Joshua Smailes

I am a Career Development Research Fellow in Computer Science, with a focus on satellite communication security. Before joining St John's, I was a DPhil student at St Anne's, working with the Systems Security Lab on the security of satellite communication and infrastructure. Prior to this, I studied at St Catherine's college, and undertook research projects in satellite and aviation security. I look forward to using my time as a CDRF to further advance these topics, expand the scope of my collaborations, and explore the potential of interdisciplinary research.

Teaching

I currently teach undergraduates in Imperative Programming. I have previously taught Linear Algebra, Functional Programming, and Computer Graphics.

I also co-supervise student projects in satellite security, and can be reached by email to discuss student projects or upcoming collaborations.

My research revolves around the security of satellite communication, with a focus on authentication and secure communication protocols. My past and ongoing work has focused on two key areas: detecting and mitigating attacks at the physical layer, and providing robust and efficient authentication through key management protocols in large interplanetary networks.

This work includes the development of techniques for physical layer fingerprinting, which can be used to identify satellite transmitters by analysing characteristics of the physical radio signal. This approach provides additional security, and is particularly useful in securing legacy systems which lack sufficient protection via cryptography. I also work to adapt protocols for use in interplanetary networks, such as for data routing or key management, facilitating seamless communication between the terrestrial internet and upcoming interplanetary networks.

Recent Publications

• Smailes, J., Köhler, S., Birnbach, S., Strohmeier, M., & Martinovic, I. (2025). SatIQ: Extensible and Stable Satellite Authentication using Hardware Fingerprinting. ACM Transactions on Privacy and Security.
  https://dl.acm.org/doi/pdf/10.1145/3768619
• Smailes, J., Futera, F., Köhler, S., Birnbach, S., Strohmeier, M., & Martinovic, I. (2025). DSNS: The Deep Space Network Simulator. In 2024 Security for Space Systems (3S). IEEE.
  https://arxiv.org/pdf/2508.04317
• Smailes, J., Salkield, E., Köhler, S., Birnbach, S., Strohmeier, M., & Martinovic, I. (2024). Sticky Fingers: Resilience of Satellite Fingerprinting against Jamming Attacks. In SpaceSec.
  https://arxiv.org/pdf/2402.05042
• Smailes, J., Köhler, S., Birnbach, S., Strohmeier, M., & Martinovic, I. (2023, November). Watch This Space: Securing Satellite Communication through Resilient Transmitter Fingerprinting. In Proceedings of the 2023 ACM SIGSAC Conference on Computer and Communications Security (pp. 608-621).
  https://dl.acm.org/doi/pdf/10.1145/3576915.3623135
• Smailes, J., Moser, D., Smith, M., Strohmeier, M., Lenders, V., & Martinovic, I. (2021, May). You talkin' to me? Exploring Practical Attacks on Controller Pilot Data Link Communications. In Proceedings of the 7th ACM on Cyber-physical System Security Workshop (pp. 53-64).
  https://dl.acm.org/doi/pdf/10.1145/3457339.3457985

Awards and Distinctions

Awards:
2023: Best of Session, Digital Avionics Systems Conference (DASC)
2023: Best Paper (Runner Up), ACM Conference on Security and Privacy in Wireless Networks (WiSec)
2021: Best Paper, ACM Cyber-Physical System Security Workshop (CPSS)
2021-2025: UKRI Engineering and Physical Sciences Research Concil studentship

Invited talks and demos:
2025: Dagstuhl Seminar, "Protecting Space Systems from Cyber Threats"
2025: ETH Zürich, "Trust and Authentication in Satellite Communication: Past, Present, and Future"
2024: CCSDS Technical Meetings, "Adapting Terrestrial PKI to Secure Future Space Networks"
2023: CySat, "Using Transmitter Fingerprints to Protect Satellite Downlinks"
2023: European Space Agency, "Security Considerations in Federated Satellite Systems"
2022: System Security Group, ETH Zürich, "Securing Satellite Communications through Physical-Layer Device Fingerprinting"
2022, 2023, 2024: armasuisse Cyber Alp Retreat; talks on CPDLC, Satellite Fingerprinting, Key Management
2021: DEF CON 29, "CPDLC: Man-in-the-middle Attacks and How to Defend Against Them"