[highwaylights]

Would you be better off using split key encryption or encrypted secret key?

If you have to put a password in before boot that needs to be combined with the TPM key to unlock the drive, it would help in scenarios where a TPM key can be found later.

I’m not sure how much anything helps against this attack though. Retrieving data from RAM in this way should work for most scenarios by changing where you look for the key (as it needs to be held somewhere by the OS to maintain read/write access to the drive).

I would assume Apple devices aren’t vulnerable to this type of attack as IIRC the keys never exit the enclave. Maybe TPM 3.0 needs to look a lot more like that.

[dist-epoch]

> If you have to put a password in before boot that needs to be combined with the TPM key to unlock the drive, it would help in scenarios where a TPM key can be found later.

Bitlocker already does this if you use a PIN/password.

[highwaylights]

You might know better than I do, but I had believed that Bitlocker used TPM PIN when you use a PIN, which is challenge/response (i.e. if PIN matches then TPM releases key) so wouldn't help in this case.

If Bitlocker PIN is split key then yes that would be ideal, but I think you can change the PIN without re-encryption (which implies it's challenge/response).