A Novel Image Encryption Technique using Multi-Coupled Map Lattice System with Generalized Symmetric Map and Adaptive Control Parameter

Image and video data make up a significant portion of the content shared over the Internet and social media. The use of image and video communication allows more information to be shared while simultaneously presenting higher risks in terms of data security. The traditional encryption schemes are general purpose; however, to encrypt image and video data, application-specific encryption solutions are needed. An image or a video frame comprises a two-dimensional matrix where pixel intensity values are integers in range [0,255], leading to data redundancy problems. Moreover, the bulk amount of image and video data adds another challenge when deploying security primitives. In this paper, a novel coupled map lattice system-based image cryptosystem has been proposed that uses generalised symmetric maps for generation of pseudo-random sequences. The generalization of symmetric maps allows the user to choose the source of pseudo-random sequence generation by varying a single control parameter. Other adaptive control parameters ensure an adequate degree of randomness in the generated sequences. The proposed encryption system relies on three independent sources of pseudo-random sequence generators, which are further re-randomized before the final encryption process. Comprehensive experimentation has been performed to test the proposed system against various attack models on publicly available datasets. A detailed comparative analysis has also been conducted with existing state-of-the-art image encryption techniques. Results show that the proposed algorithm provides high information entropy, negative correlation, large key space, and high sensitivity to key variations, and is resistant to various types of attacks, including chosen-text, statistical, and differential attacks.