Searchable Encryption Supporting General Boolean Expression Queries
Résumé
We propose a first construction of searchable encryption that supports generic boolean search over encrypted data. It is based on an original idea of considering keywords as vectors and using the Gram-Schmidt process to orthogonalize and then orthonormalize them. It further makes use of a very efficient operation, the inner product, to perform searches at the server side. The inner product indeed leverages the orthonormalized keywords to efficiently test if a boolean expression query matches the label corresponding to an encrypted document or not. The orthonormalized keywords are salted and the queries sent for retrieving encrypted documents are further randomized to guarantee the secruity of our scheme.