## Cryptology ePrint Archive: Report 2019/414

Two-Round Oblivious Transfer from CDH or LPN

Nico Döttling and Sanjam Garg and Mohammad Hajiabadi and Daniel Masny and Daniel Wichs

Abstract: We show a new general approach for constructing maliciously secure two-round oblivious transfer (OT). Specifically, we provide a generic sequence of transformations to upgrade a very basic notion of two-round OT, which we call elementary OT, to UC-secure OT. We then give simple constructions of elementary OT under the Computational Diffie-Hellman (CDH) assumption or the Learning Parity with Noise (LPN) assumption, yielding the first constructions of malicious (UC-secure) two-round OT under these assumptions. Since two-round OT is complete for two-round 2-party and multi-party computation in the malicious setting, we also achieve the first constructions of the latter under these assumptions.

Category / Keywords: cryptographic protocols / oblivious transfer, multiparty computation

Date: received 22 Apr 2019, last revised 23 Apr 2019

Contact author: wichs at ccs neu edu

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2019/414

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