Are TPM chips really a security threat?

[Pinky665]

Mr. Gibson.

I recently came across a Youtube video claiming that Microsoft is using our systems TPM chip as a tracking tool (and can even prevent you from logging in remotely). It appears very legit by a well respected security researcher, with a very in depth explanation on how it works. I immediately thought of you, and despite listening to the security now podcast religiously, I don't recall this ever coming up as a security threat topic. I would be thrilled to get your take on if we should be concerned about this. Link to video:

Loving my copy of Spinrite 6.1. Keep up the great work that you do.
- Avid Security Now Fan

 

[cschuber]

I saw that video too. That's garbage. The TPM chip produces random numbers (i.e. a nonce), stores crypto hashes (like the private key of a crypto pair). They keys that are stored within it cannot be extracted. An app or O/S must present a key for verification. Typically messages (and disks) are encrypted using a symmetric key (because symmetric keys require less processing (are faster). One would encrypt the symmetric key using a key pair storing the private key in the TPM and maintaining a copy of the public key in the media.

I can't comment about M$'s use of crypto, which the YouTuber has issue with, but various other O/S's, like the *BSDs will use the TPM for its crypto functions and to store a private key.

The TPM is just another piece of hardware that does the bidding of the software running on the machine, just like any other hardware on the machine, with the exception of the IME (Intel Management Engine).

I use TPM emulation software for my Bhyve virtual machines. No sense filling my TPMs with keys from virtual machines which may or may not be ephemeral.

 

[PHolder]

There are truths that feed into that video, but there is also a lot of paranoia I think. Yes, the TPM device DOES store the password for the full disk encryption. Yes Windows does want you to use a MS account during setup so it can "safely" backup the FDE password info into your online account in case your TPM ever gets reset by maintenance. Yes, it is theoretically possible a law authority could request access to your FDE password... one presumes they would only benefit from that if they already had the hardware too. No, the average law abiding person is not going to be affected by any of this. No you are not required to live with any of it, you can take steps to disable FDE, or replace with with something else (VeraCrypt for example), or you can just delete the backup data out of your online account. The results of any "privacy preserving" steps you take are ON YOU... if you lose data, MS is not going to care or support you if you step outside their plan for it.

 

[cschuber]

There are truths that feed into that video, but there is also a lot of paranoia I think. Yes, the TPM device DOES store the password for the full disk encryption. Yes Windows does want you to use a MS account during setup so it can "safely"

No passwords are stored in the TPM. It stores the private key of a key pair. The software would present the public key to enable it to decrypt the data. For example, the public key would be stored for on the encrypted media along with a an encrypted copy of the actual symmetric decryption key. Once the symmetric decryption key is decrypted by the public/private key pair, it is used to decrypt the rest of the drive. This is also how PGP and GPG work.

backup the FDE password info into your online account in case your TPM ever gets reset by maintenance. Yes, it is theoretically possible a law authority could request access to your FDE password... one presumes they would only

Nobody can extract the keys stored in the TPM. The TPM is write-only. Software can present the public key to the TPM in order to decrypt something. The only way the authorities could, in theory, decrypt the drive would be use the TPM to decrypt the data in question. Though, I wouldn't doubt the NSA might know of and have back doors into the TPM, because nothing in this business is totally secure. But in theory they should not be able to.

benefit from that if they already had the hardware too. No, the average law abiding person is not going to be affected by any of this. No you are not required to live with any of it, you can take steps to disable FDE, or replace with with something else (VeraCrypt for example), or you can just delete the backup data out of your online account. The results of any "privacy preserving" steps you take are ON YOU... if you lose data, MS is not going to care or support you if you step outside their plan for it.

Truecrypt and Veracrypt of old use a simple password, i.e. a symmetric key.

Regarding M$, Google, Apple and any other large corporation, we all know how that goes.

 

[PHolder]

Nobody can extract the keys stored in the TPM.

I didn't say they could. The self-same key (which is in essence the FDE password, this is just semantics) is exported into the MS Cloud under your MS Account ID. This is the supposed sole reason for MS demanding you enroll such an account when you're installing Windows, as, in current versions of Windows 11, it automatically enables FDE during install.

BitLocker recovery process

Learn how to obtain BitLocker recovery information for Microsoft Entra joined, Microsoft Entra hybrid joined, and Active Directory joined devices, and how to restore access to a locked drive.

learn.microsoft.com

A recovery key is sensitive information that allows users to unlock an encrypted drive and perform administrative tasks on the drive. For enhanced security, it's recommended to enable self-service in trusted environments only, or rely on helpdesk recovery.

Self-recovery with recovery password
If you have access to the recovery key, enter the 48-digits in the preboot recovery screen.

 

[cschuber]

I didn't say they could. The self-same key (which is in essence the FDE password, this is just semantics) is exported into the MS Cloud under your MS Account ID. This is the supposed sole reason for MS demanding you enroll such an account when you're installing Windows, as, in current versions of Windows 11, it automatically enables FDE during install.

Well, as an IT professional who's done everything from sysadmin to app programming to kernel programming in addition to management of such teams, with more than 50 years of experience, I cannot understand why M$ ties one's account to the cloud when the TPM will do the job by itself. Except for, see below...

