Paper 2016/089
On the Hardness of LWE with Binary Error: Revisiting the Hybrid Lattice-Reduction and Meet-in-the-Middle Attack
Johannes Buchmann, Florian Göpfert, Rachel Player, and Thomas Wunderer
Abstract
The security of many cryptographic schemes has been based on special instances of the Learning with Errors (LWE) problem, e.g., Ring-LWE, LWE with binary secret, or LWE with ternary error. However, recent results show that some subclasses are weaker than expected. In this work we show that LWE with binary error, introduced by Micciancio and Peikert, is one such subclass. We achieve this by applying the Howgrave-Graham attack on NTRU, which is a combination of lattice techniques and a Meet-in-the-Middle approach, to this setting. We show that the attack outperforms all other currently existing algorithms for several natural parameter sets. For instance, for the parameter set n = 256, m = 512, q = 256, this attack on LWE with binary error only requires 2^85 operations, while the previously best attack requires 2^117 operations. We additionally present a complete and improved analysis of the attack, using analytic techniques. Finally, based on the attack, we give concrete hardness estimations that can be used to select secure parameters for schemes based on LWE with binary error
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. Minor revision. Africacrypt 2016
- Keywords
- Learning with ErrorsLattice-based CryptographyCryptanalysisNTRUHybrid Attack
- Contact author(s)
- fgoepfert @ cdc informatik tu-darmstadt de
- History
- 2016-04-13: last of 2 revisions
- 2016-02-02: received
- See all versions
- Short URL
- https://ia.cr/2016/089
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2016/089, author = {Johannes Buchmann and Florian Göpfert and Rachel Player and Thomas Wunderer}, title = {On the Hardness of {LWE} with Binary Error: Revisiting the Hybrid Lattice-Reduction and Meet-in-the-Middle Attack}, howpublished = {Cryptology {ePrint} Archive, Paper 2016/089}, year = {2016}, url = {https://eprint.iacr.org/2016/089} }