Paper 2021/1470
Concurrent-Secure Two-Party Computation in Two Rounds from Subexponential LWE
Saikrishna Badrinarayanan, Rex Fernando, and Amit Sahai
Abstract
Very recently, two works were able to construct two-round secure multi-party computation (MPC) protocols in the plain model, without setup, relying on the superpolynomial simulation framework of Pass [Pas03]. The first work [ABG+21] achieves this relying on subexponential non-interactive witness indistinguishable arguments, the subexponential SXDH assumption, and the existence of a special type of non-interactive non-malleable commitment. The second work [FJK21] additionally achieves concurrent security, and relies on subexponential quantum hardness of the learning-with-errors (LWE) problem, subexponential classical hardness of SXDH, the existence of a subexponentially-secure (classically-hard) indistinguishablity obfuscation (iO) scheme, and time-lock puzzles. This paper focuses on the assumptions necessary to construct secure computation protocols in two rounds without setup, focusing on the subcase of two-party functionalities. In this particular case, we show how to build a two-round, concurrent-secure, two-party computation (2PC) protocol based on a single, standard, post-quantum assumption, namely subexponential hardness of the learning-with-errors (LWE) problem. We note that our protocol is the first two-round concurrent-secure 2PC protocol that does not require the existence of a one-round non-malleable commitment (NMC). Instead, we are able to use the two-round NMCs of [KS17a], which is instantiable from subexponential LWE.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint. MINOR revision.
- Keywords
- two-party computationlearning with errors
- Contact author(s)
-
bsaikrishna7393 @ gmail com
rex1fernando @ gmail com
amitsahai @ gmail com - History
- 2021-11-06: received
- Short URL
- https://ia.cr/2021/1470
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/1470,
author = {Saikrishna Badrinarayanan and Rex Fernando and Amit Sahai},
title = {Concurrent-Secure Two-Party Computation in Two Rounds from Subexponential LWE},
howpublished = {Cryptology ePrint Archive, Paper 2021/1470},
year = {2021},
note = {\url{https://eprint.iacr.org/2021/1470}},
url = {https://eprint.iacr.org/2021/1470}
}
