Abstract
Due to great interest in the secure storage and transmission of color images, the necessity for an efficient and robust RGB image encryption technique has grown. RGB image encryption ensures the confidentiality of color images during storage and transmission. In the literature, a large number of chaotic-based image encryption techniques have been proposed, but there is still a need for a robust, efficient and secure technique against different kinds of attacks. In this paper, a novel RGB image encryption technique is proposed for encrypting individual pixels of RGB images using chaotic systems and 16 rounds of DNA encoding, transpositions and substitutions. First, round keys are generated randomly using a logistic chaotic function. Then, these keys are used across different rounds to alter individual pixels using a nonlinear randomly generated 16 x 16 DNA Playfair matrix. Experimental results show the robustness of the proposed technique against most attacks while reducing the consumed time for encryption and decryption. The quantitative metrics show the ability of the proposed technique to maintain reference evaluation values while resisting statistical and differential attacks. The obtained horizontal, vertical and diagonal correlation is less than 0.01, and the NPCR and UACI are larger than 0.99 and 0.33, respectively. Finally, NIST analysis is presented to evaluate the randomness of the proposed technique.