Key management schemes for distributed sensor networks

• Authors: Yuan Xue
• Venue: Key management schemes for distributed sensor networks
• Year: 2008

Sensor networks are wireless ad-hoc networks consisting of a large number of low-cost computing devices, which combine wireless transmitters with specialized sensors such as temperature, humidity, light, motion, acoustic, chemical and seismic sensors. Envisioned for collecting information in harsh environments which may prohibit humans and traditional technologies, sensor nodes are expected to organize themselves into an ad hoc network and function unattended for a long period of time. Sensor networks are a promising solution for many areas: habitat monitoring, emergency response, health care, home and property monitoring, inventory tracking and traffic monitoring. Security is a critical component to achieve the real potential of a sensor network. Classical security mechanisms designed for infrastructure networks are not suitable for sensor networks due to several factors such as the lack of dedicated infrastructure, severely limited computing capability, communication capability, energy consumption of the sensor node, the lack of physical security of the sensor node and the large scale of the deployment. The increased difficulty lies in the fundamental problem of providing efficient key management in the sensor network. In this thesis, we present a state of the art key management scheme for sensor networks, which range from key pre-distribution schemes to node revocation protocols. We analyze the realistic application of key pre-distribution schemes in a sensor network from a systems perspective. A framework is proposed to evaluate key pre-distribution schemes in two metrics: resilience against node capture, and scalability in terms of maximum network coverage area. We come to the conclusion that the security performance of key pre-distribution schemes in terms of resilience and scalability is determined by the product of the memory size and the network density, in other words, the cost of the network. The dense scattering of sensor nodes, which is one of the basic characteristics of a sensor network, has been neglected by the research community when designing security schemes for sensor networks. We propose a key pre-distribution scheme, trusted neighbour reinforcement and a revocation protocol, random neighbourhood sampling, taking advantage of the dense scattering of sensor nodes. The trusted neighbour reinforcement is trivially secure if the adversary arrives after the initial network deployment. If the adversary is able to monitor a small portion of the network during the initial key establishment phase, our scheme reduces the memory requirement and communication overhead by half under the same security measurements compared to other proposed schemes. Compared to other revocation protocols, the random neighbourhood sampling is fully decentralized, incurs low communication overhead, enables fast reaction to detected intrusion, is false detection tolerant and can be implemented with any pairwise key distribution scheme.