Designing medium assurance XML-labelling guards for NATO

The eXtensible Markup Language (XML)-Labelling Guard, or XLG in short, offers a solution for cross-domain information exchange in scenarios involving connections from NATO systems to mission systems and between NATO and nonNATO nations or international organizations. The intended function of the XLG is to enable, based on the use of XML security labels, an automated data exchange between two network enclaves belonging to different security domains. In this paper we describe the security model used during the design of a medium assurance XLG, which is to be deployed between NATO Secret and Mission Secret systems.