This complete guide to security for web services and SOA considers the malicious user story of the abuses and attacks against applications as examples of how design flaws and oversights have subverted the goals of providing resilient business functionality. It reviews recent research on access control for simple and conversation-based web services, advanced digital identity management techniques, and access control for web-based workflows. Filled with illustrative examples and analyses of critical issues, this book provides both security and software architects with a bridge between software and service-oriented architectures and security architectures, with the goal of providing a means to develop software architectures that leverage security architectures.