6D Hyperchaos‐Driven Dynamic S‐Boxes and Cross‐Channel Diffusion for Secure Image Encryption

ABSTRACT The widespread transmission of visual data over networks requires robust encryption to prevent unauthorized access and leakage. Most existing image encryption schemes rely on low‐dimensional chaotic maps, and their security is compromised due to single‐channel processing and structurally simplistic designs. Therefore, developing an encryption scheme that enhances both security and interchannel dependency remains a challenging yet critical task. To overcome these limitations, this paper proposes a color image encryption scheme based on a 6D memristive hyperchaotic system. The algorithm uses a multistage encryption framework that integrates cross‐channel diffusion and nonlinear diffusion. A chaos‐driven dynamic S‐Box is introduced for nonlinear local substitution, while a 2D Arnold transform is applied for global scrambling, collectively enhancing pixel confusion. The experimental results show that the entropy of the proposed scheme reaches 7.9993, which is close to the ideal maximum value of 8. Moreover, it obtains NPCR and UACI values of 99.6095% and 33.506%, close to the ideal values (99.6094% and 33.4635%). These results not only demonstrate that the proposed algorithm provides a secure and efficient solution but also confirm its superiority over existing benchmarks, showing great potential for image encryption applications.