François-Xavier Wicht

PhD student

Bio

I am a PhD student in the Cryptology and Data Security Group at the University of Bern. My research lies at the intersection of cryptography, privacy, and distributed systems, with a particular interest in digital currencies and decentralized infrastructure.

I develop formal models to understand the guarantees systems provide and design protocols with provable security. I am interested in how privacy interacts with scalability, synchronization, and resilience, and in building systems that protect users while remaining practical to operate. More broadly, my interests include privacy-enhancing technologies and censorship-resistant systems.

My research also has an interdisciplinary dimension. In collaboration with legal researchers, I explore how cryptographic systems can reconcile individual privacy with accountability and regulatory oversight. I am particularly interested in using cryptography to make these guarantees enforceable through technical mechanisms and reduce reliance on institutional trust.

More information is available on my personal page.

Teaching

• Fall Semester 2023: Diskrete Mathematik
• Fall Semester 2024: Distributed Algorithms
• Spring Semester 2026: Privacy and Data Security
• Spring Semester 2026: Seminar on Usable Security

Bachelor and Master thesis

Besides the list of available thesis topics, I stand available to discuss interesting ideas and supervise potential thesis topics.

Papers

1. Cachin, C., & Wicht, F.-X. (2025). Toxic Decoys: A Path to Scaling Privacy-Preserving Cryptocurrencies. Proceedings on Privacy Enhancing Technologies, 2025(4), 926–943. https://doi.org/10.56553/popets-2025-0165
2. Cachin, C., Lehnherr, D., Villacis, J., & Wicht, F.-X. (2026). The Consensus Number of Untraceable Cryptocurrencies. In A. Kiayias & M. Kyropoulou (Eds.), Proc. 8th Conference on Advances in Financial Technologies (AFT) (Vol. 395, pp. 5:1–5:24). Schloss Dagstuhl - Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.AFT.2026.5
3. Wicht, F.-X., Tong, Z., Zhou, S., Yin, H., & Yaish, A. (2026). Persistent BitTorrent Trackers. Proc. 11th IEEE European Symposium on Security And Privacy (EuroS&P), 419–435. https://doi.org/10.1109/EuroSP68448.2026.00035
4. de Laage, R., Yuhala, P., Wicht, F.-X., Felber, P., Cachin, C., & Schiavoni, V. (2025). Practical Secure Aggregation by Combining Cryptography and Trusted Execution Environments. Proc. Distributed and Event-Based Systems (DEBS), 152–163. https://doi.org/10.1145/3701717.3730543
5. Wicht, F.-X., Wang, Z., Le, D. V., & Cachin, C. (2025). A Transaction-Level Model for Blockchain Privacy. In J. Clark & E. Shi (Eds.), Proc. 28th International Conference on Financial Cryptography and Data Security (FC) (Vol. 14745). Springer. https://doi.org/10.1007/978-3-031-78679-2_16
6. Wicht, F.-X., Sillaber, C., Eggen, M., & Cachin, C. (2026). Towards A Taxonomy of Privacy for Digital Currencies in Regulated Environments. Presented at the Privacy and Public Policy Conference, Georgetown University, Washingthon (DC), USA. https://privacypublicpolicy-conference.github.io/website/misc_files/2026_files/abstracts/S2-03-Abstract-Wicht.pdf
7. Amores-Sesar, I., Cachin, C., Chatterjee, R., Soezima, L., Wicht, F.-X., & Yeo, M. (2026). Track Me If You Can: Ephemeral Coin Tracing. e-print, arXiv:2608.09249 [cs.CR]. https://arxiv.org/abs/2608.09249