During the last couple years I spent some of my time working in project 5G NetMobil, which we just completed successfully. Sadly, due to SARS-CoV-2, the big live demonstration that was to conclude the project had to be canceled. However, you can learn more about the project’s results in this video on youtube.

While the project did not  primarily focus on privacy or security, there were some interesting privacy and security challenges that I could work on. In this post, I want to tell you a little bit more about those challenges and our solutions.

Put shortly, in the project we investigated ways to use 5G and related communication technology to allow various types of vehicles to communicate among each other, with road infrastructure and with backend systems. Or, in the long version: the project goal was to “develop a comprehensive communication infrastructure for tactile connected driving and to demonstrate the advantages of tactile connected driving in terms of traffic safety, traffic efficiency and environmental impact compared to autonomous driving based solely on local sensor data“…

The use case I mainly worked on revolved around longitudinal platooning where several vehicles drive in single file with very short distances between them. That way, slipstream effects can be used to save fuel and space on the road can be utilized more efficiently. You can learn more about platooning and the project’s results on the project’s website.

In platooning, participating vehicles constantly exchange messages among each other to coordinate their driving, for example to speed up in a coordinated manner or to brake at the same time and with the same force.

There are several interesting privacy and security challenges in V2X (vehicle-to-everything) communication in general and in platooning in particular. Most prominently, those challenges relate to preventing attackers from injecting commands into platoon communication as this could easily lead to dangers to life and limb. For example, an attacker could try to provoke a crash by sending messages telling the first vehicle in a platoon to execute an emergency brake maneuver while simultaneously instructing following vehicles to speed up. The most prominent privacy challenge in V2X revolves around preventing attackers to track vehicles over a longer time based on the messages they broadcast. This is particular challenging to prevent, as short-term tracking must still be possible in order to enable coordinated maneuvers.

My work on these challenges in the project resulted in two papers written together with researcher primarily from TU Dresden’s Chair of Privacy and Data Security. In our first paper, we develop and discusses different ways of distributing cryptographic keys for securing platoon communication among members of a platoon. The second paper focused more on privacy and investigates the viability of using so-called privacy-preserving attribute-based credentials (ABCs) for preserving privacy in platooning. ABCs are a cool concept that allows users to prove possession of some attributes without actually disclosing those attributes. For example, ABCs can be used to prove that a user is of legal age without disclosing her actual age. If you want to learn more about ABCs, you can find a lot more information here. Or you can just read our paper 😉