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The study of sending and receiving secret messages is called cryptography. Generally, senders and receivers are unaware about the process of encryption and decryption. Hence, encryption plays an important role in data communication and data security. The meaning of encryption is not only to keep data confidential from unwanted access but also ensuring the data integrity through available way. As the capacity of breaking the security is increasing rapidly, so, the process that hides information is one of the most concerned topics. Advanced Encryption Standard is a popular, widely used and efficient encryption algorithm, which has been used since it was invented. This paper focuses on the AES key generation process and Substitution box. It modifies the conventional key generation technique and builds the dynamic 3-Dimensional S-box of Advance Encryption Standard. The proposed approach suggests 3-Dimensioanl Key Generation Matrix and S-box. As per shown this novel technique increases the amount of time it needs during encryption and decryption. The experimental result shows that it also enhances the strength of AES algorithm. The proposed approach illustrates the theoretical analysis and corresponding experimented results., 7 pages, 14 figures, 4 tables. Published in IJCSA in 2017

Database encryption is essential for cloud database systems. For a large database, decryption could take a lot of computational time. Therefore, verifying an encryption that contains a correct plaintext without decryption becomes significant for a large database system. Plaintext-checkable encryption (PCE) is a potential tool for such database systems, which is first proposed by Canard et al. in CT-RSA 2012. Although the generic PCE in the random oracle model has been studied intensively, the generic PCE in the standard model and its efficient implementation are still challenging problems. This paper presents the first generic PCE in the standard model using smooth projective hash function (SPHF) and prove its s-priv1-cca security, which is independent of current unlink security. Based on the instantiated SPHF from DDH assumption, we obtain the most efficient PCE in the standard model, without any pairing operation. Finally, we improve two existing generic constructions in the random oracle model so that they are secure under chosen ciphertext attack.

Data encryption of sensor nodes is very important in body area networks (BANs) since the physiological data of an individual are highly sensitive. However, past encryption methods have small key space, which makes them vulnerable to attacks. In this paper, we propose a new encryption algorithm based on combined chaos. Firstly, Logistic and Kent chaotic mappings are introduced to produce two sub-matrices, and then a combined matrix is generated to perform XOR operation with the original data for encryption. The experimental results indicate that the proposed algorithm has a large key space, high key sensitivity and excellent attack resistance ability, and is feasible in privacy protection of BAN system.

Color image can provide more information than gray image, so it is used more widely in the field of the communication. In recent years, how to safely encrypt images has received increasing attention. Numerous previous image encryption algorithms are based on the symmetric encryption algorithm, but each pair of users communicating with symmetric encryption algorithm can only use the key that others do not know, so when the sender communicates with a receiver multiple times or sends the message to multiple receivers, the key number will grow at a geometric rate, and key management will become a burden on the users. In this paper, we propose an asymmetric image encryption algorithm for the advantages that the key groups and the number of keys in secret information transmission among multiple people are very small, and key transmission mode is relatively simple and secure. In our algorithm, first, the plain image is compressed and then the color image is encrypted by using the improved 4D cat map followed by asymmetric encryption which is based on elliptic curve ElGamal encryption, and finally, the encrypted image is globally diffused. The performance analysis is performed on key spaces, key sensitivity, the capability of resisting statistical attacks, differential attacks, known plaintext attacks and chosen plaintext/ciphertext attacks and quality evaluation metrics of decrypted image. Simulation results show that the proposed algorithm has better security comparing with other algorithms.

To protect receiver privacy, researchers constructed anonymous multireceiver encryption by implanting anonymity in multireceiver encryption. It allows a sender to produce the identical ciphertext for multiple designated receivers. Every designated receiver can decrypt the ciphertext, but does not know who the other designated receivers are. Recently, several anonymous multireceiver identity (ID)-based encryption (AMIBE) schemes were proposed without the utilization of certificates. However, these AMIBE schemes are not efficient because their decryption cost of each receiver grows linearly with the number of the designated receivers. Moreover, all the ID-based cryptographic schemes suffer from the key escrow problem, which has been resolved by using certificateless public key settings. Very recently, Islam et al. proposed an anonymous multireceiver certificateless encryption (AMCLE) scheme. However, the encryption cost of a sender is quadric with the number of designated receivers, whereas the decryption cost of each receiver is linear with the number. In this paper, we propose an efficient AMCLE scheme with constant decryption cost, namely, the required decryption cost of each receiver is independent of the number of receivers. When compared with previously proposed AMIBE and AMCLE schemes, our scheme solves the key escrow problem and improves the efficiency of encryption/decryption significantly as well.

Networked control systems with encrypted sensors measurements is considered. Semi-homomorphic encryption, specifically the Paillier encryption, is used so that the controller can perform the required computation on the encrypted data. Conditions on the parameters of the encryption technique are provided that guarantee the stability and the performance of the closed-loop system. The results are subsequently extended Laplacian based distributed systems, such as formation-seeking algorithms. It is shown that the problem of figuring out the state measurements of the neighbouring agents of a compromised agent upon using the proposed algorithm is numerically intractable.

