A chaotic symmetric image cipher using a pixel-swapping based permutation

Chaos-based image cipher has been extensively investigated over the last two decades or so to meet the increasing demand for secure image transmission over open networks. In this paper, a chaotic symmetric image cipher with permutation-diffusion architecture is presented. In the permutation stage, we introduce a novel shuffling method, which swaps each pixel in plain image with another pixel at a location chosen by chaotic Hénon map. Compared with conventional permutation schemes based on area-preserving chaotic maps, such as baker map, Arnold cat map, and standard map, the new scheme is superior in both effectiveness and efficiency. In the diffusion stage, each shuffled pixel is masked according to both key stream element and previous ciphered pixel so as to make the cryptosystem secure against differential attack. Intensive cryptanalysis is carried out and the experimental results demonstrate that the cryptosystem can withstand all kinds of known attacks, including brute-force attack, differential attack, known/chosen plain-text attack as well as various statistical attacks.