Abstract
Conflicts in database systems with both real-time and secu rity requirements can be unresolvable. We address this issue by allowing a database system to provide partial security in order to improve real-time performance when necessary. Systems that are partially secure allow potential security violations such as covert channel use at certain situations. We present the idea of requirement S&Pecification that enables the system designer to S&Pecify important properties of the database at an appropriate level. To help the designer, a tool can process the database S&Pecification to find unresolvable conflicts, and to allow the designer to S&Pecify the rules to follow during execution when those con flicts arise. We discuss several partial security policies and compare their performance in terms of timeliness and potential security violations.