A novel image encryption and decryption scheme integrating two-way chaotic maps, iterative cellular automata, and online tessellation automata

• Innovative Encryption Approach: The proposed scheme integrates chaotic maps, cellular automata, and online tessellation automata for high-security encryption and decryption. • Block-wise Processing: Encryption operates on 8×8-pixel blocks, applying a combination of elementary cellular automata and online tessellation automata rules. • Unlike classical cellular automata, which rely on a fixed set of rules applied uniformly across cells, tessellation automata introduce dynamic rule updates during the computation process. • Enhanced Pseudo-randomness: Chaotic maps generate unpredictable sequences, strengthening the security of the cipher matrix. • Robust Against Attacks: The scheme effectively resists statistical, brute force, and differential attacks, ensuring strong cryptographic security. Security of Image data has emerged as a critical issue in many fields, including communications, healthcare, and defense. Transmitting digital photographs over the internet poses a serious risk to information security. There is a greater need than ever for solutions to improve multimedia information security. This paper presents an innovative image encryption and decryption scheme that integrates chaotic maps with the rules of cellular automata and online tessellation automata to achieve high security and key sensitivity levels. The encryption process operates on every 8 × 8 pixel block of the scrambled image data, where a combination of elementary cellular automata and online tessellation automata rules is applied. Chaotic maps generate highly unpredictable sequences, enhancing the pseudo-randomness of the cipher matrix. The decryption scheme mirrors this approach using inverse cellular automata and online tessellation automata to reconstruct the original image accurately. The proposed technique demonstrates strong resistance to statistical, brute force, and differential attacks, making it a highly secure method for image encryption. The proposed encryption technique drastically lowers the correlation coefficient of images from high positive values of 0.9812 to values that are either close to zero or slightly negative after encryption. Its structured and coherent character is further confirmed by the high correlation values of the original pixels for all test images, which reach 0.981176 (horizontal), 0.98992 (vertical), and 0.971677 (diagonal). The encrypted images exhibit entropy values near 7.999, demonstrating high randomness and resistance to statistical attacks. All test images have NPCR values more than 99.62 %, demonstrating that a change in a single pixel in the plaintext image significantly alters the encrypted image. The experimental results further validate its effectiveness and robustness in maintaining image integrity under various cryptographic challenges.