From Diffusion to Confusion of RGB Pixels Using a New Chaotic System for Color Image Encryption

Over the past decade, the transmission of images over digital and social networks, as well as their archiving on clouds, has increased dramatically. It has become necessary and urgent to secure them during their transmission or when archiving. In this paper, we propose a new color image encryption (CIE) scheme based on a single scroll chaotic system, using neurons with two dendrites. The originality of the proposed CIE scheme is that the main encryption step is based only on color pixel scrambling, which is traditionally used for diffusion. Based on the proposed CIE scheme we have developed three different approaches. From color pixel scrambling (CPS), to full color pixel component scrambling (FCPCS), passing through intra-color pixel component scrambling (ICPCS), we show that color pixel component scrambling can act not only as a permutation, but also as a substitution, ensuring both confusion and diffusion properties. The experimental results show that using the proposed scheme, regardless of the approach used, we can efficiently obtain encrypted color images. In particular, the results obtained with the FCPCS approach show that statistical and differential attack analyses are comparable to those obtained with current state-of-the-art methods that combine permutation and substitution steps.