Nils Niehues | Searcharxiv

arXiv2026

xDECAF: An Extensible Data Flow Diagram Analysis Framework for Information Security

xDECAF is an extensible tool for architecture-based data flow analysis with a focus on information security. It combines an extended data flow diagram metamodel of labeled flows and nodes, a domain-specific constraint language with different flow operations, and a browser-based editor backed by an analysis engine. In this paper, we present the xDECAF tool library and a curated catalog of over 20 example models with documented constraints and expected violations, intended as a reusable dataset for the community. The tool has already been adopted by several research lines, providing concrete evidence of its utility. The tool, dataset, and a hosted online editor are publicly available.

cs.SE↗

arXiv2025

Same Same But Different: Preventing Refactoring Attacks on Software Plagiarism Detection

Plagiarism detection in programming education faces growing challenges due to increasingly sophisticated obfuscation techniques, particularly automated refactoring-based attacks. While code plagiarism detection systems used in education practice are resilient against basic obfuscation, they struggle against structural modifications that preserve program behavior, especially caused by refactoring-based obfuscation. This paper presents a novel and extensible framework that enhances state-of-the-art detectors by leveraging code property graphs and graph transformations to counteract refactoring-based obfuscation. Our comprehensive evaluation of real-world student submissions, obfuscated using both algorithmic and AI-based obfuscation attacks, demonstrates a significant improvement in detecting plagiarized code.

cs.SE↗