for total brain volume, we present evidence that there are genes for intelligence that act specifically on the subset of brain areas that form an efficient brain network.

  5. Proposal of Wireless Traffic Control Schemes for Wireless LANs

    Science.gov (United States)

    Hiraguri, Takefumi; Ichikawa, Takeo; Iizuka, Masataka; Kubota, Shuji

    This paper proposes two traffic control schemes to support the communication quality of multimedia streaming services such as VoIP and audio/video over IEEE 802.11 wireless LAN systems. The main features of the proposed scheme are bandwidth control for each flow of the multimedia streaming service and load balancing between access points (APs) of the wireless LAN by using information of data link, network and transport layers. The proposed schemes are implemented on a Linux machine which is called the wireless traffic controller (WTC). The WTC connects a high capacity backbone network and an access network to which the APs are attached. We evaluated the performance of the proposed WTC and confirmed that the communication quality of the multimedia streaming would be greatly improved by using this technique.

  6. A hybrid TIM-NOMA scheme for the Broadcast Channel

    Directory of Open Access Journals (Sweden)

    V. Kalokidou

    2015-07-01

    Full Text Available Future mobile communication networks will require enhanced network efficiency and reduced system overhead. Research on Blind Interference Alignment and Topological Interference Management (TIM has shown that optimal Degrees of Freedom can be achieved, in the absence of Channel State Information at the transmitters. Moreover, the recently emerged Non- Orthogonal Multiple Access (NOMA scheme suggests a different multiple access approach, compared to the orthogonal methods employed in 4G, resulting in high capacity gains. Our contribution is a hybrid TIM-NOMA scheme in K-user cells, where users are divided into T groups. By superimposing users in the power domain, we introduce a two-stage decoding process, managing “inter-group” interference based on the TIM principles, and “intra-group” interference based on Successful Interference Cancellation, as proposed by NOMA. We show that the hybrid scheme can improve the sum rate by at least 100% compared to Time Division Multiple Access, for high SNR values.

  7. Convertible Proxy Signcryption Scheme

    Institute of Scientific and Technical Information of China (English)

    李继国; 李建中; 曹珍富; 张亦辰

    2004-01-01

    In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chan and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature.However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes.To protect the receiver' s benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which carn enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu' s scheme and improved Kim' s scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.

  8. Website-based PNG image steganography using the modified Vigenere Cipher, least significant bit, and dictionary based compression methods

    Science.gov (United States)

    Rojali, Salman, Afan Galih; George

    2017-08-01

    Along with the development of information technology in meeting the needs, various adverse actions and difficult to avoid are emerging. One of such action is data theft. Therefore, this study will discuss about cryptography and steganography that aims to overcome these problems. This study will use the Modification Vigenere Cipher, Least Significant Bit and Dictionary Based Compression methods. To determine the performance of study, Peak Signal to Noise Ratio (PSNR) method is used to measure objectively and Mean Opinion Score (MOS) method is used to measure subjectively, also, the performance of this study will be compared to other method such as Spread Spectrum and Pixel Value differencing. After comparing, it can be concluded that this study can provide better performance when compared to other methods (Spread Spectrum and Pixel Value Differencing) and has a range of MSE values (0.0191622-0.05275) and PSNR (60.909 to 65.306) with a hidden file size of 18 kb and has a MOS value range (4.214 to 4.722) or image quality that is approaching very good.

  9. Experimental Demonstration of Optical Switching of Tbit/s Data Packets for High Capacity Short-Range Networks

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Kamchevska, Valerija; Hu, Hao;

    2015-01-01

    Record-high 1.28-Tbit/s optical data packets are experimentally switched in the optical domain using a LiNbO3 switch. An in-band notch-filter labeling scheme scalable to 65,536 labels is employed and a 3-km transmission distance is demonstrated.......Record-high 1.28-Tbit/s optical data packets are experimentally switched in the optical domain using a LiNbO3 switch. An in-band notch-filter labeling scheme scalable to 65,536 labels is employed and a 3-km transmission distance is demonstrated....

  10. 博弈模型上的策略自适应隐写方法%Strategic adaptive steganography based on the game theory model

    Institute of Scientific and Technical Information of China (English)

    钮可; 李军; 刘佳; 杨晓元

    2015-01-01

    在隐写博弈模型改进的基础上,提出了一种基于策略自适应的隐写方法。首先将图像变换到小波域,利用人眼视觉特性中的亮度掩蔽、频率掩蔽和纹理掩蔽效应计算失真测度函数;然后建立起基于内容自适应的失真测度函数与基于策略自适应的偏离函数之间的联系,并根据隐写博弈模型中的纳什均衡得到每一个载体嵌入秘密信息的概率,从而实现了基于策略自适应的图像隐写方法。实验结果表明,该方法的安全性高于基于内容自适应的 HUGO 算法。%On the basis of the improvement of the game theory model , we propose a Strategic adaptive steganography method . First , we use the human visual characteristics of luminance masking , texture masking and the frequency masking factor to compute the distortion measure function after the image is transformed into the wavelet domain . Then we establish a connection between content adaptive distortion measure functionand the strategic adaptive bias function , so that we can get the probability of each cover element for embedding the message according to the Nash equilibrium in the game theory model for steganography . Experimental results show that the statistical security of the proposed method is high than that of the HUGO which is the method of content adaptive steganography .

  11. An Improve LSB Matching Steganography Based on SFLA%基于蛙跳优化的安全LSB匹配隐写算法

    Institute of Scientific and Technical Information of China (English)

    欧阳春娟; 李斌; 李霞

    2012-01-01

    This paper proposes a heuristic shuffled frog leaping algorithm (SFLA) based steganographic model. An improved least significant bit matching (LSBM) image steganography ,abbreviated as SFLA-LSBM, is designed according to this new model. In SFLA-LSBM, an objective function is defined as the statistical difference between a cover image and its stego version. With the help of SFLA, an optimized plus-minus-one sequence, which is in fact the best feasible solution to the objective function, is found for each image . This sequence is embedded into the image to convey secret information as well as to minimize the change of image features. Compared with the classical LSBM steganography and other improved LSBM steganography alogrithms, SFLA-LSBM demonstrates better ability in resisting steganalytic algorithms. SFLA-LSBM is also adapted to resist newly presented steganalytic algorithms.%本文提出以隐写分析为适应度函数的启发式蛙跳优化隐写通信模型,并以该模型设计了一种改进LSBM算法,即SFLA-LSBM算法。该算法以载体图像和载密图像的统计差异为优化目标函数,采用蛙跳算法优化隐写过程中的加减1序列,从而达到在隐写过程中最小化统计差异从而达到抵抗隐写分析的目的。实验表明,与传统的 LSBM 算法和现有改进LSBM算法相比,SFLA-LSBM有效提高了LSBM隐写安全性。SFLA-LSBM算法还具有在线学习功能,可抵抗新出现的隐写分析算法。

  12. Difference Schemes and Applications

    Science.gov (United States)

    2015-02-06

    of the shallow water equations that is well suited for complex geometries and moving boundaries. Another (similar) regularization of...the solid wall extrapolation followed by the interpolation in the phase space (by solving the Riemann problem between the internal cell averages and...scheme. This Godunov-type scheme enjoys all major advantages of Riemann -problem-solver-free, non-oscillatory central schemes and, at the same time, have

  13. Efficient Threshold Signature Scheme

    Directory of Open Access Journals (Sweden)

    Sattar J Aboud

    2012-01-01

    Full Text Available In this paper, we introduce a new threshold signature RSA-typed scheme. The proposed scheme has the characteristics of un-forgeable and robustness in random oracle model. Also, signature generation and verification is entirely non-interactive. In addition, the length of the entity signature participate is restricted by a steady times of the length of the RSA signature modulus. Also, the signing process of the proposed scheme is more efficient in terms of time complexity and interaction.

  14. Stateless Transitive Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    MA Chun-guang; CAI Man-chun; YANG Yi-xian

    2004-01-01

    A new practical method is introduced to transform the stateful transitive signature scheme to stateless one without the loss of security. According to the approach, two concrete stateless transitive signature schemes based on Factoring and RSA are presented respectively. Under the assumption of the hardness of factoring and one-more- RSA-inversion problem, both two schemes are secure under the adaptive chosen-message attacks in random oracle model.

  15. Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Craig [Univ. of Hawaii, Honolulu, HI (United States); McGrady, Sean [Univ. of New Brunswick, Fredericton NB (Canada); Severa, Godwin [Univ. of Hawaii, Honolulu, HI (United States); Eliseo, Jennifer [Univ. of Hawaii, Honolulu, HI (United States); Chong, Marina [Univ. of Hawaii, Honolulu, HI (United States)

    2013-05-31

    The project was component of the US DOE, Metal Hydride Center of Excellence (MHCoE). The Sandia National Laboratory led center was established to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE/FreedomCAR 2010 and 2015 system targets for hydrogen storage materials. Our approach entailed a wide variety of activities ranging from synthesis, characterization, and evaluation of new candidate hydrogen storage materials; screening of catalysts for high capacity materials requiring kinetics enhancement; development of low temperature methods for nano-confinement of hydrides and determining its effects on the kinetics and thermodynamics of hydrides; and development of novel processes for the direct re-hydrogenation of materials. These efforts have resulted in several advancements the development of hydrogen storage materials. We have greatly extended the fundamental knowledge about the highly promising hydrogen storage carrier, alane (AlH3), by carrying out the first crystal structure determinations and the first determination of the heats of dehydrogenation of β–AlH3 and γ-AlD3. A low-temperature homogenous organometallic approach to incorporation of Al and Mg based hydrides into carbon aerogels has been developed that that allows high loadings without degradation of the nano-porous scaffold. Nano-confinement was found to significantly improve the dehydrogenation kinetics but not effect the enthalpy of dehydrogenation. We conceived, characterized, and synthesized a novel class of potential hydrogen storage materials, bimetallic borohydrides. These novel compounds were found to have many favorable properties including release of significant amounts of hydrogen at moderate temperatures (75-190 º C). However, in situ IR studies in tandem with thermal gravimetric analysis have shown that about 0.5 equivalents of diborane are released during the

  16. Final Report: DE- FC36-05GO15063, Fundamental Studies of Advanced High-Capacity, Reversible Metal Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Craig [University of Hawaii; McGrady, Sean [University of New Brunswick; Severa, Godwin [University of Hawaii; Eliseo, Jennifer [University of Hawaii; Chong, Marina [University of Hawaii

    2015-02-08

    The project was component of the US DOE, Metal Hydride Center of Excellence (MHCoE). The Sandia National Laboratory led center was established to conduct highly collaborative and multi-disciplinary applied R&D to develop new reversible hydrogen storage materials that meet or exceed DOE/FreedomCAR 2010 and 2015 system targets for hydrogen storage materials. Our approach entailed a wide variety of activities ranging from synthesis, characterization, and evaluation of new candidate hydrogen storage materials; screening of catalysts for high capacity materials requiring kinetics enhancement; development of low temperature methods for nano-confinement of hydrides and determining its effects on the kinetics and thermodynamics of hydrides; and development of novel processes for the direct re-hydrogenation of materials. These efforts have resulted in several advancements the development of hydrogen storage materials. We have greatly extended the fundamental knowledge about the highly promising hydrogen storage carrier, alane (AlH₃), by carrying out the first crystal structure determinations and the first determination of the heats of dehydrogenation of β–AlH₃ and γ-AlD₃. A low-temperature homogenous organometallic approach to incorporation of Al and Mg based hydrides into carbon aerogels has been developed that that allows high loadings without degradation of the nano-porous scaffold. Nano-confinement was found to significantly improve the dehydrogenation kinetics but not effect the enthalpy of dehydrogenation. We conceived, characterized, and synthesized a novel class of potential hydrogen storage materials, bimetallic borohydrides. These novel compounds were found to have many favorable properties including release of significant amounts of hydrogen at moderate temperatures (75-190ºC). However, in situ IR studies in tandem with thermal gravimetric analysis have shown that about 0.5 equivalents of diborane are released during the dehydrogenation making re

  17. A Secure and Robust Compressed Domain Video Steganography for Intra- and Inter-Frames Using Embedding-Based Byte Differencing (EBBD Scheme.

