Christian Tiefenau

Dr. Christian Tiefenau

Usable Security and Privacy Researcher

Friedrich-Hirzebruch-Allee 8 · D - 53115 Bonn

(+49) 228-73-54243

About Me

I am a researcher in the field of Usable Security and Privacy. Currently working at the University of Bonn in the BESEC-group of Prof. Dr. Matthew Smith.

Interests and Skills


I'm interested in the field of usability and security with special focus on administrators. If you are interested in collaboration feel free to contact me.


Since I've been 13 I enjoyed making music and constantly played in several bands:

  • They Came From Earth - 2002-2009 - bass
  • Read My Lips - 2009-2012 - bass/vocals
  • Cocoon - 2011-present - bass/vocals
  • Rooftop Kingdom - 2013-2015 - bass
  • Kaiju - 2014-2016 - bass
  • ANKA - 2014-Present - bass/synthesizer/samples


Joining a soccerteam when I was 7 was the beginning of my enthusiasm in sports. To this day I ran three half-marathons.


SOUPS 2023 - Full Paper

Adventures in Recovery Land: Testing the Account Recovery of Popular Websites When the Second Factor is Lost

Eva Gerlitz, Maximilian Häring, Charlotte Theresa Mädler, Matthew Smith, Christian Tiefenau

SOUPS 2023 - Full Paper

Evolution of Password Expiry in Companies: Measuring the Adoption of Recommendations by the German Federal Office for Information Security

Eva Gerlitz, Maximilian Häring, Matthew Smith, Christian Tiefenau

CHI 2023 - Full Paper

Less About Privacy: Revisiting a Survey about the German COVID-19 Contact Tracing App

Maximilian Häring, Eva Gerlitz, Matthew Smith, Christian Tiefenau

SOUPS 2021 - Full Paper

Never ever or no matter what: Investigating Adoption Intentions and Misconceptions about the Corona-Warn-App in Germany

Maximilian Häring, Eva Gerlitz, Christian Tiefenau, Matthew Smith, Dominik Wermke, Sascha Fahl, Yasemin Acar

SOUPS 2020 - Full Paper

Security, Availability, and Multiple Information Sources: Exploring Update Behavior of System Administrators

Christian Tiefenau, Maximilian Häring, Katharina Krombholz, Emanuel von Zezschwitz

ACM CCS 2019 - Full Paper

A Usability Evaluation of Let's Encrypt and Certbot: Usable Security Done Right

Christian Tiefenau, Emanuel von Zezschwitz, Maximilian Häring, Katharina Krombholz, Matthew Smith

SOUPS 2019 - Poster Session

Making Privacy Graspable: Can we Nudge Users to use Privacy Enhancing Techniques?

Christian Tiefenau, Maximilian Häring, Eva Gerlitz, Emanuel von Zezschwitz

SOUPS 2019 - Poster Session

"Please enter your PIN" - On the Risk of Bypass Attacks on Biometric Authentication on Mobile Devices

Christian Tiefenau, Maximilian Häring, Mohamed Khamis, Emanuel von Zezschwitz

SOUPS 2019 - Poster Session

A Case Study on (Security) Update Processes in Working Environments: Understanding the Context

Maximilian Häring, Christian Tiefenau, Eva Gerlitz, Ronald Brenner, Emanuel von Zezschwitz

SOUPS 2018 - Full Paper

Deception Task Design in Developer Password Studies: Exploring a Student Sample

Alena Naiakshina, Anastasia Danilova, Christian Tiefenau, Matthew Smith

SOUPS 2018 - Poster Session

The Struggle is Real: Analyzing Ground Truth Data of TLS (Mis-)Configurations

Christian Tiefenau, Emanuel von Zezschwitz

ACM CCS 2017 - Full Paper

Why Do Developers Get Password Storage Wrong? A Qualitative Usability Study

Alena Naiakshina, Anastasia Danilova, Christian Tiefenau, Marco Herzog, Sergej Dechand, and Matthew Smith


Research Assistant // Jun'15 - now

L3S Hannover and University of Bonn

Working and researching under the supervision of Prof. Dr. Matthew Smith at the University of Bonn.

Senior Software Developer // Oct'14 - Mar'17

GiPsy Software Solutions GmbH

Design and development of a new software product from scratch with the goal to replace the old solution. A new software called "GiPsy XPerience" came to life and is now used in production.

Software Developer Student Job // Oct'08 - Sep'14

GiPsy Beratungsgesellschaft GmbH

Maintainance and development of new features for their software product "GiPsy Provision". A solution for cardealers to manage their company.