Image Encryption Using Dynamic AES and Logistic Chaotic Map

Securing digital communication systems against evolving threats requires advanced encryption techniques. This paper presents an enhanced cryptographic scheme combining chaos theory with a dynamic version of the Advanced Encryption Standard (AES). Unlike conventional AES-128, which relies on a static S-box vulnerable to algebraic attacks, the proposed scheme employs a key-dependent dynamic S-box generated using the logistic map. This method introduces significant sensitivity to key variations, ensuring that even minor changes produce vastly different encryption outcomes. Additionally, the Cipher Block Chaining (CBC) mode strengthens the encryption by making each block dependent on the previous one, thwarting pattern detection. The scheme's effectiveness is validated by encrypting grayscale and colour images, with performance measured using NPCR, UACI, Entropy, SSIM, and PSNR metrics. Results demonstrate enhanced security, higher randomness, and robustness compared to standard AES, making the proposed approach a promising solution for securing sensitive data in modern communication systems.