基于数字全息和混沌随机相位编码的双图像加密

为了提高图像的加密效率,提出了一种基于三步 相移数字全息和混沌随机相位编码的 双图像加密方法。两幅图像分别作为振幅部分和相位部分被编码为一幅复数图像,该复数图 像被置于物光路中不同位置处的两块混沌随机相位板编码后与参考光进行干涉,从而将两幅 图像的信息隐藏于三幅全息图中。在该方法中,混沌系统的初值和控制参数取代随机相位板 做密钥,使密钥的管理和传输更为便捷。此外,衍射距离和入射波长也可作为解密过程中的 密钥,使该方法的安全性得以进一步提高。计算机模拟结果表明,任何一个密钥错误时,都 不能解密得到原图像的任何有效信息。此外,该方法对噪声攻击和剪切攻击具有较强的鲁棒 性。

Double image encryption based on digital holography and chaotic random phase enc oding

In this paper,to improve the encryption efficiency of the image,a double image e ncryption method based on three-step ph ase-shifting digital holography and chaotic random phase encoding was proposed. The two images to be encrypted were firstly encoded into the amplitude and phase of a complex image.Then the complex image was encoded into a noise-like patter n by the chaotic random phase masks placed in the object light path.Finally,th e noise-like pattern interfered with the reference light to generate three holo g rams in which the two original images were hidden.In this proposed method,the initial values and control parameters of the chaotic system can replace the rand om phase masks to serve as the secret keys,which makes the management and trans mission of the secret keys become more convenient.In addition,the diffraction distance and incident wavelength can also serve as the additional secret keys,w hich can further improve the security of the proposed method.Simulation results demonstrated that any useful information about the two original images cannot b e decrypted if any of the secret keys is incorrect.Additionally,the simulation r esults also demonstrated that the proposed method can resi st noise attack and occlusion attack with high robustness.