VPIR: an efficient verifiable private information retrieval scheme resisting malicious cloud server

Private information retrieval, which allows users to securely retrieve information stored in a single server or multiple servers without disclosing any query content to the server, has attracted much attention in recent years. However, most of the existing private information retrieval schemes cannot achieve data retrieval and data integrity authentication simultaneously. To address the above challenges, this paper proposes a verifiable private information retrieval scheme based on parity in a single-server architecture. Specifically, the data owner generates parity information for each data and extends the original database. Then the data owner generates hint information for the query client, and according to the inverse of the hint information, the matrix confusion and permutation of the extensible database are carried out on the database and the hint information is sent to the client. The client selects the corresponding element in the hint to generate the query vector and executes the reconstruction and verification phase after receiving the answer to accomplish the retrieval process. A series of security games prove that this scheme meets the privacy requirements defined by the PIR scheme, and experimental analysis shows that compared with related schemes, our scheme has certain advantages in time cost. The time of verification information generation is 0.3% of APIR and FMAPIR, the reconstruction time is 1.6% of APIR and 1.1% of FMAPIR and the query time is much less than them.