Investigation of Access Control Models with Formal Concept Analysis: A case study

Web applications manage increasingly large amounts of sensitive information and often need to implement access control (AC) models. However, documentation about the implemented AC model is often sparse and few, if no tool exists to support AC model investigation. Based on the results of a previous study, we show how formal concept analysis (FCA) can support the understanding and visualization of reverse-engineered AC models. Results of applying FCA to Moodle, a medium-sized (625 473 LOC) Web application, are presented and discussed. We show how FCA enhances the overall comprehension of reverse-engineered AC models and sheds light on previously unknown features of Moodle's AC model.