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StrongNameIdentityPermission Class

Updated: August 2010

Defines the identity permission for strong names. This class cannot be inherited.

Namespace:  System.Security.Permissions
Assembly:  mscorlib (in mscorlib.dll)

public final class StrongNameIdentityPermission extends CodeAccessPermission

Important noteImportant Note:

In the .NET Framework versions 1.0 and 1.1, identity permissions cannot have an 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 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. For information about executing version 2.0 applications with version 1.1 CAS policy, see <legacyV1CASPolicy> Element.

Use StrongNameIdentityPermission to confirm that the calling code is in a particular strong-named code assembly.

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.


Full demands for StrongNameIdentityPermission succeed only if all the assemblies in the stack have the correct evidence to satisfy the demand. Link demands that use the StrongNameIdentityPermissionAttribute attribute succeed only if the immediate caller has the correct evidence.

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.

For a complete description of strong names, see the StrongName reference page. For more information about strong-named assemblies, see Strong-Named Assemblies.

The StrongNameIdentityPermission class is used to define strong-name requirements for accessing the public members of a type. The StrongNameIdentityPermissionAttribute attribute can be used to define strong-name requirements at the assembly level. In the .NET Framework version 2.0 and later versions, you can also use the InternalsVisibleToAttribute attribute to specify that all nonpublic types in that assembly are visible to another assembly. For more information, see Friend Assemblies (C# Programming Guide) or Friend Assemblies (Visual Basic).

The following code example demonstrates the use of the StrongNameIdentityPermission class. The example is in the form of a class library, which applies both the StrongNameIdentityPermissionAttribute attribute and the StrongNameIdentityPermission to demand that the caller be signed with a specific strong name.

No code example is currently available or this language may not be supported.

The following code example demonstrates the behavior of the StrongNameIdentityPermission methods.

The example is intended to show how the methods perform if you execute the methods from your code. In general, the methods of permission classes are used by the security infrastructure; they are not typically used in applications.

No code example is currently available or this language may not be supported.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0




August 2010

Modified and reorganized the remarks.

Customer feedback.