Efficient Single-Server Private Information Retrieval Based on LWE Encryption

Private Information Retrieval (PIR) is a cryptographic protocol that allows users to retrieve data from one or more databases without revealing any information about their queries. Among existing PIR protocols, single-server schemes based on the Learning With Errors (LWE) assumption currently constitute the most practical class of constructions. However, existing schemes continue to suffer from high client-side preprocessing complexity and significant server-side storage overhead, leading to degraded overall performance. We propose ShufflePIR, a single-server protocol that marks the first introduction of an SM3-based pseudorandom function into the PIR framework for shuffling during preprocessing and utilizes cryptographic hardware to accelerate computation, thereby improving both efficiency and security. In addition, the adoption of a parallel encryption scheme based on the LWE assumption significantly enhances the client’s computational efficiency when processing long-bit data. We evaluate the performance of our protocol against the latest state-of-the-art PIR schemes. Simulation results demonstrate that ShufflePIR achieves a throughput of 9903 MB/s on a 16 GB database with 1 MB records, outperforming existing single-server PIR schemes. Overall, ShufflePIR provides an efficient and secure solution for privacy-preserving information retrieval in a wide range of applications.