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One of the most cost-effective services in cloud computing is storage, used by businesses and individuals to outsource their massive data to untrusted servers. Efforts have studied problems around this application scenario in different fronts: efficiency, flexibility, reliability, and security. In this paper we address the security concerns of cloud storage under the scenario where users encrypt-then-outsource data, share their outsourced data with other users, and the service provider can be queried for searching and retrieval of encrypted data. As main distinctive, we propose a security approach for storage, sharing and retrieval of encrypted data in the cloud fully constructed on the basis of attribute-based encryption (ABE) thus enabling access control mechanisms over both the encrypted data and also for the information retrieval task through search access control. Compared to related works, our approach considers efficient encryption at three different levels: i) bulk encryption of data outsourced to the cloud, ii) keys management for access control over encrypted data by means of digital envelopes from attribute based encryption, and iii) novel construction for attribute based searchable encryption (ABSE). Our underlying ABE algorithms are carefully selected from the body of knowledge and novel constructions for ABSE are provided over the asymmetric setting (Type-III pairings) to support security levels of 128-bits or greater. Experimental results on benchmark data sets demonstrate the viability of our approach for practical realizations using Barreto-Naehrig curves.

Security risk situation prediction and analysis is an important content in the field of information security technology and management. This paper mainly studies the problem of information security risk prediction based on dynamic agent network in complex network environment. This paper studies link encryption technology and its algorithm in dynamic proxy network. Based on this, this paper puts forward a more practical and wide-ranging network risk situation prediction method. Experiments show that this method can meet the risk situation assessment false alarm problem caused by complex network structure and different resource weights. This method has practical significance for information security risk prediction in complex network environment.

In today’s Industrial Internet of Things (IIoT) environment, where different systems interact with the physical world, the state proposed by the Industry 4.0 standards can lead to escalating vulnerabilities, especially when these systems receive data streams from multiple intermediaries, requiring multilevel security approaches, in addition to link encryption. At the same time taking into account the heterogeneity of the systems included in the IIoT ecosystem and the non-institutionalized interoperability in terms of hardware and software, serious issues arise as to how to secure these systems. In this framework, given that the protection of industrial equipment is a requirement inextricably linked to technological developments and the use of the IoT, it is important to identify the major vulnerabilities and the associated risks and threats and to suggest the most appropriate countermeasures. In this context, this study provides a description of the attacks against IIoT systems, as well as a thorough analysis of the solutions for these attacks, as they have been proposed in the most recent literature.

Nowadays, the development of information technology can be described as extremely rapid, especially with the widespread use of the Internet; the security of communications in the network has become an important issue we are facing. The purpose of this article is to solve the problems in today’s network security data encryption algorithms. Starting from the computer network communication security data encryption algorithm, we discuss the effects of several different encryption methods on improving network security. The research results show that it is known that the application of link encryption algorithm in network communication security encryption algorithm can increase the security index by 25%, the node encryption algorithm can increase the security index by 35%, and the end-to-end encryption algorithm can make the cyber activity safety index to increase by 40%. Among them, RSA algorithm and DES algorithm are two very representative algorithms; they represent different encryption systems. From the perspective of network data link, there are three methods of encryption algorithm, namely, link encryption algorithm, node encryption algorithm, and end-to-end encryption algorithm.

Symmetric ciphers are more efficient for bulk encryption than asymmetric ciphers, however there is a lack of published studies providing relevant metrics pertaining to bulk encryption with RSA in modern computing environments. As key escrow systems proposed against ransomware provide alternative routes for data restoration, ransomware developers will seek to deploy resistant cryptosystems. In this study, we examine the use of a popular asymmetric cipher (RSA) for bulk encryption. We provide metrics for both encryption time and ciphertext expansion while examining the impact of different encryption parameters such as key size and block size. In addition, we consider supplementing encryption with compression to combat both ciphertext expansion and encryption time. Our goal is to highlight the need for solutions against the ransomware that use externally generated asymmetric key pairs for bulk encryption.

