## Cryptology ePrint Archive: Report 2019/577

Improved Multiplication Triple Generation over Rings via RLWE-based AHE

Deevashwer Rathee and Thomas Schneider and K. K. Shukla

Abstract: An important characteristic of recent MPC protocols is an input-independent setup phase in which most computations are offloaded, which greatly reduces the execution overhead of the online phase where parties provide their inputs. For a very efficient evaluation of arithmetic circuits in an information-theoretic online phase, the MPC protocols consume Beaver multiplication triples generated in the setup phase. Triple generation is generally the most expensive part of the protocol, and improving its efficiency is the aim of our work. We specifically focus on computation over rings of the form $Z_{2^\ell}$ in the semi-honest model and the two-party setting, for which an Oblivious Transfer (OT)-based protocol is the currently best solution. To improve upon this method, we propose a protocol based on RLWE-based Additively Homomorphic Encryption. Our experiments show that our protocol is more scalable, and it outperforms the OT-based protocol in most cases. For example, we improve communication by up to 6.9x and runtime by up to 3.6x for 64-bit triple generation.

Category / Keywords: cryptographic protocols / Secure Two-party Computation; Beaver Multiplication Triples; Ring-LWE; Additively Homomorphic Encryption

Original Publication (with major differences): CANS'19

Date: received 27 May 2019, last revised 11 Aug 2019

Contact author: deevashwer student cse15 at iitbhu ac in

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2019/577

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