Dynamic multi-chaos color image encryption algorithm based on FWHT

To solve the problem of single chaotic system and poor correlation between key and plaintext in color image encryption, a dynamic multi-chaotic color image encryption algorithm based on FWHT is proposed. First, fast Walsh hadamar transform (FWHT) is applied to the image. Secondly, different systems are constructed based on the dynamic unified chaotic system parameters controlled by the pixel values of each channel, which can be used for channel coefficient scrambling after improvement. Finally, using Rabinovich chaotic sequence to control the PWLCM mapping parameters to construct r-p chaotic system, the two-stage compound key flow was iteratively generated to obtain the ciphertext, and the superposition was made into color ciphertext image. The results showed that the histogram of ciphertext images was evenly distributed, the correlation was almost 0, the information entropy was greater than 7.999 3, the NPCR value and UACI value were also approximate to the theoretical value, which could effectively resist all kinds of attacks and had strong encryption performance.