I am a senior researcher and adjunct lecturer at the Business Analytics Laboratory of the Athens University of Economics and Business and a scientific associate at the National Cybersecurity Authority of Greece. Until February 2026, I was an MSCA postdoctoral fellow with my project SPUCS, aiming to provide users more control over their smart devices via transparency mechanisms and novel software architectures. Before joining AUEB, I was a postdoctoral researcher at the Telecooperation Lab of TU Darmstadt, Germany, where I had previously become a Dr.-Ing. with my dissertation titled New Approaches to Software Security Metrics and Measurements. I am interested in all aspects of computer security and privacy, with a focus on software security, transparency for mobile devices, and decentralized computing. For more information about me you can take a look at my CV.
alexopoulos at aueb.gr
Department of Management Science and Technology
Athens University of Economics and Business
Athens
Greece
News
- Dec 2025: Two papers accepted at ACM SAC 2026 on mobile security and transparency with students from the Department of Management Science & Technology of AUEB.
- Oct 2025: I visited the Software Engineering research unit of TU Wien for two weeks.
- Oct 2025: Over the summer, I got the chance to review some very interesting security papers, being in the Technical Program Committee for ACSAC, ICSE, and NDSS.
- Sep 2024: Our work on vulnerability lifetimes [link] was featured in a Google Security Blog post [link] discussing the effects on security of transitioning to memory-safe languages in the Android project.
- Feb 2024: I moved to AUEB and started my MSCA project SPUCS (Software architectures for Secure, Private, User-Controlled Smart devices).
Projects
MSCA Postdoctoral Felowship SPUCS- SPUCS My MSCA PF project SPUCS: Software architectures for Secure, Private, User-Controlled Smart devices aims to provide users more transparency and control over their mobile devices via novel monitoring and isolation methods.
Selected Publications
Peer-reviewed- An Empirical Comparison of Security and Privacy Characteristics of Android Messaging Apps. Ioannis Karyotakis, Foivos-Timotheos Proestakis, Evangelos Talos, Diomidis Spinellis and Nikolaos Alexopoulos. In the 41st ACM/SIGAPP Symposium On Applied Computing (ACM SAC 2026). Poster paper. To appear. [pdf]
- Measuring the Performance of Candidate Verifiable Credential Schemes for the EU Digital Identity Wallet. Angelos Ioannis Lagos, Diomidis Spinellis and Nikolaos Alexopoulos. In the 41st ACM/SIGAPP Symposium On Applied Computing (ACM SAC 2026). To appear. [pdf]
- Towards Democratic Computing. Max Mühlhäuser, Nikolaos Alexopoulos, Uwe Gropengießer, Kamran Razavi, Lin Wang. In From Multimedia Communications to the Future Internet - Essays Dedicated to Ralf Steinmetz on the Occasion of His Retirement, 2024.
- New Approaches to Software Security Metrics and Measurements. Nikolaos Alexopoulos. Dissertation (2022)
- How Long Do Vulnerabilities Live in the Code? A Large-Scale EmpiricalMeasurement Study on FOSS Vulnerability Lifetimes. Nikolaos Alexopoulos, Manuel Brack, Jan Wagner, Tim Grube, Max Mühlhäuser. In USENIX Security 2022 (CORE A*).
- Who are Vulnerability Reporters?: A Large-scale Empirical Study on FLOSS. Nikolaos Alexopoulos, Andrew Meneely, Dorian Arnouts, Max Mühlhäuser. In ESEM '21 (CORE A).
- The Tip of the Iceberg: On the Merits of Finding Security Bugs. Nikolaos Alexopoulos, Sheikh Habib, Steffen Schulz, Max Mühlhäuser. In ACM Trans. Priv. Secur. (ACM TOPS), 2020.
- TRIDEnT: towards a decentralized threat indicator marketplace. Nikolaos Alexopoulos, Emmanouil Vasilomanolakis, Stephane Roux, Steven Rowe, Max Mühlhäuser. In SAC '20: The 35th ACM/SIGAPP Symposium on Applied Computing.
- Assessing the Threat of Blockchain-based Botnets. Leon Böck, Nikolaos Alexopoulos, Emine Saracoglu, Max Mühlhäuser, Emmanouil Vasilomanolakis. In eCrime 2019.
- Trust4App: Automating Trustworthiness Assessment of Mobile Applications. Sheikh Habib, Nikolaos Alexopoulos, Md Islam, Jens Heider, Stephen Marsh, Max Mühlhäuser. In IEEE TrustCom 2018.
- Towards Secure Distributed Trust Management on a Global Scale: An analytical approach for applying Distributed Ledgers for authorization in the IoT. Nikolaos Alexopoulos, Sheikh Habib, Max Mühlhäuser.IoT S&P@SIGCOMM 2018.
- Towards Blockchain-Based Collaborative Intrusion Detection Systems. Nikolaos Alexopoulos, Emmanouil Vasilomanolakis, Natalia Ivanko, Max Mühlhäuser. In CRITIS 2017.
- MCMix: Anonymous Messaging via Secure Multiparty Computation. Nikolaos Alexopoulos, Aggelos Kiayias, Riivo Talviste, Thomas Zacharias. In USENIX Security 2017 (CORE A*).
- Beyond the Hype: On Using Blockchains in Trust Management for Authentication. Nikolaos Alexopoulos, Jörg Daubert, Max Mühlhäuser, Sheikh Habib. In IEEE TrustCom 2017
- SliceDroid: Towards Reconstructing Android Application I/O Behaviors from Kernel Traces. Nikolaos Alexopoulos, Simon Althaus, Diomidis Spinellis. Technical report 2025.
- M-STAR: A Modular, Evidence-based Software Trustworthiness Framework. Nikolaos Alexopoulos, Sheikh Habib, Steffen Schulz, Max Mühlhäuser. Arxiv technical report 2018.
Academic Service
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Program Committee Member
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Reviewer
Teaching
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Trusted and Secure Software Development [link]
Talks
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“Vulnerability Lifetimes and more”
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“Reconstructing Android Application I/O Behaviors from Kernel Traces”
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“Vulnerability lifecycles”
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“New Approaches to Software Security Metrics”