A Multi-Purpose Implementation of Mandatory Access Control in Relational Database Management Systems Walid Rjaibi and Paul Bird   View Paper (PDF)   Return to INDUSTRIAL SESSION 1: NOVEL SQL EXTENSIONS Abstract Mandatory Access Control (MAC) implementations in Relational Database Management Systems (RDBMS) have focused solely on Multilevel Security (MLS). MLS has posed a number of challenging problems to the database research community, and there has been an abundance of research work to address those problems. Unfortunately, the use of MLS RDBMS has been restricted to a few government organizations where MLS is of paramount importance such as the intelligence community and the Department of Defense. The implication of this is that the investment of building an MLS RDBMS cannot be leveraged to serve the needs of application domains where there is a desire to control access to objects based on the label associated with that object and the label associated with the subject accessing that object, but where the label access rules and the label structure do not necessarily match the MLS two security rules and the MLS label structure. This paper introduces a flexible and generic implementation of MAC in RDBMS that can be used to address the requirements from a variety of application domains, as well as to allow an RDBMS to efficiently take part in an end-to-end MAC enterprise solution. The paper also discusses the extensions made to the SQL compiler component of an RDBMS to incorporate the label access rules in the access plan it generates for an SQL query, and to prevent unauthorized leakage of data that could occur as a result of traditional optimization techniques performed by SQL compilers. ©2005 Association for Computing Machinery