Hierarchical group key management for wireless mesh networks using multivariate symmetric polynomials

Group communication oriented applications such as multimedia streaming, distant learning, networked gaming, distributed information storage and file sharing can benefit from the community oriented nature of Wireless Mesh Networks (WMNs). However, providing secure group communication services on a WMN platform can be challenging because of the inherent vulnerabilities in wireless broadcasting, distributed network architecture, multi-hop communication and the mobility of mesh clients. Direct implementation of group key management (GKM) schemes developed for wired or other wireless platforms is difficult, if not impossible. Despite these challenges, this paper proposes a symmetric multivariable polynomial based hierarchical GKM with efficient re-keying capabilities. Efficiency in re-keying is achieved by allowing members of the secure communication group to renew the shared traffic encryption key individually and independently upon membership changes. Using the information delivered to the group members during the initial key distribution phase, this renewal process can continue during a group communication session as long as the total number of membership does not reach beyond or fall below a configurable threshold.