arXiv subjects

Julian Sturm

Publications and source records attributed to Julian Sturm.

3 recordsLinked to original sources

arXiv2026

5G Puppeteer: Chaining Hidden Command and Control Channels in 5G Core Networks

Mobile networks are essential for modern societies. The most recent generation of mobile networks will be even more ubiquitous than previous ones. Therefore, the security of these networks as part of the critical infrastructure with essential communication services is of the uttermost importance. However, these systems are still vulnerable to being compromised, as showcased in the recent discussion on supply chain security and other challenges. This work addresses problems arising from compromised 5G core network components. The investigations reveal how attacks based on command and control communication can be designed so that they cannot be detected or prevented. This way, various attacks against the security and privacy of subscribers can be performed for which no effective countermeasures are available.

cs.CR↗

arXiv2025

open5Gcube: A Modular and Usable Framework for Mobile Network Laboratories

In mobile network research, the integration of real-world components such as User Equipment (UE) with open-source network infrastructure is essential yet challenging. To address these issues, we introduce open5Gcube, a modular framework designed to integrate popular open-source mobile network projects into a unified management environment. Our publicly available framework allows researchers to flexibly combine different open-source implementations, including different versions, and simplifies experimental setups through containerization and lightweight orchestration. We demonstrate the practical usability of open5Gcube by evaluating its compatibility with various commercial off-the-shelf (COTS) smartphones and modems across multiple mobile generations (2G, 4G, and 5G). The results underline the versatility and reproducibility of our approach, significantly advancing the accessibility of rigorous experimentation in mobile network laboratories.

cs.NI↗

arXiv2023

P3LI5: Practical and Confidential Lawful Interception on the 5G Core

Lawful Interception (LI) is a legal obligation of Communication Service Providers (CSPs) to provide interception capabilities to Law Enforcement Agencies (LEAs) in order to gain insightful data from network communications for criminal proceedings, e.g., network identifiers for tracking suspects. With the privacy-enhancements of network identifiers in the 5th generation of mobile networks (5G), LEAs need to interact with CSPs for network identifier resolution. This raises new privacy issues, as untrusted CSPs are able to infer sensitive information about ongoing investigations, e.g., the identities of their subscribers under suspicion. In this work, we propose P3LI5, a novel system that enables LEAs to privately query CSPs for network identifier resolution leveraging on an information retrieval protocol, SparseWPIR, that is based on private information retrieval and its weakly private version. As such, P3LI5 can be adapted to various operational scenarios with different confidentiality or latency requirements, by selectively allowing a bounded information leakage for improved performance. We implement P3LI5 on the 5G LI infrastructure using well known open-source projects and demonstrate its scalability to large databases while retaining low latency. To the best of our knowledge, P3LI5 is the first proposal for addressing the privacy issues raised by the mandatory requirement for LI on the 5G core network.

cs.CR↗