Key Predistribution in Wireless Sensor Networks When Sensors Are Within Communication Range

Abstract

Wireless networks are more vulnerable to security threats than wirednetworks. Since sensors are resource constrained, the use of traditionalcryptographic key management techniques is not practical. Hence keys aredistributed in sensor nodes prior to their deployment. This method,called key predistribution, was investigated recently in a number ofstudies. This chapter restricts the discussion to single-hop networks,where any two sensors are within communication range of each other. Thegoal is to enable any two sensor nodes to exchange information usingtheir common key, so that other sensors, or an adversary, are unable todecode the message. If two sensor nodes do not share a common key then apath between them, via other sensor nodes, is established, with sensorson the path being able to decode a message and forward it encrypted witha new key. We describe different types of key predistribution schemesfor single-hop networks and discuss their merits and demerits in termsof resiliency (impact of node compromises), scalability, connectivity,and memory, computation, and communication resources. Shared-keydiscovery process should minimize the use of communication bandwidth. Wealso discuss the identification of compromised nodes and revocationtechniques.