The automotive trend towards autonomous driving and advanced connected services increases both complexity of the vehicle internal network and the connections to its environment. This introduced complexity further broadens the vehicle cyberattack surface. As mitigation strategy, state-of-the-art security mechanisms utilize so-called hardware trust anchors (HTAs) to protect security-sensitive data and processes in shielded locations that are isolated utilizing hardware security mechanisms. However, there is a variety of different HTAs with different functionality and security guarantees and there is currently no work done that compares and evaluates them against current and emerging automotive requirements. In this work, we evaluate the applicability of various HTAs to secure modern as well as upcoming future automotive applications. For this, we analyze and evaluate HTAs that are already established in the automotive field as well as promising HTAs from other domains. We extend our preliminary work [1] by increasing the range of the analyzed HTAs with solutions that are feasible for the most resource constrained automotive controllers and technologies that become feasible to be utilized by the introduction of high-performance controllers in future automotive architectures. We assess the different HTAs based on the evaluation criteria and in accordance to automotive requirements.

Automotive architectures get increasingly more complex both regarding internal as well as external connections to offer new services like autonomous driving. This development further broadens the cyberattack surface of modern vehicles. As mitigation mechanism, hardware trust anchors (HTAs) are increasingly integrated into the electronic control units (ECUs) of modern vehicles to shield security-sensitive data like cryptographic keys against a variety of cyberattacks. However, the provided security capabilities differ among the HTAs. There is currently no evaluation of the HTAs that also addresses current and emerging future requirements of the automotive domain. Thus, in this work, we will analyze and evaluate typical automotive HTAs regarding their feasibility to be used in modern and upcoming vehicle architectures. For this we derive comprehensive evaluation criteria from both related work as well as the automotive domain analysis and make an extensive assessment of the HTA properties in accordance to requirements of the automotive domain.