Self-adaptive permutation and combined global diffusion for chaotic color image encryption

As to color image encryption, most of the previous algorithms are to encrypt its R, G, B components, respectively, which neglected the correlations among R, G, B components. To overcome this problem, a type of chaotic color encryption scheme was proposed by Wang et al. based on combined permutation and combined diffusion. Unfortunately, there are some drawbacks in the scheme and it has been cryptanalyzed soon. To strength the security performance, a new scheme based on coupled logistic map, self-adaptive permutation, S8 S-boxes transform and combined global diffusion is proposed in this paper. Simulation results and analyses show that our cryptosystem is immune to some well-known attacks and has high security for practical color image encryption applications.