Paper 2022/1762 Original: eprint.iacr.org/2022/1762 ↗
On the Impossibility of Surviving (Iterated) Deletion of Weakly Dominated Strategies in Rational MPC
Abstract
Rational multiparty computation (rational MPC) provides a framework for analyzing MPC protocols through the lens of game theory. One way to judge whether an MPC protocol is rational is through weak domination: Rational players would not adhere to an MPC protocol if deviating never decreases their utility, but sometimes increases it. Secret reconstruction protocols are of particular importance in this setting because they represent the last phase of most (rational) MPC protocols. We show that most secret reconstruction protocols from the literature are not, in fact, stable with respect to weak domination. Furthermore, we formally prove that (under certain assumptions) it is impossible to design a secret reconstruction protocol which is a Nash equlibrium but not weakly dominated if (1) shares are authenticated or (2) half of all players may form a coalition.
Metadata
- Available format(s)
PDF- Category
- Foundations
- Publication info
- Preprint.
- History
- 2023-10-18: last updated
- 2022-12-23: published
- Short URL
- https://ia.cr/2022/1762
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2022/1762,
author = {Johannes Blömer and Jan Bobolz and Henrik Bröcher},
title = {On the Impossibility of Surviving (Iterated) Deletion of Weakly Dominated Strategies in Rational MPC},
howpublished = {Cryptology {ePrint} Archive, Paper 2022/1762},
year = {2022},
url = {https://eprint.iacr.org/2022/1762}
}