Paper 2006/284
Constant Round Group Key Exchange with Logarithmic Computational Complexity
Junghyun Nam, Youngsook Lee, and Dongho Won
Abstract
Protocols for group key exchange (GKE) are cryptographic algorithms that describe how a group of parties communicating over a public network can come up with a common secret key. Due to their critical role in building secure multicast channels, a number of GKE protocols have been proposed over the years in a variety of settings. However despite many impressive achievements, it still remains a challenging problem to design a secure GKE protocol which scales very well for large groups. Our observation is that all provably-secure constant-round GKE protocols providing forward secrecy thus far are not fully scalable, but have a computational complexity that scales only linearly in group size. Motivated by this observation, we propose a new GKE protocol that not only offers full scalability in all directions but also attains provable security against active adversaries. Full scalability is achieved by using a complete binary tree structure where users are arranged on both internal and leaf nodes. Security is proved via reduction to the decisional Diffie-Hellman assumption in a well-defined formal model of communication and adversarial capabilities.
Metadata
- Available format(s)
-
PDF
PS
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- Group key exchangescalabilitybinary treeprovable securityDDH assumption
- Contact author(s)
- jhnam @ security re kr
- History
- 2006-08-22: received
- Short URL
- https://ia.cr/2006/284
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2006/284,
author = {Junghyun Nam and Youngsook Lee and Dongho Won},
title = {Constant Round Group Key Exchange with Logarithmic Computational Complexity},
howpublished = {Cryptology {ePrint} Archive, Paper 2006/284},
year = {2006},
url = {https://eprint.iacr.org/2006/284}
}