Cryptographic architectures provide different security properties to sensitive usage models. However, unless reliability of architectures is guaranteed, such security properties can be undermined through natural or malicious faults. In this paper, two underlying block ciphers which can be used in authenticated encryption algorithms are considered, i.e., light encryption device and high security and lightweight block ciphers. The former is of the Advanced Encryption Standard type and has been considered area-efficient, while the latter constitutes a Feistel network structure and is suitable for low-complexity and low-power embedded security applications. In this paper, we propose efficient error detection architectures including variants of recomputing with encoded operands and signature-based schemes to detect both transient and permanent faults. Authenticated encryption is applied in cryptography to provide confidentiality, integrity, and authenticity simultaneously to the message sent in a communication channel. In this paper, we show that the proposed schemes are applicable to the case study of simple lightweight CFB for providing authenticated encryption with associated data. The error simulations are performed using Xilinx Integrated Synthesis Environment tool and the results are benchmarked for the Xilinx FPGA family Virtex-7 to assess the reliability capability and efficiency of the proposed architectures.

Rapid growth of digital data and their security concerns increases the significance of enhancing advanced encryption techniques. Encryption is the backbone of secure communication in networks and the physical process of scrambling and permuting data in order to make them impossible to understand for unauthorized users. This paper proposes a novel audio signal encryption method, based on a mixture of three chaos functions. Due to the reversibility of the chaos functions, the decryption process is the inverse of the encryption process. This method was applied to audio signals with various sizes and the encoded messages were compared to the original ones. Simulation results and theoretical analyses show that the proposed approach offers a significant gain in terms of robustness and computational complexity.

A new structure of pre-modular, permutation, and diffusion (PPD) cipher for image encryption is proposed.Solve the low sensitivity of the plain-image when meeting invariance of pixel summation.Self-adaptive encryption scheme is implemented, and no extra transmission is needed.The keystreams used for encryption are designed dependent on the plain-image. Differing from the traditional permutationdiffusion architecture, an efficient symmetric image encryption algorithm is designed in this paper. To resolve the issue of low sensitivity of a plain-image, which is measured by a unified averaged changing intensity and the number of changing pixel rate, pre-modular operation is proposed to be used for pre-processing a classical encryption algorithm. Because of the invariance of pixel summation in the plain-image before and after pixel positions exchange, the keystream used for the permutation operation is designed to be dependent on the plain-image. Since for most encryption algorithms it is hard to implement the diffusion operation in relation with the plain-image dependence, a self-adaptive encryption scheme is proposed as a remedy. Consequently, the keystream for diffusion becomes dependent on the plain-image, which still satisfies the requirement as a symmetric cipher. To that end, by taking full advantage of the chaotic intertwining logistic map and its unpredictability, a new cipher with pre-modular, permutation and diffusion is designed for image encryption, which is then simulated and tested. Numerical experiments and security analysis demonstrate that the new cipher is secure enough for image communication over the open network.

Efficient searching on encrypted data outsourced to the cloud remains a research challenge. Identity-based encryption with equality test (IBEET) scheme has recently been identified as a viable solution, in which users can delegate a trapdoor to the server and the server then searches on user outsourced encrypted data to determine whether two different ciphertexts are encryptions of the same plaintext. Such schemes are, unfortunately, inefficient particularly for deployment on mobile devices (with limited power/battery life and computing capacity). In this paper, we propose an efficient IBEET scheme with bilinear pairing, which reduces the need for time-consuming HashToPoint function. We then prove the security of our scheme for one-way secure against chosen identity and chosen ciphertext attacks (OWIDCCA) in the random oracle model (ROM). The performance evaluation of our scheme demonstrates that in comparison to the scheme of Ma (2016), our scheme achieves a reduction of 36.7% and 39.24% in computation cost during the encryption phase and test phase, respectively, and that our scheme is suitable for (mobile) cloud deployment. We propose an identity-based encryption with equality test (IBEET) scheme using bilinear pairing for cloud storage.We show that our proposed concrete scheme is provably secure. It satisfies required security properties.Detailed performance analysis and experimental result are given.

This paper proposes a new approach to the encryption of speech intended to be transferred on an insecure channel. The proposed technique is based on stream encryption where the original speech is pre-processed in order to select the relevant data for encryption by removing the unvoiced parts of the signal. In addition to reducing the size of the speech signal, the selection process also reduces the encryption and decryption times. The selected data is encrypted using a pseudo-random generator to make the information unable to understand by an intruder. The used pseudo-random generator is based on two 256-bits shift registers, one is linear and the other non-linear. This generator allows encryption in higher dimensional space which expands the key space and, therefore, improves security against brute force attack. Various analyzis such as histograms, key space, key sensitivity, correlation, brute force attack, signal to noise (SNR) and peak signal to noise ratio (PSNR) have been performed. The analysis shows that the proposed scheme is computationally simple, efficient with superior performance compared to other systems presented in the literature.

One of the interesting secure applications in the smart city is broadcasting information to legitimate users, desirably with user privacy. Broadcast encryption has been considered as a useful tool to protect the data security and provide data access control. Most works in broadcast encryption are about the data security, while less attention is paid to the data access control and the identity privacy. In this paper, based on broadcast encryption, we present a scheme called Fully Privacy-Preserving and Revocable Identity-Based Broadcast Encryption, which preserves the data privacy and the identity privacy of the receiver as well as the revoked user. The data can be securely protected and only the authorized user can access the data. The revocation process does not reveal any information about the data contents and the receiver identity. The public learns nothing about the receiver identity and the revoked user identity. These properties lead to nice applications in the smart city where identity privacy is desirable. The security of our scheme is proved to be semantically secure in the random oracle model.

In this paper, a novel video chaotic secure communication scheme and its ARM-embedded hardware implementation are investigated, based on the H.264 selective encryption and multi-core multi-process. A six-dimensional discrete-time hyperchaotic system equipped with a nonlinear nominal matrix is firstly constructed, and the corresponding chaotic encryption algorithm is then designed. During H.264 encoding, the difference components of motion vectors in both the horizontal and vertical directions, as well as the DC transform coefficients, are selectively encrypted by using such a chaotic encryption algorithm, respectively, so as to enhance the safety performance. To improve the processing speed and transmission frame rate of the whole hardware system, an ARM-based hardware platform with multi-core multi-process is further adopted to realize the H.264 selective video chaotic secure communication, where the sender collects and encrypts the original video with four-core four-process mode, and the receiver decrypts the encrypted video with three-core three-process mode, in which one core binds one process. Finally, the security performance of the designed system is tested using the TESTU01 statistical test suites and some other statistical security analysis. Both theoretical analysis and experimental results validate the feasibility and reliability of the proposed scheme.

Newly applies transparent and reduced encryption to scalable video.Introduces two ways to lower encryption latency in the context of scalable video.Maintains decoder compatibility and adds no bitrate overhead after encryption.Analyses overall distortion from transparent encryption, with clear base layer.Application is protection of rapidly available streaming of short-lived material. Selective encryption masks all of the content without completely hiding it, as full encryption would do at a cost in encryption delay and increased bandwidth. Many commercial applications of video encryption do not even require selective encryption, because greater utility can be gained from transparent encryption, i.e. allowing prospective viewers to glimpse a reduced quality version of the content as a taster. Our lightweight selective encryption scheme when applied to scalable video coding is well suited to transparent encryption. The paper illustrates the gains in reducing delay and increased distortion arising from a transparent encryption that leaves reduced quality base layer in the clear. Reduced encryption of B-frames is a further step beyond transparent encryption in which the computational overhead reduction is traded against content security and limited distortion. This spectrum of video encryption possibilities is analyzed in this paper, though all of the schemes maintain decoder compatibility and add no bitrate overhead as a result of jointly encoding and encrypting the input video by virtue of carefully selecting the entropy coding parameters that are encrypted. The schemes are suitable both for H.264 and HEVC codecs, though demonstrated in the paper for H.264. Selected Content Adaptive Binary Arithmetic Coding (CABAC) parameters are encrypted by a lightweight Exclusive OR technique, which is chosen for practicality.

A symmetric key image cryptosystem based on the piecewise linear map is presented in this paper. In this cryptosystem, the encryption process and the decryption process are exactly same. They both include the same operations of plaintext-related scrambling once, diffusion twice and matrix rotating of 180 degrees four times. The length of secret key in the system is 64d where d is a positive integer. The proposed system can fight against the chosen/known plaintext attacks due to the using of plaintext-related scrambling. The simulate results and comparison analysis show that the proposed system has many merits such as high encryption/decryption speed, large key space, strong key sensitivity, strong plaintext sensitivity, strong cipher-text sensitivity, good statistical properties of cipher images, and large cipher-text information entropy. So the proposed system can be applied to actual communications.

Recently, a novel image fusion encryption algorithm based on DNA sequence operation and hyper-chaotic system were proposed. It was reported that the encryption algorithm can be broken by chosen-plaintext attack. This paper re-evaluates the security of the encryption algorithm, and finds that the encryption algorithm can be broken by known-plaintext attack as well. Besides, it also gives another method of chosen-plaintext attack which is more effective. The effectiveness of the proposed know-plaintext attack and chosen-plaintext attack is supported both by rigorous theoretical analysis and experimental results.

The paper proposes a new method for designing deniable encryption protocols characterized in using RSA-like probabilistic public-key encryption algorithms. Sender-, receiver-, and bi-deniable protocols are described. To provide bi-deniability in the case of attacks perfored by an active coercer stage of entity authentication is used in one of described protocols.

Cloud computing is one of the great tasks in the business world nowadays, which provides shared processing resources. In cloud area network, security is the main challenge faced by cloud providers and their customers. The advantage of cloud computing includes reduced cost, re-provisioning of resources etc. The cloud network makes use of standard encryption method to secure documents while storing in online. In this paper, we have depicted two efficient encryption algorithms that meet security demand in cloud. Probabilistic encryption, one of these algorithms may be used to produce randomness of text encryption. With this algorithm, if the same message is encrypted twice it should yield different secret coded texts on both calculations. Another crucial algorithm is homomorphic encryption, is a cryptographic method to define the sample system and to provide a software implementation. In order to maintain quality of service (QoS) and improve customer satisfaction, we are going to propose an efficient algorithm which combines the characteristics of both probabilistic and homomorphic encryption techniques, to provide high level of security. Our proposed scheme will yield better encryption techniques reduce security attacks, increased throughput and improve the QoS.

With increasing dependence on communications over internet and networks, secure data transmission is coming under threat. One of the best solutions to ensure secure data transmissions is encryption. Multiple forms of data, such as text, audio, image, and video can be digitally transmitted, nowadays images being the most popular and old encryption techniques such as: AES,DES,RSA etc., show low security level when used for image encryption. This problem was resolved by using of chaos encryption which is an acceptable form of encryption for image data. The sensitivity to initial conditions and control parameters make chaos encryption suitable for image applications. This study discusses various chaos encryption techniques.

