An Efficient, Verifiable, and Dynamic Searchable Symmetric Encryption with Forward Privacy
Khosro Salmani · 2022
Dynamic Searchable Symmetric Encryption (DSSE) allows a cloud server to perform search queries on a user’s documents while both queries and files are encrypted. It also enables the user to update the corpus efficiently. Recently, the notion of Forward Privacy (FP) was introduced, which guarantees the privacy of a newly added document in the presence of previous queries. However, most of the existing approaches work only with honest-but-curious servers. In these schemes, it is assumed the cloud server follows the prescribed protocols, but due to the untrusted nature of the cloud servers, this assumption does not always hold in practice. Hence, it is essential to design and implement new approaches that verify the results of queries and detect malicious behavior of a cloud server. In this paper, we construct a new forward-private DSSE scheme that efficiently achieves result verifiability. To obtain this goal, along with the search results, the server provides a "proof of work" to demonstrate result completeness. Moreover, our approach support searches and updates efficiently. Finally, the security and practicality of our scheme is demonstrated by providing performance analysis and security proof.