    Directory of Open Access Journals (Sweden)

    Tarik Idbeaa

    Full Text Available 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.

  18. A Secure and Robust Compressed Domain Video Steganography for Intra- and Inter-Frames Using Embedding-Based Byte Differencing (EBBD) Scheme.

    Science.gov (United States)

    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.

  19. Steganography in clustered-dot halftones using orientation modulation and modification of direct binary search

    Science.gov (United States)

    Chen, Yung-Yao; Hong, Sheng-Yi; Chen, Kai-Wen

    2015-03-01

    This paper proposes a novel message-embedded halftoning scheme that is based on orientation modulation (OM) encoding. To achieve high image quality, we employ a human visual system (HVS)-based error metric between the continuous-tone image and a data-embedded halftone, and integrate a modified direct binary search (DBS) framework into the proposed message-embedded halftoning method. The modified DBS framework ensures that the resulting data-embedded halftones have optimal image quality from the viewpoint of the HVS.

  20. The study results steganography hiding messages in image files as vehicle security software

    Directory of Open Access Journals (Sweden)

    D. O. Navrotskyi

    2012-11-01

    Full Text Available Synergetics of steganographic and cryptographic encryption algorithms, which provide a solid security foundation, is presented in this paper. Hiding messages systems in spatial and frequency domain image are compared and studied by the author. The following questions: Compression scheme JPEG , JPEG – transformation structure, Practical recommendations for hiding data to image files, The method of least significant bits (spatial domain and the DCT coefficients values relative replacement method (frequency domain, Packing and unpacking the hidden message, Visual distortion image changing system parameters are considered.

  1. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    J. Goutsias (John); H.J.A.M. Heijmans (Henk)

    1998-01-01

    textabstract[PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis

  2. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    Goutsias, J.; Heijmans, H.J.A.M.

    1998-01-01

    [PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis and synthes

  3. Hard carbon nanoparticles as high-capacity, high-stability anodic materials for Na-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Lifen; Cao, Yuliang; Henderson, Wesley A.; Sushko, Maria L.; Shao, Yuyan; Xiao, Jie; Wang, Wei; Engelhard, Mark H.; Nie, Zimin; Liu, Jun

    2016-01-01

    Hard carbon nanoparticles (HCNP) were synthesized by the pyrolysis of a polyaniline precursor. The measured Na+ cation diffusion coefficient (10-13-10-15cm2s-1) in the HCNP obtained at 1150 °C is two orders of magnitude lower than that of Li+ in graphite (10-10-13-15cm2s-1), indicating that reducing the carbon particle size is very important for improving electrochemical performance. These measurements also enable a clear visualization of the stepwise reaction phases and rate changes which occur throughout the insertion/extraction processes in HCNP, The electrochemical measurements also show that the nano-sized HCNP obtained at 1150 °C exhibited higher practical capacity at voltages lower than 1.2 V (vs. Na/Na⁺), as well as a prolonged cycling stability, which is attributed to an optimum spacing of 0.366 nm between the graphitic layers and the nano particular size resulting in a low-barrier Na+ cation insertion. These results suggest that HCNP is a very promising high-capacity/stability anode for low cost sodium-ion batteries (SIBs).

  4. Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing

    Science.gov (United States)

    Willner, Alan E.; Ren, Yongxiong; Xie, Guodong; Yan, Yan; Li, Long; Zhao, Zhe; Wang, Jian; Tur, Moshe; Molisch, Andreas F.; Ashrafi, Solyman

    2017-02-01

    There is a continuing growth in the demand for data bandwidth, and the multiplexing of multiple independent data streams has the potential to provide the needed data capacity. One technique uses the spatial domain of an electromagnetic (EM) wave, and space division multiplexing (SDM) has become increasingly important for increased transmission capacity and spectral efficiency of a communication system. A subset of SDM is mode division multiplexing (MDM), in which multiple orthogonal beams each on a different mode can be multiplexed. A potential modal basis set to achieve MDM is to use orbital angular momentum (OAM) of EM waves. In such a system, multiple OAM beams each carrying an independent data stream are multiplexed at the transmitter, propagate through a common medium and are demultiplexed at the receiver. As a result, the total capacity and spectral efficiency of the communication system can be multiplied by a factor equal to the number of transmitted OAM modes. Over the past few years, progress has been made in understanding the advantages and limitations of using multiplexed OAM beams for communication systems. In this review paper, we highlight recent advances in the use of OAM multiplexing for high-capacity free-space optical and millimetre-wave communications. We discuss different technical challenges (e.g. atmospheric turbulence and crosstalk) as well as potential techniques to mitigate such degrading effects. This article is part of the themed issue 'Optical orbital angular momentum'.

  5. Mn 3 O 4 −Graphene Hybrid as a High-Capacity Anode Material for Lithium Ion Batteries

    KAUST Repository

    Wang, Hailiang

    2010-10-13

    We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Selective growth of Mn3O 4 nanoparticles on RGO sheets, in contrast to free particle growth in solution, allowed for the electrically insulating Mn3O4 nanoparticles to be wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ∼900 mAh/g, near their theoretical capacity, with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn 3O4 nanoparticles grown atop. The Mn3O 4/RGO hybrid could be a promising candidate material for a high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for the design and synthesis of battery electrodes based on highly insulating materials. © 2010 American Chemical Society.

  6. Ion intercalation into two-dimensional transition-metal carbides: global screening for new high-capacity battery materials.

    Science.gov (United States)

    Eames, Christopher; Islam, M Saiful

    2014-11-19

    Two-dimensional transition metal carbides (termed MXenes) are a new family of compounds generating considerable interest due to their unique properties and potential applications. Intercalation of ions into MXenes has recently been demonstrated with good electrochemical performance, making them viable electrode materials for rechargeable batteries. Here we have performed global screening of the capacity and voltage for a variety of intercalation ions (Li(+), Na(+), K(+), and Mg(2+)) into a large number of M2C-based compounds (M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta) with F-, H-, O-, and OH-functionalized surfaces using density functional theory methods. In terms of gravimetric capacity a greater amount of Li(+) or Mg(2+) can be intercalated into an MXene than Na(+) or K(+), which is related to the size of the intercalating ion. Variation of the surface functional group and transition metal species can significantly affect the voltage and capacity of an MXene, with oxygen termination leading to the highest capacity. The most promising group of M2C materials in terms of anode voltage and gravimetric capacity (>400 mAh/g) are compounds containing light transition metals (e.g., Sc, Ti, V, and Cr) with nonfunctionalized or O-terminated surfaces. The results presented here provide valuable insights into exploring a rich variety of high-capacity MXenes for potential battery applications.

  7. Stabilizing the Performance of High-Capacity Sulfur Composite Electrodes by a New Gel Polymer Electrolyte Configuration.

    Science.gov (United States)

    Agostini, Marco; Lim, Du Hyun; Sadd, Matthew; Fasciani, Chiara; Navarra, Maria Assunta; Panero, Stefania; Brutti, Sergio; Matic, Aleksandar; Scrosati, Bruno

    2017-09-11

    Increased pollution and the resulting increase in global warming are drawing attention to boosting the use of renewable energy sources such as solar or wind. However, the production of energy from most renewable sources is intermittent and thus relies on the availability of electrical energy-storage systems with high capacity and at competitive cost. Lithium-sulfur batteries are among the most promising technologies in this respect due to a very high theoretical energy density (1675 mAh g(-1) ) and that the active material, sulfur, is abundant and inexpensive. However, a so far limited practical energy density, life time, and the scaleup of materials and production processes prevent their introduction into commercial applications. In this work, we report on a simple strategy to address these issues by using a new gel polymer electrolyte (GPE) that enables stable performance close to the theoretical capacity of a low cost sulfur-carbon composite with high loading of active material, that is, 70 % sulfur. We show that the GPE prevents sulfur dissolution and reduces migration of polysulfide species to the anode. This functional mechanism of the GPE membranes is revealed by investigating both its morphology and the Li-anode/GPE interface at various states of discharge/charge using Raman spectroscopy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing.

    Science.gov (United States)

    Willner, Alan E; Ren, Yongxiong; Xie, Guodong; Yan, Yan; Li, Long; Zhao, Zhe; Wang, Jian; Tur, Moshe; Molisch, Andreas F; Ashrafi, Solyman

    2017-02-28

    There is a continuing growth in the demand for data bandwidth, and the multiplexing of multiple independent data streams has the potential to provide the needed data capacity. One technique uses the spatial domain of an electromagnetic (EM) wave, and space division multiplexing (SDM) has become increasingly important for increased transmission capacity and spectral efficiency of a communication system. A subset of SDM is mode division multiplexing (MDM), in which multiple orthogonal beams each on a different mode can be multiplexed. A potential modal basis set to achieve MDM is to use orbital angular momentum (OAM) of EM waves. In such a system, multiple OAM beams each carrying an independent data stream are multiplexed at the transmitter, propagate through a common medium and are demultiplexed at the receiver. As a result, the total capacity and spectral efficiency of the communication system can be multiplied by a factor equal to the number of transmitted OAM modes. Over the past few years, progress has been made in understanding the advantages and limitations of using multiplexed OAM beams for communication systems. In this review paper, we highlight recent advances in the use of OAM multiplexing for high-capacity free-space optical and millimetre-wave communications. We discuss different technical challenges (e.g. atmospheric turbulence and crosstalk) as well as potential techniques to mitigate such degrading effects.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).

  9. Content-adaptive pentary steganography using the multivariate generalized Gaussian cover model

    Science.gov (United States)

    Sedighi, Vahid; Fridrich, Jessica; Cogranne, Rémi

    2015-03-01

    The vast majority of steganographic schemes for digital images stored in the raster format limit the amplitude of embedding changes to the smallest possible value. In this paper, we investigate the possibility to further improve the empirical security by allowing the embedding changes in highly textured areas to have a larger amplitude and thus embedding there a larger payload. Our approach is entirely model driven in the sense that the probabilities with which the cover pixels should be changed by a certain amount are derived from the cover model to minimize the power of an optimal statistical test. The embedding consists of two steps. First, the sender estimates the cover model parameters, the pixel variances, when modeling the pixels as a sequence of independent but not identically distributed generalized Gaussian random variables. Then, the embedding change probabilities for changing each pixel by 1 or 2, which can be transformed to costs for practical embedding using syndrome-trellis codes, are computed by solving a pair of non-linear algebraic equations. Using rich models and selection-channel-aware features, we compare the security of our scheme based on the generalized Gaussian model with pentary versions of two popular embedding algorithms: HILL and S-UNIWARD.

  10. 滤波对隐藏通信系统性能影响分析%Analysis of filtering effect on performance of optical steganography transmission system

    Institute of Scientific and Technical Information of China (English)

    刘志强; 刘甲冲; 刘承禹; 孟楠; 蒲涛; 吴国锋

    2012-01-01

    According to time domain phase encoding code-division multiple access stegenography communication system model,host filter effect to stegenography system performance was analyzed.Numerical results show that introducing of filter will increase system BER performance, and reduce the recovering difficulty for the steganography signal. With the increase of filtering depth, receiving power decreases for the stegenography channel, and power ratio between host and steganography can be increased. Simulation results also show that 30dB filtering depth will be optimal for each system.%依据时域相位码分多址隐藏通信系统模型,研究了宿主滤波器对隐藏系统性能影响.系统仿真表明,滤波器的使用提高了系统性能,减低了隐藏信道的接收难度;随着滤波深度的增加,隐藏信道所需的接收功率减小,且宿主信号与隐藏信号的功率比增大;仿真研究表明当滤波深度达到30dB时可获得最佳性能.

