RDAS: A Symmetric Key Scheme for Authenticated Query Processing in Outsourced Databases

Security of outsourced databases is an important problem of current practical interest. In this paper we address the problem of authenticated query processing in outsourced databases. We describe the syntax of a generic scheme for authenticated query processing called RDAS, and provide security definitions for RDAS in line with concrete provable security. Then, we propose a new scheme called RDAS1 which enables a client to ensure both correctness and completeness of the query results obtained from a server. Our solution involves use of bitmap indices and message authentication codes in a novel manner. We prove that RDAS1 is secure relative to our security definition. Finally, we discuss a concrete improvement over RDAS1 (which we call RDAS2) and provide performance data for both RDAS1 and RDAS2 on a real data base.