摘要
针对一个对称图像加密方案在已知图像条件下的安全性,给出了求解加密方案等效密钥的攻击算法。该算法基于加密方案所使用的3D混沌猫映射的仿射特性,在已知图像的条件下,通过求解三个线性无关的加密前后的图像像素灰度值点,可获得3D混沌猫映射的全部等效密钥参数。通过穷尽方法可以求出加密算法的其余等效密钥。给出了应用该算法的具体步骤,并分析了攻击算法的计算复杂性。通过分析证明了《A Symmetric Image Encryption Scheme Based on 3D Chaotic Cat Maps》一文设计的图像加密算法在已知图像攻击下是不安全的。
To study the security of a symmetric image encryption scheme with known image, an attack algorithm of equivalent key is given. The attack algorithm is based on the affinity of 3D chaotic cat map used by the symmetric image encryption scheme. With the known image, the equivalent key of 3D chaotic cat map can be found by three linearly independent plain-cipher text image grey values. The other equivalent keys can be found by the brute attack algorithm. The concrete step and complexity of the attack algorithm is given. It is proved that the encryption algorithm proposed in 《A symmetric image encryption scheme based on 3D chaotic cat maps》 is insecure in the known image attack.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2007年第3期341-345,共5页
Systems Engineering and Electronics
基金
河南省杰出青年科学基金资助课题(0312001800)
关键词
密码技术
密钥
密码算法
图像加密
cryptographic technique
key
cryptographic algorithm
image encryption
