---
title: "rgdd.se"
---
{{< figure class="avatar" src="img/author.jpg" alt="avatar">}}

Software engineer and computer scientist based in Stockholm, Sweden.  I lead the
open-source work at [Glasklar Teknik][], a sister company of [Mullvad VPN][] and
[Tillitis][].  Some of the topics I'm passionate about include cryptography,
Linux, privacy, programming in Bash/C/Go, and transparency logs.  The last few
years I got into self hosting.  The overlap between research, development, and
operations is fun.

[Glasklar Teknik]: https://www.glasklarteknik.se/
[Mullvad VPN]: https://www.mullvad.net/
[Tillitis]: https://www.tillitis.se/

Off work you will find me reading books, playing boardgames with friends,
improving my cooking skills, cruising around on inlines, running, and such.

## Project involvement

I am a member of the following projects:

  - [C2SP][]: a project that facilitates maintenance of cryptographic
  specifications using software development methodologies rather than IETF-like
  consensus.
  - [Sigsum][]: a free and open source software project that makes a signer's
  key-usage transparent.  It can be used as a building block to secure the
  supply chain and more.
  - [System Transparency][]: an open source project that provides a security
  architecture for bare metal servers.  A system's entire boot chain becomes
  protected and auditable.
  - [Tor][]: a 501(c)(3) US nonprofit that advance human rights and defend online
  privacy through free software and open networks.
  - [Witness Network][]: a community effort that gets transparency logs
    cosigned.

[C2SP]: https://c2sp.org/
[Sigsum]: https://www.sigsum.org/
[System Transparency]: https://www.system-transparency.org/
[Tor]: https://www.torproject.org/
[Witness Network]: https://witness-network.org/

## Selected software

I develop and maintain software on my free time.  You might be interested in:

  - [silentct][]: a Certificate Transparency monitor that filters out the noise.
  - [onion-csr][]: a tool to domain-validate onion addresses with CAs.

[silentct]: https://git.glasklar.is/rgdd/silentct
[onion-csr]: https://gitlab.torproject.org/tpo/onion-services/sauteed-onions/onion-csr

## Selected publications

I don't publish much papers these days, but here's an aging selection:

  - Rasmus Dahlberg.
    [On Certificate Transparency Verification and Unlinkability of Websites Visited by Tor Users](https://www.diva-portal.org/smash/get/diva2:1751660/FULLTEXT02.pdf).
    PhD thesis, Karlstad University (2023)
  - Rasmus Dahlberg and Tobias Pulls.
  [Timeless Timing Attacks and Preload Defenses in Tor's DNS Cache](https://www.usenix.org/conference/usenixsecurity23/presentation/dahlberg).
  USENIX Security (2023)
  - Rasmus Dahlberg, Tobias Pulls, Tom Ritter, and Paul Syverson.
  [Privacy-Preserving \& Incrementally-Deployable Support for Certificate Transparency in Tor](https://petsymposium.org/2021/files/papers/issue2/popets-2021-0024.pdf).
  PETS (2021)
  - Tobias Pulls and Rasmus Dahlberg.
  [Website Fingerprinting with Website Oracles](https://petsymposium.org/2020/files/papers/issue1/popets-2020-0013.pdf).
  PETS (2020)
  - Tobias Pulls and Rasmus Dahlberg.
  [Steady: A Simple End-to-End Secure Logging System](https://eprint.iacr.org/2018/737.pdf).
  NordSec (2018)

## Contact

Feel free to reach out on email or other platforms as you see fit.