An image encryption scheme without additional key transmission based on an N-dimensional closed-loop coupled triangular wave model

Currently, many image encryption schemes either require additional secure channels for key transmission or employ a key that exhibits a lack of correlation with the plaintext, thereby reducing the security of the algorithm. This study proposes a novel image encryption scheme to address this issue. A new N-dimensional closed-loop coupled triangular wave model is developed to overcome the limitations of the sine function in chaotic systems while reducing the difficulty of the chaotic system design. Experimental analysis demonstrates that the generated chaotic systems exhibit complex chaotic behaviors and outperform other chaotic systems designed using the sine function. Specifically, we utilize difference extension technology to embed key information into the plaintext image and design a scrambling and diffusion algorithm based on Latin rectangles to encrypt the remaining pixel matrix without key information. Finally, the pixel matrix containing the key information is concealed to obtain the final ciphertext image. Simulation analysis and security evaluation demonstrate that the proposed algorithm outperforms the encryption performance and security of several advanced image encryption algorithms.