Kumar Pramod, Joseph Joby, Singh Kehar
Physics Department, Indian Institute of Technology, Delhi, 110016 India.
Appl Opt. 2011 May 1;50(13):1805-11. doi: 10.1364/AO.50.001805.
Interference-based optical encryption schemes have an inherent silhouette problem due to the equipollent nature of the phase-only masks (POMs) generated using an analytical method. One of the earlier methods suggested that removing the problem by use of exchanging process between two masks increases the computational load. This shortcoming is overcome with a noniterative method using the jigsaw transformation (JT) in a single step, with improved security because the inverse JT of these masks, along with correct permutation keys that are necessary to decrypt the original image. The stringent alignment requirement of the POMs in two different arms during the experiment is removed with an alternative method using a single spatial light modulator. Experimental results are provided to demonstrate the decryption process with the proposed method.
基于干涉的光学加密方案由于使用解析方法生成的纯相位掩模（POM）具有等效性，存在固有的轮廓问题。早期的一种方法建议通过在两个掩模之间进行交换过程来消除该问题，但这会增加计算量。一种非迭代方法通过在单一步骤中使用拼图变换（JT）克服了这一缺点，并且提高了安全性，因为这些掩模的逆JT以及解密原始图像所需的正确排列密钥。实验过程中，通过使用单个空间光调制器的替代方法，消除了两个不同臂中POM的严格对准要求。提供了实验结果以证明所提出方法的解密过程。
