Secure and Scalable Circuit-based Protocol for Multi-Party Private Set Intersection

TL;DR

This paper introduces a secure, scalable circuit-based multi-party PSI protocol that leverages two-party secure computation, hashing, and bucketing to optimize performance and reduce overhead.

Contribution

It presents the first circuit-based multi-party PSI protocol that improves scalability and efficiency using hashing and bucketing techniques.

Findings

Achieves significant reduction in computation and communication costs.

Demonstrates good scalability with two-party secure computation approach.

Optimizes circuit size through bucketing and hashing methods.

Abstract

We propose a novel protocol for computing a circuit which implements the multi-party private set intersection functionality (PSI). Circuit-based approach has advantages over using custom protocols to achieve this task, since many applications of PSI do not require the computation of the intersection itself, but rather specific functional computations over the items in the intersection. Our protocol represents the pioneering circuit-based multi-party PSI protocol, which builds upon and optimizes the two-party SCS \cite{huang2012private} protocol. By using secure computation between two parties, our protocol sidesteps the complexities associated with multi-party interactions and demonstrates good scalability. In order to mitigate the high overhead associated with circuit-based constructions, we have further enhanced our protocol by utilizing simple hashing scheme and permutation-based hash functions. These tricks have enabled us to minimize circuit size by employing bucketing techniques while simultaneously attaining noteworthy reductions in both computation and communication expenses.