Security constraint processing in a multilevel secure distributed database management system

In a multilevel secure distributed database management system, users cleared at different security levels access and share a distributed database consisting of data at different sensitivity levels. An approach to assigning sensitivity levels, also called security levels, to data is one which utilizes constraints or classification rules. Security constraints provide an effective classification policy. They can be used to assign security levels to the data based on content, context, and time. We extend our previous work on security constraint processing in a centralized multilevel secure database management system by describing techniques for processing security constraints in a distributed environment during query, update, and database design operations