Chaos-Based Medical Image Encryption Using Symmetric Cryptography

In this paper, we propose an encryption scheme for the medical image encryption based on combination of scrambling and confusion. Chaotic cat map is used for the scrambling the addresses of the medical image pixels. In order to provide security for the scheme, a modified form of Simplified version of Advance Encryption Standard (S-AES) is introduced and applied. The modification is that we make use of chaos for S-box design and replace it with that of S-AES. The so called Chaotic S-AES has all cryptographic characteristics and requirements of S-AES. Hence, the main contribution of this work is that we make use of chaos in both image diffusion and confusion parts. In order to check the performance of the method, experimental implementation has been done. It worth be noting that the resistance of the scheme against differential and linear cryptanalysis is at least as of S-AES.