Abstract: This paper presents an efficient and secure chaotic S-Box based image encryption algorithm. Firstly, by cryptanalyzing a multiple chaotic S-Boxes based image encryption algorithm, we successfully cracked the cryptosystem by using chosen-plaintext attack (CPA). Secondly, we put forward a new image encryption scheme based on a novel compound chaotic map and single S-Box. In the new scheme, a novel discrete compound chaotic system, Logistic-Sine system (LSS), is proposed, which has wider chaotic range and better chaotic properties. And a new S-Box is constructed by using LSS, which has satisfactory cryptographic performance. Based on the new S-Box and the chaotic key stream, the new image encryption algorithm is designed, which consist of a round of permutation and two rounds of substitution process. The permutation and substitution key sequences are related to the plaintext image content, this strategy enables the cryptosystem to resist CPA. The simulation results and security analysis verified the effectiveness of the proposed image encryption scheme. Especially, the new scheme has obvious efficiency advantages, showing that it has better application potential in real-time image encryption.

Abstract: The utility of virtual circuit (VC) based devices - UAVs, Drones, and similar other IoT based devices have gained immense momentum in the present day and age. These devices are predominantly used for aerial surveying in sensitive and remote areas. It is alarming that issues pertaining to stalking and information control have increased with the growth of technology. This paper presents a Blockchain Technology (BCT) based solution to improve the security and privacy of VC based device data. The proposed design is evaluated by implementing an IoT based application in a virtual vehicle monitoring system. The technical information about the instructions to the vehicle (devices), authentication, integrity, and vehicle reactions are stored in a cloud platform wherein Pentatope based Elliptic curve cryptography and SHA are used to ensure privacy in data storage. The data is later stored in an Ethereum based public blockchain to enable seamless BCT transactions. This system uses the Ganache platform for BCT that ensures data protection and privacy. Furthermore, metamask wallet for E t h balance is required to perform transactions over BCT. The proposed methodology thus helps to protect data from stalkers, plaintext attacks as well as ciphertext attacks. The results, when compared with the state-of-the-art, justify the efficiency and security aspects of the proposed approach.

Abstract: Considered as a promising fine-grained access control mechanism for data sharing without a centralized trusted third-party, the access policy in a plaintext form may reveal sensitive information in the traditional CP-ABE method. To address this issue, a hidden policy needs to be applied to the CP-ABE scheme, as the identity of a user cannot be accurately confirmed when the decryption key is leaked, so the malicious user is traced and revoked as demanded. In this paper, a CP-ABE scheme that realizes revocation, white-box traceability, and the application of hidden policy is proposed, and such ciphertext is composed of two parts. One is related to the access policy encrypted by the attribute value, and only the attribute name is evident in the access policy. Another is related to the revocation information and updated when revoking, where the revocation information is generated by the binary tree related to users. The leaf node value of a binary tree in the decryption key is used to trace the malicious user. From experimental results, it is shown that the proposed scheme is proven to be IND-CPA secure under the chosen plaintext attacks and selective access policy based on the decisional q-BDHE assumption in the standard model, efficient, and promising.

Abstract: Many chaos-based image encryption algorithms using low-dimensional chaotic mapping and permutation diffusion structures have been proposed recently. However, low-dimensional chaotic maps are less secure than high-dimensional chaotic systems. Furthermore, the permutation process is independent of the plaintext and diffusion process. As a result, they are not very resistant to chosen plaintext attacks and chosen ciphertext attacks. In this paper, we propose a hyper-chaos-based image encryption algorithm that uses a 6-dimensional hyperchaotic system; the key stream generated by hyperchaotic system is related to the plaintext image. Then, bit-level permutation is employed to strengthen the security of the cryptosystem. Finally, DNA coding and operations are employed to change pixels. Theoretical analysis and numerical simulations demonstrate that the proposed algorithm is safe and reliable for image encryption.

Abstract: This work proposes an improved reversible data hiding scheme in encrypted images using parametric binary tree labeling(IPBTL-RDHEI), which takes advantage of the spatial correlation in the entire original image but not in small image blocks to reserve room for hiding data. Then the original image is encrypted with an encryption key and the parametric binary tree is used to label encrypted pixels into two different categories. Finally, one of the two categories of encrypted pixels can embed secret information by bit replacement. According to the experimental results, compared with several state-of-the-art methods, the proposed IPBTL-RDHEI method achieves higher embedding rate and outperforms the competitors. Due to the reversibility of IPBTL-RDHEI, the original plaintext image and the secret information can be restored and extracted losslessly and separately.

