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.
I'm currently looking for PhD students. Please send me an email if you're interested in working in my group.
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
- Wyss, J. & Overdorf, R. Unfair Mistakes on Social Media: How Demographic Characteristics influence Authorship Attribution . Proceedings of the Twentieth International AAAI Conference on Web and Social Media. ICWSM 2026
- Kireev, K., Mykhno, Y., Troncoso, C., & Overdorf, R. A Telegram Dataset of Propaganda and its Moderation. Proceedings of the Ninteenth International AAAI Conference on Web and Social Media. ICWSM 2025
- Kireev, K., Mykhno, Y., Troncoso, C., & Overdorf, R. Characterizing and Detecting Propaganda-Spreading Accounts on Telegram. 34th USENIX Security Symposium. USENIX Security 25
- Breitinger, F. , Hilgert, J. and Hargreaves, C. and Sheppard, J. and Overdorf, R. Scanlon, M. DFRWS EU 10-year review and future directions in Digital Forensic Research. Forensic Science International: Digital Investigation. 2024
- Elmas, T. , Overdorf, R. , Akgül, Ö. F. , Aberer, K. Misleading Repurposing on Twitter. Proceedings of the International AAAI Conference on Web and Social Media, ICWSM 2023. 2023
- Gressel, C., Overdorf, R., Hagenstedt, I., Karaboga, M., Lurtz, H., Raschke, M., Bulling, A. Privacy-Aware Eye Tracking: Challenges and Future Directions. IEEE Pervasive Computing. 2023
- Elmas T., Ibanez T.R., Hutter A., Overdorf R., Aberer K. WayPop Machine: A Wayback Machine to Investigate Popularity and Root Out Trolls. Foundations of Open Source Intelligence and Security Informatics. 2022
- Elmas, T. , Overdorf, R. , Aberer, K. Characterizing Retweet Bots: The Case of Black Market Accounts. Proceedings of the International AAAI Conference on Web and Social Media. 2022
- Elmas T., Overdorf R., Aberer K. A Dataset of State-Censored Tweets. Proceedings of the Fifteenth International AAAI Conference on Web and Social Media, ICWSM 2021. 2021
- Elmas T., Overdorf R., Özkalay A.F., Aberer K. Ephemeral Astroturfing Attacks: The Case of Fake Twitter Trends. IEEE European Symposium on Security and Privacy, EuroS&P. 2021
- Elmas T., Overdorf R., Aberer K. Tactical Reframing of Online Disinformation Campaigns Against The Istanbul Convention. Workshop on Data for the Wellbeing of Most Vulnerable (ICWSM Workshop). 2021
- Kulynych* B., Overdorf* R., Troncoso C., Gürses S.F. POTs: protective optimization technologies. FAT* '20: Conference on Fairness, Accountability, and Transparency. 2020
- Schwartz C., Overdorf R. Disinformation from the Inside: Combining Machine Learning and Journalism to Investigate Sockpuppet Campaigns. CyberSafety (The Web Conference Workshop). 2020
- Elmas T., Hardi K., Overdorf R., Aberer K. Can Celebrities Burst Your Bubble?. Innovative Ideas in Data Science (The Web Conference Workshop). 2020
- Overdorf R., Kulynych B., Gürses S. A guide to revolutionary counter-optimization. Internet Freedom Festival (IFF). 2019
- Schwartz C., Overdorf R. Subtle Censorship via Adversarial Fakeness in Kyrgyzstan. In Workshop on Hot Topics in Privacy Enhancing Technologies (HotPETs). 2019
- Gürses S., Overdorf R., Balsa E. POTs: The revolution will not be optimized?. Workshop on Hot Topics in Privacy Enhancing Technologies (HotPETs). 2018
- Overdorf R., Kulynych B., Balsa E., Troncoso C., Gürses S. Questioning the assumptions behind fairness solutions. Critiquing and Correcting Trends in Machine Learning (NeurIPS Workshop). 2018
- Overdorf R., Troncoso C., Greenstadt R., McCoy D. Under the Underground: Predicting Private Interactions in Underground Forums. 2018
- Dauber E., Overdorf R., Greenstadt R. Stylometric authorship Attribution of Collaborative Documents. Cyber Security Cryptography and Machine Learning, (CSCML). 2017
- Overdorf R., Juárez M., Acar G., Greenstadt R., Díaz C. How Unique is Your .onion?: An Analysis of the Fingerprintability of Tor Onion Services. ACM SIGSAC Conference on Computer and Communications Security, CCS. 2017
- Overdorf R., Greenstadt R. Blogs, Twitter Feeds, and Reddit Comments: Cross-domain authorship Attribution. Proceedings on Privacy Enhancing Technologies (PoPETs). 2016
- Garg V., Afroz S., Overdorf R., Greenstadt R. Computer-Supported Cooperative Crime. Financial Cryptography and Data Security (FC). 2015
- Stolerman A., Overdorf R., Afroz S., Greenstadt R. Breaking the Closed-World Assumption in Stylometric authorship Attribution. Advances in Digital Forensics X (IFIP WG). 2014
- Overdorf R., Dutko T., Greenstadt R. Blogs and Twitter Feeds: A Stylometric Environmental Impact Study. Workshop on Hot Topics in Privacy Enhancing Technologies (HotPETs). 2014
- Overdorf R., Islam A.C., Greenstadt R. Source Code and Cross Domain Stylometry. Role of Stylometry in Privacy. Chaos Communication Congress (CCC). 2014
- Overdorf R., Lang M. Reaching out to aid in retention: empowering undergraduate women. ACM Technical Symposium on Computer science Education (SIGCSE). 2011
