Detecting conflict of heterogeneous access control policies

Policy conflicts may cause substantial economic losses. Although a large amount of effort has been spent on detecting intra-domain policy conflict, it can not detect conflicts of heterogeneous policies. In this paper, considering background knowledge, we propose a conflict detection mechanism to search and locate conflicts of heterogeneous policies. First, we propose a general access control model to describe authorization mechanisms of cloud service and a translation scheme designed to translate a cloud service policy to an Extensible Access Control Markup Language (XACML) policy. Then the scheme based on Multi-terminal Multi-data-type Interval Decision Diagram (MTMIDD) and Extended MTMIDD (X-MTMIDD) is designed to represent XACML policy and search the conflict among heterogeneous policies. To reduce the rate of false positives, the description logic is used to represent XACML policy and eliminate false conflicts. Experimental results show the efficiency of our scheme.