With the growing reliance on digital data transmission, ensuring the security of sensitive image data has become critical. This paper introduces a novel cryptographic method, the Latin Square Image Cipher (LSIC), implemented within a Substitution–Permutation Network (SPN) architecture to enhance image security. The LSIC uses symmetric encryption with keyed 256 × 256 Latin squares, which has strong properties for both diffusion and confusion. The probabilistic encryption feature introduces randomness to the least significant bits of images, significantly increasing security against differential attacks by generating varied ciphertext even with the same encryption key. Comparative analysis with existing cryptographic methods demonstrates that the proposed LSIC method outperforms others in key security metrics. The method achieves higher information entropy, which means that the encrypted images are less predictable, and it does a great job of diffusion, with a NPCR of 99.6689% and a UACI of 33.4936%. These results showcase the LSIC’s effectiveness in securing images against various forms of cryptanalysis, making it a robust solution for secure image transmission in multimedia and cloud-based applications.