arXiv subjects

Sebastian N. Peters

Publications and source records attributed to Sebastian N. Peters.

5 recordsLinked to original sources

arXiv2026

Systematic Cybersecurity Risk Analysis of European Rail Traffic Management System

European Rail Traffic Management System (ERTMS) is a widely adopted standard unifying train management in the EU. While the standard allows for use cases like fully autonomous driving, cybersecurity has been an afterthought. Risk analysis enables the systematic assessment and prioritization of threats and mitigations. To date, it remains unclear which threats are most significant in ERTMS. This study systematically models components of ERTMS and analyzes their security in light of threats identified in the underlying technologies. The results suggest a concerning state of ERTMS, despite its critical role in railway safety. The use of legacy standards like EuroBalises and GSM-Railway (GSM-R) introduces vulnerabilities that persist across minimal ERTMS implementations, deployments incorporating various optional safety measures, and prospective future evolutions of the system, e.g., adopting Future Railway Mobile Communication System (FRMCS). Fully transitioning to European Train Control System (ETCS) level 2 was identified as the most significant measure for advancing ERTMS cybersecurity. The results indicate that a shift of ERTMS toward security is required to ensure availability and safe operation. While the chosen methodology proved its feasibility and shows remaining weaknesses of ERTMS, future work is needed to develop railway-centric adaptations to improve the quantification and evaluation of the computed risks.

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arXiv2026

Secure Group Key Agreement on Cyber-Physical System Buses

Cyber-Physical Systems (CPSs) rely on distributed embedded devices that often must communicate securely over buses. Ensuring message integrity and authenticity on these buses typically requires group-shared keys for Message Authentication Codes (MACs). To avoid insecure fixed pre-shared keys and trust-on-first-use concepts, a Group Key Agreement (GKA) protocol is needed to dynamically agree on a key amongst the devices. Yet existing GKA protocols lack adaptability to constrained CPS buses. This paper targets authenticated, fully distributed GKA suitable for bus topologies under constraints of industrial and cyber-physical systems, including broadcast-only links, half-duplex operation, resource limits, dynamic membership (including unannounced leaves), a long device lifetime, and a strong Dolev-Yao adversary capable of partitioning the bus. We first systematise existing protocols, then derive the requirements necessary for an authenticated and fully distributed GKA on bus systems. Finally, we design, implement, and evaluate a custom GKA protocol based on TreeKEM.

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arXiv2024

ParsEval: Evaluation of Parsing Behavior using Real-world Out-in-the-wild X.509 Certificates

X.509 certificates play a crucial role in establishing secure communication over the internet by enabling authentication and data integrity. Equipped with a rich feature set, the X.509 standard is defined by multiple, comprehensive ISO/IEC documents. Due to its internet-wide usage, there are different implementations in multiple programming languages leading to a large and fragmented ecosystem. This work addresses the research question "Are there user-visible and security-related differences between X.509 certificate parsers?". Relevant libraries offering APIs for parsing X.509 certificates were investigated and an appropriate test suite was developed. From 34 libraries 6 were chosen for further analysis. The X.509 parsing modules of the chosen libraries were called with 186,576,846 different certificates from a real-world dataset and the observed error codes were investigated. This study reveals an anomaly in wolfSSL's X.509 parsing module and that there are fundamental differences in the ecosystem. While related studies nowadays mostly focus on fuzzing techniques resulting in artificial certificates, this study confirms that available X.509 parsing modules differ largely and yield different results, even for real-world out-in-the-wild certificates.

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arXiv2023

A Quic(k) Security Overview: A Literature Research on Implemented Security Recommendations

Built on top of UDP, the relatively new QUIC protocol serves as the baseline for modern web protocol stacks. Equipped with a rich feature set, the protocol is defined by a 151 pages strong IETF standard complemented by several additional documents. Enabling fast updates and feature iteration, most QUIC implementations are implemented as user space libraries leading to a large and fragmented ecosystem. This work addresses the research question, "if a complex standard with a large number of different implementations leads to an insecure ecosystem?". The relevant RFC documents were studied and "Security Consideration" items describing conceptional problems were extracted. During the research, 13 popular production ready QUIC implementations were compared by evaluating 10 security considerations from RFC9000. While related studies mostly focused on the functional part of QUIC, this study confirms that available QUIC implementations are not yet mature enough from a security point of view.

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arXiv2021

An Approach of Replicating Multi-Staged Cyber-Attacks and Countermeasures in a Smart Grid Co-Simulation Environment

While the digitization of power distribution grids brings many benefits, it also introduces new vulnerabilities for cyber-attacks. To maintain secure operations in the emerging threat landscape, detecting and implementing countermeasures against cyber-attacks are paramount. However, due to the lack of publicly available attack data against Smart Grids (SGs) for countermeasure development, simulation-based data generation approaches offer the potential to provide the needed data foundation. Therefore, our proposed approach provides flexible and scalable replication of multi-staged cyber-attacks in an SG Co-Simulation Environment (COSE). The COSE consists of an energy grid simulator, simulators for Operation Technology (OT) devices, and a network emulator for realistic IT process networks. Focusing on defensive and offensive use cases in COSE, our simulated attacker can perform network scans, find vulnerabilities, exploit them, gain administrative privileges, and execute malicious commands on OT devices. As an exemplary countermeasure, we present a built-in Intrusion Detection System (IDS) that analyzes generated network traffic using anomaly detection with Machine Learning (ML) approaches. In this work, we provide an overview of the SG COSE, present a multi-stage attack model with the potential to disrupt grid operations, and show exemplary performance evaluations of the IDS in specific scenarios.

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