Elisa Bertino Pierangela Samarati Sushil Jajodia V. S. Subrahmanian ACM SIGMOD Conference 1997 26 2 474 485 1667 KB Although several access control policies can be devised for controlling access to information, all existing authorization models, and the corresponding enforcement mechanisms, are based on a specific policy (usually the closed policy). As a consequence, a Software, PROGRAMMING LANGUAGES, Language Classifications. Information Systems, DATABASE MANAGEMENT, General. Information Systems, DATABASE MANAGEMENT, Physical Design, Access methods. H.2.2 Information Systems, DATABASE MANAGEMENT, Physical Design, Access methods. D.3.2 Software, PROGRAMMING LANGUAGES, Language Classifications. H.2.0 Information Systems, DATABASE MANAGEMENT, General.