Paper 2025/1393 Original: eprint.iacr.org/2025/1393 ↗
Polynomial Lattices for the BIKE Cryptosystem
Abstract
In this paper we introduce a rank $2$ lattice over a polynomial ring arising from the public key of the BIKE cryptosystem. The secret key is a sparse vector in this lattice. We study properties of this lattice and generalize the recovery of weak keys from "Weak keys for the quasi-cyclic MDPC public key encryption scheme". In particular, we show that they implicitly solved a shortest vector problem in the lattice we constructed. Rather than finding only a shortest vector, we obtain a reduced basis of the lattice which makes it possible to check for more weak keys.
Metadata
- Available format(s)
PDF- Category
- Public-key cryptography
- Publication info
- Preprint.
- History
- 2026-02-23: last updated
- 2025-08-01: published
- Short URL
- https://ia.cr/2025/1393
- License
- https://creativecommons.org/licenses/by-sa/4.0/
BibTeX
@misc{cryptoeprint:2025/1393,
author = {Michael Schaller},
title = {Polynomial Lattices for the BIKE Cryptosystem},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/1393},
year = {2025},
url = {https://eprint.iacr.org/2025/1393}
}