The application relates to an image
encryption method, which comprises the following steps: obtaining three groups of
encryption keys based on a hash method and superimposing preset real number key parameters; dividing a
plaintext image into P 11 , P 12 , P 13 ; making a five-dimensional double-memory-block
chaotic system generate sequences to globally scramble P 11 , P 12 , P 13 ; obtaining P 21 , P 22 , P 23 ; performing cat map scrambling on P 21 , P 22 , P 23 to obtain P 31 , P 32 , P 33 ; generating sequences by the second group of
encryption keys to perform block
DNA operation on P 31 , P 32 , P 33 ; performing block
cellular automaton operation on the block
DNA operation result to obtain P 41 , P 42 , P 43 ; performing block affine transformation scrambling on P 41 , P 42 , P 43 to obtain P 51 , P 52 , P 53 ; generating sequences by the third group of encryption keys to perform finite field
diffusion on P 51 , P 52 , P 53 , and then merging the
layers to obtain a
ciphertext image. The application can improve the
system differential
attack resistance, the
system key space and the image
data security.