Research On Model And Method Of Encryption And Steganography For Geospatial Data

As the national infrastructure and supporting research for earth science,geospatial data is an indispensable strategic resource of national economy and defence construction.It is the core part of the national spatial information resources,and the geographic positioning framework for all earth science research.With the continual spring up of the digital technology and network technology,the access,use,dissemination,copy,and storage of geospatial data have become more convenient than before.However,the openness of network environment makes the theft,tamper,counterfeiting,infringement,leaks and other malicious acts threaten the safety of geospatial data greatly,which also significantly limit the healthy development of geographic information sharing and service.Therefore,this thesis aims at security distribution of geospatial data,and carries out systematic and deep research on models and methods for geospatial security processing.The main work and achievements are as follows:(1)The theoretical and technical system of the security distribution of geospatial data has been built.This thesis expounds the concepts,models,techniques and methods that relevant to geospatial data security,the mapping principle between geospatial data and security mechanism is established.On this basis,the theoretical model of geospatial data security is constructed;then the conceptual and technical system of geographical spatial data is built,and the security distribution process of geospatial data is also constructed,which probes into the concrete modules of geographical spatial data security distribution.Considering the functional demands of geospatial data security,the security process of geospatial data is divided into four aspects: the compression of geospatial data,the encryption of geospatial data,the data processing of geo spatial data and the verification of the model for the distribution of geographical spatial data.(2)The strategy and method of geospatial data compression are researched.By describing the types and characteristics of geographic spatial data,the theoretical model of geographic spatial data compression is established.Then,the thesis analyses the influence of the compressing process to geospatial data accuracy,the treating process in data compression and the error are summarized,and the organizing strategy of vector data is discussed simultaneously.Based on the analysis of the error types and characteristics in the process of compression,an algorithm of vector data compression in frequency domain is proposed.(3)The models and methods of geospatial data encryption are studied.A generally theoretical model of geospatial data encryption is established.It fits the needs of security issues in transmission scenarios for the process of the acquisition and distribution of geospatial data.This thesis discusses the encryption strategy that suits the safe and efficient distribution of geospatial data,and designs the method of data organization.On this basis,encryption methods of vector data and raster data are proposed respectively.Combining with the characteristics and types of geospatial data,the reliability and security of the algorithm are analysed from different angles.(4)The models and methods of steganography for geospatial data are researched.This thesis compares the types and characteristics of geospatial data and analyses the scientific problems of current steganography,and then the general steganography model of geospatial data is built.On the basis of the using environment and the application requirements for geospatial data,an anti steganography detection model is established.Considering the availability of geospatial data,an adaptive steganography method is proposed,which is suitable for the network environment.(5)The framework and functions of security distribution system of geospatial data are studied.According to the security requirements of geospatial data distribution,the framework of the security distribution system of geospatial data is estabelished,meanwhile,the security distribution system of geospatial data is designed and implemented.Finally,the vector data and raster data are taken as examples to verify the security distribution system of geospatial data.