A Dynamic Trust Model Based on Entity Credibility in Heterogeneous Wireless Network

The characteristics of uncertainty and variability in heterogeneous wireless network bring some new security challenges. This paper proposes a dynamic trust model based on entity credibility (DTMBC) to evaluate the trustworthiness of the network. The evaluation incorporates direct trust, recommended trust, credibility of the candidate network, credibility of the evaluating entity and time stamp. Direct and recommended trusts reflect how well the candidate network has fulfilled the service agreement in the past. By introducing credibility of the candidate network and credibility of the evaluating entity, malicious behaviors of the dishonest entities are restrained effectively. Time stamp makes the evaluation pay much attention to the most recent performance records. Based on the interval threshold, FIFO strategy is introduced to discard the outdated trust records. The simulation results show the DTMBC model can accurately evaluate the trustworthiness of the network and effectively restrain the acts of slander and co-fraud.

I Introduction

The heterogeneous wireless network is an open communication system, where various access networks will be integrated to provide an optimum service at anytime from anywhere. However, it also brings some new challenges for security. The traditional access control mechanisms have been proven inadequate and inflexible for the heterogeneous network which is governed by uncertainty. Among the networks, some might be honest and provide high-quality services, some might be buggy and can not provide services with the quality that they advertise, some might be even malicious by providing bad services. Transaction of the user with an unknown network is more a norm than an exception. A security mechanism employed a satisfactory trust model that can effectively evaluate trustworthiness of the network becomes more and more necessary.