6 ms·

Unfortunately this sounds like a typical pro-Linux rant with the usual scare words such as "Microsoft", "UEFI", "secure boot", etc. To be clear, I am attacking

Unfortunately this sounds like a typical pro-Linux rant with the usual scare words such as "Microsoft", "UEFI", "secure boot", etc. To be clear, I am attacking the piece itself, not the author. The reason there is no explicit threat model defined in the TPM specs is because it defines a general-purpose hardware security module. It is up to integrator to define the threat model (TPM's security properties also depend on the rest of the system) and the application. Even if a TPM is not perfect and depends on other pieces of the puzzle to also be secure, it at least opens the possibility of making it secure in the future once those vulnerabilities are discovered & fixed. Furthermore, even in this vulnerable state, it still increases the effort required for a successful attack. Support for TPM-backed full disk encryption means you can now have FDE on by default for everyone with no usability impact at all. Even if it's not secure and a dedicated attack will still break it, it means a casual attacker can't just pull a drive or reboot the machine and run chntpw or steal sensitive data from discarded drives that haven't been properly wiped. I like TPMs. I like the fact that a rogue datacenter employee or intruder can't just pull one of my servers' drives out and get sensitive data. I like not having to worry about having sensitive keys on the filesystem somewhere because every secret is in memory and is ultimately derived from the TPM doing remote attestation at boot and handing ephemeral keys. I like not having to worry about unattended reboots or entering LUKS passphrases remotely.

