Application Research Of Multi-level Security Mechanism In GIS

With the rapid development of computer and internet technology, the application of GIS gets popular in all fields of social life. As a special MIS, the security and reliability of GIS is very important. Spatial database is the core of GIS, but there is few successful spatial database, so we use relational database and spatial data engine technology to access spatial data. Therefore, GIS security protection is based on RDBMS security and spatial data engine security.ArcSDE, the engine product for spatial database of ESRI company, is a middleware to connect the commercial RDBMS, such as Oracle and SQL Server. ArcSDE is an open, high performance spatial data server that employs client-server architecture to share data and to perform efficient spatial operations and management. Spatial data engine doesn't provide secure mechanism, so GIS's security is carried out mainly by the database.In order to assure the integrity and consistency of spatial data, we analysized the storage and management of spatial data carefully, and constructed spitial database with SQL Server and ArcSDE. In the light of spatial data properity, the semi-tuple labeling, which is foundation for multi-level security, is presented based on MLR's theory. Control policy is the premise for achieveing multi-level security mechanism and shouldn't have the ambiguity. We studied access control theory (BLP and RBAC) comprehensively, introduced the idea of TCSEC TDI, adopted TF strategy and designed a multi-level secure access control policy based on the RBAC for GIS, which has been applied to the residential area GIS effectively.