Jan von der Assen

Verifying the integrity of embedded device characteristics is required to ensure secure operation of a device. One central challenge is to securely extract and store device-specific configurations for future verification. Existing device attestation schemes suffer from notable limitations, including a lack of standardization and a failure to encompass all hardware and software aspects inherent to a platform. This paper proposes an extension of the NSA Cybersecurity Directorate's Platform Attribute Certificate Creator (PACCOR) for the ESP32, a widely-used microcontroller series. Platform Attribute Certificates store device characteristics as per the Trusted Computing Group's Platform Certificate Profile. As of today, there is little research on hybrid attestation schemes utilizing Platform Attribute Certificates on embedded devices, which this work addresses. This paper presents a collection of attacks that can be detected using PACCOR4ESP. The toolkit extracts security-relevant information from an ESP32-S3, such as the firmware hash, bootloader hash, GPIO pin configuration, and a reference to the endorsement key of the secure element, and automatically embeds it into a Platform Attribute Certificate. Lastly, this work shows how PACCOR4ESP can be integrated with existing embedded device attestation frameworks, such as RAS, CRAFT, and SEDA.

Threat modeling has emerged as a key process for understanding relevant threats within businesses. However, understanding the importance of threat events is rarely driven by the business incorporating the system. Furthermore, prioritization of threat events often occurs based on abstract and qualitative scoring. While such scores enable prioritization, they do not allow the results to be easily interpreted by decision-makers. This can hinder downstream activities, such as discussing security investments and a security control's economic applicability. This article introduces QuantTM, an approach that incorporates views from operational and strategic business representatives to collect threat information during the threat modeling process to measure potential financial loss incurred by a specific threat event. It empowers the analysis of threats' impacts and the applicability of security controls, thus supporting the threat analysis and prioritization from an economic perspective. QuantTM comprises an overarching process for data collection and aggregation and a method for business impact analysis. The performance and feasibility of the QuantTM approach are demonstrated in a real-world case study conducted in a Swiss SME to analyze the impacts of threats and economic benefits of security controls. Secondly, it is shown that employing business impact analysis is feasible and that the supporting prototype exhibits great usability.