Cryptology ePrint Archive: Report 2009/019

Communication-Efficient Private Protocols for Longest Common Subsequence

Matthew Franklin and Mark Gondree and Payman Mohassel

Abstract: We design communication efficient two-party and multi-party protocols for the longest common subsequence (LCS) and related problems. Our protocols achieve privacy with respect to passive adversaries, under reasonable cryptographic assumptions. We benefit from the somewhat surprising interplay of an efficient block-retrieval PIR (Gentry-Ramzan, ICALP 2005) with the classic “four Russians” algorithmic design. This result is the first improvement to the communication complexity for this application over generic results (such as Yao’s garbled circuit protocol) and, as such, is interesting as a contribution to the theory of communication efficiency for secure two-party and multiparty applications.

Category / Keywords: applications / longest common subsequence, secure multiparty computation

Publication Info: This is the full version of an article to appear in CT-RSA 2009.

Date: received 8 Jan 2009, last revised 13 Jan 2009

Contact author: pmohassel at ucdavis edu

Available format(s): PDF | BibTeX Citation

Note: revision to fix typos from copy-paste in title and abstract

Version: 20090113:191456 (All versions of this report)

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