Revocation and key evolving paradigms are central issues in cryptography, and in PKI in particular. A novel concern related to these areas was raised in the recent work of Sahai, Seyalioglu, and Waters (CRYPTO 2012) who noticed that revoking past keys should at times (e.g., the scenario of cloud storage) be accompanied by revocation of past ciphertexts (to prevent unread ciphertexts from being read by revoked users). They introduced revocable-storage attribute-based encryption (RS-ABE) as a good access control mechanism for cloud storage. RS-ABE protects against the revoked users not only the future data by supporting key-revocation but also the past data by supporting ciphertext-update, through which a ciphertext at time T can be updated to a new ciphertext at time T + 1 using only the public key. Motivated by this pioneering work, we ask whether it is possible to have a modular approach, which includes a primitive for time managed ciphertext update as a primitive. We call encryption which supports this primitive a "self-updatable encryption" (SUE). We then suggest a modular cryptosystems design methodology based on three sub-components: a primary encryption scheme, a key-revocation mechanism, and a time-evolution mechanism which controls the ciphertext self-updating via an SUE method, coordinated with the revocation (when needed). Our goal in this is to allow the self-updating ciphertext component to take part in the design of new and improved cryptosystems and protocols in a flexible fashion. Specifically, we achieve the following results:We first introduce a new cryptographic primitive called self-updatable encryption (SUE), realizing a time-evolution mechanism. In SUE, a ciphertext and a private key are associated with time. A user can decrypt a ciphertext if its time is earlier than that of his private key. Additionally, anyone (e.g., a cloud server) can update the ciphertext to a ciphertext with a newer time. We also construct an SUE scheme and prove its full security under static assumptions. Following our modular approach, we present a new RS-ABE scheme with shorter ciphertexts than that of Sahai et al. and prove its security. The length efficiency is mainly due to our SUE scheme and the underlying modularity. We apply our approach to predicate encryption (PE) supporting attribute-hiding property, and obtain a revocable-storage PE (RS-PE) scheme that is selectively-secure. We further demonstrate that SUE is of independent interest, by showing it can be used for timed-release encryption (and its applications), and for augmenting key-insulated encryption with forward-secure storage. A new cryptographic primitive called self-updatable encryption is introduced to realize a time-evolution mechanism.A revocable-storage attribute-based encryption scheme with shorter ciphertexts was proposed by following our modular approach.A revocable-storage predicate encryption scheme that additionally supports attribute-hiding property is presented.

Wearable devices can be potentially captured or accessed in an unauthorized manner because of their physical nature. In such cases, they are in white-box attack contexts, where the adversary may have total visibility on the implementation of the built-in cryptosystem, with full control over its execution platform. Dealing with white-box attacks on wearable devices is undoubtedly a challenge. To serve as a countermeasure against threats in such contexts, we propose a lightweight encryption scheme to protect the confidentiality of data against white-box attacks. We constructed the scheme’s encryption and decryption algorithms on a substitution-permutation network that consisted of random secret components. Moreover, the encryption algorithm uses random padding that does not need to be correctly decrypted as part of the input. This feature enables non-bijective linear transformations to be used in each encryption round to achieve strong security. The required storage for static data is relatively small and the algorithms perform well on various devices, which indicates that the proposed scheme satisfies the requirements of wearable computing in terms of limited memory and low computational power.

Nowadays, multimedia is considered to be the biggest big data as it dominates the traffic in the Internet and mobile phones. Currently symmetric encryption algorithms are used in IoT but when considering multimedia big data in IoT, symmetric encryption algorithms incur more computational cost. In this paper, we have designed and developed a resource-efficient encryption system for encrypting multimedia big data in IoT. The proposed system takes the advantages of the Feistel Encryption Scheme, an Advanced Encryption Standard (AES), and genetic algorithms. To satisfy high throughput, the GPU has also been used in the proposed system. This system is evaluated on real IoT medical multimedia data to benchmark the encryption algorithms such as MARS, RC6, 3-DES, DES, and Blowfish in terms of computational running time and throughput for both encryption and decryption processes as well as the avalanche effect. The results show that the proposed system has the lowest running time and highest throughput for both encryption and decryption processes and highest avalanche effect with compared to the existing encryption algorithms. To satisfy the security objective, the developed algorithm has better Avalanche Effect with compared to any of the other existing algorithms and hence can be incorporated in the process of encryption/decryption of any plain multimedia big data. Also, it has shown that the classical and modern ciphers have very less Avalanche Effect and hence cannot be used for encryption of confidential multimedia messages or confidential big data. The developed encryption algorithm has higher Avalanche Effect and for instance, AES in the proposed system has an Avalanche Effect of %52.50. Therefore, such system is able to secure the multimedia big data against real-time attacks.

The challenge to which the encryption of multimedia data needs to respond is ensuring the security of data intensive video stream in an efficient way. Unlike full data encryption, selective encryption manages to achieve this by encrypting only a part of the data stream, while providing a satisfactory level of video security. This optimizes the processing time and the size of encrypted data. Regardless of the encryption technique, there is a lack of cryptographic synchronization when providing random access to the selected part of the encrypted multimedia stream. In this paper we propose a novel and efficient method of cryptographic synchronization as an extension to the H.265/HEVC crypto encoder in order to support random access in selectively encrypted video stream.

