Ten years after the release of .NET 1.0 Microsoft decided to revamp the built-in infrastructure for authentication & authorization. All identities in .NET are now modeled using the claims-based paradigm, and token based authentication (which is also the basis for federation) is now a first class citizen in the framework. This has been achieved by tightly integrating the Windows Identity Foundation (WIF) into the core class library. Since these changes have been made in the base classes, all application level frameworks like ASP.NET, WCF and WPF inherit these new features. Learn what these new mechanisms have to offer, what that means to existing applications and how you migrate either from stock .NET or WIF enabled applications.