Paper 2018/114 Original: eprint.iacr.org/2018/114 ↗
Offline Assisted Group Key Exchange
Abstract
We design a group key exchange protocol with forward secrecy where most of the participants remain offline until they wish to compute the key. This is well suited to a cloud storage environment where users are often offline, but have online access to the server which can assist in key exchange. We define and instantiate a new primitive, a blinded KEM, which we show can be used in a natural way as part of our generic protocol construction. Our new protocol has a security proof based on a well-known model for group key exchange. Our protocol is efficient, requiring Diffie-Hellman with a handful of standard public key operations per user in our concrete instantiation.
Metadata
- Available format(s)
PDF- Publication info
- Preprint.
- History
- 2018-07-03: last updated
- 2018-01-31: published
- Short URL
- https://ia.cr/2018/114
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2018/114,
author = {Colin Boyd and Gareth T. Davies and Kristian Gjøsteen and Yao Jiang},
title = {Offline Assisted Group Key Exchange},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/114},
year = {2018},
url = {https://eprint.iacr.org/2018/114}
}