A color image cryptosystem based on dynamic DNA encryption and chaos

Image information security is an important research direction in the field of information security. In existed image encryption schemes, original image is transformed to meaningless random noise signal which would draw attention and thus attract attacks. In this work, aiming to encrypt image to visually meaningful encrypted image, a novel image cryptosystem based on fractal graph generating is proposed which is called Visually Meaningful Image Encryption (VMIE) scheme. The VMIE scheme is to encrypt plain images into fractal scenery or fractal plant images by using fractal graph generation parameters as keys. According to these keys, receiver can get the plain image from fractal image by a reverse process. Based on the pixel value distribution characteristics of different plain images, different fractal transformations can be selected to produce different fractal images, which can better camouflage the plain images and make the encrypted plain images safer. In this paper, a new image encryption method is proposed, which is different from VMIE based on information hiding with limited hiding capacity, and from VMIE based on image sharing, which takes up a large amount of storage space and image size. Simulation experiments show that the proposed new scheme has low computation complexity and high security and the encrypted plain images have well understandability, strong resistance to compression and small data increase.

In the field of secure communications, the robustness of cipher images transmitted in various channels is becoming increasingly important. In this paper, a robust image encryption algorithm combining a new chaotic system and discrete cosine transform is proposed, which is interlinked with plain information and is resistant to high-intensity noise attacks. First, a 5D continuous hyperchaotic system is proposed, leading to an interrelated sequence of five chaotic sequences. Second, the plain image is subjected to discrete cosine transform. Then the transform domain image is quantized, and some high-frequency components are removed, and then the high-frequency components are filled with chaotic sequences. Next, the transform domain image is scrambled, and inverse discrete cosine transform is performed, and its gray value is mapped to obtain a spatial domain image. Finally, the spatial image is scrambled by the spiral transformation, and then the diffusion operation is performed to obtain the encrypted image. Through the simulation experiment, the histogram, correlation, differential attack, and robustness are analyzed. The experimental results show that the proposed encryption algorithm can resist high-intensity noise attacks and has good encryption performance.

With the popularity of the Internet, the transmission of images has become more frequent. It is of great significance to study efficient and secure image encryption algorithms. Based on traditional Logistic maps and consideration of delay, we propose a new one-dimensional (1D) delay and linearly coupled Logistic chaotic map (DLCL) in this paper. Time delay is a common phenomenon in various complex systems in nature, and it will greatly change the dynamic characteristics of the system. The map is analyzed in terms of trajectory, Lyapunov exponent (LE) and Permutation entropy (PE). The results show that this map has wide chaotic range, better ergodicity and larger maximum LE in comparison with some existing chaotic maps. A new method of color image encryption is put forward based on DLCL. In proposed encryption algorithm, after various analysis, it has good encryption performance, and the key used for scrambling is related to the original image. It is illustrated by simulation results that the ciphered images have good pseudo randomness through our method. The proposed encryption algorithm has large key space and can effectively resist differential attack and chosen plaintext attack.

Adaptive embedding: A novel meaningful image encryption scheme based on parallel compressive sensing and slant transform

To protect the security of image information in the process of storage or transmission, we propose an efficient image encryption method using chaos and game of life (GoL). First, a plaintext-related image scrambling method based on chaos and GoL is proposed to reduce the adjacent pixel correlation of the plain image. In this method, double scrambling is performed on the original image: the first scrambling matrix is constructed by logistic map and the rules of GoL; the second scrambling matrix is generated based on two-dimensional (2D) logistic map and magic square. The original image is scrambled by the above-mentioned scrambling matrices, which can efficiently reduce the strong adjacent pixel correlation, thus enhancing the image scrambling effect. Next, the 4D hyperchaotic system and GoL are employed to diffuse the scrambled image and get the cipher image. Additionally, the average pixel value of the original image is used to generate the initial values of the logistic map and 2D logistic map in scrambling process. Therefore, our encryption scheme is very sensitive to the plain image and can effectively resist the chosen-plaintext attack and known-plaintext attack. Finally, the experimental results and performance analyses show that the proposed encryption algorithm has the advantages of large key space and good scrambling effect, and it can effectively resist various typical attacks, so it can effectively protect the security of the image information.

