Abstract:

In order to improve the safety of image encryption algorithm, an improved hyperchaotic AES (Advanced Encryption Standard) encryption algorithm which improved the generation method of S box is proposed. The method arranged chaotic sequence generated by hyperchaotic system to form the S box, replaced pixels to plaintext. Chaos sequence is used to scramble the location of row and column based on external key. Safety performance of encryption algorithm is deeply analysed, the simulation results show that the proposed algorithm has much higher security level, the algorithm not only has larger key space and higher key sensitivity, but also can effectively resist attacks, such as statistics attack and differential attack.

Key words: hyper-chaos, advanced encryption standard (AES), image encryption, differential attack