Image Encryption Algorithm Via 2D-LSIM Chaotic System

In this study, a novel two-dimensional chaotic system, 2D-LSIM, is proposed by integrating Logistic and Sine maps through a cascaded structure and extending it from 1D to 2D to generate more complex chaotic behavior. This system demonstrates a broader chaotic range than the three existing 2D chaotic systems. Based on 2D-LSIM, an image encryption algorithm (LSIM-IEA) is developed using four rounds of permutation and diffusion to enhance encryption performance. The proposed method is evaluated across eight aspects: key security, resistance to differential attack, chosen-plaintext attack, noise and data loss attack, local Shannon entropy, pixel correlation, contrast, and efficiency. A total of 22 out of 25 cipher images encrypted using LSIM-IEA achieved ideal local entropy values, indicating high randomness. In addition, the pixel correlation coefficients in horizontal, vertical, and diagonal directions were close to zero, demonstrating the algorithm’s ability to effectively eliminate statistical correlations and enhance security. Experimental results confirm the superiority of LSIM-IEA over existing algorithms in both robustness and encryption quality.