The wireless body area network (WBAN) is considered as one of the emerging wireless techniques in the healthcare system. Typical WBAN sensors, especially implantable sensors, have limited power capability, which restricts their wide applications in the medical environment. In addition, it is necessary for the healthcare center (HC) to broadcast significant notifications to different patient groups. Considering the above issues, in this paper, the novel practical WBAN system model with group message broadcasting is built. Subsequently, a secure and efficient group key management protocol with cooperative sensor association is proposed. In the proposed protocol, the Chinese remainder theorem (CRT) is employed for group key management between HC and the personal controller (PC), which also supports batch key updating. The proposed sensor association scheme is motivated by coded cooperative data exchange (CCDE). The formal security proofs are presented, indicating that the proposed protocol can achieve the desired security properties. Moreover, performance analysis demonstrates that the proposed protocol is efficient compared with state-of-the-art group key management protocols.
Keywords: Chinese remainder theorem (CRT); authentication; coded cooperative data exchange (CCDE); group key management; wireless body area networks.