A Trust Answer to Distance Query

To provide a trusted database query service, a database server returns to a client a query answer as well as a correctness proof for the answer. The trusted query result should have the following properties: (1) soundness, (2) completeness, (3) privacy. The present trust answer scheme (TrustAnswer for short) addresses a new query called as trusted distance query. Although distance query is widely used in database search, few previous schemes are applicable to trusted distance query. TrustAnswer creates a virtual database, and sets up a multi-dimensional Merkle tree for the virtual database. For each query on the original database, the server sends to the client a query result with the virtual database, as well as a proof for soundness and completeness. To demonstrate the practicality of TrustAnswer, we develop a prototype for authenticated content-aware video query on handphone. Since the prototype is light weight in computation and communication, it is suitable to be used in hand-hold devices.