Abstract: Group key exchange (GKE) allows a large group of $n$ parties to share a common secret key over insecure channels. In general, GKE is evaluated from the point of view of computational/round/communicational complexity. GKE has become attractive in secure communication among ubiquitous devices through sensor network. However, GKE needs to satisfy additional constraint such as a distance between ubiquitous devices in the ubiquitous sensor network. In our research, we focus on GKE based on a bilinear pairing. We present a new approach to change each computational/round/communicational/distance complexity per a party by changing a party graph. By using this approach, we construct a GKE suitable for a given network environment. |