File Dynamic Integrity in a Multi-user Environment

In a Dynamic Verifiable Searchable Symmetric Encryption (DVSSE) scheme, a client Alice can perform keyword-based searches on ciphertexts, and update (modify, delete and add) documents in a verifiable way. However, the DVSSE scheme is not suitable for the multi-user environment, where Alice may authorize many users to update documents. The reason is that it is hard to achieve traceability based on the symmetric key. Furthermore, the DVSSE scheme cannot distinguish incomplete search results from incomplete document set. In this paper, we propose a Multi-user Dynamic Verifiable Searchable Encryption (MDVSE) scheme, which utilizes the Proxy Re-Encryption with keyword Search (PRES) to achieve multi-user envrionment, and applies the Merkle Hash Tree (MHT) to achieve integrity verification on both search results and document set. We analyze and conduct experiments to verify its feasibility.