Subj3ct beta -Networked Planet

The World Wide Web makes it easy to share information and resources, but offers few ways to limit the manner in which these resources are shared. The specification and automated enforcement of security-related policies offer promise as a way of providing controlled sharing, but few tools are available to assist in policy specification and management, especially in an open system such as the Web, where resource providers and users are often strangers to one another and exact and correct specification of policies will be crucial. In this paper, we propose the use of ontologies to simplify the tasks of policy specification and administration, discuss how to represent policy inheritance and composition based on credential ontologies, formalize these representations and the according constraints in Frame-Logic, and present PolicyTab, a prototype implementation of our proposed scheme as a Prot�g� plug-in to support policy specification.