对一种基于动态S盒与混沌映射的图像加密算法的安全分析与改进  

Security Analysis and Improvementof an Image Encryption Algorithm Based on Dynamic S-box and Chaotic Map

作　　者：朱淑芹[1] 李秀娟 李若玉 ZHU Shu-qin;LI Xiu-juan;LI Ruo-yu(Liaocheng University,Liaocheng 252059,China)

机构地区：[1]聊城大学,山东聊城252059

出　　处：《中国电子科学研究院学报》2022年第2期162-169,共8页Journal of China Academy of Electronics and Information Technology

基　　金：聊城大学科研基金(318012027);聊城大学大学生创新创业项目(CXCY2021269)。

摘　　要：对一种基于混沌映射与动态S盒的图像加密算法进行了安全性分析。经深入分析,发现原算法的安全性完全依赖于混沌矩阵T和4个S盒,而混沌矩阵T和4个S盒的生成与明文图像或对应的密文图像没有任何关联,从而能用选择明文攻击的方法破译目标密文,解密出目标明文。理论分析和仿真实验验证了选择明文攻击策略的可行性,同时指出了原算法存在的另外两个安全缺陷。最后提出了一个改进算法,改进算法在生成置乱序列和中间扩散序列时,巧妙设置它们都与明文图像有关,因此改进算法能抵抗选择明文攻击,具有“一次一密”的加密效果,但是没有额外增加密钥传递的负担。对改进算法的安全分析表明:改进算法克服了原算法的所有缺陷,能抵抗现有的各种攻击。This paper analyzes the security of an image encryption algorithm based on chaotic mapping and dynamic S-boxes. Through in-depth analysis, it is found that the security of the original algorithm completely depends on chaotic matrix T and four S-boxes, but the generation of chaotic matrix T and four S-boxes has no relationship with plaintext image or corresponding ciphertext image, so it can be attacked by the method of chosen plaintext attackto decipher the target ciphertext and decrypt the target plaintext. Theoretical analysis and simulation experiments verify the feasibility of chosen plaintext attack strategy. At the same time, two other security flaws of the original algorithm are pointed out. Finally, an improved algorithm is proposed and its When generating scrambling sequence and intermediate diffusion sequence, the improved algorithm skillfully sets that they are related to plaintext images. Therefore, the improved algorithm can resist the chosen plaintext attack and has the encryption effect of “one encryption at a time”, but does not increase the extra burden of key transmission. The security analysis of the improved algorithm shows that it can overcomes all the defects of the original algorithm and can resist various existing attacks.

关 键 词：图像加密 动态S盒 混沌映射 选择明文攻击 安全分析 一次一密 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]