Platform Changes in 4.0: Security

The beta 1 release of .Net 4.0 has some big differences compared to previous releases for dealing with code security. If you’ve used the CAS (code access security) model then you might know it’s a fairly complicated set of policies and assertions for working out whether your program has permission to perform a particular action. In 4.0, desktop applications use a security model more similar to the simpler Silverlight model. Much of the details about the simplified security model are available on MSDN.

You can also read about how to update applications to use the new security model or switch back to the old security model on the CLR team blog.

The WCF users that will care about these changes are primarily those that were using partial trust, such as in a hosting environment.