ABSTRACT We propose an optical encryption scheme for multiple images based on angle multiplexing and computer generated hologram(CGH) in this paper. In the encryption process, the original images are firstly modulated by two random phase keys in Fresnel transform with different diffraction distances. Secondly, the modulated images are coherent superposition with solid angle multiplexed reference beams to generate interference fringes and form a compound image. Finally, the compound image is encoded to a CGH by Roman coding method. In the decrypted process, the corresponding experimental system using SLM is built, in which multiple images can be encrypted synchronously with high efficiency. Except random phase key, the proposed encryption system has multiple kind of keys including diffraction distance and wavelength to improve the security. Due to the characteristics of high storage efficiency and simple calculation, this optical multiple-image encryption scheme has important application prospect in improving the efficiency of information transmission and multi-user authentication.

中文翻译：

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基于空间角复用和计算机生成全息图的多图像光学加密方案

摘要 我们提出了一种基于角度复用和计算机生成全息图（CGH）的多幅图像光学加密方案。在加密过程中，原始图像首先通过两个不同衍射距离的菲涅耳变换随机相位密钥进行调制。其次，调制图像与立体角复用参考光束相干叠加，产生干涉条纹，形成复合图像。最后，将复合图像通过罗马编码方法编码为 CGH。在解密过程中，利用SLM搭建了相应的实验系统，可以对多张图像进行高效率的同步加密。除了随机相位密钥外，所提出的加密系统还有多种密钥，包括衍射距离和波长，以提高安全性。