No abstract

The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.

No abstract

Nowadays, accessing communication networks and systems faces multitude applications with large-scale requirements dimensions. Mobility -roaming services in particular-during urgent situations exacerbate the access control issues. Dynamic authorization then is required. However, traditional access control fails to ensure policies to be dynamic. Instead, we propose to externalize the dynamic behavior management of networks and systems through situations. Situations modularize the policy into groups of rules and orient decisions. Our solution limits policy updates and hence authorization inconsistencies. The authorization system is built upon the XACML architecture coupled with a complex eventprocessing engine to handle the concept of situations. Situationoriented attribute based policies are defined statically allowing static verification and validation.