Joint image compression and encryption method

With the advancement of multimedia technology and coming of big data era, the size of image data is significantly increased. However, the traditional image encryption methods cannot solve the emerging problems of efficient compression. To settle with this challenge, an effective content-adaptive image compression and encryption method based on compressive sensing and double random phase encoding (DRPE) is proposed in this paper. The original image is converted to one low-frequency part and three high-frequency parts by DWT and then permutated by sorting-based chaotic sequences. Afterward, a novel measurement matrix optimization algorithm based on adaptive step size is presented to measure the high-frequency components. To enhance the security of the scheme, the DRPE, quantization, and diffusion are successively performed on the complex matrix composed of the shuffled low-frequency component and three measurement value matrices to obtain the cipher image. Logistic-Sine chaotic system is utilized to produce the chaotic keystreams for the encryption process, and its system parameter and initial value are determined by the information entropy of the plain image and external key parameters, so that the proposed cipher can withstand known-plaintext and chosen-plaintext attacks effectively. Numerical experiments demonstrate the effectiveness of the proposed image compression and encryption algorithm.

In the modern society of digitalization, integration, intelligence, and networking, while people enjoy the convenience of information technology to their production and lives, information security in the network, as the cornerstone of information communication, becomes more and more important. The research is to establish a new image encryption (IE) method based on LFSR state sequence (SS)s in VHDL language, and the stream cipher of LFSR is studied in detail to induce the idea of LFSR SSs based on VHDL language. The correlation coefficient (CC) of the original image (OI) and encrypted image (EI) pixel points (PP) are analyzed from horizontal direction, vertical direction and diagonal direction, and the results show that the CC of adjacent PP of the OI is large, which approaches 1. However, using the encryption algorithm proposed in this paper, the correlation coefficient of the PP of the EI is -0.0282 in the diagonal direction, and the highest correlation coefficient in the horizontal direction is only 0.0122, which indicates that the adjacent PP of the EI are almost uncorrelated with each other. Therefore, the encryption method can well resist statistical attacks, which illustrates the effectiveness, security, and reliability of this new IE method.

Scalable asymmetric image encryption based on phase-truncation in cylindrical diffraction domain

A novel method of digital image encryption is presented. Image encryption and decryption are performed based on the continuously increasing decorrelation property and the real-valuedness of the reality-preserving fractional Fourier transform. The input and encrypted data are respectively in the spatial domain and the reality-preserving fractional Fourier transformed domain determined by encryption keys. It resists statistic analyses effectively. In addition, the encrypted image is real-valued, so it’s convenient for display and storage. The simulation result shows that the parameters of the reality-preserving fractional Fourier transform enhance the space of keys. As a method of encryption, it won’t bring data expanding, and is sensitive to parameters, with considerable robustness, security, and feasible implementation in practice, which has a good prospect and practicability in information security field.

A new method of color image encryption is proposed in this paper, with the combination of a two-dimensional (2D) Henon-like chaotic map and compressed sensing for better performance. A sinusoidal function is introduced into the 2D Henon map for increasing randomness. Image encryption algorithm includes three procedures: compression of a color image through the Bernoulli observation matrix, encryption of the compressed image by 2D-Henon map with sinusoidal factor, and reconstruction of color image based on compressed sensing algorithm of orthogonal matching pursuit (OMP). Numerical simulation shows that the proposed encryption algorithm has some advantages including being hardware-friendly, sufficient keyspace, and higher security.

Today, social communication through the Internet has become more popular and has become a crucial part of our daily life. Naturally, sending and receiving various data through the Internet has also grown a lot. Keeping important data secure in transit has become a challenge for individuals and even organizations. Therefore, the trinity of confidentiality, integrity, and availability will be essential, and encryption will definitely be one of the best solutions to this problem. Of course, for image data, it will not be possible to use conventional encryption methods for various reasons, such as the redundancy of image data, the strong correlation of adj acent pixels, and the large volume of image data. Therefore, special methods were developed for image encryption. Among the prevalent methods for image encryption is the use of DNA sequences as well as chaos signals. In this paper, a cycling 3D chaotic map and DNA sequences are used to present a new method for color image encryption. Several experimental analyses were performed on the proposed method, and the results proved that the presented method is secure and efficient.

Joint image compression and encryption using a novel column-wise scanning and optimization algorithm

For telecommunication systems, various compression and encryption techniques are proposed to satisfy a fast and secure transmission. However these two techniques have been studied separately. In this paper we propose a method combining encryption and compression based on independent component analysis (ICA) and Discrete Cosine Transform (DCT). For encryption, target images are covered with an insignificant image to hide them and their mixtures to be transmitted are obtained. The receiver reconstructs the original images applying some ICA algorithm to the mixed images. In compression process, using DCT and simple low pass filter, the size of transmission can be reduced.

