Katharina Kohls Makes Mobile Communications Safer

The newly appointed Professor for System Security is looking forward to joining the Faculty of Computer Science and returning to her beloved Ruhr region.

Katharina Kohls is the newly appointed Professor for System Security at Ruhr University Bochum. Copyright: RUB, Marquard

Katharina Kohls has been closely associated with Ruhr University Bochum since 2008 - through her studies, doctorate and postdoc period. After a stint abroad, she has now returned home: as Associate Professor for System Security and CASA PI, Kohls has been supporting the Faculty of Computer Science since 1 March 2024. Her first day at work as a professor in Bochum was also a very special one: "It was my first day back after parental leave," she says. "It was a relatively turbulent start."

This did not dampen her joy at returning to Bochum. "I love the Ruhr region, I like the direct and the simple," she raves. "For me, the Ruhr University epitomises everything I appreciate about the region." It was good to go abroad after her postdoc period. "I wasn't far away geographically in the Netherlands, but it was a different world. Now I'm happy to be back in Bochum. For me, it's not just any old place." It's always nice to come to the campus. "Maybe not everyone can understand that, but for me it's just cosy at the Ruhr University Bochum," she says.

Finding weak points in mobile phone networks
Regardless of her ties to the region, Kohls sees great opportunities in being able to help build something in the relatively newly founded Faculty of Computer Science. She is an expert in mobile phone security. She and her team are looking for weak points in the networks at various levels in order to better protect them from attacks.

Mobile networks consist of various components. "For example, end devices such as telephones and the base stations that establish the radio connection," explains Kohls. "However, the central unit is the core network, where user data is stored, for example." Can attackers penetrate the core network from outside? Are there gateways in the technical protocols on which the communication is based? And how must base stations be distributed so that attackers cannot cheat their way in? These are the questions the researcher is investigating.

"Mobile phone security is a brilliant topic," she says. "I don't need a long preamble to tell someone what I do. I'm working on a huge use case and it's a strong motivation for me to do research so close to the problems of everyday life."

Start-up founded
Katharina Kohls' work is even closer to the application because she founded the start-up "Radix Security" in 2022 together with David Rupprecht, who also completed his doctorate at Ruhr University Bochum. Here, too, everything revolves around mobile phone security. However, Kohls' focus is on research: "I'm not involved in the day-to-day business of the start-up," she says, "but the connection there creates synergies with my research."

The computer scientist likes the duality of research and entrepreneurship. "In research, I can work on crazy questions that teach me a lot about security, but that aren't directly needed in business," explains Kohls. "With Radix Security, we use our knowledge of mobile phone security to make a very direct impact in practice."

Katharina's Career Path

  • 2008-2014: Studied Applied Computer Science at Ruhr University Bochum
  • 2015-2019: Doctorate at Ruhr University Bochum
  • 2019-2020: Postdoctoral researcher at Ruhr University Bochum within the Cluster of Excellence CASA  - Cyber Security in the Age of Large-Scale Attackers
  • 2020-2024: Assistant Professor at the Radboud University Nijmegen, Netherlands
  • Since March 2024: Associate Professor for System Security at Ruhr University Bochum

General note: In case of using gender-assigning attributes we include all those who consider themselves in this gender regardless of their own biological sex.