Work

FlashPIR: low-latency FHE-based single-server PIR with low client overhead

Year: 2026

Type: article

Abstract: Toward practical and client-friendly single-server private information retrieval, we introduce FlashPIR, a scheme achieving both low client overhead and high server throughput. Constructed based on fully homomorphic encryption, our protocol possesses two distinct advantages: First, a majority of the resource-intensive computations can be performed in an offline phase, prior to query reception, significantly reducing the online response time. Second, database updates operate independently of clients, with low client computational overhead remaining nearly constant regardless of the database scale. We conducted comprehensive experiments to evaluate the performance of FlashPIR. The results demonstrate that for database sizes of 256 MB, our scheme achieves a throughput $$2.6\times$$ 2.6 × greater than KsPIR (Luo et al., CCS 2024) and $$18.5\times$$ 18.5 × greater than Spiral (Menon and Wu, S&P 2022).

Source: Cybersecurity

DOI: 10.1186/s42400-026-00601-7

Authors: Yiran Dai, Binwu Xiang, Lang Qin, Yi Deng, Jiang Zhang

Institutions: Chinese Academy of Sciences, Institute of Information Engineering, University of Chinese Academy of Sciences, East China Normal University, State Key Laboratory of Cryptology

Language: English

Topic: Cryptography and Data Security

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: diamond

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, National Key Research and Development Program of China

Awards: G2675430053, G3739984246, G4842851279, G7538674750