Paper 2024/896
Dynamic-FROST: Schnorr Threshold Signatures with a Flexible Committee
, Roma Tre University, Bank of Italy, Bank of Italy, University of Pisa, Bank of Italy, Bank of Italy, Roma Tre UniversityAbstract
Threshold signatures enable any subgroup of predefined cardinality $t$ out of a committee of $n$ participants to generate a valid, aggregated signature. Although several $(t,n)$-threshold signature schemes exist, most of them assume that the threshold $t$ and the set of participants do not change over time. Practical applications of threshold signatures might benefit from the possibility of updating the threshold or the committee of participants. Examples of such applications are consensus algorithms and blockchain wallets. In this paper, we present Dynamic-FROST (D-FROST, for short) that combines FROST, a Schnorr threshold signature scheme, with CHURP, a dynamic proactive secret sharing scheme. The resulting protocol is the first Schnorr threshold signature scheme that accommodates changes in both the committee and the threshold value without relying on a trusted third party. Besides detailing the protocol, we present a proof of its security: as the original signing scheme, D-FROST preserves the property of Existential Unforgeability under Chosen-Message Attack.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Keywords
- Proactive secret sharingThreshold signaturesDecentralizationFROSTCHURP
- Contact author(s)
-
annalisa cimatti @ unibe ch
francesco desclavis @ bancaditalia it
giuseppe galano2 @ bancaditalia it
sara giammusso @ bancaditalia it
michela iezzi @ bancaditalia it
antonio muci @ bancaditalia it
matteo nardelli @ bancaditalia it
marco pedicini @ uniroma3 it - History
- 2024-12-16: last of 2 revisions
- 2024-06-05: received
- See all versions
- Short URL
- https://ia.cr/2024/896
- License
-
CC BY-SA
BibTeX
@misc{cryptoeprint:2024/896,
author = {Annalisa Cimatti and Francesco De Sclavis and Giuseppe Galano and Sara Giammusso and Michela Iezzi and Antonio Muci and Matteo Nardelli and Marco Pedicini},
title = {Dynamic-{FROST}: Schnorr Threshold Signatures with a Flexible Committee},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/896},
year = {2024},
url = {https://eprint.iacr.org/2024/896}
}
