A Note on Constructing SIDH-PoK-based Signatures after Castryck-Decru Attack

Jesús-Javier Chi-Domínguez

Paper 2022/1479

A Note on Constructing SIDH-PoK-based Signatures after Castryck-Decru Attack

Jesús-Javier Chi-Domínguez

, Technology Innovation Institute

Abstract

This paper centers on the SIDH proof of knowledge work by De Feo, Dobson, Galbraith, and Zobernig, which points out that the Castryck-Decru attack does not apply to their first 3-special soundness construction. This work analyzes and explicitly describes an optimized recoverable Sigma protocol based on that 3-special soundness SIDH-PoK construction. We also discuss the impact of moving to B-SIDH and G2SIDH setups in terms of sizes. Due to the Castryck-Decru attack, we decided to write this paper relying on a theoretical analysis to list expected optimized signature sizes instead of updating eprint 2022/475. We point out that this work is a theoretical analysis extension of eprint 2022/475.

Note: Minor fix concerning G2SIDH size; Minor improvements concerning sizes; Move G2SIDH to Appendix; Fix few typos;

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Isogeny-based cryptography Proof-of-Knowledge Sigma protocol Signature scheme Recoverable Sigma protocol
Contact author(s): jesus dominguez @ tii ae
History: 2023-02-11: last of 5 revisions; 2022-10-27: received; See all versions
Short URL: https://ia.cr/2022/1479
License: CC BY

BibTeX

@misc{cryptoeprint:2022/1479,
      author = {Jesús-Javier Chi-Domínguez},
      title = {A Note on Constructing SIDH-PoK-based Signatures after Castryck-Decru Attack},
      howpublished = {Cryptology ePrint Archive, Paper 2022/1479},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/1479}},
      url = {https://eprint.iacr.org/2022/1479}
}