C-ITS is one of the most challenging domains in either research or industry. Their social and economic benefits are of importance for fuel consumption, traffic management, and road safety. Consequently, they have been deployed in many countries. Privacy is a critical feature of any shared system. This issue is crucial for deployed C-ITS in order to avoid tracking drivers who send continuous messages containing their locations. Anonymity is ensured by changing the identity of drivers frequently. In the meantime, authentication of messages is highly required. For this reason, adapted public key infrastructure) offers each vehicle a set of pseudonym certificates, which will be used to sign each sent message and will be used as a part of the identity. The identity change is done when the driver changes the pseudonym certificate. This change adds confusion for the tracker and protects the driver's privacy. In this article, we analyze a dataset of messages sent by vehicles, and we show, under some conditions, that it is possible to identify a driver's behavior based only on data correlation between collected data over the air. Then we can track drivers even when they change their pseudonyms frequently. Finally, we give some hints on how to protect drivers' privacy by adding some other confusion mechanisms such as introducing silent periods and exchanging pseudonyms with neighbors.

中文翻译：

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合作运输系统中隐私的假名限制


C-ITS 是研究或工业中最具挑战性的领域之一。它们的社会和经济效益对于燃料消耗、交通管理和道路安全具有重要意义。因此，它们已被部署在许多国家。隐私是任何共享系统的关键特征。这个问题对于已部署的 C-ITS 至关重要，以避免跟踪发送包含其位置的连续消息的驾驶员。通过经常更改司机的身份来确保匿名性。同时，对消息的认证也有很高的要求。因此，适应的公钥基础设施为每辆车提供一组假名证书，这些证书将用于对每条发送的消息进行签名，并将用作身份的一部分。当驱动程序更改假名证书时，身份更改就会完成。这一变化增加了跟踪器的混乱并保护了驾驶员的隐私。在本文中，我们分析了车辆发送的消息数据集，并表明，在某些条件下，可以仅根据通过空中收集的数据之间的数据相关性来识别驾驶员的行为。这样，即使司机经常更改化名，我们也可以跟踪他们。最后，我们通过添加一些其他混淆机制（例如引入沉默期和与邻居交换假名）来提供有关如何保护驾驶员隐私的一些提示。