Image encryption is crucial for ensuring the security of image data and protecting privacy. However, some existing image encryption algorithms have shortcomings in security and efficiency. To improve the security and efficiency of encryption, a new multiple-image encryption algorithm is proposed in this paper. The algorithm uses the hash of the original image and an external key to generate the initial value of the hyperchaotic map, which guarantees a larger key space and superior randomness. In the process of encryption, the input images are converted into pixel matrices by pixel recombination, and the pixel matrix is scrambled by intra-layer block scrambling and inter-layer block replacement. Then, three-dimensional dynamic diffusion of the scrambled pixel matrices is carried out to improve the encryption speed while ensuring security. Experimental results show that the proposed encryption algorithm can resist statistical attacks, brute-force attacks, chosen-plaintext attacks, cropping attacks and noise attacks. It is worth noting that the encryption time for Formula: see text images is 0.3069Formula: see textsec, so the algorithm is efficient.
Wan et al. (Wed,) studied this question.