一种新的基于双向分数傅里叶变换和RGB映射图像保护算法

摘要

Aiming at the shortcomings of existing image encryption algorithms,we propose a novel image encryption algorithm,which combines the chaotic system mapping,fractional Fourier transform (FRFT) and RGB mapping.The whole image encryption process includes three aspects.Firstly,it uses a disturbed matrix produced by chaotic system to disrupt the original image; secondly,it encrypts the image by fractional Fourier transform; thirdly,it converts the encrypted image to a visual RGB image by RGB mapping rule.Due to the randomness of the phase mask and the sensitivity of FRFT order and chaos system to initial value,the security of the algorithm is guaranteed to a great deal.Theoretical analysis and experimental results show that the algorithm has the advantage of security and research value.%针对现有图像加密算法的缺点,提出一种新的图像加密算法.该算法采用混沌系统映射、分数傅里叶变换(FRFF)以及RGB映射.整个图像加密包括三个方面:第一是利用混沌系统产生的扰乱矩阵来打乱原始图像,第二是通过分数傅里叶变换对图像进行加密,第三是使用RGB映射规则转换成可视的RGB图像.由于相位掩码的随机性、FRFT阶和混沌系统对初始值的敏感性,算法的安全性得到了极大的保证.理论分析和实验结果表明,该算法安全性好,具有良好的研究价值.