Abstract: Fully homomorphic encryption (FHE) is a technique that allows computations on encrypted data without the need for decryption and it provides privacy in various applications such as privacy-preserving cloud computing. In this article, we present two hardware architectures optimized for accelerating the encryption and decryption operations of the Brakerski/Fan-Vercauteren (BFV) homomorphic encryption scheme with high-performance polynomial multipliers. For proof of concept, we utilize our architectures in a hardware/software codesign accelerator framework, in which encryption and decryption operations are offloaded to an FPGA device, while the rest of operations in the BFV scheme are executed in software running on an off-the-shelf desktop computer. Specifically, our accelerator framework is optimized to accelerate Simple Encrypted Arithmetic Library (SEAL), developed by the Cryptography Research Group at Microsoft Research. The hardware part of the proposed framework targets the XILINX VIRTEX-7 FPGA device, which communicates with its software part via a peripheral component interconnect express (PCIe) connection. For proof of concept, we implemented our designs targeting 1024-degree polynomials with 8-bit and 32-bit coefficients for plaintext and ciphertext, respectively. The proposed framework achieves almost $12\times $ and $7\times $ latency speedups, including I/O operations for the offloaded encryption and decryption operations, respectively, compared to their pure software implementations.

Abstract: This paper proposes a color image encryption algorithm based on a cloud model Fibonacci chaotic system, as well as a matrix convolution operation that can protect image content effectively and safely. The algorithm combines the cloud model with the generalized Fibonacci, creating a new complex chaotic system that realizes the dynamic random variation of chaotic sequences. The chaotic sequence is used to scramble the pixel coordinates of the mosaic images of the R, G, and B components of the color image. Then, the chaotic sequence value is used as a matrix convolution cloud algorithm that alternately updates the input value of the matrix convolution operation and the pixel value to obtain the permutation transformation of the original pixel value. Finally, the pixel values of the replacement and cloud model Fibonacci chaotic sequence and the pixel values of the front (rear) adjacent pixel points are subjected to a two-way exclusive XOR operation. Realizing the change of the arbitrary pixel value causes a chain transformation of the pixel values of all of the pixel points, and sequentially generates an encrypted image. Experiments show that the histogram of the encrypted image is smoother and adjacent pixels of the image have low correlation. In addition, this algorithm can resist attack experiments such as differential attack, select plaintext attack and noise attack and provides high encryption security, high anti-interference, and strong robustness. The dynamic chaotic system is used to realize the color image encryption of the dynamic key, and the encryption algorithm has higher security and the validity of the algorithm.

Abstract: Fine grained access control is a requirement for data stored in untrusted servers like clouds. Owing to the large volume of data, decentralized key management schemes are preferred over centralized ones. Often encryption and decryption are quite expensive and not practical when users access data from resource constrained devices. We propose a decentralized attribute based encryption (ABE) scheme with fast encryption, outsourced decryption and user revocation. Our scheme is very specific to the context of mobile cloud as the storage of encrypted data and the partial decryption of ciphertexts are dependent on the cloud and users with mobile devices can upload data to the cloud or access data from it by incurring very little cost for encryption and decryption respectively. The main idea is to divide the encryption into two phases, offline preprocessing phase which is done when the device is otherwise not in use and an online phase when the data is actually encrypted with the policy. This makes encryption faster and more efficient than existing decentralized ABE schemes. For decryption outsourcing, data users need to generate a transformed version of the decryption key allowing an untrusted proxy server to partially decrypt the ciphertext without gaining any information about the plaintext. Data users can then fully decrypt the partially decrypted ciphertext without performing any costly pairing operations. We also introduce user revocation in this scheme without incurring too much additional cost in the online phase. Comparison with other ABE schemes shows that our scheme significantly reduces computation times for both data owners and data users and highly suitable for use in mobile devices.

