Keywords: trust establishment, trust evaluation, ad hoc networks, sensor networks
Trust establishment in sensor networks: behaviour-based, certificate-based and a combinational approach
Sensor networks highly depend on the distributed cooperation among network nodes. Trust establishment frameworks provide the means for representing, evaluating, maintaining and distributing trust within the network, and serve as the basis for higher level security services. This paper provides a state-of-the art review of trust establishment frameworks for ad hoc and sensor networks. Certain types of frameworks are identified, such as behaviour-based and certificate-based, according to their scope, purpose and admissible types of evidence. The review is complemented by a comparative study built both on criteria specific to each category and on common criteria, grouped into three distinct classes: supported trust characteristics, complexity and requirements and deployment complexity and flexibility. We then present a trust establishment framework targeted for sensor networks that combines aspects from the two alternative approaches on trust establishment on common evaluation metrics, so that it can uniformly support the needs of nodes with highly diverse network roles and capabilities.