Breaking Bitlocker - Bypassing the Windows Disk Encryption

In this video we will use a hardware attack to bypass TPM-based Bitlocker encryption as used on most Microsoft Windows devices.

Errata:
- PIN can also be enabled using manage-bde, not just using group policies

Questions:

Links:

Me:

Posts about sniffing bitlocker:

[TechX]

I work in data recovery... this could be really helpful for those who can't get their keys for whatever reason. If people can't get their keys, we have other avenues at times, but largely its just not worth it

[sarkasaa]

I've always been under the impression that once someone has physical access to your machine, you've already lost. And this video once again confirms that.

[JasonMayes]

I love the clarity of your explanations. More folk in the industry need to speak and explain like you do. Great job.

[clebbington]

don't forget - a TPM module was a requirement for Windows 11 installs for "security" 🙃

[Charles-ksht]

Congratulations! You found the FBI's backdoor.

Expect an agent to arrive at your destination in a couple of minutes for your prize!

[mekafinchi]

transmitting the key in *plaintext* is such a bafflingly obvious vulnerability I'm amazed it's in the bloody security chip. I understand the increased hardware and execution time costs that would come with doing otherwise but you'd think security would be prioritized

[matankabalo]

Your explanation is great! I really like the animations and visuals you show

[simon]

I saw your great presentation on the Iphone USB-C stuff from 37C3 and now this popped up in my feed. Really amazing work stacksmashing!

[NoDissasemble]

Really interesting video and great demonstration. Surprising how easy this is.

Of note, TPM only BitLocker configuration is documented as being one of the less secure. Definitely not recommended for a production deployment. As you have shown, it really only offers robust protection against access when the drive is removed and separated from the original system and TPM.

With TPM only there is only a single branch in the key chain. TPM Key Protector (KP) decrypts the Volume Master Key (VMK) decrypts the Full Volume Encryption Key (FVEK).

TPM + PIN is a more secure method which requires the pre-boot PIN in addition to the TPM stored key.

Actually the PIN doesn't protect the TPM as you suggested, it is really just another BitLocker KP needed to unlock decrypt the VMK. It is just designed to require both the TPM KP and the PIN KP to do so.

There's a whole lot more behind BitLocker in terms of default vs best practice for security. Why MS don't just them as default it is beyond me.

[jurgennicht]

6:48 - "It did not need any super advanced skills or tools"
Depends on who you ask. To me there is a lot of knowledge already needed to perform this kind of attack and (optionally) even build a custom PCB 👍
Well done Sir.

[kobehighlander]

Oh, I love this. The combination of ingenuity, curiosity and a great amount of knowledge. Well done.

[netroy]

There was a similar attack published a few years ago for a TPM that communicated unencrypted over SPI. I had assumed that something like this would have been addressed by now by using some kind of encryption using pre-shared keys. 🙈
Great work, BTW 👏🏼

[HollyTroll]

super informative as always, thx for the video

[DigitalMetal]

Great Video! Explained well. Thank you.

[ysidrovasquez]

well, you are the only one i found in two days that really understands the bitlocker, thanks for the video

[ipaterson]

You never cease to amaze Thomas. Incredible work my friend!

[briandeschene]

What you’ve pointed out is that providing *maximum* security is a moving point in time. What is maximum (and usually adequate) at one point in time becomes inadequate as attack techniques improve and shortcomings are identified. The protection is then improved to maximize it anew — again, for a time.

To remediate the defect you demonstrated, laptops now use integrated TPM or firmware TPM so there’s no more transmission of keys over motherboard traces to be sniffed.

Finally, your statement about preboot PIN is inaccurate. It does not require a Group Policy Object (GPO). This documented command for Windows Pro does it: Manage-BDE -Protectors -Add C: -TPMandPIN

[tpdblake]

Thanks for making this video. I thought bitlocker was enough to secure my computer. I still think it’s good enough to keep it safe from the majority of criminals but I’m going to look at editing the group policy to secure the TPM with a pin pre-boot for additional security. Thanks for making me aware of this issue

[noflashbang]

Killer work dude! This is super clean!

[eduardoandrescastilloperer]

Prior to the video I was aware of this attack but I was shocked at how practical it actually is, it even looked like a magic stick. I thought it needed a somewhat sophisticated lab and days of work