Effective Access Control Mechanism and Multilevel Security for Multilevel Secure Databases.

摘要

Security mechanisms on contemporary database systems typically inhibit system performance. However, without security, the database system which stores classified data of different classifications, will pass through classified data of different levels in order to find the properly classified data. This 'pass through' inhibits performance (i.e., reduces access precision) because unnecessary material has been retrieved which does not aid in the resolution of the query. Further, the pass-through issue also breaches the security, since the system may pass through higher classified data for the purpose of locating the lower classified one. This thesis shows for the first time, our Query Modification and Multilevel Security approach to database security, implemented into a single database system, i.e., the Multi-Backend, Multi-Lingual, Multi-Model Database System. Database security; Multilevel security; Computer security; Access control. (eg)