Robust ECDSA Threshold Signing at Scale

Carsten Baum; Anders Dalskov

Paper 2026/2493

Robust ECDSA Threshold Signing at Scale

Carsten Baum

, Technical University of Denmark

Anders Dalskov

, Partisia

Abstract

This work presents an efficient, scalable, and robust threshold ECDSA signing protocol for the $t\leq (n-1)/3$ scenario, making it suitable for e.g., bridging consensus from one Blockchain to another. Our construction allows to batch-compute pre-processing material for efficient online signing. While our protocol is based on established ideas for (Verifiable) Secret Sharing, we optimize it to scale efficiently both in terms of computation and communication with a large number of signers. We therefore combine efficient batching techniques for sharing (Fitzi & Hirt, PODC 2006), randomness extraction (Beerliova-Trubiniova & Hirt, TCC 2008) and share opening (Damgård & Nielsen, CRYPTO 2007) with recent advances in efficient Zero-Knowledge proofs (Attema & Cramer, CRYPTO 2020). We implement and evaluate the protocol experimentally and show that it is practical for large number of parties $n$.

Metadata

Available format(s): PDF
Publication info: Published by the IACR in CIC 2026
Keywords: ECDSA Threshold Signing Blockchain Bridge
Contact author(s): cabau @ dtu dk
anderspkd @ partisia com
History: 2026-10-15: approved; 2026-10-15: received; See all versions
Short URL: https://ia.cr/2026/2493
License: CC BY

BibTeX

@misc{cryptoeprint:2026/2493,
      author = {Carsten Baum and Anders Dalskov},
      title = {Robust {ECDSA} Threshold Signing at Scale},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2493},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2493}
}