Dynamic multi-client searchable symmetric encryption with support for boolean queries

With the rapid growth of cloud computing, an increasing amount of data is being outsourced to cloud servers, in the meantime, how to search data securely and efficiently has got an unprecedented concern. Searchable symmetric encryption (SSE) that enables keyword-based searches over encrypted data provides an efficient way to this problem. However, the majority of existing SSE schemes focus on single keyword searches in the single-client setting, which limits their wide application in cloud computing. In this paper, we propose a Dynamic Multi-client SSE (DMSSE) scheme with support for boolean queries, by incorporating a client's authorization information into search tokens and indexes. Our scheme allows a data owner to authorize multiple clients to perform boolean queries over an encrypted database, and limits a client's search ability to legitimate keywords. Compared with existing MSSE schemes, our DMSSE scheme has the following merits: 1) Non-interactivity. After the grant of search permission, the clients can perform queries on their own without the help of the data owner. 2) Dynamic. The data owner can efficiently update a client's search permission without affecting other clients. Experimental evaluations conducted on a real data set demonstrate that our DMSSE scheme is practical for use in a large-scale encrypted database. (C) 2019 Elsevier Inc. All rights reserved.