Color image encryption scheme combining a 2D hyperchaotic Sin–Henon system and the division algorithm

Abstract

As an important transmission medium, color images can provide more information, but in the process of image encryption, few algorithms fully consider the relationship between three color planes. To achieve a more secure and effective color image encryption effect, we propose a novel scheme combining a 2D hyperchaotic Sin–Henon system (2D-SH) and the division algorithm. 2D-SH is designed based on Sin mapping and Henon mapping, which has a broader chaotic range, better ergodicity, and more complicated chaotic behavior. The division algorithm is applied to the chaotic sequences produced by 2D-SH to generate a position matrix and two pseudo-random matrices for cross-plane scrambling and diffusion. The main encryption process involves three steps. Firstly, a color plaintext image is dimensionally reduced and preprocessed into a 2D pixel matrix to improve the efficiency of scrambling and diffusion. Secondly, the position matrix is used to achieve cross-plane scrambling. Finally, the pseudo-random matrices and the position matrix are used to realize synchronous diffusion and scrambling. The algorithm is simple in structure and can complete the encryption with only one round of the process. Simulation experiments and security analyses demonstrate that the proposed algorithm can not only encrypt images securely and fast, but also successfully pass various tests, demonstrating robustness and effectiveness. In addition, SH-CIEA outperforms some latest algorithms in terms of variance, entropy, and other aspects. The calculation time is nearly 0.61 s, showing its efficiency for practical applications.