Hey guys,
My my current employer is considering a full disk encryption (
FDE) technology which uses
TPM's instead of our current software based solutions with passwords. I'm doing some testing.
Quick aside: In short, right now, users type in a password (encryption key) when their machine boots. The solution we're considering (
BitLocker) stores the encryption keys in the special TPM chip on supported computers.
Normally, most people's experience with TPM's is on laptops. They're rare on desktop machines. I
much prefer working with desktops. Thus, my home lab had no TPM support. I have two motherboards with headers for TPM's. A quick
Amazon search found a TPM which Prime quickly delivered. So, I setup Windows 8.1 Enterprise Evaluation edition on an OCZ ssd.
I installed the TPM module in the motherboard. Then, I configured it. And booted into Windows.
This was the surprisingly difficult part. Using the Control Panel applet to configure BitLocker led to nothing but frustration. I finally
found some instructions on how to force BitLocker to use the TPM (By default, it appears to
NOT use the TPM.) Here's the command that did it:
manage-bde -on C:
Some testing indicated that everything worked as expected (could seamlessly boot into Windows 8.1; loading the drive into a forensic workstation showed a garbled mess; etc.). Now, for the fun part. The part that you can't do with a laptop.
I took the drive
and the TPM out of my initial build machine and put it in a test machine; configured the BIOS; booted. Useless. Windows wouldn't boot as it couldn't decrypt the drive. I was hoping that I'd be able to use the drive; no such luck.
Finally, I returned the TPM and drive back to the original machine. Everything worked fine. ("manage-bde -status") still shows the drive as encrypted.
I'm torn. On one hand, I'm glad that the encryption protected the data even after the drive
and the TPM were moved into a different machine. Let's face it: you'd have to have a VERY determined adversary to try something like pulling a TPM off of a laptop motherboard. On the other hand, in an enterprise environment, sometimes data recovery means that you need access to data even if the original machine is b0rked. I guess that's what
MBAM is for.
MJ