Privacy-Aware Verification of Aggregate Queries on Outsourced Databases with Applications to Historic Data Integrity

It is often desirable to be able to guarantee the integrity of historical data, ensuring that any subsequent modifications to the data can be detected. It would be especially convenient to extend such proofs of integrity to certain computations performed later using the historic data. We raise this question in the context of outsourced databases, where a data owner delegates the ability to answer users’ queries to a service provider, and distrustful users may desire to verify the integrity of responses to their queries on the data. We present a solution for integrity verification of aggregate database queries, such as SUM and MAX, with efficient proofs of correctness and completeness of responses to the queries. What makes the problem challenging is that individual data entries may be sensitive, and should not be revealed to the user. Our protocols are secure, under reasonable cryptographic assumptions.