My name is Carl Magnus Bruhner, and I’m a computer science PhD student in cybersecurity at Linköping University (LiU) since fall 2023. My position is funded by WASP¹ as part of the WASP Graduate School and WARA Ops². At LiU, I’m part of the Security and Networks Group³ of the ADIT division at the Department of Computer and Information Science (IDA). I’m supervised by Professor Niklas Carlsson.

My research focuses on Internet security and privacy, primarily the web PKI with X.509 certificate usage and management, root store and CA/Browser policies and practices, trust, and related areas. I use empirical research methods, including passive and active internet measurements to study and understand behaviors “in the wild”. I identify trends and challenges and contrast findings to practices, standards, and requirements to find non-compliance, pain points & bottlenecks, and potential improvements both technical and administrative.

Publications

• Rebecka Lindkvist, Linn Petersson, Carl Magnus Bruhner, David Hasselquist, Martin Arlitt‚ Niklas Carlsson, Characterizing the Trust Dilemma: Comparing Web Security of Malicious and Benign Domains (Extended Abstract), Proc. Network Traffic Measurement and Analysis Conference (TMA), Jun. 2025. (extended version pdf, doi)
• Marcus Döberl, York Freiherr von Wangenheim, Carl Magnus Bruhner, David Hasselquist, Martin Arlitt, Niklas Carlsson, Chain-Sawing: A Longitudinal Analysis of Certificate Chains, Proc. IFIP Networking, Jun. 2024. (pdf, doi)
• David Cerenius, Martin Kaller, Carl Magnus Bruhner, Martin Arlitt, Niklas Carlsson, Trust Issue(r)s: Certificate Revocation and Replacement Practices in the Wild, Proc. Passive and Active Measurement Conference (PAM), Mar. 2024. (pdf, doi)
• Carl Magnus Bruhner, David Hasselquist, Niklas Carlsson, Bridging the Privacy Gap: Enhanced User Consent Mechanisms on the Web, Proc. NDSS Workshop on Measurements, Attacks, and Defenses for the Web (MADWeb @NDSS), Mar. 2023. (pdf, doi) ** Best paper runner-up award **
• Carl Magnus Bruhner, Oscar Linnarsson, Matus Nemec, Martin Arlitt, Niklas Carlsson, Changing of the Guards: Certificate and Public Key Management on the Internet, Proc. Passive and Active Measurement Conference (PAM), Mar. 2022. (pdf, doi) (Also presented as poster at NDSS 2024)

Community Experience

• Shadow TPC member IMC 2025 (ACM Internet Measurement Conference)
• PC member MADWeb 2025 (Workshop on Measurements, Attacks, and Defenses for the Web; co-located with NDSS)

Academic & Teaching Experience

• Examiner & course coordinator, TDTS04: Computer Networks and Distributed Systems (2026-)
• Lecturer, TDTS04: Computer Networks and Distributed Systems (2025-)
• Thesis supervisor, TDDE53/TQxx33 bachelor/master’s level (2024-)
• Research assistant (2020)
• Lab & teaching assistant, TDTS06/11: Computer Networks and Internet Protocols (2018-2021)

Education

• Ongoing: Ph.D. in Computer Science (Cybersecurity / Web Security & Privacy), Linköping University
• M.Sc. in Engineering (Information Technology/Secure systems) (Civilingenjör i informationsteknologi), Linköping University, 2022
• B.Sc. in Business Administration (Civilekonom, part of Civilekonomprogrammet)
  Linköping University, 2021
• B.Sc. in Engineering (Information Technology) (part of Civilinjengör i informationsteknologi)
  Linköping University, 2020

Industry Experience

I’m an entrepreneurial jack-of-all-trades, with a passion for cybersecurity, research, organizational development and project management. My background spans everything from sales and marketing to politics, health, tech, non-profits and research. I have a passion for working with businesses & organizations targeting consumers and end-users. In between my bachelor/master’s and my doctoral studies, I worked as a project manager, advisor, and consultant within cloud and cybersecurity for two years. I hold several Microsoft Azure/365 certifications (including AZ-500, MS-500, SC-400, and SC-300), and am certified in Cybersecurity (CC) by ISC2.

Awards & Grants

• ACM IMC Travel Grant 2025
• IDA’s Distinguished Teacher Award (“Student’s Hero”) 2025
• MADWeb’s Best paper runner-up award 2023
• IDA’s and Dataföreningen’s Prize for Best Final Thesis (Master’s) 2022 (link)
• IDA’s and Dataföreningen’s Prize for Best Final Thesis (Bachelor’s) 2020 (link)

Memberships

• Association for Computing Machinery (ACM), including SIGSAC and SIGCOMM.
• Institute of Electrical and Electronics Engineers (IEEE), including Computer Society (with TC on Security & Privacy) and ComSoc.
• Internet Society (ISOC), including Sweden Chapter and Cybersecurity SIG.
• Electronic Frontier Foundation (EFF).
• noyb (European Center for Digital Rights – “non of your business”).
• Int’l Information System Security Certification Consortium (ISC2), Certified in Cybersecurity (CC).

To find out more, you can find me at LinkedIn. Don’t hesitate to connect!

1. Wallenberg AI, Autonomous Systems and Software Program: wasp-sweden.org ↩︎
2. WASP Research Arena for Operational Data: wara-ops.org ↩︎
3. ADIT Security and Networks Group: liu.se ↩︎