University College London
Dept. of Computer Science
Gower Street
London WC1E 6BT
United Kingdom
Email: s.meiser at
Office: MPEB 6.22

I am a PostDoc under George Danezis. Before joining UCL I wrote my doctoral thesis on "Quantitative Anonymity Guarantees for Tor" under Michael Backes.

Research interests: anonymous communication (especially low-latency AC protocols, such as Tor), privacy metrics (especially metrics based on differential privacy), machine learning (especially in a privacy-preserving fashion)

I'm currently studying how to quantify (differential) privacy in a tight and lossless fashion to maximize the trade-off between privacy and utility. I find this quite interesting, since tighter bounds, especially under composition, can be applied to improve a variety of existing privacy-preserving mechanisms, e.g., modern machine learning methods that often operate on sensitive data in a heavily repeated fashion.


Mind the overlap between the categories. For a full up-to-date list I recommend checking my Google Scholar page.

All Anonymity Differential Privacy Cryptography

  • New! Tight on Budget? Tight Bounds for r-Fold Approximate Differential Privacy (Technical Report). Sebastian Meiser and Esfandiar Mohammadi. to appear in the 25th ACM Conference on Computer and Communications Security (CCS'18)
  • New! Anonymity Trilemma: Strong Anonymity, Low Bandwidth Overhead, Low Latency-Choose Two (S&P, Full Version). Debajyoti Das, Sebastian Meiser, Esfandiar Mohammadi, and Aniket Kate. 2018 IEEE Symposium on Security and Privacy (S&P'18)
  • The Loopix Anonymity System (USENIX). Ania M. Piotrowska, Jamie Hayes, Tariq Elahi, Sebastian Meiser, and George Danezis. 26th USENIX Security Symposium (USENIX Security 17)
  • Your Choice MATor (s): large-scale quantitative anonymity assessment of Tor path selection algorithms against structural attacks (PETS, Full Version). Michael Backes, Sebastian Meiser, Marcin Slowik. Proceedings on Privacy Enhancing Technologies, 2016 Volume 2 (PETS'16)
  • Delegatable functional signatures (Full Version). Michael Backes, Sebastian Meiser, Dominique Schröder. 19th International Conference on the Theory and Practice of Public-Key Cryptography (PKC'16)
  • Secrecy without Perfect Randomness: Cryptography with (Bounded) Weak Sources (ACNS, Preliminary Version). Michael Backes, Aniket Kate, Sebastian Meiser, Tim Ruffing. Applied Cryptography and Network Security. Springer International Publishing, 2015. (ACNS'15)
  • (Nothing else) MATor (s): Monitoring the Anonymity of Tor's Path Selection (CCS). Michael Backes, Aniket Kate, Sebastian Meiser, Esfandiar Mohammadi. Proc. of the 21st Conference on Computer and Communications Security (CCS’14)
  • Differentially Private Smart Metering with Battery Recharging (Full Version). Michael Backes, Sebastian Meiser. Data Privacy Management and Autonomous Spontaneous Security. (DPM'14)
  • AnoA: A Framework for Analyzing Anonymous Communication Protocols (CSF, Full Version). Michael Backes, Aniket Kate, Praveen Manoharan, Sebastian Meiser, Esfandiar Mohammadi. Computer Security Foundations Symposium, 2013 IEEE 26th (CSF'13)