The Computer Security Incident Response Team (CSIRT)

We investigate all security breaches on our ICT infrastructure.

What is our mission?

Our mission is to provide SIDN with proactive and reactive support by maintaining and continually seeking to improve the security of our services.

What are our goals?

  • We are the single trusted point for computer security matters.

  • We promote awareness of computer security issues.

  • We make recommendations regarding computer security.

  • We support the resolution of computer security incidents.

  • We actively address threats to our services.

What do we protect?

What are we responsible for?

  • The Domain Registration System

  • The resolving of .nl domain names

  • The .nl name servers and zone file

  • The Is and Whois for .nl domain names

  • Our websites (both public and restricted access)

  • The technical infrastructure that secures our offices

  • All other ICT infrastructure

How can you reach us?

  • Preferably by e-mail:

  • If you want to encrypt your message, download our PGP key.

  • You can call us between 08:30 and 17:00 (Dutch time) on +31 26 352 5512.

  • Our mailing address:SIDNF.a.o. SIDN CSIRTPO Box 50226802 EA¬† ArnhemThe Netherlands


Bert ten Brinke

Security Officer

+31 26 352 5512

  • Thursday 11 April 2019

    .nl domain name

    Is domaining a good thing or not?


    .au plans to actively enforce ban on domaining

    Read more
  • Tuesday 12 February 2019

    About SIDN

    Outdated IPv4-based internet unsuitable for peer-to-peer applications


    NAT spoils gaming experience

    Read more
  • Monday 23 July 2018

    Internet security

    Your bank's got a new log-in system? Watch out for scams!


    Cybercrooks take advantage of the wave of new tools and services

    Read more


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