Building castles out of mud: practical access pattern privacy and correctness on untrusted storage

Abstract

We introduce a new practical mechanism for remote data storage with efficient access pattern privacy and correctness. A storage client can deploy this mechanism to issue encrypted reads, writes, and inserts to a potentially curious and malicious storage service provider, without revealing information or access patterns. The provider is unable to establish any correlation between successive accesses, or even to distinguish between a read and a write. Moreover, the client is provided with strong correctness assurances for its operations -- illicit provider behavior does not go undetected. We built a first practical system -- orders of magnitude faster than existing implementations -- that can execute over several queries per second on 1Tbyte+ databases with full computational privacy and correctness.