2D sine-logistic-tent-coupling map for image encryption

With the development of chaotic image encryption technology, chaotic system is increasingly at the core of cryptography, a good performance of the chaotic system is very important for the whole encryption algorithm. Some existing two-dimensional chaotic systems have the risk of small key space and are easy to crack. Based on this, a new two-dimensional sine-logistic-tent-coupled mapping chaotic system is proposed, and the encryption algorithm is designed on this basis. The performance analysis shows that the chaotic mapping has better chaotic behavior than the existing two-dimensional chaotic mapping. Overall, image encryption includes scrambling and diffusion of two steps. Based on the traditional zigzag scrambling, authors use the two-way zigzag traversal to disturb the whole image to reduce the correlation between pixels, which has achieved good results. And the use of pixel-level diffusion operation makes the whole image completely chaotic. In addition, the key used in the encryption process is related to the plaintext image, which further enhances the security of the encryption algorithm. Simulation results and security analysis show that the encryption algorithm has high-security performance and can resist external attacks.