The invention relates to a multi-medical image
encryption method based on a three-dimensional hyperchaotic
system, and belongs to the technical field of medical image
encryption. According to the method, in an image preprocessing stage, dual medical images are fused through an Alpha channel to generate a to-be-encrypted matrix, an SHA-512 function is combined with RGB and an Alpha channel matrix to generate a key sequence, and a dual-key matrix and a
chaotic sequence are generated through a three-dimensional hyperchaotic Logistic-Sink (3D-HCLSM)
system; in the
encryption stage, triple encryption operations are implemented: a parameter
randomization dynamic Josephh scrambling strategy is adopted to generate a primary
ciphertext, an improved zigzag bidirectional cross permutation strategy is adopted, pixel
diffusion with a key matrix is carried out to obtain a secondary
ciphertext, a novel bit-level scrambling strategy is carried out, and bit XOR operation with the key matrix is carried out to complete final encryption. According to the method, a dynamic Joseph traversal mechanism with
random parameters is provided, an optimized zigzag replacement strategy and a novel bit-level
processing technology are combined, and the
attack resistance and safety of medical image encryption are remarkably improved through the synergistic effect of multi-level chaos secret keys.