  11. 多途效应对信息隐藏技术水下应用的影响%Multi-path Effect on Steganography Underwater

    Institute of Scientific and Technical Information of China (English)

    韩树平; 刘建波; 许兆鹏

    2012-01-01

    The underwater channel is complex and changeable,which brings difficulty to the application of steganography underwater,the biggest challenge is multi-path effect.The noise which is caused by multi-path effect is analyzed through the multi-path effect model which is established.The multi-path effect on steganography algorithm is discussed,while the countermeasures are proposed.%水声信道复杂多变的特点给信息隐藏技术在水下的应用带来了很大的困难,最大的挑战就在于多途效应。通过建立简单的多途效应模型,分析了多途效应引起的误差噪声。讨论了多途效应对信息隐藏算法的影响,并提出了相应的对策。

  12. 基于相邻像素结构的信息隐藏算法%An Extended Structured Steganography Based on Adjacency Pixel

    Institute of Scientific and Technical Information of China (English)

    唐明伟; 宋文

    2012-01-01

    An extened structured steganography based on adjacency pixel (ESSA) was proposed by analyzing the SPA algorithm and SIHA algorithm. ESSA can be used to analyze some properties of the image fixel pairs. Based on the properties, a monotonous sequence of restoration was found. The sequence can keep the statistic properties of the pair unchanged. The experiment results show that the method can resist the attack of SPA and its performance is better than that of others in the efficiency and hiding capacity of information hiding.%通过对SPA方法和SIHA算法的分析,提出了一种扩展结构化的LSB信息隐藏算法(an extened structured steganography based on adjacency pixel,ESSA).通过分析图像相邻像素结构体,找到相似的相邻像素结构体,根据这些相邻像素结构体的统计性质变化来隐藏信息.实验证明:该算法不仅能够有效的抵抗SPA统计分析方法,而且实现简单、计算量小,隐藏优于其他算法.

  13. Steganography Based on Sparse Representation with Distortion Function%结合失真函数的稀疏域图像隐写算法

    Institute of Scientific and Technical Information of China (English)

    于春梅

    2014-01-01

    Steganography in sparse domain uses sparse representation to embed secret information in a cover image. It proposes to design the distortion function for steganography in sparse domain and embed secret message by minimizing the disortion function, so that the embedding impact is minimized. It's shown that the algorithm can effectively resist existing steganalysis algorithms while maintaining image visual perception.%稀疏域图像隐写利用稀疏表示在载体图像中嵌入秘密信息。提出设计稀疏域图像隐写的失真函数,通过选择使失真函数最小的修改方式进行秘密嵌入,从而减小秘密信息嵌入对载体的影响。实验结果表明,该算法可以在保持图像视觉效果的同时,更有效地抵抗现有的隐写分析算法。

  14. 基于空域差分直方图差异的MB隐藏检测%MB Steganography Detection Based on Diversity of Spatial Difference Histogram

    Institute of Scientific and Technical Information of China (English)

    韩杰思; 沈建京

    2011-01-01

    In this paper, a new steganalysis for Model-based(MB) steganography of JPEG images is proposed. MB lead the veins distributing of image tending to be accordant, but airspace gradient can measure veins of image commendably. So the new method use airspace gradient by transform of MB steganography, combined with calibration and re-embedding technology. Experimental results validate that this method is good at detecting MB1 and MB2 with low false rate.%基于模型(MB)隐藏会使图像的纹理分布趋于一致,使其难以被检测.针对该问题,利用空域差分直方图能较好度量图像纹理的特性,提出一种新的图像MB隐藏检测算法.分析JPEG图像空域差分直方图在MB隐藏前后的变化情况,结合校准和重嵌入技术,实现MB隐藏的有效检测.实验结果表明,该算法具有较高的检测率和较低的虚警率.

  15. [Peculiarities of forensic medical reconstruction of the mechanism of injuries in numerous victims of the explosion of a high-capacity blasting device].

    Science.gov (United States)

    Fradkina, N A; Kovalev, A V; Makarov, I Iu

    2013-01-01

    The systemic analysis of forensic medical practice in Moscow during the past 15 years has demonstrated the scientific, practical, and social significance of expertise of peace-time blast injuries resulting from many terrorist attacks with the use of improvised high-capacity explosive devices that caused multiple human victims. The authors emphasize the current lack of objective forensic medical criteria for the reconstruction of the mechanism of injuries in numerous victims of the explosion of a high-capacity blasting device. It dictates the necessity of their development and substantiation of their practical application.

  16. A Fuzzy Commitment Scheme

    CERN Document Server

    Al-saggaf, Alawi A

    2008-01-01

    This paper attempt has been made to explain a fuzzy commitment scheme. In the conventional Commitment schemes, both committed string m and valid opening key are required to enable the sender to prove the commitment. However there could be many instances where the transmission involves noise or minor errors arising purely because of the factors over which neither the sender nor the receiver have any control. The fuzzy commitment scheme presented in this paper is to accept the opening key that is close to the original one in suitable distance metric, but not necessarily identical. The concept itself is illustrated with the help of simple situation.

  17. Locus coeruleus galanin expression is enhanced after exercise in rats selectively bred for high capacity for aerobic activity.

    Science.gov (United States)

    Murray, Patrick S; Groves, Jessica L; Pettett, Brett J; Britton, Steven L; Koch, Lauren G; Dishman, Rod K; Holmes, Philip V

    2010-12-01

    The neuropeptide galanin extensively coexists with norepinephrine in locus coeruleus (LC) neurons. Previous research in this laboratory has demonstrated that unlimited access to activity wheels in the home cage increases mRNA for galanin (GAL) in the LC, and that GAL mediates some of the beneficial effects of exercise on brain function. To assess whether capacity for aerobic exercise modulates this upregulation in galanin mRNA, three heterogeneous rat models were tested: rats selectively bred for (1) high intrinsic (untrained) aerobic capacity (High Capacity Runners, HCR) and (2) low intrinsic aerobic capacity (Low Capacity Runners, LCR) and (3) unselected Sprague-Dawley (SD) rats with and without free access to running wheels for 3 weeks. Following this exercise protocol, mRNA for tyrosine hydroxylase (TH) and GAL was measured in the LC. The wheel running distances between the three models were significantly different, and age contributed as a significant covariate. Both selection and wheel access condition significantly affected GAL mRNA expression, but not TH mRNA expression. GAL was elevated in exercising HCR and SD rats compared to sedentary rats while LCR rats did not differ between conditions. Overall running distance significantly correlated with GAL mRNA expression, but not with TH mRNA expression. No strain differences in GAL or TH gene expression were observed in sedentary rats. Thus, intrinsic aerobic running capacity influences GAL gene expression in the LC only insofar as actual running behavior is concerned; aerobic capacity does not influence GAL expression in addition to changes associated with running.

  18. Y-doped Li8ZrO6: A Li-Ion Battery Cathode Material with High Capacity.

    Science.gov (United States)

    Huang, Shuping; Wilson, Benjamin E; Wang, Bo; Fang, Yuan; Buffington, Keegan; Stein, Andreas; Truhlar, Donald G

    2015-09-02

    We study--experimentally and theoretically--the energetics, structural changes, and charge flows during the charging and discharging processes for a new high-capacity cathode material, Li8ZrO6 (LZO), which we study both pure and yttrium-doped. We quantum mechanically calculated the stable delithiated configurations, the delithiation energy, the charge flow during delithiation, and the stability of the delithiated materials. We find that Li atoms are easier to extract from tetrahedral sites than octahedral ones. We calculate a large average voltage of 4.04 eV vs Li/Li(+) for delithiation of the first Li atom in a primitive cell, which is confirmed by galvanostatic charge/discharge cycling data. Energy calculations indicate that topotactic delithiation is kinetically favored over decomposition into Li, ZrO2, and O2 during the charging process, although the thermodynamic energy of the topotactic reaction is less favorable. When one or two lithium atoms are extracted from a primitive cell of LZO, its volume and structure change little, whereas extraction of the third lithium greatly distorts the layered structure. The Li6ZrO6 and Li5ZrO6 delithiation products can be thermodynamically metastable to release of O2. Experimentally, materials with sufficiently small particle size for efficient delithiation and relithiation were achieved within an yttrium-doped LZO/carbon composite cathode that exhibited an initial discharge capacity of at least 200 mAh/g over the first 10 cycles, with 142 mAh/g maintained after 60 cycles. Computations predict that during the charging process, the oxygen ion near the Li vacancy is oxidized for both pure LZO and yttrium-doped LZO, which leads to a small-polaron hole.

  19. Fetal muscle gene transfer is not enhanced by an RGD capsid modification to high-capacity adenoviral vectors.

    Science.gov (United States)

    Bilbao, R; Reay, D P; Hughes, T; Biermann, V; Volpers, C; Goldberg, L; Bergelson, J; Kochanek, S; Clemens, P R

    2003-10-01

    High levels of alpha(v) integrin expression by fetal muscle suggested that vector re-targeting to integrins could enhance adenoviral vector-mediated transduction, thereby increasing safety and efficacy of muscle gene transfer in utero. High-capacity adenoviral (HC-Ad) vectors modified by an Arg-Gly-Asp (RGD) peptide motif in the HI loop of the adenoviral fiber (RGD-HC-Ad) have demonstrated efficient gene transfer through binding to alpha(v) integrins. To test integrin targeting of HC-Ad vectors for fetal muscle gene transfer, we compared unmodified and RGD-modified HC-Ad vectors. In vivo, unmodified HC-Ad vector transduced fetal mouse muscle with four-fold higher efficiency compared to RGD-HC-Ad vector. Confirming that the difference was due to muscle cell autonomous factors and not mechanical barriers, transduction of primary myogenic cells isolated from murine fetal muscle in vitro demonstrated a three-fold better transduction by HC-Ad vector than by RGD-HC-Ad vector. We hypothesized that the high expression level of coxsackievirus and adenovirus receptor (CAR), demonstrated in fetal muscle cells both in vitro and in vivo, was the crucial variable influencing the relative transduction efficiencies of HC-Ad and RGD-HC-Ad vectors. To explore this further, we studied transduction by HC-Ad and RGD-HC-Ad vectors in paired cell lines that expressed alpha(v) integrins and differed only by the presence or absence of CAR expression. The results increase our understanding of factors that will be important for retargeting HC-Ad vectors to enhance gene transfer to fetal muscle.

  20. Conductive Boron-Doped Graphene as an Ideal Material for Electrocatalytically Switchable and High-Capacity Hydrogen Storage.

    Science.gov (United States)

    Tan, Xin; Tahini, Hassan A; Smith, Sean C

    2016-12-07

    Electrocatalytic, switchable hydrogen storage promises both tunable kinetics and facile reversibility without the need for specific catalysts. The feasibility of this approach relies on having materials that are easy to synthesize, possessing good electrical conductivities. Graphitic carbon nitride (g-C4N3) has been predicted to display charge-responsive binding with molecular hydrogen-the only such conductive sorbent material that has been discovered to date. As yet, however, this conductive variant of graphitic carbon nitride is not readily synthesized by scalable methods. Here, we examine the possibility of conductive and easily synthesized boron-doped graphene nanosheets (B-doped graphene) as sorbent materials for practical applications of electrocatalytically switchable hydrogen storage. Using first-principle calculations, we find that the adsorption energy of H2 molecules on B-doped graphene can be dramatically enhanced by removing electrons from and thereby positively charging the adsorbent. Thus, by controlling charge injected or depleted from the adsorbent, one can effectively tune the storage/release processes which occur spontaneously without any energy barriers. At full hydrogen coverage, the positively charged BC5 achieves high storage capacities up to 5.3 wt %. Importantly, B-doped graphene, such as BC49, BC7, and BC5, have good electrical conductivity and can be easily synthesized by scalable methods, which positions this class of material as a very good candidate for charge injection/release. These predictions pave the route for practical implementation of electrocatalytic systems with switchable storage/release capacities that offer high capacity for hydrogen storage.