The increasing use of virtualization puts stringent security requirements on software integrity and workload isolation of cloud computing. The encryption card provides hardware cryptographic services for users and is believed to be superior to software cryptography. However, we cannot use the encryption card directly in the user domain because of the complicated virtualization mechanisms and the security problems about the user key and the user private data flow. To address these challenges, we propose a new virtualization architecture to ensure the trustworthiness of encryption cards. First, we design a privacy preserving model to ensure the security of the dynamic schedule of encryption cards. Second, we present a hardware trust verification procedure based on the trusted platform module to supply a trusted virtualization hardware foundation. Third, we provide a series of security protocols to establish a trusted chain between users and encryption cards. Finally, we give security proofs of the encryption card virtualization architecture. Based on our prototype implementation, the encryption service provided by the encryption card has higher-level security and higher efficiency than software encryption. It provides strong support for security services of virtualization systems in cloud computing.

The menaces of viruses, hackers and eavesdroppers have made security to be of paramount importance. With paradigm shift of data from being textual to images, there is need for reliable, efficient and practical encryption techniques. In this paper, we propose one such novel algorithm which has its basis in genetic computation. The algorithm selects two images from the data set, applies two-point crossover and mutation on the images for encryption. A secret key is generated for two-point crossover and mutation independently. The proposed algorithm is elegant, fast and scalable. The biggest advantage is that of lossless decryption with multiple images encrypted simultaneously.

The notion of selective opening attacks (SOAs) was first introduced by Dwork et al. at FOCS'99. Informally, an encryption scheme is SOA secure if an adversary is given a vector of ciphertexts and can adaptively corrupt some fraction of them by obtaining not only their messages but also their randomness, the uncorrupted ciphertexts retain secure. Provably achieving security against SOA has been proven extremely challenging. In this paper, we propose a security model to capture simulation-based selective opening chosen-plaintext attacks (SIM-SO-CPA) for certificateless encryption. We provide a concrete construction and prove its security in our simulation-based selective opening chosen-plaintext attack security model, based on the real or random and computational Diffie–Hellman assumptions. Compared with previous SOA-secure public key encryption and identity-based encryption, our certificateless encryption scheme is more simple and efficient. Copyright © 2017 John Wiley & Sons, Ltd.

In a system that performs both encryption and lossy compression, the conventional way is to compress first and then encrypt the compressed data. This separation approach has been proved to be optimal. In certain applications where sensitive information should be protected as early as possible, it is preferable to perform the encryption first and then compress the encrypted data, which leads to the concept of the reversed system. Johnson et al. proposed an achievable scheme for the reversed system, where a modulo-sum encryption is followed by a compression using the Wyner–Ziv distributed source coding with side information. However, in general, this reversed system performs worse than the conventional system in the sense that it requires more compression rate and secrecy key rate. In this paper, we propose a new achievable scheme for the reversed system, where the encryption is conducted by a permutation cipher, and then, the encrypted data is compressed using the optimal rate-distortion code. The proposed scheme can achieve the optimal compression rate and secret key rate. As a result, we show that reversing the order of the encryption and compression does not necessarily compromise the performance of an encryption-compression system. We show that the proposed system attains strong secrecy, and the information leakage vanishes exponentially.

Cloud computing facilitates convenient and on-demand network access to a centralized pool of resources. Currently, many users prefer to outsource data to the cloud in order to mitigate the burden of local storage. However, storing sensitive data on remote servers poses privacy challenges and is currently a source of concern. SE (Searchable Encryption) is a positive way to protect users sensitive data, while preserving search ability on the server side. SE allows the server to search encrypted data without leaking information in plaintext data. The two main branches of SE are SSE (Searchable Symmetric Encryption) and PEKS (Public key Encryption with Keyword Search). SSE allows only private key holders to produce ciphertexts and to create trapdoors for search, whereas PEKS enables a number of users who know the public key to produce ciphertexts but allows only the private key holder to create trapdoors. This article surveys the two main techniques of SE: SSE and PEKS. Different SE schemes are categorized and compared in terms of functionality, efficiency, and security. Moreover, we point out some valuable directions for future work on SE schemes.

Claude Shannon proved in 1949 that information-theoretic-secure encryption is possible if the encryption key is used only once, is random, and is at least as long as the message itself. Notwithstanding, when information is encoded in a quantum system, the phenomenon of quantum data locking allows one to encrypt a message with a shorter key and still provide information-theoretic security. We present one of the first feasible experimental demonstrations of quantum data locking for direct communication and propose a scheme for a quantum enigma machine that encrypts 6 bits per photon (containing messages, new encryption keys, and forward error correction bits) with less than 6 bits per photon of encryption key while remaining information-theoretically secure., 10 Figures

Despite growing adoption of TLS, a significant fraction of TCP traffic on the Internet remains unencrypted. The persistence of unencrypted traffic can be attributed to at least two factors. First, some legacy protocols lack a signaling mechanism (such as a "STARTTLS" command) by which to convey support for encryption, making incremental deployment impossible. Second, legacy applications themselves cannot always be upgraded, requiring a way to implement encryption transparently entirely within the transport layer. The TCP Encryption Negotiation Option (TCP-ENO) addresses both of these problems through a new TCP option-kind providing out-of-band, fully backward-compatible negotiation of encryption.

