I'm Boel, and I'm passionate about learning. In fact, I like learning so much that I decided to work full-time with learning. I also really like storytelling. Both of these interests led me to become a researcher, where I get to learn about things and tell others about them.
When it comes to research, my favorite topic is privacy (in all forms and flavors). In particular, I have a soft spot for differential privacy. Generally, I like to explore holistic approaches to privacy. Speficially, I am interested in how information moves through computer systems, and if and how much information leaks during that process. In cases where data leaks I ask the question "can leakage be prevented?", and otherwise "can we quantify the leakage?". My research is focused around two main areas: data privacy and side-channels.
Currently, I'm a tenure-track assistant professor in systems-level security in the Programming Languages and Theory of Computation (PLTC) section at University of Copenhagen (UCPH).
My academic journey so far:
I was a tenure-track assistant professor in cybersecurity in the Computing Science Division at Uppsala University. Before that, I was a postdoc at Aarhus University leading my Marie Skłodowska-Curie Actions (MSCA) funded project Provable Privacy for Metadata (ProPriM). In the ProPriM project I worked together with Aslan Askarov to explore formal methods in the context of achieving transport layer privacy. I have also worked at UCPH before, that time as a postdoc in the Algorithms and Complexity section, and have been affiliated with Basic Algorithms Research Copenhagen (BARC). When I was a postdoc at UCPH I worked on Rasmus Pagh's project Providentia. Prior to joining UCPH, I was a postdoc in the Logic and Semantics group at Aarhus University, working on anonymous communication with Aslan Askarov. I earned my PhD (dissertation, topic: differential privacy) from Chalmers University of Technology. My PhD supervisor was David Sands.
Videos
Popular science:
- [Popular-science]: Anonymization—friend or foe? (MatchPoints 2024)
- [Popular-science]: Anonymization is dead... and here is why
Conference, keynote, and other presentations:
- [Invited talk]: An Invitation to Privacy Problems (PLaiD 2025)
- [Conference presentation]: Metadata Privacy Beyond Tunneling for Instant Messaging (EuroS&P 2024)
- [Conference presentation]: Efficient Error Prediction for Differentially Private Algorithms (ARES'21)
- [Keynote presentation]: Differential Privacy: Principled Foundations, and Trade-offs in Applications (Open House at Mormor Karl's)
Media coverage
Publications
- Carla F. Griggio; Boel Nelson; Zefan Sramek; Aslan Askarov, "User Perceptions and Attitudes Toward Untraceability in Messaging Platforms", Proceedings on Privacy Enhancing Technologies (PoPETS), vol 2026, no 1, 2026, doi: 10.56553/popets-2026-0007.
- Joel Daniel Andersson; Lukas Retschmeier; Boel Nelson; Rasmus Pagh, "Private Lossless Multiple Release", Proceedings of the 42nd International Conference on Machine Learning, PMLR 267:1534-1553, 2025.
- Martin Aumüller; Christian Janos Lebeda; Boel Nelson; Rasmus Pagh, "PLAN: Variance-Aware Private Mean Estimation", Proceedings on Privacy Enhancing Technologies, vol. 2024, no. 3, pp. 606–625, 2024, doi: 10.56553/popets-2024-0095.
- Boel Nelson; Elena Pagnin; Aslan Askarov, "Metadata Privacy Beyond Tunneling for Instant Messaging", In 2024 9th IEEE European Symposium on Security and Privacy (EuroS&P), July 9–11, 2024, Vienna, Austria, doi: 10.1109/EuroSP60621.2024.00044.
- Runner-up for distinguished paper award
- Ivan Damgård; Hannah Keller; Boel Nelson; Claudio Orlandi; Rasmus Pagh, "Differentially Private Selection from Secure Distributed Computing", Proceedings of the ACM on Web Conference 2024 (WWW '24) . Association for Computing Machinery, New York, NY, USA, 1103–1114, doi: 10.1145/3589334.3645435.
- Boel Nelson, "Efficient Error Prediction for Differentially Private Algorithms", In The 16th International Conference on Availability, Reliability and Security (ARES 2021), August 17–20, 2021, Vienna, Austria. ACM, New York, NY, USA, 12 pages, doi: 10.1145/3465481.3465746.
- Boel Nelson; Jenni Reuben, "SoK: Chasing Accuracy and Privacy, and Catching Both in Differentially Private Histogram Publication", Transactions on Data Privacy 13:3 (2020) 201-245.
- Mathias Johanson; Jonas Jalminger; Emmanuel Frecon; Boel Nelson; Tomas Olovsson; Mats Gjertz, "Joint Subjective and Objective Data Capture and Analytics for Automotive Applications", 2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), Toronto, ON, 2017, pp. 1-5, doi: 10.1109/VTCFall.2017.8288366.
- Boel Nelson; Tomas Olovsson, "Introducing Differential Privacy to the Automotive Domain: Opportunities and Challenges", 2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), Toronto, ON, 2017, pp. 1-7, doi: 10.1109/VTCFall.2017.8288389.
- Boel Nelson; Tomas Olovsson, "Security and Privacy for Big Data: A Systematic Literature Review", 2016 IEEE International Conference on Big Data (Big Data), Washington, DC, 2016, pp. 3693-3702, doi: 10.1109/BigData.2016.7841037.
Preprints
- Boel Nelson; Aslan Askarov, "With a Little Help from My Friends: Transport Deniability for Instant Messaging", arxiv preprint, 2022.
- Boel Nelson, "Randori: Local Differential Privacy for All", arxiv preprint, 2021.
Posters
- Boel Nelson; Jenni Reuben, "Survey of Differentially Private Accuracy Improving Techniques for Publishing Histograms and Synthetic Data", at Open Day for Privacy, Usability, and Transparency (PUT 2019) held in conjunction with PETS'19.
- Boel Nelson, "Randori: Differentially Private Data Collection Made Accessible", at EuroS&P'19.
Teaching
Current and past courses:
- Proactive Computer Security (25/26)
- Programming and Problem Solving (25/26)
- IT-Security (25/26)
- Proactive Computer Security (24/25)
- Secure Computer Systems I (24/25)
Supervision:
What projects do I supervise?
I typically supervise MSc or BSc thesis projects, as well as Projects Outside of Course Scope (POCS) focusing on security or privacy. It might be worth mentioning that security and privacy are research areas where the method used vary a lot: security and privacy researchers tend to be interested in similar problems, but the method may come from systems, programming languages, logic, cryptography, algorithms, human-computer interaction, or some other relevant domain. I have experience in several of these fields, but for certain projects it might be a good idea to involve a co-supervisor that is a methods expert.What topics am I interested in supervising?
For inspiration, here are some examples of titles of projects I've supervised:- Investigating Data Flows from User Devices towards Online Advertising Ecosystems
- Proving Eventual Delivery in the DenIM protocol
- A Formal Model of the DenIM Protocol
- Dynamic Control of Deniable Traffic in DenIM
- Deniable Group Messaging: Extending the DenIM Protocol
- Examining the Feasibility of Private Lossless Multiple Release in Practice
- Benchmarking Instant Messaging Systems under Realistic User Behavior
- Synthetic Medical Data Generation with Differential Privacy
- Active Attacks on Synthetic Data
- Identifying Optimal Privacy Budget and Bin Size for Differentially Private Histogram
- Privacy Enhancing Technologies Symposium (PETS)
- IEEE Symposium on Security and Privacy (SP)
- ACM Conference on Computer and Communications Security (CCS)
- USENIX Security Symposium
