Paper 2020/1165
Practical Isogeny-Based Key-exchange with Optimal Tightness
Bor de Kock, Kristian Gjøsteen, and Mattia Veroni
Abstract
We exploit the Diffie-Hellman-like structure of CSIDH to build a quantum-resistant authenticated key-exchange algorithm. Our security proof has optimal tightness, which means that the protocol is efficient even when instantiated with theoretically-sound security parameters. Compared to previous isogeny-based authenticated key-exchange protocols, our scheme is extremely simple, its security relies only on the underlying CSIDH-problem and it has optimal communication complexity for CSIDH-based protocols. Our security proof relies heavily on the rerandomizability of CSIDH-like problems and carries on in the ROM.
Note: This paper, with minor modifications, will appear at SAC2020.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint. MINOR revision.
- Keywords
- Post-quantumisogenieskey-exchangeprovable-securitytightnessrerandomization.
- Contact author(s)
- mattia veroni @ ntnu no
- History
- 2020-09-25: received
- Short URL
- https://ia.cr/2020/1165
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2020/1165,
author = {Bor de Kock and Kristian Gjøsteen and Mattia Veroni},
title = {Practical Isogeny-Based Key-exchange with Optimal Tightness},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/1165},
year = {2020},
url = {https://eprint.iacr.org/2020/1165}
}