Private Set Intersection for Data Exchange

PI: Dr. John T.H. Yuen, HKU

Project Abstract: 

A private set intersection (PSI) protocol is a protocol to get the intersection of two sets, each of which belongs to one party, without disclosing extra information of each party’s set to the other party. For example, after installed an e-banking app, a user wants to check which friends in his contact list have also installed the same app (so that he can make payment later). The user does not want to reveal his entire contact list due to privacy concern, and the bank cannot reveal its customer list too. PSI is a suitable solution for this application.

A number of PSI protocols have been proposed in the literature. We focus on the special case of unbalanced PSI: one party has a much larger set (the bank) than the other party (the user). However, there are not much implementation available and hence it is difficult to compare their performance. In this project, we propose new optimization techniques by using new cryptographic protocols as well as new form of data structure. We provide efficient implementation for unbalanced PSI protocol and compare it with existing schemes.