提出了一种基于矢量分解和混沌随机相位掩模编码的光学非对称彩色图像加密方法。当输入图像是一幅实值图像时,矢量分解的引入使得第一块相位掩模也能作为密钥,进而使得加密系统成为非对称加密系统。用二维Henon混沌映射生成的两个混沌相位掩模替代双随机相位掩模,将混沌系统的初始值和控制参数作为密钥,增加密钥空间,为加密系统提供更多的安全性。对加密系统的密钥敏感性、图像相邻像素间的相关性、抗剪切攻击性、抗噪声攻击性、抗选择明文攻击性等进行测试,测试结果证明了所提加密系统的可行性和安全性。

This paper proposes an asymmetric optical color-image encryption system based on vector decomposition and chaotic random phase mask. The introduction of vector decomposition makes the first phase mask also act as the main secret key when the input image is a real-value image, which makes the encryption system asymmetric. The two chaotic phase masks generated by the 2-D Henon chaotic map replace double random phase masks. The chaotic system’s initial values and control parameters were used as secret keys to increase the key space and provide more security for the encryption system. The following parameters were tested: key sensitivity, correlation coefficients of two adjacent pixels, occlusion attack resistance, noise attack resistance, and chosen-plaintext attack resistance of the encryption system. Test results validate the feasibility and security of the proposed encryption system.