数字图像空域加密技术综述

数字图像包含了大量可视化的隐私信息,其在公共信道的安全传输和云环境下的可信存储难以得到充分的保障。数字图像加密技术作为一种重要的隐私保护手段被广泛应用于各个领域。数字图像空域加密指将图像看作二维矩阵,从灰度值和像素坐标两个方面对图像进行可逆变换。数字图像的空域加密结构包括置乱与扩散。置乱是指通过改变像素的坐标实现对像素位置信息的隐藏;扩散是指建立密文图像与明文图像之间的强关联,保证加密算法的错误传播无界特性。该文详细介绍了现阶段4类主流的数字图像空域加密方法,对比分析不同空域加密的优缺点,给出7种常用的数字图像加密技术安全性的评估方法,并指出未来可能的数字图像加密技术的研究方向,提供数字图像加密技术的整体概述。

Survey of Digital Image Spatial-domain Encryption Technology

Digital image contains a large amount of visual privacy information,which is difficult to be fully guaranteed in the secure transmission of public channels and trusted storage in the cloud environment.As an important means of privacy protection,digital image encryption technology has been widely used in various fields.The spatial-domain encryption of digital image refers to the reversible transformation of image from two aspects of gray-level value and pixel coordinates by treating the image as a two-dimensional matrix.The spatial-domain encryption structure includes scrambling and diffusion.Scrambling refers to the hiding of pixel position information by changing pixel coordinates.Diffusion refers to the establishment of strong correlation between cipher-image and plain-image to ensure the unbounded error propagation of the encryption algorithm.We introduce 4 kinds of digital image spatial-domain encryption methods in detail,and compare and analyze the advantages and disadvantages of these encryption algorithms.We give 7 kinds of security evaluation methods,point out possible future research direction of digital image encryption technology,and provide overall overview of the digital image encryption technology.