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

With the widespread use of Public Key Infrastructure (PKI), some defects in PKI management have also been exposed, such as occupying a lot of valuable network resources, needing large storage resources and computing resources. Based on IBC identification cryptograph, this paper proposes a lightweight identity authentication scheme which uses SAKI private key distribution protocol and SM9 national secret algorithm. The scheme mainly includes three parts: online secure distribution of private key, identity authentication, key agreement. And the protocol interaction among Key Generation Center (KGC), Edge Computing Agent and Internet of Things terminal is introduced. Compared with common PKI verification, the lightweight authentication scheme proposed in this paper greatly saves network resources, and has higher security performance, shorter length key and more convenient key management. It can be combined with device identification in the Internet of Things to solve key security problems such as identity authentication, link encryption and data protection in the Internet of Things.

Storage services allow data owners to store their huge amount of potentially sensitive data, such as audios, images, and videos, on remote cloud servers in encrypted form. To enable retrieval of encrypted files of interest, searchable symmetric encryption (SSE) schemes have been proposed. However, many schemes construct indexes based on keyword-file pairs and focus on boolean expressions of exact keyword matches. Moreover, most dynamic SSE schemes cannot achieve forward privacy and reveal unnecessary information when updating the encrypted databases. We tackle the challenge of supporting large-scale similarity search over encrypted feature-rich multimedia data, by considering the search criteria as a high-dimensional feature vector instead of a keyword. Our solutions are built on carefully-designed fuzzy Bloom filters which utilize locality sensitive hashing (LSH) to encode an index associating the file identifiers and feature vectors. Our schemes are proven to be secure against adaptively chosen query attack and forward private in the standard model . We have evaluated the performance of our scheme on real-world high-dimensional datasets, and achieved a search quality of 99 percent recall with only a few number of hash tables for LSH. This shows that our index is compact and searching is not only efficient but also accurate.

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.

Optical cryptosystems can provide encryption and sometimes compression simultaneously. They are increasingly attractive for information securing especially for image encryption. Our studies shown that the optical cryptosystems can be used to encrypt optical data transmission. We propose and study a new method for securing fibre data communication. The paper presents a method for optical encryption of data transmitted with a single optical fibre. The encryption process relies on pseudo-random spatial light modulation, combination of two encryption keys and the Compressed Sensing framework. A linear combination of light pulses with pseudo-random patterns provides a required encryption performance. We propose an architecture to transmit the encrypted data through the optical fibre. The paper describes the method, presents the theoretical analysis, design of physical model and results of experiment.

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.

Over the past two decades, chaos-based encryption appeared as an original application for nonlinear dynamics and deterministic chaos to encrypt and decrypt data. In this paper, an implementation of digital image encryption scheme based on the Lorenz chaotic system is proposed. While in the process of generating chaotic key stream, the hash value of the plain image is embedded in the proposed cryptosystem to dynamically alter the initial secret keys to increase the security level. The proposed digital image encryption algorithm is described in detail along with its security analysis and implementation. The experimental results show that the proposed digital image encryption algorithm is efficient and has high security features and is suitable for practical uses across insecure networks.

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.

As a new broad vision of public-key encryption systems, functional encryption provides a promising solution for many challenging security problems such as expressive access control and searching on encrypted data. In this paper, we present two Sequence Aware Function Encryption (SAFE) schemes. Such a scheme is very useful in many forensics applications where the order (or pattern) of the attributes forms an important characteristic of an attribute sequence. Our first scheme supports the matching of two bit strings, while the second scheme can support the matching of general characters. These two schemes are constructed based on the standard Decision Linear and Decision Bilinear Diffie-Hellman assumptions. In addition, we show that our SAFE schemes can also provide the additional feature of attribute-hiding, which is desirable in forensics applications. Moreover, we give an interesting application of SAFE schemes in constructing Sequential Aware Keyword Search (SAKS) schemes.

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.

