中文摘要：

为了提高加密系统的抗攻击能力和加密安全性,分析了现有图像加密的方法,提出一种改进的图像加密方法。对Clifford超混沌系统和Logistic混沌系统进行嵌套组合,产生了具有更好特性的Cli-Log混沌系统,用于图像的位置置乱;在Chua超混沌系统的龙格库塔解法中插入参数,生成混沌序列与图像像素值进行异或操作,实现加密。该加密算法不但生成随机性较好的序列,而且增大了密钥空间,最重要的是这些插入的参数来自于前面用于置乱的混沌序列,实现了密文反馈。计算机仿真结果表明,该加密算法具有良好的加密效果,克服了大量加密算法只与混沌系统及密钥有关而与明文无关的缺点,使加密安全性进一步提高。

英文摘要：

In order to improve the attack-resistance＇s ability and security of encryption,this paper discussed the method for image encryption,and presented an improved method.By combining Clifford hyper chaotic system and Logistic chaotic system,got a better Cli-Log chaotic system,and it could be used for disturbing pixels＇ location.Then inserted parameters into Chua chaotic system via Runge-Kutta method,got chaotic sequences,and used the sequences to do XOR operation with image pixels.Finally realized encryption.This method not only generated a good random sequence,but also increased the key spaces.Most importantly,the inserted parameters that used for scrambling were from the chaotic sequence,so it achieved the cipher text feedback.The computer simulation proves that the method is feasible and effective in encryption,overcomes the shortcoming that lots of encryption algorithms just only related with chaotic system and keys but not with plaintext,and improves the security of encryption.