Secure and Efficient Multicast in Wireless Sensor Networks Allowing Ad hoc Group Formation

Multicast security is one of the most important security services in wireless sensor networks (WSNs) since it enables a sink to multicast messages to sensors in a secure manner. While multicast authentication has widely been addressed in the literature, the problem of multicast encryption still remains open in WSNs. In this paper, we propose a multicast encryption scheme called global-partition, local-diffusion (GPLD) that focuses on scheme efficiency and supports various multicast group semantics. GPLD partitions sensors into a series of elementary groups using their location and class information and accordingly builds a location-class-aware symmetric key management framework. Furthermore, the scheme leverages the fact that sensors are both end receivers and routers, which effectively minimizes global (sink-to-sensor) group key distribution and rekeying traffic while supporting various multicast group semantics. The efficiency and security properties of GPLD are justified through both analysis and simulations.