对一种五维混沌图像加密算法的破译与改进

Breaking and Improving an Image Encryption Algorithm Based on Five-dimension Chaotic System

根据选择明文攻击原理,对一种基于五维混沌系统的图像加密算法进行了分析,结果表明该算法不能抵抗选择明文攻击,进而提出了一种基于五维混沌系统的图像加密改进算法,并对改进算法进行了安全性分析和实验测试.理论分析及实验结果表明,改进算法不仅克服了原算法不能抵御选择明文攻击的缺陷,且在相邻像素相关性、信息熵和密钥空间等方面具有更好的密码学特性.

According to the principle of chosen plaintext attack, an image encryption algorithm based on five-dimension chaotic system was analyzed, and the results showed that this algorithm could not resist against chosen plaintext attack. Then we proposed an improved algorithm based on the five-dimension chaotic system, and made a security analysis of and experimentally tested it. The theoretical analysis and experimental results indicate that the improved algorithm can not only overcome the above flaws, but has better cryptographic performances in respect of adjacent pixels, information entropy, and key space.