Fast and Fuzzy Private Set Intersection

TL;DR

This paper introduces a faster PSI method that encrypts each set once and performs a single comparison, trading some accuracy for significant speed gains, demonstrated with English words and WordNet.

Contribution

It presents a novel PSI approach that reduces encryption rounds and simplifies comparisons, enabling faster private set intersection with controlled fuzziness.

Findings

Order of magnitude speed improvement over traditional PSI

Effective with English words using WordNet

Fuzziness in matching can be acceptable or beneficial

Abstract

Private Set Intersection (PSI) is usually implemented as a sequence of encryption rounds between pairs of users, whereas the present work implements PSI in a simpler fashion: each set only needs to be encrypted once, after which each pair of users need only one ordinary set comparison. This is typically orders of magnitude faster than ordinary PSI at the cost of some ``fuzziness" in the matching, which may nonetheless be tolerable or even desirable. This is demonstrated in the case where the sets consist of English words processed with WordNet.