  1. High-capacity lithium-ion battery conversion cathodes based on iron fluoride nanowires and insights into the conversion mechanism.

    Science.gov (United States)

    Li, Linsen; Meng, Fei; Jin, Song

    2012-11-14

    The increasing demands from large-scale energy applications call for the development of lithium-ion battery (LIB) electrode materials with high energy density. Earth abundant conversion cathode material iron trifluoride (FeF(3)) has a high theoretical capacity (712 mAh g(-1)) and the potential to double the energy density of the current cathode material based on lithium cobalt oxide. Such promise has not been fulfilled due to the nonoptimal material properties and poor kinetics of the electrochemical conversion reactions. Here, we report for the first time a high-capacity LIB cathode that is based on networks of FeF(3) nanowires (NWs) made via an inexpensive and scalable synthesis. The FeF(3) NW cathode yielded a discharge capacity as high as 543 mAh g(-1) at the first cycle and retained a capacity of 223 mAh g(-1) after 50 cycles at room temperature under the current of 50 mA g(-1). Moreover, high-resolution transmission electron microscopy revealed the existence of continuous networks of Fe in the lithiated FeF(3) NWs after discharging, which is likely an important factor for the observed improved electrochemical performance. The loss of active material (FeF(3)) caused by the increasingly ineffective reconversion process during charging was found to be a major factor responsible for the capacity loss upon cycling. With the advantages of low cost, large quantity, and ease of processing, these FeF(3) NWs are not only promising battery cathode materials but also provide a convenient platform for fundamental studies and further improving conversion cathodes in general.

  2. High-Capacity Micrometer-Sized Li 2 S Particles as Cathode Materials for Advanced Rechargeable Lithium-Ion Batteries

    KAUST Repository

    Yang, Yuan

    2012-09-19

    Li 2S is a high-capacity cathode material for lithium metal-free rechargeable batteries. It has a theoretical capacity of 1166 mAh/g, which is nearly 1 order of magnitude higher than traditional metal oxides/phosphates cathodes. However, Li 2S is usually considered to be electrochemically inactive due to its high electronic resistivity and low lithium-ion diffusivity. In this paper, we discover that a large potential barrier (∼1 V) exists at the beginning of charging for Li 2S. By applying a higher voltage cutoff, this barrier can be overcome and Li 2S becomes active. Moreover, this barrier does not appear again in the following cycling. Subsequent cycling shows that the material behaves similar to common sulfur cathodes with high energy efficiency. The initial discharge capacity is greater than 800 mAh/g for even 10 μm Li 2S particles. Moreover, after 10 cycles, the capacity is stabilized around 500-550 mAh/g with a capacity decay rate of only ∼0.25% per cycle. The origin of the initial barrier is found to be the phase nucleation of polysulfides, but the amplitude of barrier is mainly due to two factors: (a) charge transfer directly between Li 2S and electrolyte without polysulfide and (b) lithium-ion diffusion in Li 2S. These results demonstrate a simple and scalable approach to utilizing Li 2S as the cathode material for rechargeable lithium-ion batteries with high specific energy. © 2012 American Chemical Society.

  3. Sum-SINR/sum-capacity optimal multisignature spread-spectrum steganography

    Science.gov (United States)

    Wei, Lili; Pados, Dimitris A.; Batalama, Stella N.; Medley, Michael J.

    2008-04-01

    For any given digital host image or audio file (or group of hosts) and any (block) transform domain of interest, we find an orthogonal set of signatures that achieves maximum sum-signal-to-interference-plus-noise ratio (sum- SINR) spread-spectrum message embedding for any fixed embedding amplitude values. We also find the sumcapacity optimal amplitude allocation scheme for any given total distortion budget under the assumption of (colored) Gaussian transform-domain host data. The practical implication of the results is sum-SINR, sumcapacity optimal multiuser/multisignature spread-spectrum data hiding in the same medium. Theoretically, the findings establish optimality of the recently presented Gkizeli-Pados-Medley multisignature eigen-design algorithm.

  4. CSR schemes in agribusiness

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Haas, Rainer; Balzarova, Michaela

    2013-01-01

    Purpose – The rise of CSR followed a demand for CSR standards and guidelines. In a sector already characterized by a large number of standards, the authors seek to ask what CSR schemes apply to agribusiness, and how they can be systematically compared and analysed. Design....../methodology/approach – Following a deductive-inductive approach the authors develop a model to compare and analyse CSR schemes based on existing studies and on coding qualitative data on 216 CSR schemes. Findings – The authors confirm that CSR standards and guidelines have entered agribusiness and identify a complex landscape...... of schemes that can be categorized on focus areas, scales, mechanisms, origins, types and commitment levels. Research limitations/implications – The findings contribute to conceptual and empirical research on existing models to compare and analyse CSR standards. Sampling technique and depth of analysis limit...

  5. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  6. Bead Injection Extraction Chromatography using High-capacity Lab-on-Valve as a Front End to Inductively Coupled Plasma Mass Spectrometry for Rapid Urine Radiobioassay

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    A novel bead injection (BI) extraction chromatographic microflow system exploiting high-capacity lab-on-valve (LOV) platform coupled with inductively coupled plasma mass spectrometric detection is developed for rapid and automated determination of plutonium in human urine. A microconduit (1 mL) i...

  7. XTR-Kurosawa-Desmedt Scheme

    Institute of Scientific and Technical Information of China (English)

    DING XIU-HUAN; FU ZHI-GUO; ZHANG SHU-GONG

    2009-01-01

    This paper proposes an XTR version of the Kurosawa-Desmedt scheme. Our scheme is secure against adaptive choeen-ciphertext attack under the XTR version of the Decisional Diffie-Hellman assumption in the standard model. Comparing efficiency between the Kurosawa-Desmedt scheme and the proposed XTR-Kurosawa-Desmedt scheme, we find that the proposed scheme is more efficient than the Kurosawa-Desmedt scheme both in communication and computation without compromising security.

  8. Adaptive PVD Steganography Using Horizontal, Vertical, and Diagonal Edges in Six-Pixel Blocks

    Directory of Open Access Journals (Sweden)

    Anita Pradhan

    2017-01-01

    Full Text Available The traditional pixel value differencing (PVD steganographical schemes are easily detected by pixel difference histogram (PDH analysis. This problem could be addressed by adding two tricks: (i utilizing horizontal, vertical, and diagonal edges and (ii using adaptive quantization ranges. This paper presents an adaptive PVD technique using 6-pixel blocks. There are two variants. The proposed adaptive PVD for 2×3-pixel blocks is known as variant 1, and the proposed adaptive PVD for 3×2-pixel blocks is known as variant 2. For every block in variant 1, the four corner pixels are used to hide data bits using the middle column pixels for detecting the horizontal and diagonal edges. Similarly, for every block in variant 2, the four corner pixels are used to hide data bits using the middle row pixels for detecting the vertical and diagonal edges. The quantization ranges are adaptive and are calculated using the correlation of the two middle column/row pixels with the four corner pixels. The technique performs better as compared to the existing adaptive PVD techniques by possessing higher hiding capacity and lesser distortion. Furthermore, it has been proven that the PDH steganalysis and RS steganalysis cannot detect this proposed technique.

  9. Succesful labelling schemes

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Stacey, Julia

    2001-01-01

    It is usual practice to evaluate the success of a labelling scheme by looking at the awareness percentage, but in many cases this is not sufficient. The awareness percentage gives no indication of which of the consumer segments that are aware of and use labelling schemes and which do not. In the ......It is usual practice to evaluate the success of a labelling scheme by looking at the awareness percentage, but in many cases this is not sufficient. The awareness percentage gives no indication of which of the consumer segments that are aware of and use labelling schemes and which do not....... In the spring of 2001 MAPP carried out an extensive consumer study with special emphasis on the Nordic environmentally friendly label 'the swan'. The purpose was to find out how much consumers actually know and use various labelling schemes. 869 households were contacted and asked to fill in a questionnaire...... it into consideration when I go shopping. The respondent was asked to pick the most suitable answer, which described her use of each label. 29% - also called 'the labelling blind' - responded that they basically only knew the recycling label and the Government controlled organic label 'Ø-mærket'. Another segment of 6...

  10. 一种针对彩色 JPEG 图像的安全隐写算法%A Secure Steganography for Colour JPEG Image

    Institute of Scientific and Technical Information of China (English)

    刘辉; 余世干; 李林国

    2013-01-01

      为进一步增强载密彩色JPEG图像的安全性,提出一种针对彩色JPEG图像的安全隐写算法。算法把原始彩色JPEG图像的每个8×8分块进行DCT变换后,对各块中具有相同频率的R,G,B各分量的AC系数用密钥控制生成一个近似服从高斯分布的整数序列进行整除取余,将余数的LSB构成序列br bg bb ,对br bg bb 采用矩阵编码嵌入秘密信息。实验结果表明:与同类算法相比,该方法对彩色JPEG图像可提供较大的嵌入容量,载密彩色JPEG图像具有较好的视觉质量,且能够抵几种常见的隐写分析方法。%To enhance further the security of the colour JPEG stego-image,a secure steganography for colour JPEG image is proposed.In DCT domain of colour JPEG image,first of all,this steganography selects 8 ×8 sub-block,the quantized AC coefficients having same frequency of R ,G,B component in each selected 8 ×8 sub-block are disposed by modulus operator with an integer gaussian sequence .Then embed secret information in the br bg bb sequence which consists of the least significant bit by using matrix coding technology .The experimental results show that the proposed new steganography has achieved the hiding capacity remarkably ,while enhancing the visual quality of the JPEG stego-image,and can be resistant several well-known steganalytic methods.

  11. 基于统计模型及SVM的低速率语音编码QIM隐写检测%Detection of QIM Steganography in Low Bit-Rate Speech Codec Based on Statistical Models and SVM

    Institute of Scientific and Technical Information of China (English)

    李松斌; 黄永峰; 卢记仓

    2013-01-01

    QIM(Quantization Index Modulation,量化索引调制)隐写在标量或矢量量化时嵌入机密信息,可在语音压缩编码过程中进行高隐蔽性的信息隐藏,文中试图对该种隐写进行检测.文中发现该种隐写将导致压缩语音流中的音素分布特性发生改变,提出了音素向量空间模型和音素状态转移模型对音素分布特性进行了量化表示.基于所得量化特征并结合SVM(Support Vector Machine,支持向量机)构建了隐写检测器.针对典型的低速率语音编码标准G.729以及G.723.1的实验表明,文中方法性能远优于现有检测方法,实现了对QIM隐写的快速准确检测.%Quantization Index Modulation (QIM) steganography,which embeds the secret information during the Vector Quantization,can hide information in low bit-rate speech codec with high imperceptibility.This paper tries to detect this type of steganography.For this purpose,starting from the speech generation and compress coding theory,this paper firstly analyzes the possible significant feature degradation through the QIM steganography in compressed audio stream deeply.And it finds that the QIM steganography will disturb the phoneme sequence in the stream,and inevitably make the imbalance and correlation characteristics of phoneme distribution in the sequence change.According to this discovery,this paper adopts the phoneme distribution characteristics as the key for the detection of the QIM steganography.In order to get the quantitative features of phoneme distribution characteristics,this paper designs the Phoneme Vector Space Model and the Phoneme State Transition Model to quantify the imbalance and correlation characteristics respectively.By combining the quantitative vector features with supervised learning classifier,this paper builds a high performance detector towards the QIM steganography in low bit-rate speech codec.The experiments show that,for the two typical low bit-rate speech codec:G.729 and G.723.1,the

  12. Application of Improved Audio Steganography Method in Police Mobile Terminals%改进音频隐写方法在警用移动终端中的应用

    Institute of Scientific and Technical Information of China (English)

    刘琦; 王翠平; 唐步天; 卢玉军

    2012-01-01

    For the purpose of guaranteeing convenience secure communication between police mobile and servers, this paper studies the design of audio steganography and its application in police mobile secure communication based on speech interaction, because of the imperceptible charater of audio steganography and convenient and fast of speech interaction. And it proposes an improved audio steganography method. Original signal is segmented by hamming function. Redundant interval is determined by short-time energy. Embedding interval is decideded, according to redundant interval and statistic data, then embed steganography information. Simulation experiment shows the excellent subjective imperceptibility of the audio steganography method. On this basis, the audio steganography method is applied in police mobile secure communication based on speech interaction. This kind of secure communication model based on this method is proposed and related experimental results show the correctness and feasibility of the model.%音频隐写不会引起人的听觉感知,且语音具有交互方便、快捷的特点.为保障管用移动终端与服务器之间安全方便地通信,探讨音频隐写方法的设计,及其在基于语音交互的警用移动终端安全通信中的应用,提出一种改进的音频隐写方法.该方法用汉明窗函数对原始信号分帧,根据计算的短时能量确定冗余区间,结合统计经验及滞后掩蔽效应确定嵌入区间,顺序嵌入信息.模拟实验结果表明,该音频隐写方法具有良好的主观不可感知性,且基于该方法的通信模式是正确可行的.

  13. Compact Spreader Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  14. Towards Symbolic Encryption Schemes

    DEFF Research Database (Denmark)

    Ahmed, Naveed; Jensen, Christian D.; Zenner, Erik

    2012-01-01

    Symbolic encryption, in the style of Dolev-Yao models, is ubiquitous in formal security models. In its common use, encryption on a whole message is specified as a single monolithic block. From a cryptographic perspective, however, this may require a resource-intensive cryptographic algorithm......, namely an authenticated encryption scheme that is secure under chosen ciphertext attack. Therefore, many reasonable encryption schemes, such as AES in the CBC or CFB mode, are not among the implementation options. In this paper, we report new attacks on CBC and CFB based implementations of the well......-known Needham-Schroeder and Denning-Sacco protocols. To avoid such problems, we advocate the use of refined notions of symbolic encryption that have natural correspondence to standard cryptographic encryption schemes....

  15. Labeling Schemes with Queries

    OpenAIRE

    2006-01-01

    We study the question of ``how robust are the known lower bounds of labeling schemes when one increases the number of consulted labels''. Let $f$ be a function on pairs of vertices. An $f$-labeling scheme for a family of graphs $\\cF$ labels the vertices of all graphs in $\\cF$ such that for every graph $G\\in\\cF$ and every two vertices $u,v\\in G$, the value $f(u,v)$ can be inferred by merely inspecting the labels of $u$ and $v$. This paper introduces a natural generalization: the notion of $f$-...

  16. Low Cost, High Capacity Regenerable Sorbent for Carbon Dioxide Capture from Existing Coal-fired Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan [TDA Research, Inc., Wheat Ridge, CO (United States); Jayaraman, Ambalavanan [TDA Research, Inc., Wheat Ridge, CO (United States); Dietz, Steven [TDA Research, Inc., Wheat Ridge, CO (United States)

    2016-03-03

    In this project TDA Research, Inc (TDA) has developed a new post combustion carbon capture technology based on a vacuum swing adsorption system that uses a steam purge and demonstrated its technical feasibility and economic viability in laboratory-scale tests and tests in actual coal derived flue gas. TDA uses an advanced physical adsorbent to selectively remove CO2 from the flue gas. The sorbent exhibits a much higher affinity for CO2 than N2, H2O or O2, enabling effective CO2 separation from the flue gas. We also carried out a detailed process design and analysis of the new system as part of both sub-critical and super-critical pulverized coal fired power plants. The new technology uses a low cost, high capacity adsorbent that selectively removes CO2 in the presence of moisture at the flue gas temperature without a need for significant cooling of the flue gas or moisture removal. The sorbent is based on a TDA proprietary mesoporous carbon that consists of surface functionalized groups that remove CO2 via physical adsorption. The high surface area and favorable porosity of the sorbent also provides a unique platform to introduce additional functionality, such as active groups to remove trace metals (e.g., Hg, As). In collaboration with the Advanced Power and Energy Program of the University of California, Irvine (UCI), TDA developed system simulation models using Aspen PlusTM simulation software to assess the economic viability of TDA’s VSA-based post-combustion carbon capture technology. The levelized cost of electricity including the TS&M costs for CO2 is calculated as $116.71/MWh and $113.76/MWh for TDA system integrated with sub-critical and super-critical pulverized coal fired power plants; much lower than the $153.03/MWhand $147.44/MWh calculated for the corresponding amine based systems. The cost of CO2 captured for TDA’s VSA based system is $38

  17. Alternative health insurance schemes

    DEFF Research Database (Denmark)

    Keiding, Hans; Hansen, Bodil O.

    2002-01-01

    In this paper, we present a simple model of health insurance with asymmetric information, where we compare two alternative ways of organizing the insurance market. Either as a competitive insurance market, where some risks remain uninsured, or as a compulsory scheme, where however, the level...... competitive insurance; this situation turns out to be at least as good as either of the alternatives...

  18. 基于图像LSB的隐藏检测算法研究%Detection Algorithm Research Based on Image LSB Steganography

    Institute of Scientific and Technical Information of China (English)

    孙碧容; 马春波

    2012-01-01

    This paper researches on three algorithms of RS,QRS,and IRS(only R),detecting LSB steganography in images and presents an improved algorithm based on the QRS and IRS(only R) algorithms,called QRS(only R).Simulation results of a large number of images show that: compared to the RS,the QRS and the IRS(only R),this new algorithm has improved performances on the detection rate,the accuracy and the executive time,and their improved relative values can be up to 17%,30% and 38%.The algorithm can detect all kinds of LSB steganography algorithms reliably and is a simple and practical steganalysis algorithm.%文章研究了RS(Regular Groups and Singular Groups)、QRS(Quadratic RS Steganalysis)和IRS(仅R)(Improved RS by OnlyRegular Groups)三种图像隐藏检测算法,并提出了一种将QRS和IRS(仅R)算法思想相结合的改进算法,即QRS(仅R)。通过大量图像的仿真表明:该算法相比于RS、QRS、IRS(仅R)算法,在检测率、估计精度和检测时间上均有所改善,改善的相对值分别高达17%、30%和38%。该算法对各种LSB(Least Signification Bit)隐藏算法均能有效检测,是一种简单实用的隐写分析算法。

  19. Development of Advanced Li Rich xLi2MO3 (1 x)LiMO2 Composite Cathode for High Capacity Li Ion Batteries

    Science.gov (United States)

    2016-12-22

    powders. The XRD spectra were collected in a range of 2θ values from 10 o to 70 o at a scanning rate of 0.5 degrees per min and a step size of 0.02 o...AFRL-AFOSR-JP-TR-2017-0003 Development of Advanced Li Rich xLi2MO3-(1-x)LiMO2 Composite Cathode for High Capacity Li Ion Batteries Kuan-Zong Fung...Li Rich xLi2MO3-(1-x)LiMO2 Composite Cathode for High Capacity Li Ion Batteries 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-15-1-4115 5c.  PROGRAM

  20. Conception of PIPERADE: A high-capacity Penning-trap mass separator for high isobaric contamination at DESIR

    Energy Technology Data Exchange (ETDEWEB)

    Minaya Ramirez, E., E-mail: minaya@ipno.in2p3.fr [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Alfaurt, P.; Aouadi, M.; Ascher, P.; Blank, B. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Blaum, K. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Cam, J.-F. [Laboratoire de Physique Corpusculaire, Caen (France); Chauveau, P. [Grand Accélérateur National d’Ions Lourds CEA/DSM-CNRS-IN2P3, Caen (France); Daudin, L. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Delahaye, P. [Grand Accélérateur National d’Ions Lourds CEA/DSM-CNRS-IN2P3, Caen (France); Delalee, F. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Dupré, P. [Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay (France); El Abbeir, S.; Gerbaux, M.; Grévy, S.; Guérin, H. [Centre d’Etudes Nucléaires de Bordeaux-Gradignan (France); Lunney, D. [Centre de Sciences Nucléaires et de Sciences de la Matière, Orsay (France); Metz, F. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Naimi, S. [Riken, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Perrot, L. [Institut de Physique Nucléaire, Orsay (France); and others

    2016-06-01

    The DESIR (decay, excitation and storage of radioactive ions) facility at GANIL-SPIRAL2 will receive a large variety of exotic nuclei at low energy (up to 60 keV) with high intensities. However, the production methods of radioactive beams are non selective, limiting the purity of the beams of interest. Moreover, the high precision needed for nuclear structure and astrophysics studies using beta decay spectroscopy, laser spectroscopy and trap-based experiments at DESIR requires highly pure samples of exotic nuclei. The aim of the double-Pennig-trap mass separator PIPERADE is to deliver large and very pure samples of exotic nuclei to the different experiments in DESIR. New excitation schemes and a large inner diameter of the first trap will mitigate space charge effects to attempt trapping of up to 10{sup 5} ions per pulse. The purification cycle will be performed in a few milliseconds so that short-lived nuclei can be purified. To extract the nuclides of interest from the large amount of isobaric contaminants, a resolving power of 10{sup 5} is mandatory. Afterwards the ions of interest will be accumulated in the second trap until they constitute a sufficiently pure sample for the measurements. The status of the project is presented.

  1. Digital image steganography algorithm based on genetic algorithm and high hidden capacity%基于遗传算法和高隐藏容量的数字图像隐写算法

    Institute of Scientific and Technical Information of China (English)

    谭志伟; 孙新领; 杨观赐

    2016-01-01

    In order to obtain bigger steganography capacity and higher steganography security level,a digital image safety steganography algorithm based on genetic algorithm and high hidden capacity is proposed. The steganography is modeled as a search problem. The genetic algorithm is used to find out the optimal direction and starting point in the host image to hide the enciphered data,and make the steganography image obtain the maximal peak signal⁃to⁃noise ratio(PSNR),whose fitting func⁃tion is PSNR. Firstly,the host image,confidential image and chromosome should be prepared,after that the bit plane and bit direction genes are used to convert the host pixel sequence into bit sequence. And then,the confidential pixel bits are embed⁃ded into the corresponding pixel bits. Finally,the fitting function is used to determine the iteration times. The PSNR and struc⁃tural similarity index measure (SSIM) are used to assess the steganography result. Compared with other steganography algo⁃rithms,the proposed algorithm can significantly improve the steganography quality and safety. Its PSNR and SSIM are higher than those of other algorithms. In addition,its hidden capacity is big enough,which can reach up to 49.5%.%为了获得更大的隐写容量和更高的隐写安全级别,提出一种基于遗传算法和高隐藏容量的数字图像安全隐写算法。将隐写术作为一个搜索问题进行建模,遗传算法的目的是在宿主图像中找到最优的方向和最优的起始点用于隐藏加密数据,使得隐写图像获取最大的峰值信噪比,其拟合函数为峰值信噪比。首先准备宿主图像,机密图像和染色体,利用比特位面和比特方向基因将宿主像素序列转化为比特位序列;然后将机密像素位嵌入到相应的比特像素位;最后利用拟合函数决定迭代结束次数。运用峰值信噪比(PSNR)和结构相似性度量(SSIM)评估隐写结果,与其他隐写算法相比,该

  2. Cobalt Oxide Porous Nanofibers Directly Grown on Conductive Substrate as a Binder/Additive-Free Lithium-Ion Battery Anode with High Capacity.

    Science.gov (United States)

    Liu, Hao; Zheng, Zheng; Chen, Bochao; Liao, Libing; Wang, Xina

    2017-12-01

    In order to reduce the amount of inactive materials, such as binders and carbon additives in battery electrode, porous cobalt monoxide nanofibers were directly grown on conductive substrate as a binder/additive-free lithium-ion battery anode. This electrode exhibited very high specific discharging/charging capacities at various rates and good cycling stability. It was promising as high capacity anode materials for lithium-ion battery.

