A chaotic image encryption scheme based on cat map and MMT permutation

Abstract

This paper proposes an image encryption scheme based on cat mapping and matrix magic transformation (MMT) replacement method. First, the secure hash algorithm SHA-512 is used to generate 12 sets of keys, which are used for the initial values of the system and the required values of the algorithm for cat mapping and 2D-Logistic-adjusted-Sine map (LASM). Secondly, the plaintext image is scrambled by the cat mapping. Then, the matrix after the cat map replacement is again scrambled by the MMT replacement method to generate the permutation matrix. Finally, the permutation matrix is used for the bitxor operation with the chaotic sequence matrix generated by the 2D LASM system to realize the diffusion process of the scrambled image. Experimental results and security analysis show that the encryption algorithm has good performance and can resist various typical attacks.