Abstract: Over the last few years, lots of chaotic image encryption schemes have been proposed. However, most of the schemes are permutation-diffusion architectures which still have some shortcomings, such as weak key streams, small key spaces, small information entropy, and so on. To eliminate the above weaknesses, in this paper, we propose a hyper-chaotic image encryption scheme based on quantum genetic algorithm (QGA) and compressive sensing (CS), which is a new image encryption scheme and has not been proposed so far. Firstly, QGA can update the population with the quantum rotation gate, which can enhance the randomness of the population and avoid falling into local optimum. Then compressive sensing technology is used to reduce data storage and speed up the encryption and decryption process. Moreover, we utilize the SHA-512 hash function of the plain image to calculate the initial values of the hyper-chaotic system, which is capable of enhancing the relationships between encryption schemes and plain images. The simulation experiments and security analysis reveal that the proposed scheme is more efficient in resisting statistical attack and plaintext attack and shows better performance in peak signal-to-noise ratio (PSNR) and information entropy compared with other image encryption schemes based on chaos theory.

Abstract: Visual selective image encryption can both improve the efficiency of the image encryption algorithm and reduce the frequency and severity of attacks against data. In this article, a new form of encryption is proposed based on keys derived from Deoxyribonucleic Acid (DNA) and plaintext image. The proposed scheme results in chaotic visual selective encryption of image data. In order to make and ensure that this new scheme is robust and secure against various kinds of attacks, the initial conditions of the chaotic maps utilized are generated from a random DNA sequence as well as plaintext image via an SHA-512 hash function. To increase the key space, three different single dimension chaotic maps are used. In the proposed scheme, these maps introduce diffusion in a plain image by selecting a block that have greater correlation and then it is bitwise XORed with the random matrix. The other two chaotic maps break the correlation among adjacent pixels via confusion (row and column shuffling). Once the ciphertext image has been divided into the respective units of Most Significant Bits (MSBs) and Least Significant Bit (LSBs), the host image is passed through lifting wavelet transformation, which replaces the low-frequency blocks of the host image (i.e., HL and HH) with the aforementioned MSBs and LSBs of ciphertext. This produces a final visual selective encrypted image and all security measures proves the robustness of the proposed scheme.

Abstract: This paper proposes a fully homomorphic encryption encapsulated difference expansion (FHEE-DE) scheme for reversible data hiding in encrypted domain (RDH-ED). The homomorphic circuits and ciphertext operations are elaborated. Key-switching and bootstrapping techniques are introduced to control the ciphertext extension and decryption failure of homomorphic encryption. A key-switching based least-significant-bit (KS-LSB) data hiding method has been designed to realize data extraction directly from the encrypted domain without the private key. In application, the user first encrypts the plaintext and uploads ciphertext to the server. The server embeds additional data into the ciphertext by performing FHEE-DE data hiding and KS-LSB data hiding. Additional data can be extracted directly from the marked ciphertext by the server without the private key. The user owns the private key and can decrypt the marked ciphertext to obtain the marked plaintext. Then additional data or plaintext can be obtained from the marked plaintext by using the standard DE extraction or recovery. The server could also implement FHEE-DE recovery or extraction on the marked ciphertext to return the ciphertext of original plaintext or additional data to the user. Experimental results demonstrate that the embedding capacity and reversibility of the proposed scheme are superior to existing RDH-ED methods, and fully separability is achieved without reducing the security of encryption.

Abstract: A secure optical digital image encryption scheme with authentication capability is proposed using double random-phase encoding (DRPE) and compressed sensing (CS). Phase information of the plaintext image is obtained using DRPE and quantized to generate authentication information. Simultaneously, the plaintext image is compressed by CS and its measurements are quantized using the sigmoid map. Then the ciphertext image is obtained by permutation and diffusion after authentication information is embedded in quantified measurements. At receiving end, the authentication information is first extracted by inverse permutation and diffusion, and then the authentication image is obtained by inverse DRPE. Finally, the ciphertext image can be blindly authenticated using a nonlinear cross-correlation method with authentication image and reconstructed image. Experimental results demonstrate the effectiveness of our proposed scheme.