  3. Image steganography algorithm based on human visual system and nonsubsampled contourlet transform%基于人类视觉系统的非抽样Contourlet变换域图像隐写算法

    Institute of Scientific and Technical Information of China (English)

    梁婷; 李敏; 何玉杰; 徐朋

    2013-01-01

    To improve the capacity and invisibility of image steganography, the article analyzed the advantage and application fields between Nonsubsampled Contourlet Transform ( NSCT) and Contourlet transform. Afterwards, an image steganography was put forward, which was based on Human Visual System (HVS) and NSCT. Through modeling the human visual masking effect, different secret massages were inserted to different coefficient separately in the high-frequency subband of NSCT. The experimental results show that, in comparison with the steganography of wavelet, the proposed algorithm can improve the capacity of steganography at least 70 000 b, and Peak Signal-to-Noise Ratio ( PSNR) increases about 4 dB. Therefore, the invisibility and embedding capacity are both considered preferably, which has a better application outlook than the wavelet project.%为提高图像信息隐藏的容量和隐蔽性,对比分析了非抽样Contourlet变换(NSCT)和Contourlet变换各自的优缺点和适用范围,提出了一种基于NSCT和人类视觉系统(HVS)的图像隐写方案.通过对人眼的视觉掩蔽效应进行建模,在NSCT分解的最精细尺度的各方向子带中,对不同系数分别嵌入不同的秘密信息量.仿真实验表明,新的算法相比小波域中的隐写方案,隐写的嵌入量至少提高了70000 b,峰值信噪比(PSNR)提高约4 dB,较好地兼顾了隐写在不可见性和嵌入容量上的要求,较小波域中的隐写方案具有更好的应用前景.

  4. On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme

    Directory of Open Access Journals (Sweden)

    Wang Daoshun

    2010-01-01

    Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.

  5. Advanced unrepeatered systems using novel Raman amplification schemes

    Science.gov (United States)

    Chang, Do-il; Pelouch, Wayne; Burtsev, Sergey; Perrier, Philippe; Fevrier, Herve

    2015-01-01

    Unrepeatered transmission systems provide a cost-effective solution to transmit high capacity channels in submarine networks to communicate between coastal population centers or in terrestrial networks to connect remote areas where service access is difficult. The main goal of unrepeatered systems has traditionally been to achieve the longest reach, however, increasing traffic demands now require unrepeatered systems to support both longer reach and higher transport capacity. As a result, transmission rate of unrepeatered systems has quickly moved from 10 Gb/s to 40 Gb/s or 100 Gb/s. This paper reviews the key basic technologies, with a specific focus on Raman amplification, required for long-reach, high-capacity unrepeatered optical transmission systems. We will discuss novel Raman amplification schemes, enhanced remote optically pumped amplifiers (ROPA), ultra-low loss / large effective area fibers, and coherent transmission with advanced modulation format and high FEC coding gain. We will also report recent experimental demonstrations that show how these technologies have been combined to achieve industry's leading capacity and reach transmission.

  6. A New Deferred Sentencing Scheme

    Directory of Open Access Journals (Sweden)

    N. K. Chakravarti

    1968-10-01

    Full Text Available A new deferred sentencing scheme resembling double sampling scheme has been suggested from viewpoint of operational and administrative. It is recommended particularly when the inspection is destructive. The O.C. curves of the scheme for two sample sizes of 5 and 10 have been given.

  7. Bonus schemes and trading activity

    NARCIS (Netherlands)

    Pikulina, E.S.; Renneboog, L.D.R.; ter Horst, J.R.; Tobler, P.N.

    2014-01-01

    Little is known about how different bonus schemes affect traders' propensity to trade and which bonus schemes improve traders' performance. We study the effects of linear versus threshold bonus schemes on traders' behavior. Traders buy and sell shares in an experimental stock market on the basis of

  8. Bonus Schemes and Trading Activity

    NARCIS (Netherlands)

    Pikulina, E.S.; Renneboog, L.D.R.; Ter Horst, J.R.; Tobler, P.N.

    2013-01-01

    Abstract: Little is known about how different bonus schemes affect traders’ propensity to trade and which bonus schemes improve traders’ performance. We study the effects of linear versus threshold (convex) bonus schemes on traders’ behavior. Traders purchase and sell shares in an experimental stock

  9. Bonus schemes and trading activity

    NARCIS (Netherlands)

    Pikulina, E.S.; Renneboog, L.D.R.; ter Horst, J.R.; Tobler, P.N.

    2014-01-01

    Little is known about how different bonus schemes affect traders' propensity to trade and which bonus schemes improve traders' performance. We study the effects of linear versus threshold bonus schemes on traders' behavior. Traders buy and sell shares in an experimental stock market on the basis of

  10. Two Improved Digital Signature Schemes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, two improved digital signature schemes are presented based on the design of directed signaturescheme [3]. The peculiarity of the system is that only if the scheme is specific recipient, the signature is authenticated.Since the scheme adds the screen of some information parameters, the difficulty of deciphered keys and the security ofdigital signature system are increased.

  11. CONSIDERATIONS CONCERNING GUARANTEE SCHEMES

    Directory of Open Access Journals (Sweden)

    EMILIA CLIPICI

    2013-05-01

    Full Text Available When a large withdrawal from banks occurs, customers withdraw their deposits, so banks are likely to go bankrupt because of liquidity problems. There are several mechanisms that allow the banking system to avoid the phenomenon of massive withdrawals from banks. The most effective one is the deposit insurance. The deposit insurance is seen primarily as a means of protecting depositors of credit institutions, and secondly as a means of ensuring the stability of the banking system. This article described deposit guarantee scheme in Romania and other country.

  12. Secure mediated certificateless signature scheme

    Institute of Scientific and Technical Information of China (English)

    YANG Chen; MA Wen-ping; WANG Xin-mei

    2007-01-01

    Ju et al proposed a certificateless signature scheme with instantaneous revocation by introducing security mediator (SEM) mechanism. This article presents a detailed cryptoanalysis of this scheme and shows that, in their proposed scheme, once a valid signature has been produced, the signer can recover his private key information and the instantaneous revocation property will be damaged. Furthermore, an improved mediated signature scheme, which can eliminate these disadvantages, is proposed, and security proof of the improved scheme under elliptic curve factorization problem (ECFP) assumption and bilinear computational diffie-hellman problem (BCDH) assumption is also proposed.

  13. Randomness-optimal Steganography

    CERN Document Server

    Kiayias, Aggelos; Shashidhar, Narasimha

    2009-01-01

    Steganographic protocols enables one to "embed" covert messages into inconspicous data over a public communication channel in such a way that no one, aside from the sender and the intended receiver can even detect the presence of the secret message. In this paper, we provide a new provably-secure, private-key steganographic encryption protocol. We prove the security of our protocol in the complexity-theoretic framework where security is quantified as the advantage (compared to a random guess) that the adversary has in distinguishing between innocent covertext and stegotext that embeds a message of his choice. The fundamental building block of our steganographic encryption protocol is a "one-time stegosystem" that allows two parties to transmit messages of length at most that of the shared key with information-theoretic security guarantees. The employment of a pseudorandom generator (PRG) permits secure transmission of longer messages in the same way that such a generator allows the use of one-time pad encrypt...

  14. Based on Local Linear Transformation HUGO Image Steganography Detection%基于局部线性变换的HUGO图像隐写检测

    Institute of Scientific and Technical Information of China (English)

    邓裕; 袁晓红; 秦姣华

    2014-01-01

    Since Pevný put forward a kind of the most advanced Highly Undetectable Steganography in 2010,which approximately preserves the joint distribution of the ifrst-order differences between four neighboring pixels and has a strong resistance to detection performance.Now there is a lack of effective methods in HUGO detection at home and abroad. Steganographic embedding with HUGO changed parts of the textural feature,this paper proposes a new detection method,which is ifrst obtained textural residual image by local linear transformation,to get 22130 dimensionality co-occurrence matrix feature vector,ifnal y using the ensemble classiifer to classify.The experimental results show that when the embedding rate is 0.4 bit per pixel,we obtain a detection rate of 82.71%on average using BOSSRank Image Sets,which is better than 80.3%of Hugobreakers,76.8%of Guel, also in less than 0.4 bit per pixel,the detection effect also improved.%Pevný等人2010年提出一种最先进的高度不可检测的自适应空域隐写算法HUGO(Highly Undetectable Steganography),其保护了相邻四个像素的一阶统计特性,具有很强的抗检测性能,目前国内外针对HUGO检测缺乏有效的方法。由于用HUGO隐写算法进行隐写嵌入时改变部分纹理特征,本文提出一种新的检测方法,利用局部线性变换得到纹理残差图像,计算共生矩阵得到22130维特征向量,最后使用集成分类器进行分类。实验结果表明:在嵌入率为0.4bpp时,针对BOSSRank图像集,获得平均82.71%的检测率,优于Hugobreaker的80.3%和Guel的76.8%,并在低于0.4bpp嵌入率时,其检测效果有所提高。

  15. 基于奇异值的鲁棒图像隐写算法%Robust image steganography algorithm based on singular value

    Institute of Scientific and Technical Information of China (English)

    姚楚茂; 汤光明; 辜刚林

    2015-01-01

    A image steganography algorithm based on singular value decomposition (SVD) and matrix encoding was proposed , which improved the robustness and imperceptibility of the data hiding method .After analyzing the stability of the singular value and using the EMD (exploiting modification direction) ,secret bits were embedded into the singular value obtained from the sin‐gular value decomposition of image blocks .The robustness of algorithm is insured by the singular value’s stability ,and the usage of EMD encoding method improves the embedding efficiency of the proposed algorithm .Experimental results show that the algo‐rithm has little embedding distortion ,and it also has better robustness compared with the original method .This method can be well applied in the image steganography in noise environment .%为提高数字图像隐写算法的鲁棒性和透明性,提出一种基于奇异值分解和矩阵编码的图像隐写算法。分析奇异值分解的稳定性,采用EMD (exploiting modification direction)矩阵编码方法,将秘密信息嵌入在将图像块进行奇异值分解所得的奇异值向量中。图像块奇异值的稳定性保证隐写算法的鲁棒性,采用EM D编码算法嵌入秘密信息比特使得算法具有较高的嵌入效率。实验结果表明,该算法嵌入秘密信息后图像失真小,与原始 EM D算法相比,该算法具有更好的鲁棒性。该算法能够很好的应用于噪声环境下的图像隐写技术。

  16. A steganography algorithm based on remainder embedded%一种基于余数嵌入的隐写算法

    Institute of Scientific and Technical Information of China (English)

    高原; 李新华; 韦雄; 张启杨

    2015-01-01

    Aiming at the existing disadvantages of least significant bit (LSB ) embedded numerical method , a new embedded numerical method was designed . According to the embedded remainder method ,it was based on a remainder mapping table ,the remainder of the carrier numerical was modified to the random value within a region ,at the same time , the quotient of the carrier numerical was modified to make sure that the carrier numerical value of the embedded information is close before and after the approach is adopted .The design of the mapping table was free so the embedded became more flexible and security .At the same time ,in view of the existing steganography algorithm for hiding information more in the discrete cosine transform (DCT ) domain and lacking in variability in hidden area ,a steganography algorithm which used the remainder embedding method in the wavelet domain was constructed . Experiments showed that the constructing algorithm had a good concealment ,robustness and security when the length of the remainder mapping table was not too large .%针对最低有效位嵌入数值的方法存在的缺点,设计一种新的数值嵌入方法———基于余数的嵌入法。该嵌入法根据余数映射表将载体数值的余数修改为某一区域内的随机值,同时修改载体数值的商,使得载体值在嵌入信息前后接近。映射表可自由设计,使得嵌入更加灵活和安全。与此同时,鉴于现有隐写算法多在离散余弦变换域隐藏信息、隐藏区域缺乏可变性的缺点,构造出在小波域内使用余数嵌入法的隐写算法。实验证明,当余数映射表的长度不太大时,该隐写算法具有很好的隐蔽性和安全性。

  17. A New Subfamily of Sucrose Transporters, SUT4, with Low Affinity/High Capacity Localized in Enucleate Sieve Elements of Plants

    Science.gov (United States)

    Weise, Andreas; Barker, Laurence; Kühn, Christina; Lalonde, Sylvie; Buschmann, Henrik; Frommer, Wolf B.; Ward, John M.

