This study proposes a scale-invariant digital image encryption method that includes three main steps rows-columns diffusion, the 3D scale-invariant modular chaotic map, and Hill diffusion. Pixels substitution, and mixing adjacency pixels of the plain image are performed using rows-columns diffusion and Hill diffusion. The 3D scale-invariant chaotic maps are used to permutation image pixels without image size restriction. Modular arithmetic is used in the 3D scale-invariant chaotic maps and Hill diffusion to increase keyspace and enhance security parameters. With repeat at least two rounds of main steps, the proposed encryption scheme reaches to optimum parameter values and it is highly sensitive to minor differences in both secret key and plain image, resulting in resisting chosen/known plaintext attacks effectively. Experimental results show that the proposed scheme demonstrates excellent security capacity with high efficiency, compared with existing approaches in digital image encryption.

这项研究提出了一种尺度不变的数字图像加密方法，该方法包括三个主要步骤：行-列扩散，3D尺度不变的模块化混沌映射和Hill扩散。使用行列扩散和希尔扩散来执行普通图像的像素替换和混合邻接像素。3D尺度不变混沌映射用于对图像像素进行置换，而没有图像大小限制。在3D尺度不变混沌映射和Hill扩散中使用模块化算法，以增加键空间并增强安全性参数。通过重复至少两轮主要步骤，提出的加密方案达到了最佳参数值，并且对秘密密钥和纯图像中的细微差异高度敏感，从而有效地抵抗了选定的/已知的纯文本攻击。