Ephemeral vehicular ad hoc networks (VANETs) are large decentralized, distributed networks that communicate by exchanging information about their surroundings to make informed, real time decisions. However, a VANET, is neither trustworthy nor scalable. Currently, centralized trusted authorities determine the trustworthiness of the vehicles in the network. This is very inefficient. This paper addresses the following question: How can we determine, without central authority, the trustworthiness of a message sent by a vehicle on a distributed, decentralized, dynamic vehicular ad hoc network? The solution is based on the blockchain. We propose a Bayesian trust inference model that considers both the trustworthiness of the message and the vehicle sending the message. The model uses real time event data reports as priors in the beta distribution computation. We also introduce dynamic metrics in our model that captures the trustworthiness of the message with respect to time and distance. To reduce message overhead and increase scalability, we partition the road network into zones. The vehicles within a zone are therefore localized. Each zone consists of road side units (RSUs). Collectively, the RSUs form a blockchain network. The vehicles upload the calculated trust values to the RSU blockchain nodes. There is no need for extra infrastructure as the existing connections between the on-board units in vehicles and RSUs can be utilized. The blockchain network is implemented on a Hyperledger framework. We perform various experiments on blockchain and VANET parameters to test the feasibility of our model using the data from Winnipeg Public Works Department, Manitoba, Canada. We show that the use of previous reports as probabilistic priors in our blockchain framework model is more resilient than other research models that focus on using historical data or estimates for their simulations.

临时车辆自组织网络（VANET）是大型分散式分布式网络，可通过交换有关其周围环境的信息进行通信，从而做出明智的实时决策。但是，VANET既不可靠也不具有可扩展性。当前，集中的可信机构确定网络中车辆的可信度。这是非常低效的。本文解决了以下问题：在没有中央授权的情况下，我们如何确定车辆在分布式，分散式，动态车辆自组织网络上发送的消息的可信赖性？该解决方案基于区块链。我们提出了一个贝叶斯信任推断模型，该模型同时考虑了消息的可信度和发送消息的媒介。该模型使用实时事件数据报告作为Beta分布计算中的先验条件。我们还在模型中引入了动态指标，该指标可以捕获消息在时间和距离方面的可信度。为了减少消息开销并增加可伸缩性，我们将道路网络划分为多个区域。因此，区域内的车辆已本地化。每个区域都由路边单元（RSU）组成。RSU共同构成了一个区块链网络。车辆将计算出的信任值上载到RSU区块链节点。无需额外的基础设施，因为可以利用车辆车载单元和RSU之间的现有连接。区块链网络是在Hyperledger框架上实现的。我们使用来自加拿大曼尼托巴省温尼伯公共工程部门的数据对区块链和VANET参数进行了各种实验，以测试我们模型的可行性。我们证明，在我们的区块链框架模型中将先前报告用作概率先验比其他专注于使用历史数据或估计进行模拟的研究模型更具弹性。