Re-Randomized FROST

Conrado P. L. Gouvea; Chelsea Komlo

Paper 2024/436

Re-Randomized FROST

Conrado P. L. Gouvea, Zcash Foundation

Chelsea Komlo, Zcash Foundation

Abstract

We define a (small) augmentation to the FROST threshold signature scheme that additionally allows for re-randomizable public and secret keys. We build upon the notion of re-randomizable keys in the literature, but tailor this capability when the signing key is secret-shared among a set of mutually trusted parties. We do not make any changes to the plain FROST protocol, but instead define additional algorithms to allow for randomization of the threshold public key and participant’s individual public and secret key shares. We show the security of this re-randomized extension to FROST with respect to the algebraic one-more discrete logarithm (AOMDL) problem in the random oracle model, the same security assumptions underlying plain FROST.

Metadata

Available format(s): PDF
Publication info: Preprint.
Contact author(s): conrado @ zfnd org
me @ chelseakomlo com
History: 2024-03-15: approved; 2024-03-13: received; See all versions
Short URL: https://ia.cr/2024/436
License: CC BY

BibTeX

@misc{cryptoeprint:2024/436,
      author = {Conrado P. L. Gouvea and Chelsea Komlo},
      title = {Re-Randomized {FROST}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/436},
      year = {2024},
      url = {https://eprint.iacr.org/2024/436}
}