Robust image encryption scheme based on 6D hyper-chaos and DPA-resistant S-box

Image encryption is widely used for securing digital images, with chaos-based schemes among the most promising solutions. Recently, Khalid M. Hosny proposed an image encryption scheme based on a 6D hyperchaotic system and Fibonacci Q-matrix. While this scheme offers notable benefits, it suffers from significant weaknesses, such as improper utilization of initial parameters, weak keys, and flaws in key management, making it vulnerable to attacks. Additionally, it fails to encrypt homogeneous images, after any iteration. This paper proposes an enhanced encryption scheme that addresses these weaknesses. The statistical and simulation test results show that our scheme outperforms the original scheme in terms of security and performance. It passed standard security tests (such as image histogram, chi-square distribution, NPCR, UACI, entropy, correlation, and key space analysis) for standard images at n = 2 iterations. The proposed scheme includes a cryptographic key with low computational cost, a high-resistant S-box to DPA attacks, and improved chaos parameter transfer to provide security. Experimental results show that the proposed scheme outperforms similar schemes in both security and bandwidth consumption.