DESIGN AND EVALUATION OF A HYBRID HENON-LOGISTIC CHAOTIC GENERATOR FOR IMAGE ENCRYPTION: A COMPARATIVE STUDY WITH TRADITIONAL ENCRYPTION METHODS FOR DIGITAL DATA PROTECTION

Abstract

This paper presents a Hybrid Chaotic Encryption System (HCES) for image encryption based on the unidirectional coupling of a two-dimensional Hénon map and a one-dimensional Logistic map. The Hénon dynamics modulate the Logistic control parameter, generating a hybrid chaotic sequence used to construct a dynamic substitution box (S-box) and perform confusion and diffusion operations. The proposed scheme was implemented in Python and evaluated using six standard test images through visual inspection, Shannon entropy, correlation coefficients, chi-square testing, the Number of Pixels Change Rate (NPCR), and the Unified Average Changing Intensity (UACI). The experimental results show that the encrypted images exhibit noise-like patterns, with entropy values approaching 8 bits and correlation coefficients generally close to zero. A comparative evaluation using the Lena image and an identical data size of 268,098 bytes was also conducted against AES-128 and AES-256.