截断傅里叶变换加密系统的安全性分析  

Analysis of the Security of Asymmetric Cryptosystem Based on Phase-truncated Fourier Transform

作　　者：高雄[1] 陈林飞[1] 

机构地区：[1]杭州电子科技大学理学院,浙江杭州310018

出　　处：《杭州电子科技大学学报（自然科学版）》2015年第4期106-110,共5页Journal of Hangzhou Dianzi University：Natural Sciences

基　　金：国家自然科学基金资助项目(11147138);浙江省自然科学基金资助项目(LQ12A04001);浙江省新苗人才计划资助项目(2014R407066);杭州电子科技大学研究生创新基金资助项目(2014KYJJ020)

摘　　要：基于截断傅里叶变换的非对称加密系统在应用迭代傅里叶变换的一种特殊攻击下,其加密系统的安全性存在一定的隐患。在加密系统的傅里叶域加入一个振幅调制,可以使加密系统的安全性得到一定程度的提升,但发现在一种新的攻击方法中依然很脆弱。采用不同的变量并对其进行模拟,分析表明,振幅调制作用于加密系统使某一像素的周围像素值扩大或缩小超过10倍以上时,图像像素之间的关联性得到破坏,图像就很难被攻击。根据振幅调制的设计和改变提出了一种改进的非对称加密系统,模拟实验表明,在现有的各种攻击下,系统有很强的抗攻击能力,安全性得到了很大的提升。The optical PTFT-based cryptosystem is vulnerable to a specific attack,which is based on a twostep iterative amplitude-phase retrieval algorithm. The security of the cryptosystem would be improved by adding an amplitude mask in the Fourier plane. But it is also vulnerable under a new attack. The errors induced by different amplitude modulation in the attacks are analyzed in computer simulations. Results show that when the surrounding pixel values are enlarged or reduced more than 10 times,the relation between the pixels are broken,the plaintext information is difficult to obtain. Therefore,we need design an effective amplitude modulation to enhance the security of the cryptosystem. In this paper,the authors propose a proved asymmetric cryptosystem based on amplitude modulation,which has strong robustness under various attacks and greatly improves its security.

关 键 词：傅里叶变换 相位截断 振幅调制 非对称加密 

分 类 号：O438.2[机械工程—光学工程]