Root of trust: survey, taxonomy, and open challenges

The Root of Trust (RoT) serves as the cornerstone for establishing trust in modern telecommunication infrastructures, ensuring integrity and trust across distributed, latency-sensitive networks such as 5G, 6G, and the Internet of Things (IoT). To the best of our knowledge, this study provides a comprehensive survey of RoT, encompassing both industrial and academic literature on hardware and software-based approaches, including Trusted Execution Environments, Trusted Platform Modules, Physically Unclonable Functions, and emerging Software Roots of Trust (SRoT). We propose a novel taxonomy categorizing RoT solutions by core functionalities–secure boot, attestation, secure storage–and evaluate their contributions to achieving critical security goals such as confidentiality, integrity, and authentication. Through rigorous analysis, we identify the limitations of hardware-centric solutions in resource-constrained environments and explore the potential of software-centric alternatives to overcome scalability and flexibility challenges. Additionally, we outline open research challenges and provide design principles for developing a robust SRoT. To the best of our knowledge, this is the only survey in the literature to holistically address both hardware and software RoT, providing a unique contribution to the field of trusted computing and IoT security.