A new color image encryption algorithm based on iterative mixing of color channels and chaos

Abstract

In this paper, we present a novel secure cryptosystem for direct encryption of color images, based on an iterative mixing spread over three rounds of the R, G and B color channels and three enhanced chaotic maps. Each round includes an affine transformation that uses three invertible matrices of order 2 2, whose parameters are chosen randomly from a chaotic map. The proposed algorithm has a large secret key space and strong secret key sensitivity, which protects our approach from a brutal attack. The simulation results show that our algorithm is better for color images in terms of Peak Signal to Noise Ratio (PSNR), entropy, Unified Average Changing Intensity (UACI) and Number of Pixels Change Rate (NPCR).