[Resource Topic] 2023/276: Threshold and Multi-Signature Schemes from Linear Hash Functions

Welcome to the resource topic for 2023/276

Title:
Threshold and Multi-Signature Schemes from Linear Hash Functions

Authors: Stefano Tessaro, Chenzhi Zhu

Abstract:

This paper gives new constructions of two-round multi-signatures and threshold signatures for which security relies solely on either the hardness of the (plain) discrete logarithm problem or the hardness of RSA, in addition to assuming random oracles. Their signing protocol is partially non-interactive, i.e., the first round of the signing protocol is independent of the message being signed.

We obtain our constructions by generalizing the most efficient discrete- logarithm based schemes, MuSig2 (Nick, Ruffing, and Seurin, CRYPTO ’21) and FROST (Komlo and Goldberg, SAC ’20), to work with suitably defined linear hash functions. While the original schemes rely on the stronger and more controversial one-more discrete logarithm assumption, we show that suitable instantiations of the hash functions enable security to be based on either the plain discrete logarithm assumption or on RSA. The signatures produced by our schemes are equivalent to those obtained from Okamoto’s identification schemes (CRYPTO ’92).

More abstractly, our results suggest a general framework to transform schemes secure under OMDL into ones secure under the plain DL assumption and, with some restrictions, under RSA.

ePrint: https://eprint.iacr.org/2023/276

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .