The invention discloses an image
encryption method combining an
S box and a hyper-
chaotic integrated
system because of continuous development of an
attack technology and increasing requirements on the anti-
attack capability of an
encryption algorithm. Firstly, a
particle swarm optimization algorithm is designed based on a
fitness function considering multiple safety indexes and an S-type function
inertia weight strategy to search for an
S box. And the searched
S box has excellent performance in the aspects of nonlinearity, difference uniformity, algebraic times, strict avalanche criterion and the like. Furthermore, a hyperchaos Chen
system is taken as a core, and a hyperchaos integrated
system is constructed by combining a
Lorenz system and a Henon system. A three-order
diffusion mechanism is adopted in the
encryption process, and an S box obtained through searching of a
particle swarm optimization algorithm and a
chaotic sequence generated by a hyperchaotic integrated system are fully fused in first two-order
diffusion so as to improve the safety and randomness of an encryption algorithm. The encryption algorithm has strong anti-
noise and anti-
cutting capabilities for encryption. The image encryption algorithm combining the S box and the hyper-chaos integrated system provided by the invention has relatively
high security and is suitable for the field of image encryption with high requirements.