Improvements in CAS in .NET 4.0

Question

Specify the various improvements made in the CAS in .NET 4.0?

Answer 1

CAS mechanism in .NET is used for controlling and configuring the ability of the managed code. Earlier, since this policy was applicable only for the native applications, the security guarantee was restricted. Thus, the developers need to look for the alternative solutions, for example: operating system-level solutions. This difficulty was resolved in .NET Framework 4 by turning off the machine-wide security. The shared and hosted Web applications will now run with more security. The security policy in .NET Framework 4 has been simplified by using transparency model. This model permits to run the Web applications without concerning the CAS policies.

As a result of changes in the security policy in .NET Framework 4.0, you can encounter compilation warnings and exceptions of runtime, if you try to use obsolete CAS policy types and members either explicitly or implicitly. But, you can avoid the warnings and errors by using the <NetFx40_LegacySecurityPolicy> configuration element within the runtime settings schema to opt into the obsolete CAS policy behaviour.