Paper 2018/114
Offline Assisted Group Key Exchange
Colin Boyd, Gareth T. Davies, Kristian Gjøsteen, and Yao Jiang
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.
Note: Formatting changes and typo fixes.
Metadata
- Available format(s)
-
PDF
- Publication info
- Published elsewhere. Minor revision. ISC 2018
- Keywords
- Authenticated Key ExchangeGroup Key ExchangeForward SecrecyCloud StorageBlinded Key Encapsulation
- Contact author(s)
- yao jiang @ ntnu no
- History
- 2018-07-03: last of 3 revisions
- 2018-01-31: received
- See all versions
- Short URL
- https://ia.cr/2018/114
- License
-
CC BY
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}
}