Traditional cipher systems are not appropriate for video encryption due to the high computation overhead. Video encryption must take account of the trade-off of both data security and real-time performance. In this paper, an efficient chaos pseudo-random number generator is designed to generate key stream for encrypting video syntax elements of H.264/AVC. In view of the efficiency and security, the intra-prediction mode (IPM), signs of trailing ones (T1s), signs of non-zero (NZ) coefficients, signs of motion vector difference (MVD) are chosen for selective encryption. The proposed scheme provides sufficient protection for the video commercial value. Experimental results demonstrate that the course of encryption will not affect the coding efficiency of H.264/AVC by keeping exactly the same bitrate and negligible time overhead. Security analysis shows that the proposed scheme has the ability to resist malicious attacks.

A crypto-marking technique can be used to provide a solution to the secure transmission and storage of highly valuable and detailed vector maps. Such a solution would fulfill the requirements for integrity verification, content security, copyright protection, and authentication. However, existing methods cannot ensure the perceptual invisibility of the watermarking in the encryption domain and can leak the encryption key while decrypting a crypto-marked map. In response to these issues, we present a vector map crypto-marking method using both watermarking and progressive perceptual encryption that are independent of each other. The first watermarking step embeds the watermark using the mean of the Euclidian distance (MED) while preserving the object shape and being robust to geometric attacks. The second perceptual encryption step encrypts the progressive regions in a layer, the objects of a region, and the vertices in an object so that a direct random-access object can be enabled in the encryption/decryption processes. To attain the mutual independence of watermarking and encryption, we encrypted the attributes of objects by using random permutations of the position and orientation of the vertices while preserving the SEDs of all the objects. Hence, the watermark can be extracted in a crypto-marked map or progressive encrypted map without decrypting all the objects. From the experimental results, we found that our method is robust to attacks that damage the vector map during the decryption step and does not produce a leakage of the encryption key during the watermark detecting step. Furthermore, we found that the time required by our method is proportional to the number of objects in vector maps, 0.59 [s] for 7,765 objects and 3.52 [s] for 50,679 objects. Our MED-based watermarking takes less time (about 0.07–0.43 [s] than conventional watermarking methods while our progressive encryption takes less time, at about 0.09 [s] - 0.37 [s], than conventional encryption methods.

With the rapid growth of multimedia message exchange and digital communication, multimedia big data has become a research hotspot in various fields. The storage and transmission of multimedia big data have high requirements for security. Images, covering the highest proportion of multimedia data, should be processed and transmitted with high security. Compressive sensing (CS) has a beneficial property for the encryption that the image can be recovered with fewer samples than conventional approaches use. In recent years, CS has been studied not only to reduce the resource requirements for signal acquisition but also to ensure the security of data. It is still an open challenge to improve security and enhance the quality of the decrypted image simultaneously using the key with small size. In this article, a CS-based encryption method is presented that associates the quantization with random measurement permutation. An enormous number of experiments have been conducted on both standard test images and face images chosen from the big database LFW. Experimental results show that our proposal has dramatic improvements on ensuring the security, enhancing the quality of the decrypted image, and raising the efficiency. Additionally, this proposal remarkably reduces storage and transmission resources. Accordingly, this encryption scheme can be applied to ensure the security of multimedia transmission.

Cloud security is a huge concern when users and enterprises consider to deploy cloud computing services. This article mainly presented an important aspect of cloud security which is called searchable encryption. Searchable encryption is a scheme that enable users to?secure search on encrypted data stored in cloud. To guarantee privacy of users' data, users encrypt their data files before uploading, then when they need to fetch some files, they can use searchable encryption to execute keyword search on encrypted data. Searchable encryption can be classified by three models, each is corresponding with different application scenario. Two of them are suitable with cloud architecture. They are called searchable public key encryption and searchable symmetric encryption respectively. Searchable public key encryption is mainly for data sharing scenario. A user wants to share some data files with other users privately. He can encrypt these files with receivers' public key. And receivers can securely search on it with their private keys. Searchable symmetric encryption can enable users securely using their online storage. They can upload data files which are encrypted with their secret keys. And then they can securely search on these encrypted data with the secret key no matter when and where they are. Comprehensive survey on searchable encryption for cloud security.A new classification of searchable encryption applicable to cloud security.Open and future research directions and questions.

Predicate encryption is a cryptographic primitive that provides fine-grained control over access to encrypted data. It is often used for encrypted data search in a cloud storage environment. In this paper, we propose an enabled/disabled predicate encryption scheme, which is the first work that provides timed-release services and data self-destruction (they correspond to the terms "enabled" and "disabled," respectively). Owing to these properties, the sender can set the readable/unreadable time of the files to be sent to the receiver. The receiver can read the sent file only after the readable time. After the unreadable time, the structure of the file will be destroyed and the file will become unreadable. Furthermore, for practical usage purposes, the extended scheme, which is based on the proposed scheme, provides not only timed-release services and data self-destruction but also long message encryption and undecryptable search. In the extended scheme, the length of encrypted messages does not depend on the order of the group. Moreover, the cloud server can obtain only the matched ciphertexts after the search. We model timed-release and data self-destruction functionalities for predicate encryption in clouds.A sender can set the readable/unreadable time of the files to be sent to the receiver.It also supports long message encryption and undecryptable search.The cloud server can obtain only the matched ciphertexts after the search.

