Most security books are targeted at security engineers and specialists. Few show how build security into software. None breakdown the different concerns facing security at different levels of the system: the enterprise, architectural and operational layers. Security Patterns addresses the full spectrum of security in systems design, using best practice solutions to show how to integrate security in the broader engineering process. It is essential for designers building large-scale systems who want best practice solutions to typical security problems. Real world case studies illustrate how to use the patterns in specific domains.