A new controllable multi-wing chaotic system: applications in high-security color image encryption

Due to its rich dynamic behaviors and diversity, the multi-wing chaotic system has garnered widespread research interest, and its applications are currently under intensive investigation. In this paper, a new four-dimensional controllable multi-wing chaotic system is proposed by introducing a cosine function on the basis of three-dimensional Sprott-A system. The system can generate a controllable number of wings by adjusting its parameters, thus realizing the precise control of chaotic behavior. Through numerical simulation, the high randomness and complexity of the system are verified. On account of the superiority of the system, a new color image encryption method is designed based on this new system. The method uses chaotic sequences to implement DNA-level image scrambling operation and discrete wavelet transform (DWT) to decompose the scrambled image, and then scramble these decomposed components. The scrambled matrices are reconstructed with inverse discrete wavelet transform (IDWT), and bidirectional traversal diffusion produces the ciphertext image. Performance analysis shows that the average NPCR and UACI values of the encryption scheme are 99.60% and 33.49%, respectively, and the rigorous significance tests are passed. Robustness analysis indicates that the algorithm effectively resists various levels of noise and cropping attacks. Additionally, the encryption time for a 256 × 256 image is only 0.2 s. These results demonstrate the algorithm’s excellent performance in encryption security as well as its outstanding efficiency.