Improvement of an Encryption Algorithm Based on Hyper-Chaos

In order to solve the problems of Gao algorithm, an improvement of Gao algorithm is proposed in this paper. Firstly, the shuffling procedure is combined with pixel diffusion to solve the problem that permutation isn´t relative to the pixel values in Gao algorithm. Secondly, to solve the problem that the keystream isn´t sensitive to plaintext in Gao algorithm, the feedback mechanism is introduced in the pixel encryption procedure, which makes the generation of keystream relative with plaintext. Finally, it is from analysis and experiments that the improved algorithm is secure and valid.