Netinfo Security ›› 2026, Vol. 26 ›› Issue (4): 542-551.doi: 10.3969/j.issn.1671-1122.2026.04.003

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A Secure and Scalable Variant-Threshold Multiparty Private Set Intersection Protocol

ZHENG Dong, LIU Yanrong, QIN Baodong()   

  1. School of Cyberspace Security, Xi’an University of Posts and Telecommunications, Xi’an 710121, China
  • Received:2025-09-15 Online:2026-04-10 Published:2026-04-29

Abstract:

The ability of multi-party private intersection (MPSI) protocols is to securely find the intersection of multi-party sets and output it without disclosing any other information. However, there are some special and useful scenarios that cannot be solved directly using traditional MPSI protocols. One of such scenarios is to compute the set of elements that appear in some but not all sets (at least k times) for only a third party. However, the previous method(Quorum PSI) can only addresse the problem of getting special intersections of known elements. The over-threshold PSI can address the issue, but needs to perform times, which is inefficient when the number of participants is large. This paper proposed a secure and scalable variant-threshold multiparty private set intersection protocol. It only executes nk + 1 times, which is more efficient in cases with a high threshold k.

Key words: private set intersection, private set membership test, private information retrieval, equal test

CLC Number: