1789

Recently, a security researcher has revealed a new method of extracting BitLocker encryption keys from a computer's Trusted Platform Module (TPM) that uses something that he has named a "logic analyzer" which is a piece of hardware that is plugged into the computer to execute the attack. Details about this attack can be found here. 

As a result, you may have questions about how this could affect SecureDoc. Based on our analysis, WinMagic has the following commentary: 

1. When SecureDoc is used configured to utilize the TPM for Pre-Boot-Authentication is it susceptible to the same attack?

ANSWER: No, because SecureDoc requires the user to be present to enter a PIN before getting the TPM to decrypt the key. The user is in possession of the computer and is going to notice the logic analyzer (etc.) attached to the bus and not enter the PIN. This differs from BitLocker in the default mode where it programs the TPM to unseal the volume master key and boots up into Windows WITHOUT requiring the user to enter a PIN (i.e. no-PBA) and without requiring the user to be present.
 
2. When SecureDoc is used “on top” of BitLocker to manage it is it susceptible to the same attack?

ANSWER: No, because with SDOT (SecureDoc On Top) of BitLocker we perform Pre-Boot-Authentication. With SDOT pre-boot authentication a TPM is not required but if one is configured to be used SecureDoc requires the user to be present to enter a PIN before getting the TPM to decrypt the key. (see answer to question 1 above)
 
3. When SecureDoc is used in SDBM (SecureDoc BitLocker Management) mode is it susceptible to the same attack?

ANSWER: Possibly, because with SDBM SecureDoc doesn’t perform Pre-Boot Authentication. If BitLocker is configured in the default mode it programs the TPM to unseal the volume master key and boots up into Windows WITHOUT requiring the user to enter a PIN (i.e. no-PBA) and without requiring the user to be present and is therefore susceptible to this attack.

WinMagic has also posted a blog post written by WinMagic CEO Thi Nguyen-Huu with additional commentary. This can be found here.