A Pairing-based Group Key Exchange with an Edge-based Tree

摘要

Group key exchange (GKE) allows a large group of n users to share a common secret key over insecure channels and, thus, afterwards users in the group can encrypt and decrypt mes­sages to and from the group. The goal of this paper is to propose efficient GKE using bilinear pairings. Instead of making only a theoretical analysis, we focus on the exact costs. Moreover, besides focusing on computational/round/communicational complexity we also consider the size of the software and hardware required. The previous schemes in this area required entities to support various different architectures such as elliptic curve scalar multiplication, bilinear pairing, multiplication over two different finite fields, and finite-field inversion. We propose a new efficient group key exchange protocol in which any inverse operation is removed.