Cryptology ePrint Archive: Report 2020/620

Private Identity Agreement for Private Set Functionalities

Ben Kreuter and Sarvar Patel and Ben Terner

Abstract: Private set intersection and related functionalities are among the most prominent real-world applications of secure multiparty computation. While such protocols have attracted significant attention from the research community, other functionalities are often required to support a PSI application in practice. For example, in order for two parties to run a PSI over the unique users contained in their databases, they might first invoke on a support functionality to agree on the primary keys to represent their users. This paper studies a secure approach to agreeing on primary keys. We introduce and realize a functionality that computes a common set of identifiers based on incomplete information held by two parties, which we refer to as private identity agreement. We explain the subtleties in designing such a functionality that arise from privacy requirements when intending to compose securely with PSI protocols. We also argue that the cost of invoking this functionality can be amortized over a large number of PSI sessions, and that for applications that require many repeated PSI executions, this represents an improvement over a PSI protocol that directly uses incomplete or fuzzy matches.

Category / Keywords: applications / private set interection, private identity agreement, garbled circuits

Date: received 26 May 2020

Contact author: benkreuter at google com,bterner@cs ucsb edu

Available format(s): PDF | BibTeX Citation

Version: 20200526:231454 (All versions of this report)

Short URL: ia.cr/2020/620


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