The invention relates to an image
encryption method. The method comprises the steps of obtaining three groups of
encryption keys based on a Hash method and superposition of preset real number key parameters; dividing the
plaintext image into P11, P12 and P13; enabling the five-dimensional dual-
memristor chaotic system to generate a sequence through the first group of
encryption keys, and carrying out the global scrambling of P11, P12 and P13, thereby obtaining P21, P22 and P23; performing cat mapping scrambling on the P21, the P22 and the P23 to obtain P31, P32 and P33; performing block
DNA operation on the P31, the P32 and the P33 through the second group of encryption
key generation sequences; performing block
cell automaton operation on the block
DNA operation result to obtain P41, P42 and P43; performing block affine transformation scrambling on the P41, the P42 and the P43 to obtain P51, P52 and P53; and carrying out finite field
diffusion on P51, P52 and P53 through the third group of encryption
key generation sequences, and then merging
layers to obtain a
ciphertext image. According to the method, the differential
attack resistance of the
system can be improved, the
key space of the
system is improved, and the security of image data is improved.