Threshold ECDSA with an Offline Recovery Party [article]

Michele Battagliola, Riccardo Longo, Alessio Meneghetti, Massimiliano Sala
2021 arXiv   pre-print
A (t,n)- threshold signature scheme enables distributed signing among n players such that any subgroup of size t can sign, whereas any group with fewer players cannot. Our goal is to produce signatures that are compatible with an existing centralized signature scheme: the key generation and signature algorithm are replaced by a communication protocol between the parties, but the verification algorithm remains identical to that of a signature issued using the centralized algorithm. Starting from
more » ... the threshold schemes for the ECDSA signature due to R. Gennaro and S. Goldfeder, we present the first protocol that supports multiparty signatures with an offline participant during the Key Generation Phase, without relying on a trusted third party. Following well-established approaches, we prove our scheme secure against adaptive malicious adversaries.
arXiv:2007.04036v2 fatcat:5n2rmzsqrzamdbylowbp532e4e