Constant-Round Group Key Exchange from the Ring-LWE Assumption

Published

July 14, 2019

Author(s)

Daniel C. Apon, Dana Dachman-Soled, Huijing Gong, Jonathan Katz

Abstract

Group key-exchange protocols allow a set of N parties to agree on a shared, secret key by communicating over a public network. A number of solutions to this problem have been proposed over the years, mostly based on variants of Diffie-Hellman (two-party) key exchange; to the best of our knowledge, however, there has been almost no work looking at candidate post-quantum group key-exchange protocols. Here, we propose a constant-round, scalable protocol for unauthenticated group key exchange (i.e., with security against a passive eavesdropper) based on the hardness of the Ring-LWE problem. By applying the Katz-Yung compiler using any post-quantum signature scheme, we obtain a (scalable) protocol for authenticated group key exchange with post-quantum security. Our protocol is constructed by generalizing the Burmester-Desmedt protocol to the Ring-LWE setting, which requires addressing several technical challenges.

Proceedings Title

The Tenth International Conference on Post-Quantum Cryptography

Volume

11505

Conference Dates

May 8-10, 2019

Conference Location

Chongqing

Conference Title

n/a

Pub Type

Conferences

Download Paper

https://doi.org/10.1007/978-3-030-25510-7_11

Keywords

Ring Learning With Errors, Group Key-Exchange

Citation

Apon, D. , Dachman-Soled, D. , Gong, H. and Katz, J. (2019), Constant-Round Group Key Exchange from the Ring-LWE Assumption, The Tenth International Conference on Post-Quantum Cryptography, Chongqing, -1, [online], https://doi.org/10.1007/978-3-030-25510-7_11 (Accessed October 10, 2025)