This policy setting lets you allow signature key-based certificates to be enumerated and available for logon. If you enable this policy setting then any certificates available on the smart card with a signature only key will be listed on the logon screen. If you disable or do not configure this policy setting, any available smart card signature key-based certificates will not be listed on the logon screen. Fix: (1) GPO: Computer Configuration\Administrative Templates\Windows Components\Smart Card!Allow signature keys valid for Logon (2) REG: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\SmartCardCredentialProvider!AllowSignatureOnlyKeys