Privacy-Preserving Large-Scale Set Intersection: an Efficient Method with Enhanced Security

Private set intersection (PSI) has emerged as a key cryptographic protocol, enabling secure data sharing and facilitating collaborative computing among distributed data providers in recent years. However, it remains challenging to achieve efficient multiparty PSI (MPSI) for large-scale data and numerous participants in an open environment. To this end, we propose EL-MPSI, an efficient and lightweight MPSI scheme based on vector oblivious linear evaluation (VOLE) and oblivious key-value store (OKVS), which enables secure data sharing in settings with millions of datasets and dozens of participants. By simplifying the interaction process among multiple participants, the proposed scheme achieves constant-level round complexity and provides resistance against malicious adversaries, as well as collusion attack. Through theoretical analysis and experiments, we demonstrate that the security, efficiency, and scalability of our scheme perform better than existing state-of-the-art (SOTA) works. For millions of datasets and dozens of participants, EL-MPSI achieves second-level latency while keeping client communication overhead to approximately 10 MB. Moreover, in scenarios of malicious adversary setting, the extra execution overhead is negligible, which effectively facilitates large-scale data sharing.