一种密文图像安全性评价方案

在图像加密技术领域中,已存在多种图像加密方法,但很多图像加密方法因安全性不够而存在被破解的风险。现行的很多密文图像安全性评判方法,选择的参数较为单一,评价结果不够全面。对此,提出一种基于像素数量改变率、密钥空间大小、信息熵、相邻像素相关系数等多种指标参数的密文图像安全性评价方案。通过同一图像使用不同加密算法分别得到的多种指标参数横向比较,得出综合情况下安全性更好的算法。针对现阶段加密应用中使用较多的两类图像进行实验、分析和对比,结果表明方案非常有效、可靠、实用性强。

A CRYPTOGRAPHIC IMAGE SECURITY EVALUATION SCHEME

In the field of image encryption technology, there are many image encryption methods, but many image encryption methods are not secure enough and there is a risk of being cracked. Many existing cryptographic image security evaluation methods choose a single parameter, and the evaluation results are not comprehensive. To solve this problem, we proposed a cryptographic image security evaluation scheme based on pixel number change rate, key space size, information entropy, correlation coefficient of adjacent pixels and other index parameters. Through the horizontal comparison of various index parameters obtained by different encryption algorithms for the same image, it could be concluded which algorithm has better security under the comprehensive situation. Two kinds of images which are widely used in current encryption applications were experimented, analyzed and compared. The results show that the scheme is very effective, reliable and practical.