Abstract: Aiming at the disadvantages of traditional AES（Advanced Encryption Standard） encryption algorithms, such as key space is small and fixed, a new hyper-chaotic system and AES combined with image encryption algorithm are proposed. Firstly, the hyperchaotic sequence is generated by hyperchaotic Qi system, and the chaotic sequence is intercepted as the target key of AES encryption algorithm. The mean value of plaintext image pixels is introduced as a parameter to adapt to the change of plaintext image. Then, the target key is substituted into the AES encryption algorithm for two cycles of encryption, and the S-boxes and round keys in each round of encryption are generated by chaotic sequences, which enhances the key randomness. Simulation results show that the algorithm can well combine the advantages of both to achieve a very good encryption effect.

Key words: hyperchaos system, Advanced Encryption Standard（AES）, image encryption

摘要： 针对传统AES（高级加密标准）加密算法存在密钥空间小、固定不变等缺点，提出了一个新的超混沌系统和AES结合的图像加密算法。该算法首先利用超混沌Qi系统产生超混沌序列，截取混沌序列作为AES加密算法的目标密钥，且截取过程中引入了明文图像像素的平均值作为参数，以适应明文图像的变化。然后，将目标密钥代入AES加密算法进行两轮循环加密，且每轮加密过程中的S盒和轮密钥由混沌序列产生，增强了密钥的随机性。仿真实验结果表明，该算法能够很好地结合两者的优点，达到很好的加密效果。

关键词: 超混沌系统, 高级加密标准（AES）, 图像加密