EXTree: Towards Supporting Explainability in Attribute-based Access Control

Computer Science > Cryptography and Security [Submitted on 14 Apr 2026] EXTree: Towards Supporting Explainability in Attribute-based Access Control Shanampudi Pranaya Chowdary (Indian Institute of Technology Kharagpur, India), Shamik Sural (Indian Institute of Technology Kharagpur, India) With increasing emphasis on transparency in digital governance, users expect more than silence when their access requests are denied by a system. However, authorization methods are notorious for their inability to provide any form of meaningful feedback under such situations. This paper shows a direction towards how the problem of explainability can be mitigated in the context of Attribute-based Access Control (ABAC), arguably the most researched topic in access control in recent years. We introduce EXTree, which represents ABAC policies optimized for both fast evaluation (Efficiency) and human-centric feedback (Explainability) in the form of a tree. Two strategic dimensions are investigated, namely, Feedback Evaluation Strategies - how to craft actionable explanations when access is denied, and Tree Construction Strategies - how the policy trees should be structured for efficient yet interpretable decisions. Through extensive experiments, we compare entropy-based, changeability-based, and randomly generated trees across multiple configurations. Our results demonstrate that EXTree, built for efficiency and interpretability, can bridge the gap between complex authorization logic and human understanding. Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2604.12850 [cs.CR]   (or arXiv:2604.12850v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2604.12850 Focus to learn more Submission history From: Shamik Sural [view email] [v1] Tue, 14 Apr 2026 15:06:11 UTC (1,297 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-04 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)