Proxy Aided Key Pre-distribution Schemes for Sensor Networks

Classical sensor network applications involve deployments of a large number of resource constrained wireless sensors in conjunction with a few "more capable" proxy devices. Many key distribution schemes employing only symmetric cryptographic primitives have been proposed for establishing pairwise secrets between sensors. At one end of the spectrum are Kerberos-like approaches where proxy devices are trusted with secrets of sensors, and mediate establishment of pairwise secrets between sensors. At the other end of the spectrum are many collusion susceptible key pre-distribution schemes that do not rely on the proxy devices for establishment of pairwise secrets. In this paper we propose a third approach where while the proxies aid the sensors in the process of establishment of pairwise secrets, the proxy devices are not trusted with the secrets of the sensors.