Li Shaozu, Shen Xueju, Zhou Bing, Wang Long
Appl Opt. 2018 Aug 1;57(22):6503-6509. doi: 10.1364/AO.57.006503.
A noiseless optical cryptosystem based on a joint Fresnel transform correlator (JFTC) with a Billet split lens (BSL) was designed. Benefitting from the adjustable structure of the BSL, we can control the size and recording position of the joint Fresnel transform power distribution by changing the split width of the BSL. To avoid the text being affected by noise, we converted the text into quick response (QR) code in advance, then used the QR code as the plaintext and utilized the noise tolerance ability of the QR code to realize noiseless recovery of the text. In this cryptosystem, we designed a complex secret key (CSK) to replace the secret key made from a random phase mask, and the CSK consists of a QR code filter and a spiral phase mask. Because the QR code and spiral phase can be determined by a few simple data, the transmission and preservation of the CSK is convenient. Finally, the validity and feasibility of the cryptosystem were demonstrated, and the sensitivity of the CSK was researched by simulation and experiment.
设计了一种基于带有比累分束透镜（BSL）的联合菲涅耳变换相关器（JFTC）的无噪声光学密码系统。得益于BSL的可调节结构，我们可以通过改变BSL的分束宽度来控制联合菲涅耳变换功率分布的大小和记录位置。为避免文本受到噪声影响，我们预先将文本转换为二维码（QR），然后将二维码用作明文，并利用二维码的抗噪声能力实现文本的无噪声恢复。在该密码系统中，我们设计了一个复数密钥（CSK）来替代由随机相位掩模制成的密钥，并且CSK由一个二维码滤波器和一个螺旋相位掩模组成。由于二维码和螺旋相位可以由一些简单数据确定，CSK的传输和保存很方便。最后，证明了该密码系统的有效性和可行性，并通过仿真和实验研究了CSK的敏感性。