With the introduction of the deep learning (DL), joint source and channel coding (JSCC) has achieved great success and has been demonstrated to have better performance especially in the case of low signal-to-noise ratios (SNRs) and limited bandwidth. As a promising wireless transmission technology, DL based JSCC (DJSCC) can serve different kinds of applications. However, some applications (e.g., biomedical, surveillance, financial and military) have strict requirements on data privacy and data security. Traditional image encryption methods are based on the shuffle operation and changing the intensity of each pixel in the plain image, which changes the ambient structure of the picture and degrades the reconstruct performance of the DJSCC. Perceptual image encryption methods for deep neural networks (DNNs) have been demonstrated to have similar classification accuracy in comparison to the DNNs trained on plain images. However, it is unknown how to conduct image encryption methods in the DJSCC framework. In this paper, we investigate different image encryption methods at first and compare their reconstruction performance. This research work provide a guidance for selecting the image encryption method suitable for DJSCC transmission.

To improve the security level of image encryption based on chaos theory, a novel bit-level transform method which could enhance the dynamical performance of chaotic maps is proposed and a new image encryption algorithm based on a random irregular blocking method is also designed in this paper. Firstly, in the bit-level transform method, three chaotic maps are combined to generate a novel chaotic sequence. From a series of performance analyses results, the generated sequence not only successfully passes NIST tests, but also performs better than the original sequence, with a larger chaotic parametrial range, high complexity, etc. Then, an image encryption algorithm based on the newly generated chaotic sequence is proposed, in which a random irregular blocking method is adopted. Random irregular blocking could solve the problem of insecurity in the fixed blocking method. With a color Lena image as an encryption example, we analyze the security of the encryption algorithm by conducting a sufficiently large number of experiments using the encrypted image. For the encrypted Lena image, the average values of information entropy, NPCR, and UACI are 7.9931, 0.9961, and 0.3352, respectively. The experimental results and security analyses results provide evidence that the proposed encryption algorithm has good performance and can resist various typical attacks.

Lightweight image encryption refers to the use of encryption algorithms designed to secure images while considering the limitations of resources, such as processing power and memory, typically found in devices like IoT devices, mobile phones, and embedded systems. This paper proposes a lightweight image encryption based on an LED encryption algorithm and a method for a pseudo number generator called Rossler attractor. Image is split into their three-color bands (RGB) and then partitioned into a block for encryption, a three-equations model (Rossler Attractor) is used for a pseudo number generator, a specific operation applied for producing key scheduled for rounds in LED to seem as random as possible. The experiment explains the objective test to ensure the performance. The contribution of this work is to present an efficient method for lightweight encryption that is applied to color images with a pseudo number generator-based Rossler attractor dependent on a three-dimensional equation. The technique makes it sensitive to initial conditions and could seem like dynamic encryption that resisted many types of attacks. Visually test represented by the histogram of the image before and after encryption is noted that the result is uniform and differs from the input one. The correlation of the output image is a low value which means no correlation is there between pixels horizontal, vertical and diagonal. The similarity test also applied such as MSE, PSNR and SSIM which also explain no similarity between plain and encrypted images. The randomness of generated numbers was tested using the standard test NIST for evaluation of the input key

In this paper, a novel image encryption algorithm is presented based on self-cited pixel summation. With the classical mechanism of permutation plus diffusion, a pixel summation of the plain image is employed to make a gravity influence on the pixel positions in the permutation stage. Then, for each pixel in every step of the diffusion stage, the pixel summation calculated from the permuted image is updated. The values from a chaotic sequence generated by an intertwining logistic map are selected by this summation. Consequently, the keystreams generated in both stages are dependent on both the plain image and the permuted image. Because of the sensitivity of the chaotic map to its initial conditions and the plain-image-dependent keystreams, any tiny change in the secret key or the plain image would lead to a significantly different cipher image. As a result, the proposed encryption algorithm is immune to the known plaintext attack (KPA) and the chosen plaintext attack (CPA). Moreover, experimental simulations and security analyses show that the proposed permutation-diffusion encryption scheme can achieve a satisfactory level of security.

This study proposes a self-adaptive image encryption algorithm based on the quantum logistic map. First, the initial values are substituted into the quantum logistic map based on an iteration process to generate three random sequences. After preprocessing, three new random sequences with better randomicity were obtained from the generated random sequences. In particular, the correlation coefficients for random sequences before and after preprocessing are compared to determine the best model to make the correlation coefficients closer to zero. Second, one random sequence in the scrambling stage is selected with respect to the plain image. The selected random sequence is then used to perform row-column perturbation on the plain image. Finally, the remaining two random sequences are used to perform forward and reverse diffusion to obtain the final cipher image. Because of the dependence on the plain image, the algorithm can frustrate the chosen-plaintext and known-plaintext attacks. Experimental results show that the proposed encryption algorithm can achieve secure communications.

