Reliability estimation in mobile ad hoc networks

We describe a system for estimating the reliability of nodes in a mobile ad hoc network. The goal of the system is to detect insider attacks on the control plane of wireless protocols at the link and network layers, and to generate and propagate corresponding reliability estimates for nodes across the network. Our contributions are two-fold: first, we implement a cross-layer invariant-based technique for attack detection, where rules about correct combined behavior of protocols are specified based on data collected from multiple layers of the protocol stack. Next, we use the results of our attack detection techniques to compute reliability estimates for network nodes, where a reliability estimate represents the estimate of a node N for another node M. The form of our reliability estimate for a node is expressed as (t, c), where t indicates the trust for that node, and c indicates the confidence in this trust value. Reliability estimates are propagated across the network in a manner that is resilient to malicious nodes that propagate false reliability estimates, and minimizes network overheads. Our simulation results show that the above techniques result in highly accurate reliability estimates even in the presence of multiple malicious nodes in the network.