Chaotic Image Encryption Scheme Based on Double Substitution and Diffusion Process

In this article, we suggest a color image encryption algorithm. The proposed approach is based on a double substitution by chaotic Substitution Box (SBOX), and a strong diffusion mechanism that mixes the color channels of the plain image. The encryption algorithm is carried out in three steps: Generation of encryption keys from three one-dimensional chaotic maps, construction of SBOX, substitution and diffusion. The three chaotic maps are iterated to generate three sequences of keys used for the construction of the SBOX and in the diffusion and confusion process. The key space used is large enough to protect the proposed algorithm from an exhaustive attack, and the results of the statistical and differential simulations show the robustness and efficiency of our approach against statistical and differential attacks.