Key pre-distribution based secure backbone formation in wireless sensor networks

Security is a prime concern in large-scale wireless sensor networks used for collaborative mission critical applications. A backbone network in the form of a cluster tree can enhance upper layer functions such as routing, broadcasting, in-network query processing and network management. A secure backbone based on the cluster tree enables secure upper layer functions and dynamic distribution of cryptographic keys among different nodes and users of collaborative networks. A secure cluster tree formation algorithm is presented that is independent of key pre-distribution scheme, network topology, and does not require a-priori neighborhood information or location awareness. Simulation based results show that the algorithm retains most of the desirable cluster and cluster tree characteristics while building the secure cluster tree. Availability of neighborhood information further improves the performance. Our simulations also suggest that hierarchical networks are more vulnerable to node capture than non-hierarchical networks.