Leona Lassak, Ph.D.
I'm a postdoctoral researcher at the Max Planck Institute for Security and Privacy in
Bochum, Germany. My research
covers computer security and human-computer interaction (HCI), specializing in
passwordless authentication and privacy.
During my Ph.D., I also closely collaborated with legal scholars on data privacy
regulations as part of the interdisciplinary research program SecHuman.
Education & Work
Postdoctoral Researcher
Max Planck
Institute for Security and Privacy, System Security Group
since 2026
PhD Student
Ruhr University
Bochum, Mobile Security Group
2021 - 2026
M. Sc. in IT Security /
Information Engineering
Ruhr University
Bochum
2019 - 2021
B.Sc. in Psychology
(ongoing)
Ruhr University
Bochum
since 2017
B.Sc. in IT Security /
Information Engineering
Ruhr University
Bochum
2015 - 2019
Publications
2026
Exploring
the Complexities of Passkey Revocation
Anna Giacomello,
Leona Lassak, Jonas Hielscher, and Maximilian Golla
ACM Conference on
Computer and Communications Security (CCS '26)
Defining the
Usability of Digital Forensics in Criminal Proceedings: Reconciling the
Technical and the Legal Sides
Tobias Hoppmann,
Leona Lassak, M. Angela Sasse, Felix C. Freiling, and Zinaida
Benenson
Digital Forensics
Doctoral Symposium (DFDS '26)
2025
Scanned and Scammed: Insecurity by ObsQRity? Measuring User
Susceptibility and Awareness of QR Code-Based Attacks
Marvin Kowalewski,
Leona Lassak, Markus Dürmuth, and Theodor Schnitzler
USENIX Security Symposium (SSYM '25)
From TOTPs to Security Keys: Studying the Reality of
Passwordless FIDO2 Authentication With PIN and Biometrics in a Corporate
Environment
Leona
Lassak, Nicklas Lindemann, and Marvin Kowalewski
Symposium
on Usable Privacy and Security (SOUPS '25)
Balancing
Privacy and Data Utilization: A Comparative Vignette Study on User
Acceptance of Data Trustees in Germany and the US
Leona
Lassak, Hanna Püschel, Oliver D. Reithmaier, Tobias Gostomzyk, and
Markus Dürmuth
Network and
Distributed System Security Symposium (NDSS '25)
From Assistance to
Autonomy - A Researcher Study on the Potential of AI Support for Qualitative
Data Analysis
Elisabeth Kirsten,
Annalina Buckmann, Leona Lassak, Nele Borgert, Abraham Mhaidli, and
Steffen Becker
arXiv
2024
Why Aren't We Using Passkeys? Obstacles Companies Face
Deploying FIDO2 Passwordless Authentication
Leona
Lassak, Elleen Pan, Blase Ur, and Maximilian Golla
USENIX Security Symposium (SSYM '24)
A
Comparative Long-Term Study of Fallback Authentication Schemes
Leona
Lassak, Philipp Markert, Maximilian Golla, Elizabeth Stobert, and
Markus Dürmuth
Conference on Human Factors
in Computing Systems (CHI '24)
Understanding Users' Interaction with Login
Notifications
Philipp Markert,
Leona Lassak, Maximilian Golla, and Markus Dürmuth
Conference on Human Factors
in Computing Systems (CHI '24)
2023
POSTER: Introducing Data Trustees: A Vignette-Based Study
Approach to Get Users in the Loop
Leona
Lassak, Hanna Püschel, Tobias Gostomzyk, and Markus Dürmuth
Symposium
on Usable Privacy and Security (SOUPS '23)
2022
POSTER: "It's Stored, Hopefully, on an Encrypted Server":
Mitigating Users' Misconceptions About FIDO2 Biometric WebAuthn
Leona
Lassak, Annika Hildebrandt, Maximilian Golla, and Blase Ur
Symposium
on Usable Privacy and Security (SOUPS '22)
Exploring User Authentication with Windows Hello in a Small
Business Environment
Florian M. Farke,
Leona Lassak, Jannis Pinter, and Markus Dürmuth
Symposium
on Usable Privacy and Security (SOUPS '22)
“Fast, Easy, Convenient.” Studying Adoption and Perception
of Digital Covid Certificates
Franziska Herbert,
Marvin Kowalewski, Theodor Schnitzler, Leona Lassak, and Markus
Dürmuth
Symposium
on Usable Privacy and Security (SOUPS '22)
2021
"It's Stored, Hopefully, on an Encrypted Server": Mitigating
Users' Misconceptions About FIDO2 Biometric WebAuthn
Leona
Lassak, Annika Hildebrandt, Maximilian Golla, and Blase Ur
USENIX Security Symposium (SSYM '21)