基于混合幅度-相位检索技术与二维耦合混沌映射的光学图像加密算法

目的为了解决当前光学图像加密算法主要将单色光束直接作用于明文,使其在解密过程中易出现丢失颜色信息等问题。方法文中设计基于混合幅度-相位检索技术与二维耦合混沌映射的光学图像加密算法。首先,提取彩色图像的R, G, B分量;随后,引入Logistic映射与Sine映射,通过对二者进行非线性耦合,形成二维复合混沌映射;利用彩色图像的像素信息来迭代复合映射,获取3个混沌序列,通过构建位置引擎混淆机制,对R,G,B分量进行置乱;基于Logistic映射,利用明文像素生成的初值条件对其进行迭代,输出一个混沌随机掩码;最后,基于幅度-相位截断方法和Gyrator变换,设计混合幅度-相位检索技术,利用单向二进制相位函数和随机掩码,对置乱后的R, G, B分量进行加密,获取相应的检测振幅,再将其进行组合,形成实值函数的加密密文。结果实验结果显示,与当前光学图像加密机制相比,所提算法具有更高的安全性与解密质量,具备较强的抗明文攻击能力。结论所提加密技术具有较高的抗攻击能力,能够安全保护图像在网络中传输,在信息防伪等领域具有较好的应用价值。

Optical Image Encryption Algorithm Based on Hybrid Amplitude-Phase Retrieval Technique and Two-dimensional Coupled Chaotic Map

The work aims to solve such defects as easy occurrence of color information loss in the decryption process induced by the current optical image encryption algorithm that mainly directly applies the monochromatic beam to the plaintext. An optical image encryption algorithm based on hybrid amplitude-phase retrieval technique and two-dimensional coupled chaotic map was designed herein. Firstly, the R, G and B components of the color image were extracted. Then, the two-dimensional composite map was formed by nonlinearly coupling the Logistic map and Sine map. The three chaotic sequences were obtained by the pixel information of color image that iterated the composite map, so that the R, G and B components were scrambled by constructing the position engine obfuscation mechanism. Based on Logistic map, the initial value conditions generated by the plaintext pixels were used for the iteration of the Logistic map to output one chaotic random mask. Finally, the hybrid amplitude-phase retrieval technique was designed based on the amplitude-phase truncation method and Gyrator transform. The scrambled R, G and B components were encrypted by the unidirectional binary phase function and random mask to obtain the corresponding detection amplitude. Then, these components were combined to form the encrypted ciphertext of real-valued function. The experimental results showed that, with higher security and decryption quality, the proposed algorithm had stronger ability to resist plaintext attack compared with the current optical image encryption mechanism. The proposed encryption algorithm has higher anti-attack ability and can protect the safe transmission of images in the network. It has better application value in the field of information security and anti-counterfeiting.