Access control policy combining: theory meets practice

Many access control policy languages, e.g., XACML, allow a policy to contain multiple sub-policies, and the result of the policy on a request is determined by combining the results of the sub-policies according to some policy combining algorithms (PCAs). Existing access control policy languages, however, do not provide a formal language for specifying PCAs. As a result, it is difficult to extend them with new PCAs. While several formal policy combining algebras have been proposed, they did not address important practical issues such as policy evaluation errors and obligations; furthermore, they cannot express PCAs that consider all sub-policies as a whole (e.g., weak majority or strong majority). We propose a policy combining language PCL, which can succinctly and precisely express a variety of PCAs. PCL represents an advancement both in terms of theory and practice. It is based on automata theory and linear constraints, and is more expressive than existing approaches. We have implem...

• Type: Conference
• Year: 2009
• Where: SACMAT
• Authors: Ninghui Li, Qihua Wang, Wahbeh H. Qardaji, Elisa Bertino, Prathima Rao, Jorge Lobo, Dan Lin
• Keywords: Access Control Policy, Control Policy Languages, Policy, SACMAT 2009, Security Privacy