Paper 2025/830
Simple Power Analysis Attack on SQIsign
, Graz University of Technology, Graz University of Technology, Graz University of Technology, Graz University of TechnologyAbstract
The isogeny-based post-quantum digital signature algorithm SQIsign offers the most compact key and signature sizes among all candidates in the ongoing NIST call for additional post-quantum signature algorithms. To the best of our knowledge, we present the first Simple Power Analysis (SPA) side-channel attack on SQIsign, demonstrating its feasibility for key recovery. Our attack specifically targets secret-dependent computations within Cornacchia's algorithm, a fundamental component of SQIsign's quaternion module. At the core of this algorithm, a secret-derived yet ephemeral exponent is used in a modular exponentiation subroutine. By performing SPA on the modular exponentiation, we successfully recover this ephemeral exponent. We then develop a method to show how this leaked exponent can be exploited to ultimately reconstruct the secret signing key of SQIsign. Our findings emphasize the critical need for side-channel-resistant implementations of SQIsign, highlighting previously unexplored vulnerabilities in its design.
Note: Accepted in Africacrypt 2025
Metadata
- Available format(s)
-
PDF
- Category
- Attacks and cryptanalysis
- Publication info
- Published elsewhere. Africacrypt 2025
- Keywords
- IsogenySQIsignSide-Channel AnalysisPQC
- Contact author(s)
-
anisha mukherjee @ tugraz at
maciej czuprynko @ tugraz at
david jacquemin @ student tugraz at
kutasp @ gmail com
sujoy sinharoy @ tugraz at - History
- 2025-05-12: approved
- 2025-05-09: received
- See all versions
- Short URL
- https://ia.cr/2025/830
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2025/830,
author = {Anisha Mukherjee and Maciej Czuprynko and David Jacquemin and Péter Kutas and Sujoy Sinha Roy},
title = {Simple Power Analysis Attack on {SQIsign}},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/830},
year = {2025},
url = {https://eprint.iacr.org/2025/830}
}
