Rich Queries On Encrypted Data: Beyond Exact Matches

We extend the searchable symmetric encryption (SSE) protocol of [Cash et al., Crypto'13] adding support for range, substring, wildcard, and phrase queries, in addition to the Boolean queries supported in the original protocol. Our techniques apply to the basic singleclient scenario underlying the common SSE setting as well as to the more complex Multi-Client and Outsourced Symmetric PIR extensions of [Jarecki et al., CCS'13]. We provide performance information based on our prototype implementation, showing the practicality and scalability of our techniques to very large databases, thus extending the performance results of [Cash et al., NDSS'14] to these rich and comprehensive query types.