A Novel Chaotic Image Encryption Algorithm Based on Pixel and Bit Level Scrambling-diffusion
Ruisong Ye, Jiebin Su, Yuhan Tang, Haoran Li, Haoyu Zhi · 2022
A color chaotic image cryptosystem algorithm based on pixel level and bit level scrambling-diffusion is proposed. The cryptosystem includes key stream generation, scrambling process and diffusion process. In scrambling process, the proposed algorithm uses row-column exchange to get the scrambled pixel matrix at pixel level; it also manipulates the random exchange of higher bits and lower bits of the scrambled pixels based on sorting the key streams. The scrambling process effectively weakens the correlation between adjacent pixels as well as higher bit-planes. In diffusion process, the algorithm establishes a two-way diffusion mechanism using bitwise XOR and additive modular operations to improve the security and performance of the proposed image cryptosystem. The key streams applied to control the encryption process are produced by 3D skew tent map, which has large range of cipher key and excellent chaotic performance. Experimental results demonstrate that the proposed cryptosystem has high security and good performance.