Efficient dynamic multi-client searchable encryption supporting fuzzy search

Searchable symmetric encryption (SSE) enables the client to outsource its encrypted database to the untrusted server, while maintaining the ability to efficiently search over it. However, most of the existing solutions focus mainly on exact keyword search. That is, it will fail to fetch the desired result even though mild typos. To this end, SSE with fuzzy keyword search has attracted considerable concerns in the literature. We note that the current works support merely single-client setting. How to design fuzzy keyword search-based SSE scheme in the multi-client setting is still open. In this work, we first introduce a dynamic multi-client fuzzy keyword search scheme by employing Intel SGX, which can achieve forward privacy at the expense of multiple trapdoors communication. The proposed construction can reduce client-side computation and communication overload with the aid of Intel SGX. Furthermore, we present an enhanced multi-client fuzzy keyword search scheme that achieves forward privacy even in the presence of the corrupted user. The evaluation of security and efficiency indicates that our schemes are capable of meeting the desired security level and are well-suited for real-world applications. •We propose a dynamic multi-client fuzzy keyword search SSE scheme named MUFKS by integrating Intel SGX and multi-client SSE. Specifically, the client generates the corresponding trapdoors of fuzzy set with the aid of Intel SGX, which reduces the communication overload between the client and the server. Further, the decryption of the matched (encrypted) identifiers are performed by enclave. Thus, the client-side cost in MUFKS is almost equal to that of traditional exact search.•We propose an enhanced multi-client fuzzy keyword search scheme (MUFKS++), which features forward privacy in multi-client setting by state-chain technique. By applying randomized state method in, the search cost can be optimized in MUFKS ++, achieving efficient search without the need for additional decryption operations.•We prove the security of our proposed schemes and compare them with existing work. The results show that our schemes can achieve efficient fuzzy keyword search while satisfying the desirable security guarantee.