基于分层变换的地理测绘成果图像加密技术研究

Research on Image Encryption Technology of Geographic Surveyingand Mapping Based on Hierarchical Transformation

为提高地理测绘信息管理的安全性与稳定性,根据分层变换算法,研究了一种地理测绘成果图像的加密技术。根据图像像素密度分布情况,对地理测绘图像分层,利用图像置乱技术,变换加密测绘图像,进行分层变换图像的解密计算,完成地理测绘成果图像加密技术的研究。为检测本文方法的加密效果,设计了仿真模拟试验,结果显示,对于不同大小的测绘图像,加密解密的总运算时间分别为88 ms、92 ms、97 ms,具有实时性与高效性,对于随机500组测绘图像,应用加密技术后,像素的平均改变率为99.74%,像素的平均改变强度为33.83%,对明文变化的敏感性与抗差分攻击能力非常强,具有安全性与有效性。

In order to improve the security and stability of geo-mapping information management,based on the hierarchical transformation algorithm,a kind of encryption technology of geo-mapping image was studied.According to the distribution of the pixel density of the image,we divide the geographic mapping image into layers,use the image scrambling technology,transform and encrypt the mapping image,and then decode and calculate the layer transformation image,finish the research on image encryption technology of geographic mapping.In order to test the encryption effect of this method,a simulation experiment is designed.The results show that the total operation time of encryption and decryption is 88MS,92MS and 97ms respectively for different-size surveying and mapping images,which is real-time and efficient,for 500 random mapping images,the average change rate of pixels is 99.74%,and the average change intensity of pixels is 33.83%,has the security and the validity.