Paper 2019/414

Two-Round Oblivious Transfer from CDH or LPN

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


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.

Available format(s)
Cryptographic protocols
Publication info
A minor revision of an IACR publication in EUROCRYPT 2020
oblivious transfermultiparty computation
Contact author(s)
wichs @ ccs neu edu
2020-05-06: last of 3 revisions
2019-04-22: received
See all versions
Short URL
Creative Commons Attribution


      author = {Nico Döttling and Sanjam Garg and Mohammad Hajiabadi and Daniel Masny and Daniel Wichs},
      title = {Two-Round Oblivious Transfer from CDH or LPN},
      howpublished = {Cryptology ePrint Archive, Paper 2019/414},
      year = {2019},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.