Automatic Dependent Surveillance-Broadcast (ADS-B) is one of the key technologies for future “e-Enabled” aircrafts. ADS-B uses avionics in the e-Enabled aircrafts to broadcast essential flight data such as call sign, altitude, heading, and other extra positioning information. On the one hand, ADS-B brings significant benefits to the aviation industry, but, on the other hand, it could pose security concerns as channels between ground controllers and aircrafts for the ADS-B communication are not secured, and ADS-B messages could be captured by random individuals who own ADS-B receivers. In certain situations, ADS-B messages contain sensitive information, particularly when communications occur among mission-critical civil airplanes. These messages need to be protected from any interruption and eavesdropping. The challenge here is to construct an encryption scheme that is fast enough for very frequent encryption and that is flexible enough for effective key management. In this paper, we propose a Staged Identity-Based Encryption (SIBE) scheme, which modifies Boneh and Franklin's original IBE scheme to address those challenges, that is, to construct an efficient and functional encryption scheme for ADS-B system. Based on the proposed SIBE scheme, we provide a confidentiality framework for future e-Enabled aircraft with ADS-B capability.

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.

Encryption, itself doesn’t prevent interception, but denies the message content to the interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is impossible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, large computational resources and skills are required to decrypt it. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients, but not to unauthorized interceptors. Data hiding is the skill of hiding messages in such a ways the only the sender and the receiver of the message knows that the message has been hidden. In the context of secured information transmission and reception, efficient techniques for data encryption and decryption are very much essential. In this paper, a message transfer application is developed which mainly focusses on secret message transfer between two parties. Used scheme not only focusses on text but also the encryption of images and videos. A unique algorithm i-Se4GE is used for the transfer of keys required for the encryption and decryption of messages. This algorithm makes use of a set of random numbers, timestamp of the two users, a set of public keys and dynamic keys. The algorithm uses a two-step authentication request-reply process which provides it a double layer security.

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.

In this paper, we propose a key space enhanced chaos-based encryption scheme with no requirement of redundant sideband information in an orthogonal frequency division multiplexing passive optical network (OFDM-PON). For the first time, a simple 1-D chaotic logistic map is employed to scramble the chaotic subcarrier allocation both in time/frequency domain and logical operation, which provides a huge key space to enhance the physical layer confidentiality. Due to the dynamic chaotic permutations, the largest key space is achieved in comparison with the reported encryption schemes in OFDM-PON. In addition, a ∼10-Gb/s secure transmission with encrypted OFDM data is experimentally demonstrated over 25-km standard single-mode fiber. The proposed encryption scheme demonstrates the excellent security of data transmission in OFDM-PON and the robustness against exhaustive attacks.

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 paradigm of forward security provides a promising approach to deal with the key exposure problem as it can effectively minimize the damage caused by the key exposure. In this paper, we develop a new forward-secure identity-based encryption scheme without random oracles. We formally prove that the proposed scheme is secure against adaptive chosen-ciphertext attacks in the standard model. In the proposed scheme, the running time of the private key extraction and decryption algorithms and the sizes of the user's initial private key and the ciphertext are independent on the total number of time periods, and any other performance parameter has at most log-squared complexity in terms of the total number of time periods. Compared with the previous forward-secure identity-based encryption schemes, the proposed scheme enjoys obvious advantage in the overall performance. To the best of our knowledge, it is the first forward-secure identity-based encryption scheme that achieves direct chosen-ciphertext security in the standard model.

Based on research about network mobility, this paper analyzes the security requirements of internet of things and wireless network based on 6LoWPAN, and designs the security architecture based on 6LoWPAN network, especially for the frequent mobile handoff access and data multi-hop forwarding. The access authentication scheme and data encryption method are designed and implemented based on 6LoWPAN mobile switching. Through comparing with non-symmetric encryption and symmetric encryption, AES pre-shared key encryption scheme is determined to use for 6LoWPAN, and is compared with typical cryptographic algorithms on internet of things platform and Contiki operate system. In experiment, the lightweight security of IoT mobile communication is realized on CC2530 nodes, including the advanced encryption standard, the payload encryption of network data packet and wireless nodes access authentication. Security architecture for mobile switching scenarios are verified, the feasibility of proposed scheme is confirmed.

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