What are the improvements made in CAS in .NET 4.0?
The CAS mechanism in .NET is used to control and configure the ability of managed code. Previously, as this policy was applicable for only native applications, the security guarantee was limited. Thus, developers used to look for alternating solutions, such as operating system-level solutions. This problem was solved in .NET Framework 4 by turning off the machine-wide security. The shared and hosted Web applications can now run more securely. The security policy in .NET Framework 4 has been simplified using the transparency model. This model permits you to run the Web applications without concerning about the CAS policies.