Welcome

I am a Professor of Computer Science at the University of Münster. I also hold a part-time appointment at the University of Twente.

I work in computer networks and security. My research interests revolve around understanding and improving security on the Internet, taking an empirical approach. Broadly speaking, this encompasses

  • global-scale measurement of Internet service deployments and their security
  • empirical analysis of security technology
  • implications for policy and governance

In my work, I care foremost about the real-world implications of technology. Hence, I work with other disciplines and industry alike to make the Internet a safer, more secure, and altogether more interesting and useful place.

News

  • Teaching schedule for winter term 2025/26 is out. I am going to teach Empirical Security Analysis and Engineering (MSc), Betriebssysteme (BSc), Ringvorlesung Netzwerke und Sicherheit (BSc)

Bio

Before joining the University of Münster as full professor, I was an Associate Professor at the University of Twente in the Netherlands. Before that, I was a Lecturer and Senior Lecturer at the University of Sydney in Australia. Until 2016, I was a Researcher at NICTA (later Data61), also in Sydney, where I worked on network security and was part of the Security Business Team. I hold a PhD from Technical University of Munich. I did both my post-grad and under-grad studies at Eberhard Karls University, Tuebingen, one of Germany’s classic universities.

Selected publications

All publications

Advising

Prospective PhD students

PhD positions at the University of Münster and at the University of Twente are generally fully funded and part of a research project. I advertise these positions publicly, but you can also write me an email to find out if there are any vacancies at the moment.

Before you do that, please read the take the time to find out what I like to work on. I do not reply to inquiries that don’t make such an effort. Prospective PhD students must have a strong background in computer security and/or networks. I expect that incoming PhD students can articulate clearly why they want to work in a particular research area and have some research experience, e.g., from a Master thesis.

I currently work with the following PhD students:

  • Gerrit Seifert (University of Münster)
  • Nils Kempen (University of Münster)
  • Gustavo Luvizotto (University of Twente)
  • Bulut Ulukapi (University of Twente)
  • Shyam Krishna Khadka (University of Twente)
  • Matteo Liberato (University of Twente)
  • Sousan Tarahomi (University of Twente)
  • Pascal Huppert (University of Twente)

Bachelor and Master students

My group always has open topics in the area of Internet measurement and network security. Please contact me if you are interested in doing a thesis with me. Please note: I do not offer Bachelor theses at the University of Twente, and I accept only one Master student per year at the University of Twente.

Teaching

For the current list of course offerings, please see my website at the University of Münster.

In general, I teach some of the following in the winter term:

  • Empirical Security Analysis & Engineering (co-taught in Münster and Twente)
  • Netzwerke und Sicherheit (in German)
  • Developing Tools for Empirical Internet Measurement (project seminar format, in German)
  • Empirical Research in Computer Networks (seminar format)

In the summer term, I usually teach a selection of courses from the following:

  • Network and System Security
  • Computernetzwerke (in German)
  • Empirical Research in Computer Networks (seminar format)

I also offer a Graduates’ Seminar (Oberseminar) year-round and run the Joint Internet Measurement (JIM) PhD workshop with the University of Twente.

Contact and legal notice

  • Prof Dr Ralph Holz
  • Institut für Informatik, FB 10, University of Münster
  • Einsteinstr. 62, 48149 Münster, Germany
  • +49 251 83 38 447
    • Responsible for this website under Section 5 of the German Digitale-Dienste-Gesetz:
    Prof Dr Ralph Holz (address as above)

    Hinweis/Disclaimer. This website presents my academic activities and does not represent an official publication of the University of Münster, the University of Twente, or the University of Sydney./Diese Website dient der Darstellung meiner wissenschaftlichen Tätigkeiten und ist keine offizielle Publikation der Universität Münster, der Universität Twente oder der University of Sydney./Deze website is bedoeld om mijn wetenschappelijke werkzaamheden te presenteren en vormt geen officiële publicatie van de Universiteit van Münster, de Universiteit Twente of de University of Sydney.

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