基于三维混沌序列的DEM置乱与还原方法

DEM是地形的真实表达,蕴含着丰富的地理空间信息。如何保证涉密DEM在网络环境中的安全传输是当前亟待解决的关键问题之一。本文采用三维混沌序列,对DEM文件先后进行高程置乱、位置置乱和文件头置乱,可使置乱后的数据失去高程变化的空间连续性与数值连续性。置乱数据经网络传输后,接收方仅凭用户密钥就可以实现置乱DEM数据的无损、盲式还原。基于ASCII格式DEM的置乱与还原试验表明:本文方法可以有效破坏原始DEM数据的空间形态特征和空间连续性,并具有较高的安全性。此外,在无原始数据参与的情况下,用户可以将置乱数据恢复至初始形态,且不会造成任何精度损失。本文算法特性基本满足了DEM数据在安全传输、封装存储等方面的应用需求。

A method for DEM scrambling and recovering based on three-dimensional chaotic sequence

DEM contains rich geo-spatial information and represents the true terrain. How to ensure the transmission security of secret DEM in network environment is a significant question in recent years. In this article, we use the three-dimension chaotic sequence to encrypt DEM files by scrambling its elevation value, pixel location and file header which break the value continuity and spatial continuity of elevations. When receivers get the scrambling DEM through the Internet, they can blind decrypt the data lossless by using secret key. The scrambling and recovering experiment based on ASCⅡ format DEM proves that the method can break the spatial characteristic and continuity of origin DEM with high security. Furthermore, user can recover the scrambling data back to origin lossless without original data. The features of the algorithm basically meet the application requirements of DEM data in secure transmission, encapsulation and storage.