摘要： 分析基于Lorenz三维超混沌系统的图像加密算法在已知图像条件下的安全性，给出原算法的一个等效加密算法，并在此基础上，提出一个等效密钥求解算法。该密钥求解算法同样适用于原算法的等效密钥求解，对比穷举攻击方法，其计算复杂度大幅减小。实验结果表明，该算法能够对原算法进行已知图像攻击。

关键词: 混沌序列, 图像加密, 已知明文攻击, Lorenz系统

Abstract: Aiming at an image encryption algorithm based on the Lorenz system, this paper analyzes the security properties of the algorithm in the case of known plaintext attack. An equivalent encryption algorithm is proposed, and thereafter its corresponding equivalent key-solved algorithm, which is also suitable for attacking the former algorithm, is presented. Compared with the brute attack algorithm, the equivalent key-solved algorithm has a lower complexity. Experimental result shows the former algorithm can be successfully attacked by using the equivalent key-solved algorithm, and therefore it is insecure.

Key words: chaotic sequence, image encryption, known plaintext attack, Lorenz system

中图分类号: 

• TP311.52