He Mingzhao, Tan Qiaofeng, Cao Liangcai, He Qingsheng, Jin Guofan
State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University, Beijing, 100084, China.
Opt Express. 2009 Dec 7;17(25):22462-73. doi: 10.1364/OE.17.022462.
Conventional double random phase encoding (DRPE) encrypts plaintext to white noise-like ciphertext which may attract attention of eavesdroppers, and recent research reported that DRPE is vulnerable to various attacks. Here we propose a security enhanced optical encryption system that can hide the existence of secret information by watermarking. The plaintext is encrypted using iterative fractional Fourier transform with random phase key, and ciphertext is randomly permuted with permutation key before watermarking. Cryptanalysis shows that linearity of the security system has been broken and the permutation key prevent the attacker from accessing the ciphertext in various attacks. A series of simulations have shown the effectiveness of this system and the security strength is enhanced for invisibility, nonlinearity and resistance against attacks.
传统的双随机相位编码（DRPE）将明文加密为类似白噪声的密文，这可能会引起窃听者的注意，并且最近的研究报告称DRPE容易受到各种攻击。在此，我们提出一种安全增强型光学加密系统，该系统可以通过水印隐藏秘密信息的存在。明文使用具有随机相位密钥的迭代分数傅里叶变换进行加密，并且密文在水印之前用置换密钥进行随机置换。密码分析表明，安全系统的线性已被打破，并且置换密钥可防止攻击者在各种攻击中访问密文。一系列模拟表明了该系统的有效性，并且在不可见性、非线性和抗攻击能力方面增强了安全强度。
