With policy management being a popular mechanism for providing flexible security, the number of policy languages being proposed is constantly increasing. The use of disparate policy languages makes collaboration between and integration over applications and domains difficult and requires prior negotiation and agreement between them. These problems could be eased by the adoption of a standard policy language. Users, however, should not be forced to conform to a single language as that will reduce their flexibility and autonomy. Rule Interchange Format (RIF) is a W3C recommendation that allows the exchange of rules between rule systems. We propose creating a policy interchange language grounded in RIF.  This policy interchange language will allow systems to use their own policy language while still collaborating securely with those that do not. We plan to study several policy languages and capture their main functionality in RIF with an aim to identifying their common subset. Our intuition leads us to believe that a generalized form of this common subset, expressed in RIF, will act as a policy interlingua. eXtensible Access Control Markup Language (XACML) is an OASIS standard language for the specification of access control policies and has been deployed in many Web-based systems. As a first step, we show how the semantics of XACML can be expressed in RIF. In this paper, we present our translation between XACML and RIF that allows XACML and non-XACML systems to collaborate while maintaining their security policies.