xinayder 3y ago
I might be a bit ignorant towards the topic but so far everything I've seen about TPM has no actual benefits for the home user. For cloud, sure, there are benefits. It seems like it's a sunken cost fallacy that big tech spent a lot of money on and they are trying to get it back by convincing average Joe that a TPM is good for your PC.
- als0 3y ago
  Home users take their PC to airports, hostels and cafes. Criminals who break into homes steal laptops. Of course there are benefits.
sim7c00 3y ago
you are right that tpm and such technologies are a right step, you have to start somewhere. (i know it didnt start at tpm ofcourse). The author is also right that some claims are too markety while in the real world device are still vulnerable. The piece also goes on to say theres further efforts such as TXT etc. taking place, so in essence for me it reads like you mostely agree. microsoft, uefi etc. arent scare words here imho, they are very closely related to claims made and technologies involved. I thought the piece was ok, but it doesnt add anything new. its another piece pointing at the puzzle a lot of people including you already know exists. its not aimed at you for that matter. (so fair comments, but perhaps a bit harsh?)
candiddevmike 3y ago
What's the point of TPM-backed full disk encryption with no usability impact (meaning password/pin-less) for the average user who is more likely to get their device stolen vs some covert disk image shenanigan?
- riedel 3y ago
  Why go pin less? I like the fact that the TPM can restrict retry counts and I do not need a rediculously long password. The only thing I do not get is why this is not done by a simple SIM card like in any mobile phone. Then one could choose a TPM. Even more: I do not get why I cannot encrypt my android phone with my SIM card.
  - lostmsu 3y ago
    I have many machines, some headless.
- Nextgrid 3y ago
  If the device is stolen it can still enforce OS-level authentication (including potentially phoning home, invalidating its access to remote resources, or erasing itself), except now you can't bypass it by rebooting and running chntpw. Will this stop a dedicated attacker? Probably not, although a fTPM with an up to date OS would require the attacker to find an exploit for this machine's early boot firmware (UEFI, etc) or burn a Windows zero-day, both of which are very costly. It does however prevent your casual thief from watching a YT video "how to reset windows password using linux live cd" and then getting access to your sensitive data (browser's saved passwords, etc), so it's a major improvement.
  - vlovich123 3y ago
    I prefer to require entering a master password on boot manually and then configuring the OS to auto login to my non root user (with a different password than the disk). The longer and more complex your dependency chain for security, the more opportunity for it to be compromised. The encrypted “password on boot” partition then contains the keys to mount the other disks. I’d really like Apple’s model on my machine where the root image is just the stock OS image unencrypted and the co-processor owns the responsibility of managing IO (and done efficiently) using my master key. TPM seems like it misses the mark from that perspective.
hooverd 3y ago
While that's a very good use case, the desired one where you're not allowed to use the Internet unless you're using a big three approved device that can attest you're not using an ad blocker isn't so much.
- md_ 3y ago
  A core argument the post makes is that TPMs are insufficient for verifying full stack integrity and thus ineffective for FDE. (Eg by exploiting vulnerable drivers, an attacker can dump the disk encryption key from kernel memory.) But in such a scenario, an attacker can also use such an attack to bypass any remote attestation/DRM/etc! I guess you could argue that such attacks are too much work for consumers, and that low fences control big dumb animals…but I think, fundamentally, the same argument applies to consumer security functions like FDE! Tl;dr: I think it’s hard to argue that TPMs are both useless for practical user security and a threat to free computing. It’s gotta be one or the other!
- Nextgrid 3y ago
  > he desired one where you're not allowed to use the Internet unless you're using a big three approved device that can attest you're not using an ad blocker isn't so much. There's no reason to believe this will require a TPM or depend on the presence of one. As far as I know, Widewine and similar DRM schemes successfully achieved this without any hardware assistance. Yes, bypasses exist and all the major piracy groups have them, but the objective of preventing the masses from having access to a working bypass is clearly achieved and doesn't require hardware.
  - lxgr 3y ago
    > Widewine and similar DRM schemes successfully achieved this Do you have any references to back that statement up? Software-only DRMs are ultimately always either plain obfuscation or some variant of white-box cryptography, which is also anything but proven to actually work.
  - sudosysgen 3y ago
    Widevine and other schemes are trivially defeated as far as manipulating the results of what you see on the screen. The best they've been able to do is sometimes protect the compressed original stream, but they also routinely fail at that, and that's not the kind of security that can defeat an adblocker. The kind of security you're talking about would require some kind of TPM-like solution to attest you're running approved software and don't have root.
osy 3y ago
> This sounds like the rant of a typical Linux fanboy Hi, it's me the Linux fanboy whose entire personality is making Hackintosh and VM apps for iOS. Just a friendly reminder that attacks on the author's credentials have no baring on the weight of the arguments. > The reason there is no explicit threat model defined in the TPM specs is because it defines a general-purpose hardware security module It sounds like you have zero experience in security :) > it defines a general-purpose hardware security module No it doesn't. I think you're hinting at HSM which is another beast I may write another fanboy FUD piece about at some point. But no, HSMs are not the same as TPMs. And TPMs are not HSMs. For one thing, and HSM defines something called a trust boundary where keys should never leave. TPMs will happily hand you the keys when you meet a certain condition. HSMs support key migration and provides a secure way to transfer keys from one HSM to another without leaving the trust boundary. I can go on and on... > TPM's security properties also depend on the rest of the system The