一种图像加密算法的等效密钥攻击方案

An Equivalent Key Attack on an Image Cryptosystem

本文分析了一个基于3D混沌Baker映射设计的图像加密方案的安全性,在已知图像的条件下,基于3D混沌Baker映射的仿射特性,通过求解三个线性无关的加密前后的图像像素灰度值点,获得了3D混沌Baker映射的全部等效密钥参数,再通过穷尽方法求出了加密算法的其余等效密钥.分析了攻击方法的计算复杂性,证明了该图像加密算法在已知图像攻击下是不安全的.

This paper examines the security of an image cryptosystem based on 3D chaotic Baker map.With known image,based on the affinity of 3D chaotic Baker map,the equivalent key of Baker map can be found by three linearly independent plain-cipher image grey values.The other equivalent key can be found by exhaustive attack.We estimate the computational complexity of our attack and prove that this image cryptosystem is insecure under the known image attack.