Security feature that can be applied to .net applications?

.NET Framework role-based security supports authorization by making information about the Principal, which is constructed from an associated identity, available to the current thread. The identity (and the principal it helps to define) can be either based on a Windows account or be a custom identity unrelated to a Windows account. .NET Framework applications can make authorization decisions based on the principal's identity or role membership, or both. A role is a named set of principals that have the same privileges with respect to security (such as a teller or a manager). A principal can be a member of one or more roles. Therefore, applications can use role membership to determine whether a principal is authorized to perform a requested action.