Abstract: Single image encryption schemes are not efficient enough when a bunch of images is to be encrypted in some real-world setting To overcome this problem, an efficient and secured multiple images encryption scheme is proposed in this study using two chaotic maps and simple row and column swapping operations in a 3D image space The N input images are piled to make a 3D image To confuse the given pixel data, two images are chosen randomly from this pile The randomly chosen two rows from the two randomly chosen images are swapped with each other In the same way, two randomly chosen columns are swapped with each other The operation of randomly chosen two images, two rows, and two columns have been iterated an arbitrary number of times to throw the confusion effects in the pixels data Intertwining Logistic Map (ILM) and Improved Piecewise Linear Chaotic Map (MPWLCM) have been used to get the four streams of random numbers The three streams of the former map have been used to create the confusion effects, whereas the fourth stream of random numbers given by the latter map has been used for the diffusion effects SHA-256 hash codes have been used to throw the plaintext sensitivity in the proposed cipher Besides, a 256-bit user key has been employed to increase the key space Both the simulation and the exhaustive security analyses carried out at the end vividly prove the security, resistance to the varied attacks, and the real-world applicability of the proposed cipher

Abstract: To obtain a more secure colour image cryptosystem without complex construction, this paper presents a general simple colour image encryption model with a very high level of security, and that is based on two nearby orbits of chaotic systems. First, the initial value of a one-dimensional (1D) chaotic map is obtained using plaintext. Then, we obtain two nearby orbits of 1D chaotic maps to generate three new chaotic signals. Next, the generated systems independently encrypt the red, green and blue components (RGB) of the colour image. Finally, the three encrypted images are combined to obtain the final encrypted image. Simulation results show that our method is simple, effective and passed all NIST tests and part of TestU01 test. Since the proposed method is related to plaintext, it has much higher security level compared with the most recently reported chaos-based image algorithms. More importantly, the 1D logistic cryptosystem based on our method has a large key space with higher security.

Abstract: In order to obtain chaos with a wider chaotic scope and better chaotic behavior, this paper combines the several existing one-dimensional chaos and forms a new one-dimensional chaotic map by using a modular operation which is named by LLS system and abbreviated as LLSS. To get a better encryption effect, a new image encryption method based on double chaos and DNA coding technology is proposed in this paper. A new one-dimensional chaotic map is combined with a hyperchaotic Qi system to encrypt by using DNA coding. The first stage involves three rounds of scrambling; a diffusion algorithm is applied to the plaintext image, and then the intermediate ciphertext image is partitioned. The final encrypted image is formed by using DNA operation. Experimental simulation and security analysis show that this algorithm increases the key space, has high sensitivity, and can resist several common attacks. At the same time, the algorithm in this paper can reduce the correlation between adjacent pixels, making it close to 0, and increase the information entropy, making it close to the ideal value and achieving a good encryption effect.

Abstract: A number of techniques for securing plaintext, images and video frames have been developed in cryptography using jointly DNA computing and Chaos Theory. With the advancement of DNA/quantum computing, the threats of security breaches to information have an increasing possibility. In this paper, we propose a symmetric encryption algorithm for color images by extending the current encryption/decryption techniques. Our encryption algorithm is based on three chaotic systems (PWLCM, Lorenz and 4D Lorenz-type), a Secure Hash Algorithm, a scrambler, a chaotic generator and DNA sequence based Linear Feedback Shift Register. We introduce multilevel security to increase the degree of diffusion and confusion. Through experiments, we present security analysis for key irreproducibility and sensitivity, Gray Level Co-occurrence Matrix based analysis, maximum deviation, irregular deviation, entropy, histogram, variance and correlation, number of pixel change rate, unified average cipher intensity, known/chosen-plaintext attacks, mean absolute error, robustness against noises of various types using PSNR and occlusion attacks. It is demonstrated that mostly our proposed encryption algorithm has enhanced performance as compared to contemporary works in information security, while comparable in other cases.

Abstract: In this study, an enhanced quadratic map (EQM) is proposed and has been applied in a new colour image encryption scheme. The performance evaluations show that the EQM has excellent performances such as better Lyapunov exponent and larger chaotic ranges when compared with the classical quadratic map. The sequences generated from this EQM are successfully used in a new proposed colour image encryption scheme with excellent confusion and diffusion properties. The encryption structure is based on the permutation–diffusion process, and then adopted on the classical permutation, it is characterised by a high speed of diffusion, which enables the encryption of the three components of the plaintext image at the same time, and these encrypted components are simultaneously related to each other. The proposed scheme is tested on the USC-SIPI image dataset and on the real-life image dataset; its effectiveness is also compared with five latterly proposed image encryption schemes. The simulation results indicate that the proposed scheme has the properties of large key space, a weaker correlation between neighbouring pixels, higher sensitivity towards key, greater randomness of pixels and the capacity to withstand statistical analysis, plaintext/chosen-plaintext attacks, and differential attacks, thus that it has higher security and can be appropriate for image encryption.

