Multi-Image Encryption Scheme Based on Chaotic Pseudo-Random Signal Generator and DWT Compression

To solve the problem of resource consumption and information security during color image transmission, multiple color images encryption scheme according to a three-dimensional discrete chaotic map with pseudo-random number signal generator and discrete wavelet transform (DWT) compression is proposed. Firstly, dynamics of three-dimensional discrete chaotic map is analyzed and found to provide better randomness for encryption schemes. Next, multiple color images of different sizes are compressed to 1/4 of the original size after DWT processing. The multiple compressed images are merged into a plaintext cube, and the plaintext parameters associated with the cube are generated. The generated plaintext parameters are combined with the chaotic map to form the key. A series of sequences are generated by iteration for image confusion and diffusion to get cipher images. The final simulation results show that recovered plaintext image is still clearly visible even with lossy DWT compression. The security analysis results indicate that this scheme has high level of security protection for color images.