Multichannel image encryption using dynamic substitution and JSMP map

Abstract

The confidentiality of images is crucial in medical, military, satellite, and IoT fields. Encipherment ensures confidentiality, relying on strong Substitution boxes (S-boxes) and Permutation boxes (P-boxes). Dynamic S-boxes prevent fixed weak points, while randomness weakens pixel correlations. Numerous techniques are proposed in the field but are highly complex or complicated. This paper presents a simplified approach for constructing a robust dynamic S-box that utilizes the properties of modular arithmetic and JoanS-MuraliP’s (JSMP) chaotic map. Several tests were performed that proved that the suggested S-box is highly non-linear and has strict avalanche criterion (SAC) value above 0.5. Additionally, a powerful encipherment system is proposed, utilizing dynamic substitution boxes and JSMP chaotic map. Dynamic substitutions and permutations are applied separately to the image’s red, green, and blue channels. Experimental results demonstrate resistance to statistical and differential attacks, outperforming advanced algorithms with a simpler design. The system achieves 100 % NPCR across all channels, a benchmark typically only reached by complex systems. Comparative analysis validates the proposed algorithm’s efficacy over established methods.