With the rapid advancement of information technology, the secure transmission and storage of digital images have garnered increasing attention. To safeguard image information from theft and enhance security during network transmission, a novel image encryption algorithm based on a two-dimensional chaotic system named the two-dimensional sine-cubic modular map (2D-SCMM) and a rotating dial model is proposed. First, the 2D-SCMM is designed, and comprehensive dynamic analyses along with randomness assessments are conducted. Second, in the scrambling phase, a diagonal cyclic-shift transformation is employed to dynamically update the distribution of pixel positions. Third, during the diffusion phase, inspired by the dial phone, the rotating dial model is utilized to achieve dynamic pixel updates. Finally, extensive testing and comparative analyses reveal that image pixels are evenly distributed, the average entropy value for grayscale images is 7.9993, and the correlation coefficients approach 0. Meanwhile, the encryption algorithm is highly secure against various attacks, such as noise attacks and cropping attacks.
Zhang et al. (Thu,) studied this question.