Rebekah Overdorf

Chair for Security and Trustworthiness of Online Information, Ruhr University Bochum



sometext

first.last (at) rub.de

I'm a professor of computer science at the Ruhr University Bochum and the Research Center for Trustworthy Data Science and Security. I work in security and privacy, focusing on information integrity in online platforms and using data science and machine learning to study security. Prior, I was an assistant professor at the University of Lausanne, a postdoctoral researcher at EPFL and a postdoctoral researcher in the Computer Security and Industrial Cryptography (COSIC) at KU Leuven in Belgium. I completed my Ph.D. in Computer Science at Drexel University in the College of Computing and Informatics under the direction of Rachel Greenstadt.

We’re currently offering bachelor and masters thesis topics on how online information (e.g. on social media) can be manipulated. Topics span from data collection and analysis, applied machine learning for detection, and privacy/security of online information. Please contact me for more information.


Research Output

2026
MuC
It is not enough to give your moderation rules to ChatGPT — Policy-as-Prompt Moderation and Its Potential Impacts on Community Governance
Anna Neumann, Jasmin Wyss, Ivy Turk, Rebekah Overdorf
Human-Centered Moderation (Mensch und Computer Workshop)
ICWSM
(Un)fair Mistakes on Social Media: How Demographic Characteristics influence Authorship Attribution
Jasmin Wyss, Rebekah Overdorf
International AAAI Conference on Web and Social Media
2025
ICWSM
A Telegram Dataset of Propaganda and its Moderation
Klim Kireev, Yevhen Mykhno, Carmela Troncoso, Rebekah Overdorf
International AAAI Conference on Web and Social Media
USENIX Security
Characterizing and Detecting Propaganda-Spreading Accounts on Telegram.
Klim Kireev, Yevhen Mykhno, Carmela Troncoso, Rebekah Overdorf
34th USENIX Security Symposium
2024
DFRWS EU
DFRWS EU 10-year review and future directions in Digital Forensic Research
Frank Breitinger, Jan-Niclas Hilgert, Christopher Hargreaves, John Sheppard, Rebekah Overdorf, Mark Scanlon
Digital Forensics Research Conference Europe / Forensic Science International: Digital Investigation
2023
ICWSM
Misleading Repurposing on Twitter
Tugrulcan Elmas, Rebekah Overdorf, Karl Aberer
International AAAI Conference on Web and Social Media
IEEE Pervasive Computing
Privacy-Aware Eye Tracking: Challenges and Future Directions
Celine Gressel, Rebekah Overdorf, Inken Hagenstedt, Murat Karaboga, Helmut Lurtz, Michael Raschke, Andreas Bulling
IEEE Pervasive Computing
2022
FOSINT-SI
WayPop Machine: A Wayback Machine to Investigate Popularity and Root Out Trolls
Tuğrulcan Elmas, Thomas Romain Ibanez, Alexandre Hutter, Rebekah Overdorf, Karl Aberer
Foundations of Open Source Intelligence and Security Informatics (ASONAM Workshop)
ICWSM
Characterizing Retweet Bots: The Case of Black Market Accounts
Tuğrulcan Elmas, Rebekah Overdorf, Karl Aberer
International AAAI Conference on Web and Social Media
2021
ICWSM
A Dataset of State-Censored Tweets
Tuğrulcan Elmas, Rebekah Overdorf, Karl Aberer
International AAAI Conference on Web and Social Media
EuroS&P
Ephemeral Astroturfing Attacks: The Case of Fake Twitter Trends
Tuğrulcan Elmas, Rebekah Overdorf, Ahmed Furkan Özkalay, Karl Aberer
IEEE European Symposium on Security and Privacy
Data for the Wellbeing of Most Vulnerable
Tactical Reframing of Online Disinformation Campaigns Against The Istanbul Convention
Tuğrulcan Elmas, Rebekah Overdorf, Karl Aberer
Workshop on Data for the Wellbeing of the Most Vulnerable (ICWSM Workshop)
2020
FAccT
POTs: Protective Optimization Technologies
Bogdan Kulynych*, Rebekah Overdorf*, Carmela Troncoso, Seda Gürses
Conference on Fairness, Accountability, and Transparency
CyberSafety
Disinformation from the Inside: Combining Machine Learning and Journalism to Investigate Sockpuppet Campaigns
Christopher Schwartz, Rebekah Overdorf
CyberSafety (The Web Conference Workshop)
Innovative Ideas in Data Science
Can Celebrities Burst Your Bubble?
Tuğrulcan Elmas, Kristina Hardi, Rebekah Overdorf, Karl Aberer
Innovative Ideas in Data Science (The Web Conference Workshop)
2019
HotPETs
Subtle Censorship via Adversarial Fakeness in Kyrgyzstan
Christopher Schwartz, Rebekah Overdorf
Workshop on Hot Topics in Privacy Enhancing Technologies
2018
HotPETs · Workshop
POTs: The revolution will not be optimized?
Seda Gürses, Rebekah Overdorf, Ero Balsa
Workshop on Hot Topics in Privacy Enhancing Technologies
Critiquing and Correcting Trends in Machine Learning
Questioning the assumptions behind fairness solutions
Rebekah Overdorf, Bogdan Kulynych, Ero Balsa, Carmela Troncoso, Seda Gürses
Critiquing and Correcting Trends in Machine Learning (NeurIPS Workshop)
2017
CSCML
Stylometric Authorship Attribution of Collaborative Documents
Edwin Dauber, Rebekah Overdorf, Rachel Greenstadt.
Cyber Security Cryptography and Machine Learning
CCS
How Unique is Your .onion?: An Analysis of the Fingerprintability of Tor Onion Services
Rebekah Overdorf, Marc Juárez, Gunes Acar, Rachel Greenstadt, Claudia Díaz
ACM SIGSAC Conference on Computer and Communications Security
2016
PoPETs
Blogs, Twitter Feeds, and Reddit Comments: Cross-Domain Authorship Attribution
Rebekah Overdorf, Rachel Greenstadt
Proceedings on Privacy Enhancing Technologies
2015
FC
Computer-Supported Cooperative Crime
Vaibhav Garg, Sadia Afroz, Rebekah Overdorf, Rachel Greenstadt
Financial Cryptography and Data Security
2014
IFIP WG
Breaking the Closed-World Assumption in Stylometric Authorship Attribution
Ariel Stolerman, Rebekah Overdorf, Sadia Afroz Rachel Greenstadt
Advances in Digital Forensics X (IFIP WG 11.9)
HotPETs · Workshop
Blogs and Twitter Feeds: A Stylometric Environmental Impact Study
Rebekah Overdorf, Travis Dutko, Rachel Greenstadt
Workshop on Hot Topics in Privacy Enhancing Technologies
CCC
Source Code and Cross-Domain Stylometry: The Role of Stylometry in Privacy
Rebekah Overdorf, Aylin Caliskan, Rebekah Greenstadt
Chaos Communication Congress
2011
SIGCSE
Reaching Out to Aid in Retention: Empowering Undergraduate Women
Rebekah Overdorf, Marion Lang
ACM Technical Symposium on Computer Science Education