Chapter 7 BRINGING SEMANTIC SECURITY TO SEMANTIC WEB SERVICES Authors: Richard S. Patterson 1 , John A. Miller 1 , Jorge Cardoso 2 , Mike Davis 3 1 University of Georgia, 2 University of Madeir, 3 U.S. Department of Veterans Affairs& Chair HL7 Security Committee Abstract: Semantic Web services begin to emerge as the next evolution of the Service Oriented Architecture. It is become clear that authorization is going to be one of the biggest challenges. The typical obstacles which most areas of Semantic Web services have had to overcome are what parts of a Web services need semantic information, how best to use the semantics, and agreeing on standards. However, for authorization there are the fine grained security implications as well. For instance, how much authorization information is necessary to aid in Semantic Discovery of Web services? Is the authorization information opening any new security holes? We will examine a framework for expressing the proper authorization information in order to aid in the Semantic Discovery of Web services in which the requesting service most likely has the authority to invoke. Key words: Web Services Discovery, Authorization, Semantic Matching of Web Services, Ontology-based matching of Authorization, Web Service Authorization Discovery, Semantic Web Services 1. INTRODUCTION 1.1 The Semantic Web Currently, the World Wide Web is primarily composed of documents written in HTML (Hyper Text Markup Language), a language that is useful for visual presentation. HTML is a set of “markup” symbols contained in a Web page intended for display on a Web browser. Most of the information