Color image encryption based on a fractional-order hyperchaotic system and cross-plane bit-level permutation and eight-base DNA-level diffusion

Abstract In the age of big data, information security has been garnering growing attention. As a widely used information carrier, images need to ensure their security throughout the entire process of generation, storage, and transmission. Image encryption is a direct and useful approach to achieve this goal. This paper proposes a novel color image encryption scheme based on a newly designed 5D fractional-order hyperchaotic system, cross-plane bit-level permutation, and eight-base DNA-level diffusion, termed FHBPDD. Given that fractional-order hyperchaotic systems generally have better nonlinearity to help image encryption, we analyze the complex dynamical characteristics of the presented fractional-order system using multiple metrics. Then, FHBPDD first generates a sufficiently long hyperchaotic sequence from the 5D fractional-order hyperchaotic system for consequent operations. Second, the input color image is converted to several bit-level planes, and the cross-plane permutation is performed for them. Third, the cross-plane diffusion is conducted on non-corresponding rows and columns of multiple eight-base DNA-level planes via dynamic DNA encoding and algebraic operations. Finally, DNA decoding is executed to yield the cipher image. It is worth noting that all encryption operations involve the participation of the hyperchaotic sequence. Various experimental results verify that FHBPDD has excellent security performance for color image encryption.