In this chapter, you have learned about the concepts relevant to Code Access Security and have seen how the Code Access Security paradigm fits within the Trustworthy Computing initiative. You have learned about the difference between Identity-Based Security and Code Access Security. The chapter explains the basic building blocks that are important in Code Access Security, such as permissions, named permission sets, evidence, code groups, membership conditions, stack walk modifiers and security demands. You have also learned how to read and create SharePoint Server 2007 security policy files. Then the chapter discussed what partially trusted callers and APTCA are. The chapter concluded with an explanation of how to use Visual Studio 2005 to calculate the required security permissions for .NET assemblies.