AnonPSI: An Anonymity Assessment Framework for PSI

Bo Jiang

Network and Distributed System Security (NDSS) Symposium 2024 · Day 1 · Crypto Protocols

This talk introduces AnonPSI, a comprehensive framework designed for assessing the anonymity and privacy leakage of Private Set Intersection (PSI) protocols. PSI is a foundational cryptographic primitive enabling two parties to compute the intersection of their datasets without revealing the individual elements of those sets. Its applications span diverse fields, including friend recommendations, advertising measurement, and even sensitive areas like contagious disease tracking. However, recent research has exposed a critical vulnerability: **Set Membership Inference Attacks (SMIA)**. These attacks allow an adversary, through repeated PSI invocations, to infer whether a specific individual is part of the intersection set, even in stringent variants like **PSI-CA (PSI-Cardinality)**, which only reveal the intersection size.