Paper 2020/1431

Information-Theoretic 2-Round MPC without Round Collapsing: Adaptive Security, and More

Huijia Lin, Tianren Liu, and Hoeteck Wee


We present simpler and improved constructions of 2-round protocols for secure multi-party computation (MPC) in the semi-honest setting. Our main results are new information-theoretically secure protocols for arithmetic NC1 in two settings: (i) the plain model tolerating up to $t < n/2$ corruptions; and (ii) in the OLE-correlation model tolerating any number of corruptions. Our protocols achieve adaptive security and require only black-box access to the underlying field, whereas previous results only achieve static security and require non-black-box field access. Moreover, both results extend to polynomial-size circuits with computational and adaptive security, while relying on black-box access to a pseudorandom generator. In the OLE correlation model, the extended protocols for circuits tolerate up to $n-1$ corruptions. Along the way, we introduce a conceptually novel framework for 2-round MPC that does not rely on the round collapsing framework underlying all of the recent advances in 2-round MPC.

Available format(s)
Cryptographic protocols
Publication info
Published by the IACR in TCC 2020
multi-party computation
Contact author(s)
rachel @ cs washington edu
wee @ di ens fr
liutr @ mit edu
2020-11-15: received
Short URL
Creative Commons Attribution


      author = {Huijia Lin and Tianren Liu and Hoeteck Wee},
      title = {Information-Theoretic 2-Round {MPC} without Round Collapsing: Adaptive Security, and More},
      howpublished = {Cryptology ePrint Archive, Paper 2020/1431},
      year = {2020},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.