Abstract:
Private information retrieval techniques can protect users' query privacy while conducting data retrieval. However, existing privacy information retrieval protocols are still not sufficiently efficient and often lack in functionality. An efficient ciphertext matching mechanism based on homomorphic encryption and number theory principles is proposed. Building upon this, we design a non-interactive symmetric private data retrieval protocol that supports fuzzy queries, aiming to significantly improve the efficiency of privacy information retrieval and expand the functionality of the protocol. Specifically, in our proposed scheme, a single query on tens of thousands of records only requires a delay at the level of seconds, outperforming the most efficient keyword-based privacy information retrieval schemes currently available in terms of server-side latency. Additionally, the protocol allows fuzzy queries with wildcards and multi-keyword queries, enabling users to obtain an experience close to plaintext queries while ensuring the protection of user and data privacy.