Blog posts and open-source work



  • Security software engineer
  • david@tweedegolf.com

David was once one of the core developers of identity wallet IRMA. Currently David is the lead developer for the Rust implementation of the Network Time Protocol, ntpd-rs. He is also working on the other component of the Pendulum Project, the Rust implementation of the Precision Time Protocol called Statime. And let's not forget his considerable contributions to the Verder Helpen platform, which provides authentication services to local governments.

Obviously, David is a privacy and security expert. He isn't only experienced though; he is also friendly, broadly interested and meticulously analytic. Present him with a complex problem and he will get to the heart of the matter in no time. Did we mention that David is also a highly skilled cryptographer...?

David combines his work for Tweede golf with a PhD in physics. In his spare time, he plays the piano and likes to show his competitive side in programming contests. For example, he attended the World programming championships for students.


Open-source work

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ntpd-rs is an implementation of NTP completely written in Rust, with a focus on exposing a minimal attack surface. In this blog post the process of implementing a new open-source version of the Network Time Protocol is explained.

The project originates from ISRG's Prossimo, as part of their mission to achieve memory safety for the Internet's most critical infrastructure. Prossimo funded the initial development of the NTP client and server, and NTS support. The NTP initiative page on Prossimo's website tells the story.

ntpd-rs is part of Project Pendulum.


Statime is an initiative of Tweede golf, a work-in-progress implementation of the Precision Time Protocol (PTP) in Rust.

High-precision timing is part of crucial networking infrastructure. With Statime we aim to provide a memory-safe alternative for existing implementations.

The first milestones of the project were kindly co-funded by the NLnet Foundation.

Statime is part of Project Pendulum.





Rust library for interfacing with IRMA servers.

IRMA is a set of free and open-source software projects implementing the Idemix attribute-based credential scheme, created by the Privacy by Design Foundation.

It allows users to safely and securely authenticate themselves as privacy-preserving as the situation permits.


For ID Contact we researched the possibilities of digital identification: how can residents organize their personal government affairs in a simpler and more reliable way? By telephone, via chat or via a video call.

The ID Contact innovation pilot is a collaboration between the municipalities of Arnhem, Nijmegen and the Drechtsteden and knowledge partners such as the Tax Authorities and iHub (Radboud University).

Within the ID Contact team we developed the software that makes secure digital identification possible.

Blog posts

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It is common wisdom that one should avoid implementing their own cryptography if at all possible. This is generally good wisdom as writing correct cryptography code can be very tricky and takes quite a bit of time to get done right.
KubiKey as a project started out with one main goal: streamline and make more secure the process of accessing the kubernetes cluster used by Tweede golf.