Multiimage Encryption Algorithm Based on 2D Hyperchaotic Map and 3D Random Cyclic Diffusion

With increasing remote work and online learning, there is a growing demand for image encryption algorithms with sufficient capacity and efficiency. In this paper, we propose an effective multiimage encryption algorithm. By coupling the Sine map and some useful mathematical functions, we design a two-dimensional hyperchaotic system (2D SFCM). After evaluating different chaos indicators, it is found that the Lyapunov exponent and the permutation entropy of 2D SFCM are significantly higher than those of other chaotic mappings. Additionally, its sample entropy has an average value of 1.916. These results indicate that the chaotic sequences generated by 2D SFCM exhibit a high level of randomness. The pseudo-random sequences generated by this chaotic system are combined with image encryption algorithms to shuffle 3D images by accessing pixels from different planes. Using randomly determined pixel points, cyclic diffusion is performed on each plane to ensure that the pixel information at any point extends to the whole 3D image. Experimental results demonstrate that the proposed algorithm exhibits good key sensitivity and robustness. Numerical results show that the algorithm has considerable capabilities in resisting common attacks. Compared to related algorithms, our algorithm shows certain advantages in terms of information entropy and resistance to differential attacks.