Paper 2022/1479 Original: eprint.iacr.org/2022/1479 ↗
A Note on Constructing SIDH-PoK-based Signatures after Castryck-Decru Attack
Abstract
In spite of the wave of devastating attacks on SIDH, started by Castryck-Decru (Eurocrypt 2023), there is still interest in constructing quantum secure SIDH Proofs of Knowledge (PoKs). For instance, SIDH PoKs for the Fixed Degree Relation, aim to prove the knowledge of a fixed degree d isogeny ω between the elliptic curve E0 and the public keys E1, E2. In such cases, the public keys consist of only the elliptic curves (without image of auxiliary points), which suggests that the Castryck- Decru-like attack does not apply these scenarios. In this paper we focus on the SIDH proof of knowledge of De Feo, Dobson, Galbraith, and Zobernig (Asiacrypt 2022); more precisely, we focus on their first 3-special soundness construction. In this work, we explicitly describe an optimized recoverable Σ-protocol based on their 3-special soundness SIDH-PoK. We also analyze the impact of building a signature scheme based on the optimized protocol and study the impact of moving to B-SIDH and G2SIDH setups, on the signature sizes.
Metadata
- Available format(s)
PDF- Category
- Public-key cryptography
- Publication info
- Preprint.
- History
- 2023-07-31: last updated
- 2022-10-27: published
- Short URL
- https://ia.cr/2022/1479
- License
- https://creativecommons.org/licenses/by/4.0/
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},
url = {https://eprint.iacr.org/2022/1479}
}