Robust secure image encryption scheme using a 6D hyper-chaotic system with dynamic parameters and DNA encoding
Mohammed Salih Mahdi, Hayder Najm, Amjed Abbas Ahmed, Sumaia Mohammed Al-Ghuribi · Franklin Open · 2026
In this paper, we suggest a highly efficient and safe image encryption algorithm that is synergistic in combining a new 6D hyper-chaotic system with dynamically encoded DNA. Our method has two innovations to overcome the shortcomings of the current chaos-based cryptosystems, which lack key space, use fixed parameters, and do not provide diffusion. First, a six-dimensional Chen hyper-chaotic system generates complex pseudo-random sequences, significantly increasing the key space to 2 384 . Second, the system parameters are made time-varying and dynamic by coupling with Ikeda maps, significantly increasing unpredictability and immunity to parameter estimation attacks. Encryption is divided into two phases: pixel scrambling to permutation, then DNA encoding, which dynamically chooses one of six rules per image row to cause as much confusion as possible, and a diffusion process consisting of XOR operations with a multi-sequence chaotic mask. Thorough security evaluations prove that the scheme has outstanding performance: almost ideal information entropy (> 7.997 bits/pixel), insignificant correlation coefficients between neighbouring pixels, and high sensitivity to alterations in plaintext (NPCR > 99.61% and UACI 33.45%). The system can pass NIST statistical tests, confirming the ciphertext's randomness.