After installing Windows, I turned on Bitlocker for a full C:\ drive encryption. I saved the recovery keys and then let Bitlocker proceed with encrypting the full drive.
When I rebooted, I was surprised that the system booted completely fine without prompting for a pin. I guess Bitlocker is asking the TPM (AMD fTPM) for keys to decrypt the drive, tell me if I'm wrong.
So I tried to make the TPM require a pin before giving away all his little secrets. I found how to change the "Local Computer Policy" and configured the "Require additional authentication at startup" settings, requiring a pin.
I then proceeded to set a pin for my C:\ drive, which went perfectly fine. I rebooted and was prompted for a pin, which I thought was the end of the story.
But I wanted to test clearing the TPM to be sure that it was the component storing the keys (I have the Bitlocker recovery key, so that shouldn't be a problem). I cleared the TPM using the windows TPM GUI.
To my big surprise, when I rebooted Windows, I wasn't prompted for a pin, NOR A RECOVERY KEY! The system booted perfectly fine, but Bitlocker was in a suspended state! How is this possible after clearing the TPM? The keys should be gone forever! Have them been copied to a readable zone on my disk?
Am I misunderstanding how Bitlocker and the TPM work together?