Source Where are the encryption keys stored?
Where are the encryption keys stored?
The full volume encryption key is encrypted by the volume master key and stored in the encrypted drive. The volume master key is encrypted by the appropriate key protector and stored in the encrypted drive. If BitLocker has been suspended, the clear key that is used to encrypt the volume master key is also stored in the encrypted drive, along with the encrypted volume master key.
This storage process ensures that the volume master key is never stored unencrypted and is protected unless you disable BitLocker. The keys are also saved to two additional locations on the drive for redundancy. The keys can be read and processed by the boot manager.
So if you wipe the drive you lose both the encryption keys as well as all data that was on the drive.