Evaluating the applicability of hardware trust anchors for automotive applications

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 (Plappert et al., 2022b) 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.