    2000-01-01

    A new subfamily of sucrose transporters from Arabidopsis (AtSUT4), tomato (LeSUT4), and potato (StSUT4) was isolated, demonstrating only 47% similarity to the previously characterized SUT1. SUT4 from two plant species conferred sucrose uptake activity when expressed in yeast. The Km for sucrose uptake by AtSUT4 of 11.6 ± 0.6 mM was ∼10-fold greater than for all other plant sucrose transporters characterized to date. An ortholog from potato had similar kinetic properties. Thus, SUT4 corresponds to the low-affinity/high-capacity saturable component of sucrose uptake found in leaves. In contrast to SUT1, SUT4 is expressed predominantly in minor veins in source leaves, where high-capacity sucrose transport is needed for phloem loading. In potato and tomato, SUT4 was immunolocalized specifically to enucleate sieve elements, indicating that like SUT1, macromolecular trafficking is required to transport the mRNA or the protein from companion cells through plasmodesmata into the sieve elements. PMID:10948254

  18. Reversible conversion-alloying of Sb2O3 as a high-capacity, high-rate, and durable anode for sodium ion batteries.

    Science.gov (United States)

    Hu, Meijuan; Jiang, Yinzhu; Sun, Wenping; Wang, Hongtao; Jin, Chuanhong; Yan, Mi

    2014-11-12

    Sodium ion batteries are attracting ever-increasing attention for the applications in large/grid scale energy storage systems. However, the research on novel Na-storage electrode materials is still in its infancy, and the cycling stability, specific capacity, and rate capability of the reported electrode materials cannot satisfy the demands of practical applications. Herein, a high performance Sb(2)O(3) anode electrochemically reacted via the reversible conversion-alloying mechanism is demonstrated for the first time. The Sb(2)O(3) anode exhibits a high capacity of 550 mAh g(-1) at 0.05 A g(-1) and 265 mAh g(-1) at 5 A g(-1). A reversible capacity of 414 mAh g(-1) at 0.5 A g(-1) is achieved after 200 stable cycles. The synergistic effect involving conversion and alloying reactions promotes stabilizing the structure of the active material and accelerating the kinetics of the reaction. The mechanism may offer a well-balanced approach for sodium storage to create high capacity and cycle-stable anode materials.

  19. A High-Capacity and Long-Cycle-Life Lithium-Ion Battery Anode Architecture: Silver Nanoparticle-Decorated SnO2/NiO Nanotubes.

    Science.gov (United States)

    Kim, Chanhoon; Jung, Ji-Won; Yoon, Ki Ro; Youn, Doo-Young; Park, Soojin; Kim, Il-Doo

    2016-12-27

    The combination of high-capacity and long-term cyclability has always been regarded as the first priority for next generation anode materials in lithium-ion batteries (LIBs). To meet these requirements, the Ag nanoparticle decorated mesoporous SnO2/NiO nanotube (m-SNT) anodes were synthesized via an electrospinning process, followed by fast ramping rate calcination and subsequent chemical reduction in this work. The one-dimensional porous hollow structure effectively alleviates a large volume expansion during cycling as well as provides a short lithium-ion duffusion length. Furthermore, metallic nickel (Ni) nanoparticles converted from the NiO nanograins during the lithiation process reversibly decompose Li2O during delithiation process, which significantly improves the reversible capacity of the m-SNT anodes. In addition, Ag nanoparticles uniformly decorated on the m-SNT via a simple chemical reduction process significantly improve rate capability and also contribute to long-term cyclability. The m-SNT@Ag anodes exhibited excellent cycling stability without obvious capacity fading after 500 cycles with a high capacity of 826 mAh g(-1) at a high current density of 1000 mA g(-1). Furthermore, even at a very high current density of 5000 mA g(-1), the charge-specific capacity remained as high as 721 mAh g(-1), corresponding to 60% of its initial capacity at a current density of 100 mA g(-1).

  20. Electrostatic Self-Assembly of Fe3O4 Nanoparticles on Graphene Oxides for High Capacity Lithium-Ion Battery Anodes

    Directory of Open Access Journals (Sweden)

    Jung Kyoo Lee

    2013-09-01

    Full Text Available Magnetite, Fe3O4, is a promising anode material for lithium ion batteries due to its high theoretical capacity (924 mA h g−1, high density, low cost and low toxicity. However, its application as high capacity anodes is still hampered by poor cycling performance. To stabilize the cycling performance of Fe3O4 nanoparticles, composites comprising Fe3O4 nanoparticles and graphene sheets (GS were fabricated. The Fe3O4/GS composite disks of mm dimensions were prepared by electrostatic self-assembly between negatively charged graphene oxide (GO sheets and positively charged Fe3O4-APTMS [Fe3O4 grafted with (3-aminopropyltrimethoxysilane (APTMS] in an acidic solution (pH = 2 followed by in situ chemical reduction. Thus prepared Fe3O4/GS composite showed an excellent rate capability as well as much enhanced cycling stability compared with Fe3O4 electrode. The superior electrochemical responses of Fe3O4/GS composite disks assure the advantages of: (1 electrostatic self-assembly between high storage-capacity materials with GO; and (2 incorporation of GS in the Fe3O4/GS composite for high capacity lithium-ion battery application.

  1. Finite element analysis of strength for high capacity roller dollies%大载荷滚轮推车强度有限元分析

    Institute of Scientific and Technical Information of China (English)

    郭子逸; 郑卫刚; 龚苏生

    2012-01-01

    In combination with UC 3D modeling software and ADINA software, the finite element models respectively for both the integral dolly and double-roller of high capacity roller dolly are established in the paper. Then based on the nonlinear contact method, the contact stress of the roller contact surface is analyzed. With comparison of the calculation results under the two conditions, it's concluded that the finite element result of double-roller is close to that by the traditional Hertz theory. The static strength calculation for the roller dolly is performed as well, providing theoretical basis for the design of high capacity roller dolly.%将UG三维建模软件和ADINA软件相结合,分别建立了大载荷滚轮推车的整体和双滚轮的有限元模型.基于非线性接触算法对滚轮接触面的接触应力进行分析,对比2种情况下的计算结果,得到双滚子的有限元结果与传统的赫兹理论较接近.同时对滚轮推车的结构静强度进行了计算,为大载荷滚轮推车的设计提供理论依据.

  2. Bio-inspired 2-line ferrihydrite as a high-capacity and high-rate-capability anode material for lithium-ion batteries

    Science.gov (United States)

    Hashimoto, Hideki; Ukita, Masahiro; Sakuma, Ryo; Nakanishi, Makoto; Fujii, Tatsuo; Imanishi, Nobuyuki; Takada, Jun

    2016-10-01

    A high-capacity and high-rate-capability anode material for lithium-ion batteries, silicon-doped iron oxyhydroxide or 2-line ferrihydrite (2Fh), was prepared by mixing iron nitrate powder, tetraethyl orthosilicate, 2-propanol, and ammonium hydrogen carbonate powder at room temperature. The design of this material was inspired by a bacteriogenic product, a nanometric amorphous iron-based oxide material containing small amounts of structural Si. The atomistic structure of the prepared Si-doped 2Fh was strongly affected by the Si molar ratio [x = Si/(Fe + Si)]. Its crystallinity gradually decreased as the Si molar ratio increased, with a structural variation from nanocrystalline to amorphous at x = 0.25. The sample with x = 0.20 demonstrated the best Li storage performance. The developed material exhibited a high capacity of ∼400 mAh g-1 at the 25th cycle in the voltage range of 0.3-3.0 V and at a current rate of 9 A g-1, which was three times greater than that of the Si-free 2Fh. This indicates that Si-doping into the 2Fh structure realizes good rate capability, which are presumably because of the specific nanocomposite structure of iron-based electrochemical centers embedded in the Si-based amorphous matrix, generated by reversible Li insertion/deinsertion process.

  3. Pretzel scheme for CEPC

    Science.gov (United States)

    Geng, Huiping

    2016-11-01

    CEPC was proposed as an electron and positron collider ring with a circumference of 50-100 km to study the Higgs boson. Since the proposal was made, the lattice design for CEPC has been carried out and a preliminary conceptual design report has been written at the end of 2014. In this paper, we will describe the principles of pretzel scheme design, which is one of most important issues in CEPC lattice design. Then, we will show the modification of the lattice based on the lattice design shown in the Pre-CDR. The latest pretzel orbit design result will also be shown. The issues remained to be solved in the present design will be discussed and a brief summary will be given at the end.

  4. Improved Ternary Subdivision Interpolation Scheme

    Institute of Scientific and Technical Information of China (English)

    WANG Huawei; QIN Kaihuai

    2005-01-01

    An improved ternary subdivision interpolation scheme was developed for computer graphics applications that can manipulate open control polygons unlike the previous ternary scheme, with the resulting curve proved to be still C2-continuous. Parameterizations of the limit curve near the two endpoints are given with expressions for the boundary derivatives. The split joint problem is handled with the interpolating ternary subdivision scheme. The improved scheme can be used for modeling interpolation curves in computer aided geometric design systems, and provides a method for joining two limit curves of interpolating ternary subdivisions.

  5. Formal Verification of NTRUEncrypt Scheme

    Directory of Open Access Journals (Sweden)

    Gholam Reza Moghissi

    2016-04-01

    Full Text Available In this paper we explore a mechanized verification of the NTRUEncrypt scheme, with the formal proof system Isabelle/HOL. More precisely, the functional correctness of this algorithm, in its reduced form, is formally verified with computer support. We show that this scheme is correct what is a necessary condition for the usefulness of any cryptographic encryption scheme. Besides, we present a convenient and application specific formalization of the NTRUEncrypt scheme in the Isabelle/HOL system that can be used in further study around the functional and security analysis of NTRUEncrypt family.

  6. Development and Application of a High Capacity Medical Information Card%大容量医疗信息卡的研究与应用

    Institute of Scientific and Technical Information of China (English)

    刘晓荣; 刘振全; 朱洪平; 陈国良; 张鹭鹭; 刘建; 皇甫明放; 齐亮

    2011-01-01

    Objective To implement collection, analysis, using, transmitting, storage and management of information of mass casualties in diversified military mission, make prompt classification and automatic management of the information, and promote the ability and informationized level of military health service. Methods taking advantage of modernization information technology, a new high capacity medical information card was developed, combined with radio-frequency identification and mobile storage technology. Results The high capacity medical information card could meet the demand of collection, analysis, using, transmitting, storage and management of information of mass casualties in diversified military mission. Conclusion High capacity medical information card can improve the abilitry of classification for mass casualties in diversified military mission in a large extent, and guarantee the continuity of the information transmission, which is important to improve the level of informationization of military health administration. [Chinese Medical Equipment Journal,2011,32(12): 1-2,5]%目的:实现多样化军事行动批量伤员伤情与救治信息的快速采集、处理、利用、传输、存储和管理,实现对批量伤员的快速分类、对伤员信息的自动化管理,提升军队卫勤保障能力及信息化水平.方法:利用现代信息技术,将RFID技术和移动存储技术融为一体,开发研制大容量医疗信息卡.结果:大容量医疗信息卡能够满足多样化军事行动批量伤员伤情与救治信息的快速采集、处理、利用、传输、存储和管理的需求.结论:大容量医疗信息卡可大大提高多样化军事行动批量伤员伤情与救治信息采集、处理、利用、传输、存储和管理速率,实现了伤员信息的智能化管理,保证了信息传输的时效性和连续性,对提升军队卫勤保障能力及信息化水平具有重要作用.

