Forward Private Verifiable Dynamic Searchable Symmetric Encryption With Efficient Conjunctive Query

Dynamic searchable symmetric encryption (DSSE) allows efficient searches over encrypted databases and also supports clients in their updating of the data, such as those stored in a remote cloud server. However, recent attacks suggest the risk of leakage during such updates, which consequently impacts on the privacy of the queries. In addition, existing DSSE schemes that support forward privacy generally rely on the honest-but-curious server and support only single-keyword retrieval, which limits the application scenarios. In this paper, we present the design of a verifiable DSSE protocol, which supports efficient conjunctive query with forward privacy. In our scheme, the forward index is constructed by a novel form, i.e., $ t$t-puncturable PRFs, and the authentication tag is designed by symmetric cryptography. During conjunctive queries, we narrow the scope by an inverted index, and then we determine the results of the final query through the forward index. Meanwhile, we can use verification tag to check the correctness and completeness of the result. In addition, we present an extension to support backward privacy, and our experimental evaluations show that our proposed approach achieves better performance on both conjunctive queries and updates than other competing solutions and ensures efficient verification.