Chaotic encryption algorithm is implemented in 32 bit microcontroller to protect text.Security analysis shows the effectiveness of the encryption for real-time applications.Performance and resources analysis justify the implementation of the system.The implementation has high potential to be used in embedded systems in military, telemedicine, etc. Currently, several embedded applications in military, industry, banking transference, e-commerce, biometric systems and others use insecure communication channels such as Internet to transmit or store confidential information. Therefore, the integrity and security of information are an important issue in continuous research. In last years, chaotic systems have been proposed in cryptography due they have several properties related with cryptography properties such as extreme sensibility on initial conditions with confusion and ergodicity with diffusion. In this paper, we present a 32-bit microcontroller implementation of an improved text encryption algorithm (based on Murillo-Escobar's algorithm 13) for real-time embedded systems and we present a complete security analysis such as key size analysis, key sensitivity, plain text sensitivity, floating frequency, histograms, N-grams, autocorrelation, information entropy, robustness against classic attacks, randomness analysis, and security characteristics. In addition, the digital implementation and performance are analyzed such as programming details, memory required, frequency system, implementation costs and encryption time. In contrast with recent approaches presented in literature, we present a complete security analysis in both statistical and implementation level, to justify the proposed scheme in a real application. Based in the results, the proposed embedded text encryption system is secure, effective and at low cost, and it could be implemented in real-time cryptosystem based on microcontroller.

Radio Frequency Identification RFID technology provides a seamless link between physical world and the information system in cyber space. However, the emerging Internet of Things and cloud systems are full of security holes, which introduce new challenging security problems in both tag identification and data privacy. In this paper, we present efficient methods for identity authentication and data encryption to enhance RFID privacy. The proposed techniques aim to ensure no adversary interacting with the tags and the reader, to infer any information on a tag's identity from the communication. The main idea, a symmetric cryptography technique, termed as Advanced Encryption Standard, was applied to implement both mutual authentication and data encryption between the front and back ends of RFID systems. The Advanced Encryption Standard cryptographic algorithm was adopted because of its low hardware complexity and high security strength. In addition, the proposed key management protocol is proved resistant to several known RFID attacks such as Man-in-the-Middle, Denial-of-Service, replay, clone attack, and backward/forward traceability. The computational time complexity of the proposed scheme through the entire identity authentication and data encryption phases is 3Tencrypt+1Tnonce+4Txor, which is superior to most existing approaches. The proposed scheme was also proved to be able to provide higher data encryption performance than other symmetric cryptographic algorithms with regard to the same level of security strength. Copyright © 2016 John Wiley & Sons, Ltd.

The capability of selectively sharing encrypted data with different users via public cloud storage may greatly ease security concerns over inadvertent data leaks in the cloud. A key challenge to designing such encryption schemes lies in the efficient management of encryption keys. The desired flexibility of sharing any group of selected documents with any group of users demands different encryption keys to be used for different documents. However, this also implies the necessity of securely distributing to users a large number of keys for both encryption and search, and those users will have to securely store the received keys, and submit an equally large number of keyword trapdoors to the cloud in order to perform search over the shared data. The implied need for secure communication, storage, and complexity clearly renders the approach impractical. In this paper, we address this practical problem, which is largely neglected in the literature, by proposing the novel concept of key-aggregate searchable encryption and instantiating the concept through a concrete KASE scheme, in which a data owner only needs to distribute a single key to a user for sharing a large number of documents, and the user only needs to submit a single trapdoor to the cloud for querying the shared documents. The security analysis and performance evaluation both confirm that our proposed schemes are provably secure and practically efficient.

Despite the great efforts to secure wireless sensor network (WSN), the dynamic nature and the limited resources of sensor nodes make searching for a secure and optimal network structure an open challenge. In this paper, we propose a novel encryption schema based on Elliptic Curve Cryptography (ECC) and homomorphic encryption to secure data transmission in WSN. The proposed encryption schema is built upon GASONeC algorithm (Elhoseny et al., 2014) that uses genetic algorithm to build the optimum network structure in the form of clusters. ECC is used to exchange public and private keys due to its ability to provide high security with small key size. The proposed encryption key is 176-bit and is produced by combining the ECC key, node identification number, and distance to its cluster head (CH). To reduce energy consumption of CH, homomorphic encryption is used to allow CH to aggregate the encrypted data without having to decrypt them. We demonstrated that the proposed method is capable to work with different sensing environments that need to capture text data as well as images. Compared with the state-of-the-art methods, our experimental results demonstrated that our proposed method greatly improve the network performance in terms of lifetime, communication overhead, memory requirements, and energy consumption.

GSM system is widely used by hundreds of millions of people. In fact there is no encryption scheme provides the reasonable security level (user-to-user encryption), it’s just provide the Air-interface encryption i.e. between the mobile station and the base station. Furthermore, there are other wireless links are vulnerable to attacks. It is therefore of great importance to provide reasonable security techniques to ensure the privacy of the mobile users especially circuit switching-based services, as well as prevent unauthorized use of the service. In this paper, a new approach is proposed to provide end-to-end encryption for the GSM system (EEE-GSM). This is achieved by using CL-PKC with some modifications and follow some assumptions in GSM system architecture in order to make the scheme compliant to the GSM cellular system. However, the proposed scheme not only efficient due to end-to-end security, but can also provide a secure system against IMSI catcher, man-in-the-middle, and replay attacks.

