XACML policy integration algorithms

XACML is the OASIS standard language specifically aimed at the specification of authorization policies. While XACML fits well with the security requirements of a single enterprise (even if large and composed by multiple departments), it does not address the requirements of virtual enterprises in which several autonomous subjects collaborate by sharing their resources to provide better services to customers. In this article we highlight such limitation, and we propose an XACML extension, the policy integration algorithms, to address them. In the article we also present the implementation of a system that makes use of the policy integration algorithms to securely replicate information in a P2P-like environment. In our solution, the data replication process considers the policies specified by both the owners of the data shared and the peers sharing data storage.