In recent years, encryption technology has been developed quickly and many image encryption methods have been put forward. Chaos based image encryption technique is a new encryption technique for images. It utilizes chaos random sequence to encrypt image, which is an efficient way to deal with the intractable problem of fast and highly secure image encryption. However, the Chaos based image encryption technique has some deficiencies, such as the limited accuracy problem. This paper researches on the chaotic encryption, DES encryption and a combination of image encryption algorithm, and simulate these algorithms, through analysis of the algorithm to find the gaps. And on this basis, the algorithm has been improved. The new encryption scheme realizes the digital image encryption through the chaos and improving DES. Firstly, new encryption scheme uses the Logistic chaos sequencer to make the pseudo-random sequence, carries on the RGB with this sequence to the image chaotically, then makes double time encryptions with improvement DES, displays they respective merit. Theoretical analysis and the simulation indicate that this plan has the high starting value sensitivity, and enjoys high security and the encryption speed. In addition it also keeps the neighboring RGB relevance close to zero. The algorithm can be used in the actual image encryption.

Recently, diagnosing diseases using medical images became crucial. As these images are transmitted through the network, they need a high level of protection. If the data in these images are liable for unauthorized usage, this may lead to severe problems. There are different methods for securing images. One of the most efficient techniques for securing medical images is encryption. Confusion and diffusion are the two main steps used in encryption algorithms. This paper presents a new encryption algorithm for encrypting both grey and color medical images. A new image splitting technique based on image blocks introduced. Then, the image blocks scrambled using a zigzag pattern, rotation, and random permutation. Then, a chaotic logistic map generates a key to diffuse the scrambled image. The efficiency of our proposed method in encrypting medical images is evaluated using security analysis and time complexity. The security is tested in entropy, histogram differential attacks, correlation coefficient, PSNR, keyspace, and sensitivity. The achieved results show a high-performance security level reached by successful encryption of both grey and color medical images. A comparison with various encryption methods is performed. The proposed encryption algorithm outperformed the recent existing encryption methods in encrypting medical images.

This paper is introducing a new image encryption method using hyper chaos based keys, multi step group-based binary gray encryption, bit shifting logic and finally prepares a cipher image, an encrypted image recognizing the plaintext image is very next to impossible. The principal advantage of chaos base encryption is there are sequences of key for multiple times execution of the encryption process. Initially enormous Hyper-chaos numbers are to be generated considering a set of equation and finally generating a decimal key and bit shifting key using these Hyper-chaos numbers. These keys are the entity of the multi step group based binary gray conversion and bit shifting logic performed on every individual pixel of plain image. And lastly a set of comparison studies like histogram analysis, information entropy, correlation coefficient, sensitivity test of the pfoin image with cipher image have been run. The experimental results show the key space analysis and the security in the encryption algorithm It is shown here the encryption scheme deal with the bit-wise operation on the plain image pixel provides high performance on security and reliability, robustness and invisibility.

Images are important information carriers in our lives, and images should be secure when transmitted and stored. Image encryption algorithms based on chaos theory emerge in endlessly. Based on previous various chaotic image fast encryption algorithms, this paper proposes a color image sector fast encryption algorithm based on one-dimensional composite sinusoidal chaotic mapping. The main purpose of this algorithm is to improve the encryption and decryption speed of color images and improve the efficiency of image encryption in the big data era. First, four basic chaos maps are combined in pairs and added with sine operations. Six one-dimensional composite sinusoidal chaos maps (CSCM) were obtained. Secondly, select the two best chaotic mappings LCS and SCS. The randomness of these two chaotic mappings was verified through Lyapunov index and NIST SP 800-22 randomness tests. Thirdly, the encryption process is carried out according to the shape of a traditional Chinese fan, and the diffusion and scrambling of each pixel of the image are performed in parallel. This greatly improves encryption speed. When diffusing, changing the value of one pixel can affect the values of multiple subsequent pixels. When scrambling, each pixel changes position with the three pixels before it according to the chaotic sequence. Finally, through many experiments, it is proved that the image encryption algorithm not only greatly improves the encryption and decryption speed, but also improves various indexes. The key space reached 2192, the average information entropy was 7.9994, the average NPCR was 99.6172, and the average UACI was 33.4646. The algorithm can also resist some common attacks and accidents, such as exhaustion attack, differential attack, noise attack, information loss and so on.

Currently, common image encryption methods mainly include symmetric encryption (such as AES, DES) and public key encryption (such as RSA, ECC). Although these traditional encryption methods perform well in terms of data security, they still have certain limitations in terms of multi-source data protection, efficient encryption and decryption, key management and protection against eavesdropping attacks. For example, symmetric encryption requires a secure shared secret between both sides of communication, while public key encryption is computationally complex and difficult to meet the real-time requirements of large-scale data transmission. In addition, existing encryption methods are often unable to make full use of the relevance between sources to optimize the efficiency and security of data encryption. To this end, this paper studies a source joint coding scheme based on a multi-level diversity coding system (MDCS) and applies it to image encryption. The scheme combines Shamir threshold secret sharing and source joint encryption to achieve hierarchical encryption of data by dividing images into multiple source blocks, and uses joint coding technology to improve anti-eavesdropping capabilities. On this basis, this paper further improves the shortcomings of the original source joint coding scheme, optimizes the encryption process, and enhances the security, reliability and computing efficiency of the system. Experimental results show that the scheme can improve the ability to resist attacks while ensuring the security of image encryption, providing an effective solution for image data protection in cloud computing, the Internet of Things and distributed storage environments.

Image encryption based on 3D Cubic-Sine Logistic Coupled Map and Improved Chirikov Map

Optimal algorithm for color medical encryption and compression images based on DNA coding and a hyperchaotic system in the moments