A fast image encryption algorithm based on high-dimension chaotic system

Based on the three-dimension Chen´s chaotic system, a fast image encryption algorithm which follows a different direction in each round of process is proposed in this paper. The plain-image is first scrambled only by the XOR and the modulo-256 addition operations independent of any chaotic map for two rounds. Then the scrambled image is encrypted using the XOR operations under the control of a pseudorandom number sequence. Since there is no iteration of any chaotic map in the scrambling process, the encryption speed is improved significantly. To avoid the defects caused by the machine precision, a small perturbation based on the last one byte encrypted message will be given to one of the parameters of the Chen´s chaotic system after iterating it every time. Simulation results and theoretical analysis show that the proposed scheme is immune to information extracting by statistical analysis and differential analysis which has achieved the expected cryptographic properties.