In Microsoft .NET you have two types of security, Code Access Security and Role Based Security. In this article we will explore what the latter implies, how it can be used, etc. So, what is Code Access Security then? Code Access Security (CAS) is a security feature of .NET that enables the code that is to be executed to be properly verified and different levels of trust granted accordingly. It actually provides the flexibility to define what the code could perform and what not to perform. This article discusses CAS, the functions and benefits of CAS, permissions and permission sets.