Paper 2026/2492
Exploring Fault Injection Attacks on HQC and BIKE Beyond Fujisaki-Okamoto Verification
Abstract
Fault injection attacks have been extensively studied in the context of post-quantum cryptography, yet existing analyses on code-based KEMs largely focus on faults targeting the Fujisaki-Okamoto transform. This work presents new fault injection attacks against BIKE and HQC that operate beyond this commonly protected component and target less obvious instructions within the decapsulation process. The proposed attacks achieve full key recovery using only valid ciphertexts under NIST Level 1 parameters, requiring 17392 and approximately 3 million decapsulation queries for HQC and BIKE, respectively. In addition, we introduce a general approach to identify effective fault locations by analyzing decoder behavior under perturbed conditions. The attacks are experimentally validated on an STM32H7 microcontroller using laser fault injection, demonstrating high repeatability. These results reveal a broader attack surface and provide a foundation for more efficient fault attack analyses in future work.
Metadata
- Available format(s)
-
PDF
- Category
- Attacks and cryptanalysis
- Publication info
- Published by the IACR in TCHES 2027
- Keywords
- HQCBIKEFault InjectionFujisaki-Okamoto Transform
- Contact author(s)
-
thales paiva @ usp br
lcardoso @ larc usp br
keerthi kamalakshan @ ntu edu sg
HARIPRAS003 @ e ntu edu sg
mjunior @ larc usp br
sbhasin @ ntu edu sg - History
- 2026-10-15: approved
- 2026-10-15: received
- See all versions
- Short URL
- https://ia.cr/2026/2492
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2026/2492,
author = {Thales B. Paiva and Lucas C. Cardoso and Keerthi Kamalakshan and Hariprasad Valsaraj Kelassery and Marcos A. Simplicio Jr. and Shivam Bhasin},
title = {Exploring Fault Injection Attacks on {HQC} and {BIKE} Beyond Fujisaki-Okamoto Verification},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/2492},
year = {2026},
url = {https://eprint.iacr.org/2026/2492}
}
