Information
This policy setting specifies whether a password is required to unlock BitLocker-protected fixed data drives.
Note: This setting is enforced when turning on BitLocker, not when unlocking a volume. BitLocker will allow unlocking a drive with any of the protectors available on the drive.
The recommended state for this setting is: Disabled.
Rationale:
Using a dictionary-style attack, passwords can be guessed or discovered by repeatedly attempting to unlock a drive. Since this type of BitLocker password does include anti-dictionary attack protections provided by a TPM, for example, there is no mechanism to slow down rapid brute-force attacks against them.
Solution
To establish the recommended configuration via GP, set the following UI path to Disabled:
Computer Configuration\Policies\Administrative Templates\Windows Components\BitLocker Drive Encryption\Fixed Data Drives\Configure use of passwords for fixed data drives
Note: This Group Policy path may not exist by default. It is provided by the Group Policy template VolumeEncryption.admx/adml that is included with the Microsoft Windows 7 & Server 2008 R2 Administrative Templates (or newer).
Impact:
The password option will not be available when configuring BitLocker for fixed drives.