Cryptology ePrint Archive: Report 2021/1463

3-Party Distributed ORAM from Oblivious Set Membership

Brett Hemenway Falk and Daniel Noble and Rafail Ostrovsky

Abstract: Distributed Oblivious RAM (DORAM) protocols allow a group of participants to obliviously access a secret-shared array at a secret-shared index, and DORAM is the key tool for secure multiparty computation (MPC) in the RAM model. In this work, we present a novel 3-party semi-honest DORAM protocol with O((κ + D) log N) communication per access, where N is the size of the memory, κ is a security parameter and D is the block size. Our protocol performs polylogarithmic computation and does not require homomorphic encryption. Under natural parameter choices, this is the most communication-efficient DORAM with these properties. To build this DORAM protocol, we first present an extremely efficient oblivious data structure for answering set membership queries. From this we build an oblivious hash table with asymptotically optimal memory usage and access cost and with negligible failure probability. We believe these are of independent interest.

Category / Keywords: cryptographic protocols / distributed cryptography, secure multiparty computation, secret sharing, oblivious ram, distributed oblivious ram

Date: received 1 Nov 2021

Contact author: dgnoble at cis upenn edu

Available format(s): PDF | BibTeX Citation

Version: 20211106:154708 (All versions of this report)

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