Trust-Based Approaches to Solve Routing Issues in Ad-Hoc Wireless Networks: A Survey

Trust is important in Ad-hoc networks because collaboration and cooperation among nodes are critical towards achieving the system´s goals, such as routing reliability. In this paper, we seek to provide an understanding of the process of reputation-based trust approaches and related issues as they apply to routing in ad-hoc networks. We discuss the concept and properties of trust. We survey the following issues: the way wireless ad-hoc nodes first assume trust; the evidences that are collected to calculate trust; the calculations that are performed over the evidences; the way the decision is made to determine a trusted node; and how trust is updated to maintain a trusted environment. We provide a comparison of three well-established approaches and discuss some potential attacks against reputation-based trust.