This field is used to prevent users from changing the key of a keyed hash algorithm during a hash operation. When a key change is legitimate, the value of this field is zero both before and after a hash operation. When a key change is not legitimate, the value of this field is nonzero.
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.