Fast Multiparty Threshold ECDSA with Fast Trustless Setup

Rosario Gennaro; Steven Goldfeder

Paper 2019/114

Fast Multiparty Threshold ECDSA with Fast Trustless Setup

Rosario Gennaro and Steven Goldfeder

Abstract

A threshold signature scheme enables distributed signing among $n$ players such that any subgroup of size $t+1$ can sign, whereas any group with $t$ or fewer players cannot. While there exist previous threshold schemes for the ECDSA signature scheme, we present the first protocol that supports multiparty signatures for any $t \leq n$ with efficient, dealerless key generation. Our protocol is faster than previous solutions and significantly reduces the communication complexity as well. We prove our scheme secure against malicious adversaries with a dishonest majority. We implemented our protocol, demonstrating its efficiency and suitability to be deployed in practice.

Note: Fixes some issues in the protocol and security proof.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Major revision. ACM CCS 2018
Contact author(s): goldfeder @ cornell edu
History: 2021-12-17: revised; 2019-02-07: received; See all versions
Short URL: https://ia.cr/2019/114
License: CC BY

BibTeX

@misc{cryptoeprint:2019/114,
      author = {Rosario Gennaro and Steven Goldfeder},
      title = {Fast Multiparty Threshold ECDSA with Fast Trustless Setup},
      howpublished = {Cryptology ePrint Archive, Paper 2019/114},
      year = {2019},
      note = {\url{https://eprint.iacr.org/2019/114}},
      url = {https://eprint.iacr.org/2019/114}
}