I direct SIDN Labs, the research arm of Stichting Internet Domeinregistratie Nederland (SIDN), the not-for-profit company that manages the national Internet Top-level Domain (TLD) of the Netherlands, .nl.

SIDN's key task is to securely manage the .nl server infrastructure in the Domain Name System (DNS), a worldwide system that maps domain names to IP addresses and that is part of the public core of the Internet. Our services are essential for the Netherlands and the wider Internet community because domain names are used in nearly every Internet interaction. Our DNS infrastructure therefore consists of dozens of anycasted name servers distributed across the world, which process around 2.5 billion DNS queries a day. We also manage the registration database for .nl, which is a multi-site facility that holds all of .nl's 6.2 million domain names and serves around 1,500 domestic and international registrars. 3.5 million .nl domain names have been secured with DNSSEC, which makes .nl the largest DNSSEC-enabled TLD worldwide in absolute terms. (Check out our stats page for more details.)

SIDN Labs conducts research and develops new technologies to further improve the operational security of the Internet infrastructure, in particular for the Netherlands and Europe. Our work is motivated by the recognition that a secure, resilient, and transparent Internet infrastructure is of increasing social and economic importance. Our role stems naturally from SIDN's public, neutral status as operator and custodian of the .nl domain. We concentrate on use-inspired research in close collaboration with the Dutch and international research and operational communities.

SIDN Labs revolves around our technical experts, who focus on three research areas: network security (e.g., DNS, routing, and NTP), domain name and IoT security, and secure future Internet infrastructures. They write open source software, analyze vast amounts of data, run experiments, write high quality papers, and actively contribute to Internet organizations such as the IETF, RIPE, and ICANN. And most important of all: they have a lot of fun doing so (I sure know I am :-)

In addition to guiding SIDN Labs, I am also a member of SIDN's leadership team and I'm a professor at the Design and Analysis of Communication Systems (DACS) group at the University of Twente one day a week, a position that SIDN funds as part of SIDN's mission to advance the security of the Internet. Furthermore, I serve as the chair of the board of directors at NLnet Labs, and as a member of the advisroy board of the ACademic CyberSecurity Society (ACCSS).

I was previously a member of the Security and Stability Advisory Committee (SSAC) at ICANN and I led the creation of TLD-OPS, the incident global response community for country code TLD operators, also in the context of ICANN (ccNSO). I was also on the founding board of Abuse Information Exchange, where I guided the development of AbuseHUB, a service for Dutch access providers to automatically share information on botnet infections and other types of abuse.

Before I joined SIDN, I was with Telematica Instituut, a former public-private research facility, where I led and developed large national and international research projects. I also worked as a senior researcher on topics such as mobility management in IP networks, distributed sensor systems, adaptive multimodal user interfaces, and telco service platforms. I started as a software engineer at Lucent Technologies.

I hold a Ph.D. (2005) and an M.Sc. (1996) in Computer Science, both from the University of Twente, the Netherlands.

Outside the space of Internet security, I'm on the Supervisory Board ("Raad van Toezicht") of the Enschede Public Library.

Feel free to check out my LinkedIn profile for more information.