针对基于感知器模型的混沌图像加密算法的选择明文攻击

对一种基于感知器模型的混沌图像加密算法进行了安全性分析,发现该算法的本质就是根据等效密钥流来改变明文图像像素值的比特位,从而得到密文图像。而等效密钥流与明文图像和对应的密文图像没有任何关系,因此运用选择明文攻击的方法破解出了算法中的等效密钥流,解密出了目标明文图像；同时指出了原算法存在的另外两个安全缺陷；最后对原算法进行了改进,弥补了其缺陷。理论分析和实验结果均证实了所提出的选择明文攻击策略的可行性以及改进算法的有效性。

Chosen Plaintext Attack on Chaotic Image Encryption Algorithm Based on Perceptron Model

This paper analyzed the security of a chaotic image encryption algorithm based on preceptron model and found that the essence of the algorithm is to change the value of bits of the plaintext image according to the equivalent key stream to get the cipher image.However,there is no relation between the equivalent key stream and the plain text image or the corresponding cipher text image.By applying chosen plaintext attacks,this paper found that the equivalent key can be cracked,which can be further exploited to decrypt the target plain image.In addition,two other security defects were also reported.Finally,the original algorithm was improved to overcome the shortcomings of the original algorithm.Both mathematical analysis and experimental results show that the feasibility of the proposed chosen plaintext attack strategies and the effectiveness of the improved algorithm are verified.