Paper 2020/1232
On the Existence of Weak Keys for QC-MDPC Decoding
Nicolas Sendrier and Valentin Vasseur
Abstract
We study in this work a particular class of QC-MDPC codes for which the decoding failure rate is significantly larger than for typical QC-MDPC codes of same parameters. Our purpose is to figure out whether the existence of such weak codes impacts the security of cryptographic schemes using QC-MDPC codes as secret keys. A class of weak keys was exhibited in [DGK19]. We generalize it and show that, though their Decoding Failure Rate (DFR) is higher than normal, the set is not large enough to contribute significantly to the average DFR. It follows that with the proper semantically secure transform [HHK17], those weak keys do not affect the IND-CCA status of key encapsulation mechanisms, like BIKE, which are using QC-MDPC codes.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- code-based cryptographyQC-MDPC codesBIKEbit flipping algorithmweak keys
- Contact author(s)
-
nicolas sendrier @ inria fr
valentin vasseur @ inria fr - History
- 2020-10-09: received
- Short URL
- https://ia.cr/2020/1232
- License
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CC BY
BibTeX
@misc{cryptoeprint:2020/1232,
author = {Nicolas Sendrier and Valentin Vasseur},
title = {On the Existence of Weak Keys for {QC}-{MDPC} Decoding},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/1232},
year = {2020},
url = {https://eprint.iacr.org/2020/1232}
}
