Automotive Cybersecurity: From Risk Assessment to Mitigation

Doctoral thesis, 2025

As road vehicles are increasingly defined by their software capabilities and connected service infrastructure, it has become widely accepted that cybersecurity is vital to keep road users and their environment safe and secure. Failures of vehicular cybersecurity can lead to loss of life, severe
injuries, financial losses and breaches of privacy.

Automotive system development faces several challenges, including long development lead times and system life-times, highly heterogeneous hardware, multi-tiered supply chains and legal, safety and real-time requirements. These challenges frame the available design choices. An effective cybersecurity concept must be rooted in a thorough understanding of the risks associated with connected vehicles. Furthermore, efficient processes are essential for responding to newly discovered vulnerabilities and incidents. This thesis aims to deepen our understanding of these issues through three primary objectives: (1) to explore the systematization of threat analysis and risk assessment to facilitate cybersecurity requirements engineering, (2) to examine how cybersecurity engineering processes can be implemented to address cybersecurity issues effectively, and (3) to analyze the influence of automotive technology on the design of cybersecurity measures.

The first part of this thesis focuses on risk assessment and standardization by (a) developing a risk assessment methodology which influenced ISO/SAE 21434, an automotive cybersecurity engineering standard, (b) updating the risk assessment methodology to fully align with the standard, and (c) critically analyzing ISO/SAE 21434 to identify conceptual weaknesses, while proposing improvements to its threat analysis and risk assessment framework, and vulnerability and incident handling processes. The second part focuses on the design and implementation of risk mitigation measures by examining (i) common automotive cybersecurity design issues, (ii) memory exploitation and protection techniques for resource-constrained electronic control units, (iii) the impact of the CAN bus’s technical constraints on authentication protocols and (iv) the potential of 5G telecommunication technology to strengthen security in vehicle-to-everything communication.