Abstract: Nowadays, many image cryptosystems have been cracked by chosen-plaintext attacks, for they are not highly sensitive to plain image. To solve this problem, we introduce a plaintext-related mechanism for secure color image encryption, and it is established in the generation and selection of chaotic sequences, permutation and diffusion. In the proposed image cryptosystem, the architecture of permutation and diffusion is adopted. Firstly, plaintext-related Latin-square-based block permutation is proposed to randomly shuffle pixels of the color plain image, diffusion method dependent on the plaintext and scrambled image is further given to modify pixels of permutated image, and finally cipher image is gotten. The chaotic sequence for diffusing the current pixel is dynamically generated according to the plain image and scrambled image, and diffusion operations of red, green and blue components of color plain image affect each other. Besides, chaotic sequences used in encryption are produced by new one-dimensional chaotic systems and dynamically selected, and initial values of chaotic systems are computed by plain image and external keys. Experimental results and security analyses demonstrate that our image encryption has large key space and high security level, and it can be applied for the secure communication of image information.

Abstract: The image encryption system based on joint transform correlation has attracted much attention because its ciphertext does not contain complex value and can avoid strict pixel alignment of ciphertext when decryption occurs. This paper proves that the joint transform correlation architecture is vulnerable to the attack of the deep learning method-convolutional neural network. By giving the convolutional neural network a large amount of ciphertext and its corresponding plaintext, it can simulate the key of the encryption system. Unlike the traditional method which uses the phase recovery algorithm to retrieve or estimate optical encryption key, the key model trained in this paper can directly convert the ciphertext to the corresponding plaintext. Compared with the existing neural network systems, this paper uses the sigmoid activation function and adds dropout layers to make the calculation of the neural network more rapid and accurate, and the equivalent key trained by the neural network has certain robustness. Computer simulations prove the feasibility and effectiveness of this method.

Abstract: With the development of machine learning, it is popular that mobile users can submit individual symptoms at any time anywhere for medical diagnosis. Edge computing is frequently adopted to reduce transmission latency for real-time diagnosis service. However, the data-driven machine learning, which requires to build a diagnosis model over vast amounts of medical data, inevitably leaks the privacy of medical data. It is necessary to provide privacy preservation. To solve above challenging issues, in this paper, we design a lightweight privacy-preserving medical diagnosis mechanism on edge, called LPME. Our LPME redesigns the extreme gradient boosting (XGBoost) model based on the edge-cloud model, which adopts encrypted model parameters instead of local data to remove amounts of ciphertext computation to plaintext computation, thus realizing lightweight privacy preservation on resource-limited edge. In addition, LPME provides secure diagnosis on edge with privacy preservation for private and timely diagnosis. Our security analysis and experimental evaluation indicates the security, effectiveness and efficiency of LPME.

Abstract: Fault attacks (FA) are one of the potent practical threats to modern cryptographic implementations. Over the years the FA techniques have evolved, gradually moving towards the exploitation of device-centric properties of the faults. In this paper, we exploit the fact that activation and propagation of a fault through a given combinational circuit (i.e., observability of a fault) is data-dependent. Next, we show that this property of combinational circuits leads to powerful Fault Template Attacks (FTA), even for implementations having dedicated protections against both power and fault-based vulnerabilities. The attacks found in this work are applicable even if the fault injection is made at the middle rounds of a block cipher, which are out of reach for most of the other existing fault analysis strategies. Quite evidently, they also work for a known-plaintext scenario. Moreover, the middle round attacks are entirely blind in the sense that no access to the ciphertexts (correct/faulty) or plaintexts are required. The adversary is only assumed to have the power of repeating an unknown plaintext several times. Practical validation over a hardware implementation of SCA-FA protected PRESENT, and simulated evaluation on a public software implementation of protected AES prove the efficacy of the proposed attacks.