  7. 集体噪声信道上错误容忍量子隐写%Fault tolerant quantum steganography over collective noise channels

    Institute of Scientific and Technical Information of China (English)

    叶天语

    2015-01-01

    本文提出两个集体噪声信道上错误容忍量子隐写(Quantum Steganography,QS)协议.一个是抗集体退相位噪声的,另一个是抗集体旋转噪声的.逻辑Bell态(即4量子比特DF态)被用于克服这两类集体噪声.构建在常规量子安全直接通信(Quantum Secure Direct Communication,QSDC)信道的用于传递秘密消息的量子隐秘信道是通过对2个逻辑Bell态交换纠缠来建立.Bell态测量而非4量子比特联合测量被用于解码.而且,信道容量高达4比特每轮隐秘通信.另外,协议的不可见性和安全性都能得到保证.

  8. AUTISTIC CHILDREN PROTECTION SCHEME

    Directory of Open Access Journals (Sweden)

    Dragan LUKIC

    1998-09-01

    Full Text Available The present article sets forth the theoretical grounds which make the basis for the organizational scheme of the autistic persons social protection. This protection consists of the below listed forms of work:· Health service with the role of an early detection and participation in the creation of rehabilitation programs;· Social protection with its programs of work from the diagnostics where the defectologist makes a team together with the physician and the psychologists to the systems of rehabilitation institutions where the defectologist’s is the main responsibility.The present article underlines two facts, namely:· that an autistic person requires to be followed and every spare moment used to promote and advance the activities the doer commenced himself instead of having him carry out the programs which are beyond his internal motivations and which he finds emotionally inaccessible;· that and form of work organization with autistic persons must subordinate its administrative part to the basic professional requirements this kind of disorder (handicap sets in front of each professional.

  9. High capacity and high density functional conductive polymer and SiO anode for high-energy lithium-ion batteries.

    Science.gov (United States)

    Zhao, Hui; Yuca, Neslihan; Zheng, Ziyan; Fu, Yanbao; Battaglia, Vincent S; Abdelbast, Guerfi; Zaghib, Karim; Liu, Gao

    2015-01-14

    High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated in the reduction of thickness and porosity, as well as the increase of density. SiO particle size remains unchanged after calendering. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and overcalendered electrode. The calendered electrode has a high-density of ∼1.2 g/cm(3). A high loading electrode with an areal capacity of ∼3.5 mAh/cm(2) at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendering method.

  10. A Biodegradable Polydopamine-Derived Electrode Material for High-Capacity and Long-Life Lithium-Ion and Sodium-Ion Batteries.

    Science.gov (United States)

    Sun, Tao; Li, Zong-Jun; Wang, Heng-Guo; Bao, Di; Meng, Fan-Lu; Zhang, Xin-Bo

    2016-08-26

    Polydopamine (PDA), which is biodegradable and is derived from naturally occurring products, can be employed as an electrode material, wherein controllable partial oxidization plays a key role in balancing the proportion of redox-active carbonyl groups and the structural stability and conductivity. Unexpectedly, the optimized PDA derivative endows lithium-ion batteries (LIBs) or sodium-ion batteries (SIBs) with superior electrochemical performances, including high capacities (1818 mAh g(-1) for LIBs and 500 mAh g(-1) for SIBs) and good stable cyclabilities (93 % capacity retention after 580 cycles for LIBs; 100 % capacity retention after 1024 cycles for SIBs), which are much better than those of their counterparts with conventional binders. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 小波域最小嵌入失真函数设计及其在隐写中的应用%Design of minimizing embedding impact function in DWT domain and its applications in steganography

    Institute of Scientific and Technical Information of China (English)

    李军; 潘峰; 杨晓元; 刘镇

    2012-01-01

    In order to improve the security of steganography system, an image steganography method based on Minimizing Embedding Impact and Syndrome-Trellis Codes is proposed. First, a distortion function in discrete wavelet transform (DWT) domain was designed according to human visual system and integer lifting wavelet transform, which is mainly concerned about the influences of frequency, luminance, and texture masking factor to the cover distortion. Then, the Syndrome-Trellis Codes are combined with the distortion function to propose the steganography method, to make sure that the embedding impact on the cover minimizing and centralizing is in the un-sensitivity domain. Experiments show that the proposed approach maintains a good visual quality of the stego-image and has a high security against steganalysis in space and wavelet domain. The security capacity can be about 0. 4 bits/pixel.%为了提高隐写方案的安全性,提出一种基于最小嵌入失真原理和网格码的图像隐写算法.首先在离散小波域结合人眼视觉特性和整数提升小波变换设计了失真测度函数,主要考虑了亮度、频率和纹理掩蔽因子对载体失真的影响.然后结合网格码设计了隐写算法,将嵌入信息对载体的修改最小化并且集中在人眼不敏感区域.实验结果显示,方案具有良好的视觉不可见性,且能抵抗空域、小波域等隐写分析的攻击,安全容量达到0.4 bits/pixel.

  12. Image Texture Complexity Estimation Approach for Steganography Evaluation%一种用于隐写测评的图像纹理复杂度估计方法

    Institute of Scientific and Technical Information of China (English)

    邓果; 赵险峰; 黄炜; 盛任农

    2012-01-01

    The steganographic payload is a well-known metric to evaluate the security of steganography and performance of steganalysis, while the impact of image texture diversity on steganography is usually ignored. This paper presents a new metric of image texture complexity based on the high dimensional image statistical model to measure the texture difference of images. Extensive experiments are conducted to make comparison of the detection performance under different embedding rates and image complexities. Experimental results indicate that the proposed method can be effectively used to evaluate the security of steganography.%在评估图像隐写算法安全性及隐写分析性能时,隐写嵌入率等参数是重要的评价指标,而图像纹理差异对评价的影响很容易被忽略.为此,基于图像高维统计模型,提出一种新的针对隐写应用的图像纹理复杂度度量方法,用于衡量图像间的纹理差异.根据纹理复杂度对图像进行分类,单独在每一类不同纹理复杂度的图像集上评估隐写分析的检测性能.实验结果表明,该方法能有效地评价隐写的安全性.

  13. High capacity carbon dioxide sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  14. High capacity immobilized amine sorbents

    Science.gov (United States)

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Filburn, Thomas

    2007-10-30

    A method is provided for making low-cost CO.sub.2 sorbents that can be used in large-scale gas-solid processes. The improved method entails treating an amine to increase the number of secondary amine groups and impregnating the amine in a porous solid support. The method increases the CO.sub.2 capture capacity and decreases the cost of utilizing an amine-enriched solid sorbent in CO.sub.2 capture systems.

  15. A pharmacologically validated, high-capacity, functional thallium flux assay for the human Ether-à-go-go related gene potassium channel.

    Science.gov (United States)

    Schmalhofer, William A; Swensen, Andrew M; Thomas, Brande S; Felix, John P; Haedo, Rodolfo J; Solly, Kelli; Kiss, Laszlo; Kaczorowski, Gregory J; Garcia, Maria L

    2010-12-01

    The voltage-gated potassium channel, human Ether-à-go-go related gene (hERG), represents the molecular component of IKr, one of the potassium currents involved in cardiac action potential repolarization. Inhibition of IKr increases the duration of the ventricular action potential, reflected as a prolongation of the QT interval in the electrocardiogram, and increases the risk for potentially fatal ventricular arrhythmias. Because hERG is an appropriate surrogate for IKr, hERG assays that can identify potential safety liabilities of compounds during lead identification and optimization have been implemented. Although the gold standard for hERG evaluation is electrophysiology, this technique, even with the medium capacity, automated instruments that are currently available, does not meet the throughput demands for supporting typical medicinal chemistry efforts in the pharmaceutical environment. Assays that could provide reliable molecular pharmacology data, while operating in high capacity mode, are therefore desirable. In the present study, we describe a high-capacity, 384- and 1,536-well plate, functional thallium flux assay for the hERG channel that fulfills these criteria. This assay was optimized and validated using different structural classes of hERG inhibitors. An excellent correlation was found between the potency of these agents in the thallium flux assay and in electrophysiological recordings of channel activity using the QPatch automated patch platform. Extension of this study to include 991 medicinal chemistry compounds from different internal drug development programs indicated that the thallium flux assay was a good predictor of in vitro hERG activity. These data suggest that the hERG thallium flux assay can play an important role in supporting drug development efforts.

  16. Chaotic communication scheme with multiplication

    Science.gov (United States)

    Bobreshov, A. M.; Karavaev, A. A.

    2007-05-01

    A new scheme of data transmission with nonlinear admixing is described, in which the two mutually inverse operations (multiplication and division) ensure multiplicative mixing of the informative and chaotic signals that provides a potentially higher degree of security. A special feature of the proposed scheme is the absence of limitations (related to the division by zero) imposed on the types of informative signals.

  17. Homographic scheme for Riccati equation

    CERN Document Server

    Dubois, François

    2011-01-01

    In this paper we present a numerical scheme for the resolution of matrix Riccati equation, usualy used in control problems. The scheme is unconditionnaly stable and the solution is definite positive at each time step of the resolution. We prove the convergence in the scalar case and present several numerical experiments for classical test cases.

  18. Differential operators and automorphism schemes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The ring of global differential operators of a variety is in closed and deep relation with its automorphism scheme.This relation can be applied to the study of homogeneous schemes,giving some criteria of homogeneity,a generalization of Serre-Lang theorem,and some consequences about abelian varieties.

  19. Histograms Difference and Quantitative Steganalysis of JPEG SteganographyBased on Relative Entropy%基于相对熵的直方图差异与JPEG隐写的定量分析

    Institute of Scientific and Technical Information of China (English)

    杨春芳; 刘粉林; 罗向阳

    2011-01-01

    For the histogram features, which are usually used in image steganalysis, a category of algorithms based on relative entropy are given to measure the difference between the histograms of the given image and the estimated cover image. And a quantitative steganalysis method based on relative entropy is proposed for JPEG image steganography. Firstly, according to the likelihood ratio test, which is the optimum test for two hypotheses, the superiority of measuring the distance between the two histograms based on relative entropy is analyzed, and two algorithms are given to measure the difference between the two histograms based on relative entropy. Secondly, for the histogram-like features used in the blind steganalysis methods, the new histograms difference features are calculated by the given algorithms, and fed to the support vector regression to train the quantitative steganalyzers for JPEG image steganography. Finally, the proposed steganalysis methods are applied to the quantitative steganalysis of two categories of typical JPEG image steganography: Jsteg and the improved F5 steganography. Experimental results show that compared with the other typical algorithms, the steganalyzers based on the histograms difference features calculated by the proposed algorithms have higher accuracy and stability.%针对图像隐写分析中常用的直方图特征,给出了一类基于相对熵的直方图差异计算方法,并提出了一种基于相对熵的JPEG隐写的定量分析方法.首先根据两假设检验中的最优检验——似然比检验,分析了相对熵在衡量2个直方图间的距离时的优越性,并给出了2种基于相对熵的直方图差异计算方法.然后,以新的直方图差异特征为基础,训练支持向量回归分析器,以估计隐写对DCT系数的更改比率.针对JSteg和改进的F5隐写的实验结果表明:与其他的直方图差异特征相比,根据所提出的基于相对熵的直方图差异特征所训练的定量隐写

  20. The Occupational Pension Schemes Survey 2006

    OpenAIRE

    Sarah Levy; David Miller

    2008-01-01

    Presents findings on the number of schemes, their membership and contributions to schemes by employers and employeesThis article presents findings on the number of occupational pension schemes in 2006, their membership and contributions to schemes by employers and employees. It is based on the Occupational Pension Schemes Annual Report (2006 edition). The findings distinguish between public and private sector schemes and include breakdowns by scheme status (open, closed, frozen or winding up)...