Cluster-Based Trust Evaluation Scheme in an Ad Hoc Network

Abstract

This paper presents a new trust evaluation scheme in an ad hoc network. To overcome the limited information about unfamiliar nodes and to reduce the required memory space, we propose a cluster-based trust evaluation scheme, in which neighboring nodes form a cluster and select one node as a cluster head. The head issues a trust value certificate that can be referred to by its non-neighbor nodes. In this way, an evaluation of an unfamiliar node's trust can be done very efficiently and precisely. In this paper, we present a trust evaluation metric using this scheme and some operations for forming and managing a cluster. An analysis of the proposed scheme over some security problems is also presented. node. Based on the evaluated trust, security measures are taken, or security decisions are made. In the previous schemes of trust evaluation (2), (3), each node has to evaluate the trust of every other node in the network. It is quite difficult for a node to evaluate accurately the trust of the nodes of which it has little interaction. Furthermore, these schemes require a great deal of memory space to store each of the other node's trust value. Such constraining of resources in an ad hoc network is a severe problem.