Paper 2018/1198 Original: eprint.iacr.org/2018/1198 ↗
On Lions and Elligators: An efficient constant-time implementation of CSIDH
Abstract
The recently proposed CSIDH primitive is a promising candidate for post quantum static-static key exchanges with very small keys. However, until now there is only a variable-time proof-of-concept implementation by Castryck, Lange, Martindale, Panny, and Renes, recently optimized by Meyer and Reith, which can leak various information about the private key. Therefore, we present an efficient constant-time implementation that samples key elements only from intervals of nonnegative numbers and uses dummy isogenies, which prevents certain kinds of side-channel attacks. We apply several optimizations, e.g. Elligator and the newly introduced SIMBA, in order to get a more efficient implementation.
Metadata
- Available format(s)
PDF- Publication info
- Preprint.
- History
- 2019-02-12: last updated
- 2018-12-18: published
- Short URL
- https://ia.cr/2018/1198
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2018/1198,
author = {Michael Meyer and Fabio Campos and Steffen Reith},
title = {On Lions and Elligators: An efficient constant-time implementation of CSIDH},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/1198},
year = {2018},
url = {https://eprint.iacr.org/2018/1198}
}