This policy setting allows you to specify whether a password is required to unlock BitLocker-protected removable data drives. Note: This setting is 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. 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 not include anti-dictionary attack protections provided by a TPM, for example, there is no mechanism to slow down use of 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\Removable Data Drives\Configure use of passwords for removable 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 removable drives. Default Value: Passwords are supported, without complexity requirements and with an 8 character minimum.