Calculating a node´s reputation in a mobile ad hoc network

Behavior grading is crucial to the operation of a mobile ad-hoc network (MANET). Our Key Management System project has established a behavior grading and tracking mechanism through the use of X.509 v3 certificates with appropriate extensions. Our distributed, node-centric approach to reputation management processes nodal behavior feedback and provides a reputation index that nodes use to determine trustworthiness of their peers before establishing IPsec security associations. Behavior feedback is "aged" in a three-window weighted average, which emphasizes current behavior while conservatively approximating behavior trends over time. The windowed approach maintains non-reputable evidence, which supports the reputation calculation and facilitates the exchange of behavior information with new nodes as they join the network.