An image encryption algorithm based on spatiotemporal chaos in DCT domain

To solve the drawbacks of some chaotic image encryption schemes, an image encryption algorithm based on spatiotemporal chaos in DCT domain is proposed in this paper. The image after DCT transformation and quantization is encrypted block by block. Every block is first permuted by placing the value on the same position of a chosen block using Logistic map, then the signs of the permuted block are extracted and encrypted by the spatiotemporal. Propagating cipher-block chaining mode (PCBC) is adopted in the scheme, and it´s from analysis and experiments that the scheme can resist chosen plaintext and ciphertext attacks without influence on the compression efficiency.