Details
This policy setting specifies the constraints for passwords used to unlock BitLocker-protected operating system 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.
Impact:
The password option will not be available when configuring BitLocker for the operating system drive.
Solution
To establish the recommended configuration via GP, set the following UI path to Disabled:
Computer ConfigurationPoliciesAdministrative TemplatesWindows ComponentsBitLocker Drive EncryptionOperating System DrivesConfigure use of passwords for operating system 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 8.0 & Server 2012 (non-R2) Administrative Templates (or newer).
Default Value:
Passwords are supported, without complexity requirements and with an 8 character minimum.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: Risk Assessment.This control applies to the following type of system Windows.