BitLocker recovery process

Learn how to obtain BitLocker recovery information for Microsoft Entra joined, Microsoft Entra hybrid joined, and Active Directory joined devices, and how to restore access to a locked drive.

learn.microsoft.com

Continuing from above, storing keys in the cloud a) protects users from themselves because people forget things and b) put's M$ in the drivers seat.

Case in point. The Tarsnap people do not store your key. They have no knowledge of it. Losing or forgetting your key means the loss of all your backed up data. Imagine people forgetting their Bitlocker key when it's needed. M$ would never hear the end of it.

Personally, I'd rather take full responsibility for my security and my keys than trust some other entity. Then again I know my way around. Most people don't. For them it's an appliance just as a lamp is an appliance. It has to work without any thought. This opens up to big tech a huge opportunity. And here we are.

 

[ABSG]

Rob Braxman has been around for a while, and I’ve watched a number of his videos. Some of the topics he covers—like how cellphones function as surveillance tools even when they are "off"—overlap with my own expertise, and there’s definitely truth to those concerns. The challenge with social media, though, is that creators often exaggerate or sensationalize things to drive engagement.

When I first listened to this particular video, it struck me as more of that same overblown commentary in this particular case. But with the recent disclosures about Microsoft allegedly sharing keys with federal agencies, along with BitLocker recovery keys being uploaded to users’ Microsoft accounts by default, it’s hard not to see why people are alarmed. None of this is good news.

 

[ABSG]

Well, as an IT professional who's done everything from sysadmin to app programming to kernel programming in addition to management of such teams, with more than 50 years of experience, I cannot understand why M$ ties one's account to the cloud when the TPM will do the job by itself. Except for, see below...
Continuing from above, storing keys in the cloud a) protects users from themselves because people forget things and b) put's M$ in the drivers seat.

Case in point. The Tarsnap people do not store your key. They have no knowledge of it. Losing or forgetting your key means the loss of all your backed up data. Imagine people forgetting their Bitlocker key when it's needed. M$ would never hear the end of it.

Personally, I'd rather take full responsibility for my security and my keys than trust some other entity. Then again I know my way around. Most people don't. For them it's an appliance just as a lamp is an appliance. It has to work without any thought. This opens up to big tech a huge opportunity. And here we are.

Yes! Agree! This is why I am moving to Linux in 2026-2027. FREEDOM as Free from M$! Free to NOT be linked to the Cloud. Free to loose my data! Free to not have third party have keys to my encrypted data--can we say One Drive?!?!

When I was oh so young and starting with NT 3.51 I thought this was the second best OS next VAX VMS.

 

[cschuber]

Yes! Agree! This is why I am moving to Linux in 2026-2027. FREEDOM as Free from M$! Free to NOT be linked to the Cloud. Free to loose my data! Free to not have third party have keys to my encrypted data--can we say One Drive?!?!

When I was oh so young and starting with NT 3.51 I thought this was the second best OS next VAX VMS.

You know, Dave Cutler, the VMS architect, also built NT.

 

[ABSG]

You know, Dave Cutler, the VMS architect, also built NT.

Thanks. Yes, That was the most very FUN of times! I was very active in DECUS from 1984 to about 1992 and eventually was the Chairperson of GAP SIG.

DEC and M$ jointly(?) developed Pathworks for VAX VMS, aka Windows File Sharing such that a VAX could even be a DC in the early NT days!

As a youngen I did not realize I was watching the History of Computing opening before me.

I worked for a regional Bank and at the time that had a room full of VAXen -- I designed the computer room that initially housed two VAXen. By the time I left we had a very large six node Cluster with what you would call a RAID Array -- across 8 small refrigerator looking devices. We also were one of a few beta testers that received a DECnet 8 Port Serial Terminals over Ethernet Coax ThickNet devices. Also, after the AT&T break-up we could get T1s then we converted everything over to Reverse Terminal Servers.

One of the top secrets at the time, was DEC was working on Alpha CPU a 64‑bit RISC Chip which broke the the 1GHz barrier by ~1992--before any one else. Most of the DEC Silicon Technology was ultimately purchased by Intel making Intel what it is TODAY. This was the roots of Intel’s Itanium project. DEC also had their own StrongARM which became Intel XScale which was sold onto Marvel. If Intel had only saw the future and gone Alpha RISC or ARM--they had it in their hands?!?! Ultimately what a History--what could have been!?!?!

Now adays we just plug into an Ethernet Port of one kind or another for most everything. I've been working on 25GBps Fiber as of late which is now considered SLOW!

 

[PHolder]

VAX VMS

When I was a student in high school I worked for a company that had a fairly large DECNET footprint, something like 20 or so VAXen. In my 2nd work term (I did two summers in high school) I was entrusted to be in the server room on a weekend applying an update to one of the VAXes. I remember I was listening to the soundtrack to Beverly Hills Cop2, which had just come out, on my Walkman. (So I guess that places it around 1987?) I remember feeling pretty special to be so trusted, when they had university students that also worked in my department... but probably I was just the cheapest trustworthy labour Anyway, the upside was that my access in the building (by mag-swipe card) got upgraded, and never got downgraded, so for all the years that I continued to work there in university I had the run of the place

 

[GreenWine]

I did not watch the video but as far as tracking goes, can the OS get the tpm serial number? If so, then they could build a database of every user account and their associated tpm serial numbers across each device they use their Microsoft account on. Not the biggest privacy invasion but if they can, why wouldn't they.