In the smart cities context, Cooperative Intelligent Transportation Systems (C-ITS) represent one of the main use cases that aim to improve peoples' daily lives. Within these environments, messages are exchanged continuously. The latter must be secure and must ensure users' privacy. In this regard, Public Key Infrastructures (PKIs) represent the major solution to meet security needs. In this work, we present a holistic survey that describes all the different functions and services of a C-ITS PKI and focus on the different standards and consortia works that have been adopted to regulate such PKIs. Relying on the survey, we highlight the main research problems and open challenges for ITS PKIs. Then, we propose a generic model for a C-ITS PKI architecture.

在智慧城市背景下，协作式智能交通系统 (C-ITS) 代表了旨在改善人们日常生活的主要用例之一。在这些环境中，消息不断交换。后者必须是安全的，并且必须确保用户的隐私。在这方面，公钥基础设施 (PKI) 代表了满足安全需求的主要解决方案。在这项工作中，我们进行了一项全面调查，描述了 C-ITS PKI 的所有不同功能和服务，并重点关注为规范此类 PKI 而采用的不同标准和联盟工作。根据调查，我们强调了 ITS PKI 的主要研究问题和开放挑战。然后，我们为 C-ITS PKI 架构提出了一个通用模型。