A color image encryption method based on a CML–ECA neurodynamic chaotic system and TV-BST architecture
Xin Xie, Sen Yang, Hao Ning, Yu Zhou, Kun Zhang · Scientific Reports · 2026
Existing chaotic image encryption schemes have made progress in improving keystream randomness and dynamic substitution; however, the coupling between the underlying chaotic dynamics, S-box construction, and the overall encryption architecture remains limited, especially for high-resolution color images. To address this issue, this paper proposes a color image encryption method that integrates a CML-ECA neurodynamic chaotic system with a TV-BST-based permutation-diffusion framework. Specifically, an ECA-CML composite chaotic model is first established, in which a local-entropy adaptive coupling strategy is combined with Wilson-Cowan excitatory-inhibitory neurodynamic feedback to modulate the Logistic-sine control parameters and lattice states, thereby generating spatiotemporal chaotic sequences with enhanced sensitivity, entropy, and finite-precision robustness. The resulting chaotic flow is then used to construct an initial S-box through a Fisher-Yates shuffle, which is further optimized by a genetic mechanism under joint cryptographic objectives to obtain a high-quality chaotic S-box. At the architecture level, the TV-BST module performs key-dependent row-column permutation for global scrambling, while each color channel undergoes forward and backward chained diffusion together with S-box substitution. Experimental results show that the proposed method produces nearly uniform histograms, low adjacent-pixel correlation, high key sensitivity, and NPCR/UACI values close to their theoretical expectations. In addition, the scheme exhibits robustness against common disturbances such as noise contamination and cropping attacks. These results indicate that the proposed co-designed framework provides an effective and secure solution for color image encryption.