This policy setting allows you to specify whether smart cards can be used to authenticate user access to BitLocker-protected removable data drives on a computer.If you enable this policy setting smart cards can be used to authenticate user access to the drive. You can require a smart card authentication by selecting the "Require use of smart cards on removable data drives" check box.Note: These settings are enforced when turning on BitLocker not when unlocking a drive. BitLocker will allow unlocking a drive with any of the protectors available on the drive.If you disable this policy setting users are not allowed to use smart cards to authenticate their access to BitLocker-protected removable data drives.If you do not configure this policy setting smart cards are available to authenticate user access to a BitLocker-protected removable data drive.