Paper 2024/117
Breaking HWQCS: a code-based signature scheme from high weight QC-LDPC codes
, Eindhoven University of TechnologyAbstract
We analyse HWQCS, a code based signature scheme presented at ICISC 2023, which uses quasi-cyclic low density parity check codes (QC-LDPC). The scheme introduces high Hamming weight errors and signs each message using a fresh ephemeral secret key rather than using only one secret key, so to avoid known attacks on QC-LDPC signature schemes. In this paper, we show that the signatures of HWQCS leak substantial information concerning the ephemeral keys and formally describe this behaviour. Furthermore, we show that for each security level, we can exploit the leakage to efficiently reconstruct partial secret data from very few signatures, and finally mount a universal forgery attack.
Note: Revised version, fixes few bugs.
Metadata
- Available format(s)
-
PDF
- Category
- Attacks and cryptanalysis
- Publication info
- Preprint.
- Keywords
- post-quantum cryptographycode-based cryptographyuniversal forgery attack
- Contact author(s)
-
alex pellegrini @ live com
giovanni tognolini @ unitn it - History
- 2024-09-30: revised
- 2024-01-26: received
- See all versions
- Short URL
- https://ia.cr/2024/117
- License
-
CC0
BibTeX
@misc{cryptoeprint:2024/117,
author = {Alex Pellegrini and Giovanni Tognolini},
title = {Breaking {HWQCS}: a code-based signature scheme from high weight {QC}-{LDPC} codes},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/117},
year = {2024},
url = {https://eprint.iacr.org/2024/117}
}
