18.9.11.3.8 Ensure 'Choose how BitLocker-protected removable drives can be recovered: Configure storage of BitLocker recovery information to AD DS:' is set to 'Enabled: Backup recovery passwords and key packages'

Information

This policy setting allows you to control how BitLocker-protected removable data drives are recovered in the absence of the required credentials. This policy setting is applied when you turn on BitLocker.

In 'Save BitLocker recovery information to Active Directory Domain Services' choose which BitLocker recovery information to store in AD DS for removable data drives. If you select 'Backup recovery password and key package', both the BitLocker recovery password and key package are stored in AD DS. If you select 'Backup recovery password only', only the recovery password is stored in AD DS.

The recommended state for this setting is: Enabled: Backup recovery passwords and key packages.

Rationale:

Administrators should always have a safe, secure way to access encrypted data in the event users cannot access their data.

Additionally, as with any authentication method, a drive can be compromised by guessing or finding the authentication information used to access the drive.

To use BitLocker a Data Recovery Agent will need to be configured for removable drives. To recover a drive will require highly-controlled access to the Data Recovery Agent private key.

Impact:

None - this value is ignored when the checkbox above it (Save BitLocker recovery information to AD DS for removable data drives) is False (unchecked), as is required in Rule 18.9.11.3.7. If that checkbox is set to True (checked), both recovery passwords and key packages for removable drives will be saved to AD DS.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: Backup recovery passwords and key packages:

Computer Configuration\Policies\Administrative Templates\Windows Components\BitLocker Drive Encryption\Removable Data Drives\Choose how BitLocker-protected removable drives can be recovered: Configure storage of BitLocker recovery information to AD DS:

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).

Default Value:

BitLocker recovery information for removable drives is not backed up to AD DS.

See Also

https://workbench.cisecurity.org/files/4167