Conflict analysis and detection based on model checking for spatial access control policy

In this paper, we propose a Multi-granularity Spatial Access Control (MSAC) model, in which multigranularity spatial objects introduce more types of policy rule conflicts than single-granularity objects do. To analyze and detect these conflicts, we first analyze the conflict types with respect to the relationship among the policy rules, and then formalize the conflicts by template matrices. We designed a model-checking algorithm to detect potential conflicts by establishing formalized matrices of the policy set. Lastly, we conducted experiments to verify the performance of the algorithm using various spatial data sets and rule sets. The results show that the algorithm can detect all the formalized conflicts. Moreover, the algorithm's efficiency is more influenced by the spatial object granularity than the size of the rule set.