"ASP.NET 2.0 includes a number of new features to make securing your ASP.NET applications easier than before. See how you can use the new controls, tools, and APIs to control access to pages, and make it easier to store information about your users."
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvs05/html/SecFeatNT2.asp
