Image Encryption Algorithm Based on Bit-Level Permutation and Dynamic Overlap Diffusion

Abstract

In order to guarantee the security of digital images, image encryption is a good tool. This paper puts forward a novel image encryption/decryption algorithm based on bit-level permutation and dynamic overlap diffusion. Firstly, location information set by users is used to scramble the plain image in the bit-level, changing the pixel position of the image while changing the pixel value. Then, using the plaintext related method to control the iteration parameters of Arnold transform. These two parts together form the permutation process of the algorithm. Thirdly, the overlap steps are set according to the encryption security requirements, and dynamic overlap diffusion is performed on the permutation image. At the same time, the plaintext information entropy and variance are used to update the diffusion key in the fivedimensional hyperchaotic system to achieve the plaintext correlation of the encryption key. Arnold transform and dynamic overlap diffusion can ensure that different key streams are generated when encrypting different images. Finally, experimental analysis and numerical simulation show that our algorithm has high efficiency, high security, high sensitivity, and can effectively resist various attacks.INDEX TERMS bit-level permutation, dynamic overlap diffusion, hyperchaotic system, image encryption, plaintext related key

Review of Image Security approaches: Concepts, Issues, Challenges and Applications

“…The article [6] gives an image encryption and decryption algorithm based on bit-level permutation and dynamic overlap diffusion. Firstly, the plain image is scrambled in the bit-level, changing the pixel position of the image while changing the pixel value using controlled Arnold transform and get the permutation image.…”

“…• NPCR [1,[4][5][6][7][8][9][10][11][12][13][14][15][17][18][19]: For better decryption algorithm NPCR value should be low. • UACI [1,[4][5][6][7][8][9][10][11][12][13][14][15][17][18][19]: For good decrypted image quality UACI value should be low. • PSNR [5,6,10,13,14,17,18]: The larger the PSNR value, the more similar the decrypted image is to the original image.…”

“…4. Correlation Coefficients [1,[4][5][6][7][8][9][10][11][12][13][14][15][17][18][19]: For a plain image, each pixel is highly correlated with its neighbor and adjacent pixels either in horizontal, vertical or diagonal direction. However, an efficient image cryptosystem should produce the cipher image with sufficiently low correlation (close to zero) in the adjacent pixels.…”

“…8. Encryption Efficiency: Peak signal to noise ratio (PSNR) [5,6,10,13,14,17,18] is used to measure the difference between the original image and the encrypted image. Also, the PSNR is usually used to assess the performance of image reconstruction.…”

A Secure Image Encryption Scheme based on Fully-Connected-Like Neural Network and Edge Pixel Reset

“…However, some existing chaotic-based encryption algorithms have some shortcomings. Such as, the key design is simple [19,20], cannot resist some plaintext attacks [21][22][23] and requires a large number of pseudorandom numbers [9,23,26]. These methods may lead to inefficient encryption processes and lower security levels.…”