Secure Mediation: Requirements and Design. - Joachim Biskup; Ulrich Flegel; Yücel Karabulut (DBSec, 1998)

Threshold-based identity recovery for privacy enhanced applications. - Joachim Biskup; Ulrich Flegel (CCS, 2000)

On Pseudonymization of Audit Data for Intrusion Detection. - Joachim Biskup; Ulrich Flegel (Workshop on Design Issues in Anonymity and Unobservability, 2000)

Transaction-Based Pseudonyms in Audit Data for Privacy Respecting Intrusion Detection. - Joachim Biskup; Ulrich Flegel (Recent Advances in Intrusion Detection, 2000)

Ausgleich von Datenschutz und Überwachung mit technischer Zweckbindung am Beispiel eines Pseudonymisierers. - Joachim Biskup; Ulrich Flegel (GI Jahrestagung, 2002)

Pseudonymizing Unix Log Files. - Ulrich Flegel (InfraSec, 2002)

Ein Architektur-Modell für anonyme Autorisierungen und Überwachungsdaten. - Ulrich Flegel (GI Jahrestagung (Schwerpunkt "Sicherheit - Schutz und Zuverlässigkeit"), 2003)

Anonyme Audit-Daten im Überblick - Architekturen für anonyme Autorisierungen und Audit-Daten. - Ulrich Flegel (Datenschutz und Datensicherheit, 2003)

Secure Mediation: Requirements, Design, and Architecture. - Christian Altenschmidt; Joachim Biskup; Ulrich Flegel; Yücel Karabulut (J. Comput. Secur., 2003)

Reactive Security - Intrusion Detection, Honeypots, and Vulnerability Assessment. - Michael Meier 001; Ulrich Flegel; Hartmut König (Prax. Inf.verarb. Kommun., 2004)

Evaluating the Design of an Audit Data Pseudonymizer Using Basic Building Blocks for Anonymity. - Ulrich Flegel (Sicherheit, 2005)

Pseudonymizing audit data for privacy respecting misuse detection. - Ulrich Flegel (2005)

Requirements of Information Reductions for Cooperating Intrusion Detection Agents. - Ulrich Flegel; Joachim Biskup (ETRICS, 2006)

Simplifying Signature Engineering by Reuse. - Sebastian Schmerl; Hartmut König; Ulrich Flegel; Michael Meier 001 (ETRICS, 2006)

Vereinfachung der Signaturentwicklung durch Wiederverwendung. - Sebastian Schmerl; Ulrich Flegel; Michael Meier 001 (Sicherheit, 2006)

Privacy-Respecting Intrusion Detection - Ulrich Flegel (Springer, 2007)

Efficiency Issues of Rete-Based Expert Systems for Misuse Detection. - Michael Meier 001; Ulrich Flegel; Sebastian Schmerl (ACSAC, 2007)

Authorization Architectures for Privacy-Respecting Surveillance. - Ulrich Flegel; Michael Meier 001 (EuroPKI, 2007)

Systematic Signature Engineering by Re-use of Snort Signatures. - Sebastian Schmerl; Hartmut König; Ulrich Flegel; Michael Meier 001; René Rietz (ACSAC, 2008)

08102 Working Group – Intrusion and Fraud Detection for Web Services. - Marc Dacier; Ulrich Flegel; Ralph Holz; Norbert Luttenberger (Network Attack Detection and Defense, 2008)

Collaborative Fraud Detection in Outsourcing Scenarios: Issues of and Solutions for Privacy and Confidentiality. - Ulrich Flegel; Florian Kerschbaum; Richard Wacker (Countering Insider Threats, 2008)

Fraud Detection from a Business Perspective: Future Directions and Challenges. - Ulrich Flegel; Julien Vayssière; Gunter Bitz (Countering Insider Threats, 2008)

Supporting Evidence-Based Compliance Evaluation for Partial Business Process Outsourcing Scenarios. - Philip Miseldine; Ulrich Flegel; Andreas Schaad (RELAW, 2008)

A Secure Task Delegation Model for Workflows. - Khaled Gaaloul; Andreas Schaad; Ulrich Flegel; François Charoy (SECURWARE, 2008)

Towards Validating Security Protocol Deployment in the Wild. - Luca Compagna; Ulrich Flegel; Volkmar Lotz (COMPSAC (2), 2009)

Towards Early Warning Systems - Challenges, Technologies and Architecture. - Martin Apel; Joachim Biskup; Ulrich Flegel; Michael Meier 001 (CRITIS, 2009)

Technischer Datenschutz für IDS und FDS durch Pseudonymisierung. - Ulrich Flegel; Oliver Raabe; Richard Wacker (Datenschutz und Datensicherheit, 2009)

Editorial. - Ulrich Flegel; Eric Filiol (J. Comput. Virol., 2009)

Privacy Compliant Internal Fraud Screening. - Ulrich Flegel (ISSE, 2010)

Cooperation enablement for centralistic early warning systems. - Ulrich Flegel; Johannes Hoffmann; Michael Meier 001 (SAC, 2010)

Fraud Detection in ERP Systems Using Scenario Matching. - Asadul K. Islam; Malcolm Corney; George M. Mohay; Andrew J. Clark; Shane Bracher; Tobias Raub; Ulrich Flegel (SEC, 2010)

Legally Sustainable Solutions for Privacy Issues in Collaborative Fraud Detection. - Ulrich Flegel; Florian Kerschbaum; Philip Miseldine; Ganna Monakova; Richard Wacker; Frank Leymann (Insider Threats in Cyber Security, 2010)

A State of the Art Survey of Fraud Detection Technology. - Ulrich Flegel; Julien Vayssière; Gunter Bitz (Insider Threats in Cyber Security, 2010)

Detecting Collusive Fraud in Enterprise Resource Planning Systems. - Asadul K. Islam; Malcolm Corney; George M. Mohay; Andrew J. Clark; Shane Bracher; Tobias Raub; Ulrich Flegel (IFIP Int. Conf. Digital Forensics, 2011)

Monitoring Security and Safety of Assets in Supply Chains. - Ganna Monakova; Cristina Severin; Achim D. Brucker; Ulrich Flegel; Andreas Schaad (Future Security, 2012)

Reactive Security. - Ulrich Flegel (it Inf. Technol., 2012)

Modeling and Describing Misuse Scenarios Using Signature-Nets and Event Description Language. - Ulrich Flegel; Michael Meier 001 (it Inf. Technol., 2012)

Detecting zero-day attacks using context-aware anomaly detection at the application-layer. - Patrick Düssel; Christian Gehl; Ulrich Flegel; Sven Dietrich; Michael Meier 001 (Int. J. Inf. Sec., 2017)

Tracing Privilege Misuse Through Behavioral Anomaly Detection in Geometric Spaces. - Patrick Düssel; Shoufu Luo; Ulrich Flegel; Sven Dietrich; Michael Meier 001 (SADFE, 2020)