Secure and fault-tolerant event boundary detection in wireless sensor networks

Event boundary detection is in and of itself a useful application in wireless sensor networks (WSNs). Typically, it includes the detection of a large-scale spatial phenomenon such as the transportation front line of a contamination or the diagnosis of network health. In this paper, we present SEBD, a fully distributed and light-weight Secure Event Boundary Detection scheme, which implements secure and fault-tolerant detection of event boundaries in an adversarial environment. An efficient key establishment protocol is first proposed which establishes location based keys at each sensor node to secure the communications. The idea of location based keys also effectively minimizes the impact of node compromise such that a compromised node cannot impersonate other nodes at locations other than where it is. Then a collaborative endorsement scheme is designed to allow multiple nodes collectively endorsing a valid boundary claim for increased resilience against node compromise. SEBD further develops an enhanced (nonparametric) statistical model that supports localized detection and shows a much better accuracy and fault tolerance property as compared to previous models. The security strength and performance of SEBD are evaluated by both analysis and simulations.