Communication by Credence: Trust Communication in Vehicular Ad Hoc Networks.

High mobility is the essential feature of vehicular ad-hoc networks (VANETs), which however challenges the low cost and real-time security of the network. The concept of Trust Communication (TC) is proposed to address the issue. Following this concept, each vehicle gains a trust value depending on its performance of communication. Then, other vehicles choose to communicate with the vehicle owning a high enough trust value. In this way, the security of VANETs is improved with low cost and high timeliness, since the storage space and computing time are obviously reduced compared with traditional methods. However, how to allocate the trust value and how to make a trust communication method to adapt the complex scenario of VANETs are crucial and unsolved problems. In this paper, we make an in-depth investigation on the Trust Communication issue in VANETs. Firstly, we introduce the background of the Trust Problems in VANETs. Then, the most basic trust models for VANETs and a classification of these models are surveyed and discussed. Given the limitations of these basic models, we further present various improvement measures for each model. Finally, we discuss the performances of the trust models under various application scenarios. In particular, the suitable application scenario for each model and potential improvements are proposed. [ABSTRACT FROM AUTHOR]