Trusted Boolean Search on Cloud Using Searchable Symmetric Encryption

Abstract

A Searchable Symmetric Encryption (SSE) scheme allows a server to search a user's data without having to decrypt the data. This provides the user with a high degree of privacy and is particularly useful when data is stored on Cloud. Numerous SSE schemes have already been proposed and while most have excellent security properties, few meet high performance requirements and most only support searching for a single keyword at a time. The SSE scheme of Cash et al. (CRYPTO 2013) is notable for its high efficiency on restricted forms of Boolean queries, but has low efficiency for, or does not support, other common forms of boolean queries. In this paper, we propose a generalization and optimization of the Cash et al. SSE scheme, which extends to support a much larger class of Boolean queries, and performs no worse, and often with much higher efficiency than the Cash et al. scheme for the remaining queries.