See Also: StrongNameIdentityPermission Members
Starting with the net_v40_long, identity permissions are not used.
In the .NET Framework versions 1.0 and 1.1, identity permissions cannot have an PermissionState.Unrestricted permission state value. In the .NET Framework version 2.0 and later, identity permissions can have any permission state value. This means that in version 2.0 and later versions, identity permissions have the same behavior as permissions that implement the System.Security.Permissions.IUnrestrictedPermission interface. That is, a demand for an identity always succeeds, regardless of the identity of the assembly, if the assembly has been granted full trust.
Use System.Security.Permissions.StrongNameIdentityPermission to confirm that the calling code is in a particular strong-named code assembly. Full demands for System.Security.Permissions.StrongNameIdentityPermission succeed only if all the assemblies in the stack have the correct evidence to satisfy the demand. Link demands that use the System.Security.Permissions.StrongNameIdentityPermissionAttribute attribute succeed only if the immediate caller has the correct evidence.
A strong name identity is based on a cryptographic public key called a binary large object (BLOB), which is optionally combined with the name and version of a specific assembly. The key defines a unique namespace and provides strong verification that the name is genuine, because the definition of the name must be in an assembly that is signed by the corresponding private key.
Note that the validity of the strong name key is not dependent on a trust relationship or on any certificate necessarily being issued for the key.
In the .NET Framework versions 1.0 and 1.1, demands on the identity permissions are effective even when the calling assembly is fully trusted. That is, even if the calling assembly has full trust, a demand for an identity permission fails if the assembly does not meet the demanded criteria. In the .NET Framework version 2.0 and later, demands for identity permissions are ineffective if the calling assembly has full trust. This ensures consistency for all permissions and eliminates the treatment of identity permissions as a special case.
The System.Security.Permissions.StrongNameIdentityPermission class is used to define strong-name requirements for accessing the public members of a type. The System.Security.Permissions.StrongNameIdentityPermissionAttribute attribute can be used to define strong-name requirements at the assembly level. In the .NET Framework version 2.0 and later, you can also use the System.Runtime.CompilerServices.InternalsVisibleToAttribute attribute to specify that all nonpublic types in that assembly are visible to another assembly. For more information, see Friend Assemblies (C# and Visual Basic).