We present a new scheme for optical encryption of a binary image. In our method, the original binary data page is first divided into two identical pages. In each data page, the “on” and “off” pixels are represented by two discrete phases that are 90° apart. The first page corresponds to the phase conjugation of the second page, and vice versa. In addition, the wavefront of the two data pages is changed simultaneously from planar to spherical, for better encryption. The wavefront modification is represented by an extra phase shift, which is a function of position on the wavefront. In this way the two separate pages are both encrypted, and therefore the pages cannot be distinguished in a CCD. If the first page is used as an encrypted data page, then the second page is used as the decryption key, and vice versa. The decryption can be done by simply combining the two encrypted data pages. It is shown in our experiment that encryption and decryption can be fully accomplished in the optical domain.

Certificate-based encryption (CBE) is an important class of public key encryption but the existing schemes are secure only under the premise that the decryption key (or private key) and master secret key are absolutely secret. In fact, a lot of side channel attacks and cold boot attacks can leak secret information of a cryptographic system. In this case, the security of the cryptographic system is destroyed, so a new model called leakage-resilient (LR) cryptography is introduced to solve this problem. While some traditional public key encryption and identity-based encryption with resilient-leakage schemes have been constructed, as far as we know, there is no leakage-resilient scheme in certificate-based cryptosystems. This paper puts forward the first certificate-based encryption scheme which can resist not only the decryption key leakage but also the master secret key leakage. Based on composite order bilinear group assumption, the security of the scheme is proved by using dual system encryption. The relative leakage rate of key is close to 1/3. We put forward the formal definition and security model of LR-CBE.We present first certificate-based encryption scheme with leakage resilience.The security of the scheme is reduced to composite order bilinear group assumption.The relative leakage rate of key is close to 1/3.

Ciphertext-policy attribute-based encryption (CP-ABE) has been a preferred encryption technology to solve the challenging problem of secure data sharing in cloud computing. The shared data files generally have the characteristic of multilevel hierarchy, particularly in the area of healthcare and the military. However, the hierarchy structure of shared files has not been explored in CP-ABE. In this paper, an efficient file hierarchy attribute-based encryption scheme is proposed in cloud computing. The layered access structures are integrated into a single access structure, and then, the hierarchical files are encrypted with the integrated access structure. The ciphertext components related to attributes could be shared by the files. Therefore, both ciphertext storage and time cost of encryption are saved. Moreover, the proposed scheme is proved to be secure under the standard assumption. Experimental simulation shows that the proposed scheme is highly efficient in terms of encryption and decryption. With the number of the files increasing, the advantages of our scheme become more and more conspicuous.

In recent years, a wide variety of cryptographic algorithms based on chaos have been put forward and most of them have been proved to be successful by adopting the traditional permutation-diffusion architecture. However, one drawback these methods mostly hold is that they have little connection with the plaintext or, properly speaking, the relationship between them is rather less. The drawback makes the encryption algorithms vulnerable to the known-plaintext and chosen-plaintext attack. In addition, the secret keys are stationary at most times, and they can't be selected dynamically by the corresponding plain image pixels. In order to overcome these disadvantages mentioned above, we introduce a new chaos-based image encryption algorithm with dynamic key selection mechanisms in this paper, and present a dynamic keystream sequence group selection mechanism (DKSGSM) and a dynamic keystream selection mechanism (DKSM). They strongly enhance the relationship between the plaintext and the encryption scheme. In particular, the DKSGSM and DKSM expand the selection range of the keys and allow us to select the keys dynamically by the corresponding plaintext pixels. What's more, by adopting the bidirectional encryption, we can spread the influence to the whole image once a tiny change in plain image and this can greatly increase the security level of our encryption method. Simulation results and numerical analyses indicate that our encryption scheme is safe and efficient.

in data communication is a very important concern today. It is used in almost every region like e-commerce, education, and industry and data warehouse. Securely sending and receiving data in the above area is an important as the data is crucial. Image security plays an important role in this age. As the demand of image based message sending is improving day by day. In this paper, we have proposed an efficient image cryptography system based on RC6. The key size and number of variable rounds makes RC6 more secure. The key size is variable up to 2040 bits. The results are achieved in terms of entropy and correlation coefficients. The less variation in entropy is achieved from our approach. KeywordsChaos, Steganography, Security Measures. So in the ensuing segment we talk about data encryption method for picture encryption. We additionally talk about the pivotal angles which are utilized as a part of picture encryption with their points of interest and drawbacks. At long last taking into account the discourses we additionally recommend some future comment which may be productive in this bearing. There are niacumerous essential techniques which are second- hand pervasive cryptography, for example, private or mystery key cryptography, open fundamental or kilter, computerized mark, and hash capacities (15). In private key cryptography, a solitary key is leftover for both encryption and decoding. This obliges meander if all else fails part convey offering an impersonation of the key and the key be struck by be passed swear off a safe channel to the next individual (13-22). Private-key calculations are level indestructible and effectively actualized in equipment. Along these lines they are over and again second-hand for mass measurements encryption. The vast please of the all-around adjusted encryption rely on upon plaintext, encryption calculation, key and unscrambling calculation. The plaintext is the size ahead requiring the encryption calculation. It is joining of the inputs to the encryption calculation. The encryption calculation is the calculation used to continue on b deal with the information stranger plaintext to figure relieve. The mystery key is a comparable to repel of the encryption calculation and of the plaintext and it is associate of the encryption's inputs calculation (23)(24). The figure content is the defiant content discover as yield (14)(15). The steganography technique with cryptography will enhance the security as the cryptic content and the randomization quality can be improved.