This paper proposes a dynamic RNA-encoded color image encryption scheme based on a chain feedback structure. Firstly, the color pure image is decomposed into red, green, and blue components, and then a chaotic sequence based on plaintext association is introduced to encrypt the red component. Secondly, the intermediate ciphertext is obtained by diffusion after encryption by bit-level permutation, RNA dynamic encoding, RNA dynamic operation rules, and RNA dynamic decoding. Finally, to enhance the security of the image cryptosystem, the green and blue components of the image are repeatedly encrypted using the chain encryption mechanism associated with the intermediate ciphertext to obtain the color cryptographic image. In this paper, a 2D-SFHM chaotic system is used to provide pseudo-random chaotic sequences, and its initial key is calculated by combining the hash function and external parameters of the image, and the one-time ciphertext encryption strategy causes the proposed encryption to effectively resist cryptographic attacks. Experimental results and security analysis show that our encryption algorithm has excellent encryption effects and security performance against various typical attacks.

DNA computing based image encryption is a new, promising field. In this paper, we propose a novel image encryption scheme based on DNA encoding and spatiotemporal chaos. In particular, after the plain image is primarily diffused with the bitwise Exclusive-OR operation, the DNA mapping rule is introduced to encode the diffused image. In order to enhance the encryption, the spatiotemporal chaotic system is used to confuse the rows and columns of the DNA encoded image. The experiments demonstrate that the proposed encryption algorithm is of high key sensitivity and large key space, and it can resist brute-force attack, entropy attack, differential attack, chosen-plaintext attack, known-plaintext attack and statistical attack.

In this paper, we propose a new color image encryption method using color scrambling based on the chaotic permutation multiple circular shrinking and expanding (CPMCS/ CPMCE). The plain color image with a size of m x n x 3 is arranged in two-dimensional array, where each row consists of the Red, Green, and Blue (RGB) component, forming two-dimensional array with a size of m x 3n. The arranged 2D array then permuted by CPMCS for the each row and column. To reconstruct the original image, the ciphered image is arranged in 2D array then is permuted by CPMCE for each column and row. The proposed method is characterized by very high key space that reaches 22,895,713 for an image size of 256x256, so that resistance to brute force attack and can anticipate the emergence of quantum computers. It also resistant to a differential attack due to change a single bit in the plain image causes a significant change in the ciphered image. The proposed encryption also yield completely difference ciphered image series from the same plain image just using arbitrary increment sequence key. It is also robust to JPEG compression so the ciphered image can be stored in smaller size, such as for the ciphered Lena image only needs 1/5.2 of the original one when compressed using JPEG 70 %. It also resistant to noise scheme (Gaussian, Poisson, Salt&Pepper, and spekle), data loss, and brightness-contrast adjustment, so the ciphered image can be transmitted in a non error free communication system.

Hundreds of image encryption algorithms have been developed for the security and integrity of images through the combination of DNA computing and chaotic maps. This combination of the two instruments is not sufficient enough to thwart the potential threats from the cryptanalysis community as the literature review suggests. To inject more robustness and security stuff, a novel image encryption scheme has been written in this research by fusing the chaotic system, DNA computing and Castle—a chess piece. As the plain image is input, its pixels are shifted to the scrambled image at the randomly chosen pixel addresses. This scrambling has been realized through the routine called Image Scrambler using Castle (ISUC). Castle randomly moves on the hypothetical large chessboard. Pixels taken from the plain image are shifted to the addresses of the scrambled image, where Castle lands in each iteration. After the plain image is scrambled, it is DNA encoded. Two mask images are also DNA encoded. Then to throw the diffusion effects in the cipher, DNA Addition and DNA XOR operations between the DNA encoded pixels data and the DNA encoded mask images have been conducted. Next, the pixels data are converted back into their decimal equivalents. Four dimensional chaotic system has been used to get the chaotic vectors. The hash codes given by the SHA-256 function have been used in the cipher to introduce the plaintext sensitivity in its design. We got an information entropy of 7.9974. Simulation carried out through the machine, and the thorough security analyses demonstrate the good security effects, defiance to the varied attacks from the cryptanalysis community, and the bright prospects for some real world application of the proposed image cipher.

– In recent years, with rapid development in information and communication technologies, sharing digital images in social media have facilitated. However, since images privacy matters in our society, keeping images protected became a big challenge we have to deal with. In this paper, we propose a new image encryption method using Image Pixel Shuffling and 3D Chaotic map. First, the plain image is encoded using pixel shuffling, then the result is XORed with a key, and finally, the 3D chaotic map is performed on it. The security will be increased by using three steps to encrypt the image. Our results show that the proposed approach has a good performance and it is better than those of some notable image encryption algorithms. We got entropy value 7.9901 of cipher image, NPCR of 99.6628%, and UACI of 33.6781%. MATLAB was used to implement the proposed image encryption approach.