Cryptology ePrint Archive: Report 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.

Category / Keywords: cryptographic protocols /

Original Publication (with minor differences): PQC 2020

Date: received 26 Nov 2019, last revised 29 Jan 2020

Contact author: daniele cozzo at kuleuven be, nigel smart at kuleuven be

Available format(s): PDF | BibTeX Citation

Version: 20200129:163241 (All versions of this report)

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