Sashimi: Cutting up CSI-FiSh secret keys to produce an actively secure distributed signing protocol

Daniele Cozzo; Nigel P.  smart

Paper 2019/1360

Sashimi: Cutting up CSI-FiSh secret keys to produce an actively secure distributed signing protocol

Daniele Cozzo and Nigel P. smart

Abstract

We present the first actively secure variant of a distributed signature scheme based on isogenies. The protocol produces signatures from the recent CSI-FiSh signature scheme. Our scheme works for any access structure, as we use a replicated secret sharing scheme to define the underlying secret sharing; as such it is only practical when the number of maximally unqualified sets is relatively small. This, however, includes the important case of full threshold, and $(n,t)$-threshold schemes when $n$ is small.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Minor revision. PQC 2020
Contact author(s): daniele cozzo @ kuleuven be
nigel smart @ kuleuven be
History: 2020-01-29: last of 2 revisions; 2019-11-27: received; See all versions
Short URL: https://ia.cr/2019/1360
License: CC BY

BibTeX

@misc{cryptoeprint:2019/1360,
      author = {Daniele Cozzo and Nigel P.  smart},
      title = {Sashimi: Cutting up {CSI}-{FiSh} secret keys to produce an actively secure distributed signing protocol},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/1360},
      year = {2019},
      url = {https://eprint.iacr.org/2019/1360}
}