argument isn't TPM versus no security. The argument is TPM versus the existing security you have on Windows. (Passwords, FDE, etc). Of course all this depends on the system. TPM doesn't add anything (* with the exception already listed in the article). > it at least opens the possibility of making it secure in the future once those vulnerabilities are discovered & fixed Nope. Architecturally flawed. But I'd just be repeating the argument from the article. > means a casual attacker can't just pull a drive or reboot the machine and run chntpw or steal sensitive data from discarded drives that haven't been properly wiped They can with a $80 FPGA. Read the appendix. > I like the fact that a rogue datacenter employee or intruder can't just pull one of my servers' drives out and get sensitive data. They can with a $80 FPGA. (Unless your datacenter uses Intel TXT and tboot and other prerequisites that were talked about in the article) > I like not having to worry about having sensitive keys on the filesystem somewhere If you use BitLocker, they are always in kernel memory > derived from the TPM doing remote attestation at boot That's not what "remote attestation" means :) > I like not having to worry about unattended reboots or entering LUKS passphrases remotely If you like that, just disable your password and you'll get the same result
- lxgr 3y ago
  > Just a friendly reminder that attacks on the author's credentials have no baring on the weight of the arguments. > It sounds like you have zero experience in security :) Seems like you're countering an ad hominem with an ad hominem here...? I don't know the TPM specifications in detail myself, but I do know that TPMs are in fact quite general-purpose HSMs, of which assisting in attestation/measurements for the purpose of trusted computing is only one (although certainly the most controversial) subfeature. If I can store my SSH keys on my TPM and just don't use trusted computing at all... How is that "zero practical security"?
alerighi 3y ago
There are two issues. One is a false sense of security. You think that you have the same level of security of a full disk encryption, but you don't. On a full disk encryption only who knows the password can access your data. On this system the disk is automatically decrypted at boot, so any flaw in Windows that permits a privilege escalation done by that PC can give access to your data. If somebody that wants your data steals your PC he will be likely to find a way to access your personal data. It's a protection against a casual thief that is probably not interested in your data and can't probably even figure out how to bypass the Windows password screen. But if this doesn't make harm, why not have it? Because having disk encryption enabled by default to a user that doesn't know that is enabled by default is not necessary a good thing. Let's face it: users don't do backups. I know even companies that have all their data on a single server with no backups. Now if the motherboard breaks and you don't have backup... you can't just take the disk out of that computer, connect to another PC and recover the data. You have lost your data! But wait, you say Microsoft tought about that, indeed if you signed in with a Microsoft account you can recover your Bitlocker encryption key from the Microsoft portal... wait what? Exactly. No security at all! Microsoft knows your encryption keys and it stores it on their servers... again: false sense of security is worse than no security at all! Finally, even if this system was 100% secure: do you trust the hardware? The same hardware produced by the same manufacturer of the products where nearly once in a year a big security flaw is discovered? The same hardware where we know that the NSA, and probably other government agencies, placed backdoors? Whatever, typing a password when booting up the computer (that is once in a day) is such a big deal?
- dist-epoch 3y ago
  > indeed if you signed in with a Microsoft account you can recover your Bitlocker encryption key from the Microsoft portal. ... No security at all! Microsoft knows your encryption keys and it stores it on their servers. This is complete disinformation. Microsoft gives you the OPT-IN OPTION to save your Bitlocker encryption key to your account. It's clearly labeled and you need to click on it to activate it: https://allthings.how/content/images/wordpress/2021/11/allthings.how-what-is-bitlocker-recovery-and-how-to-find-the-recovery-key-on-windows-11-image-13.png https://allthings.how/content/images/wordpress/2021/11/allth...
- 3y ago
cm2187 3y ago
Likewise, I am not too concerned about the NSA breaking into my laptop. I just want that if some kid finds it and tries to plug the SSD into his computer, my files aren't all there to be read.
mixmastamyk 3y ago
This "middle-brow dismissal" should be downvoted and flagged on the first sentence alone. Not be the top comment. The datacenter use case sounds useful—should have led with that.
- Nextgrid 3y ago
  I've edited my comment to hopefully clarify that I am talking about the piece and not accusing the author himself. My problem with the piece is that it reads like the usual knee-jerk pro-Linux FUD that typically originates around scare words like "Microsoft", "secure boot" and "UEFI".
  - mixmastamyk 3y ago
    I didn’t read it that way. Was spirited, but no insults that I noticed. And it’s not like those “scare words” didn’t become scary for a reason. Your response starts with reverse FUD.

xinayder 3y ago

I might be a bit ignorant towards the topic but so far everything I've seen about TPM has no actual benefits for the home user. For cloud, sure, there are benefits. It seems like it's a sunken cost fallacy that big tech spent a lot of money on and they are trying to get it back by convincing average Joe that a TPM is good for your PC.

als0 3y ago
Home users take their PC to airports, hostels and cafes. Criminals who break into homes steal laptops. Of course there are benefits.

sim7c00 3y ago

you are right that tpm and such technologies are a right step, you have to start somewhere. (i know it didnt start at tpm ofcourse). The author is also right that some claims are too markety while in the real world device are still vulnerable. The piece also goes on to say theres further efforts such as TXT etc. taking place, so in essence for me it reads like you mostely agree. microsoft, uefi etc. arent scare words here imho, they are very closely related to claims made and technologies involved. I thought the piece was ok, but it doesnt add anything new. its another piece pointing at the puzzle a lot of people including you already know exists. its not aimed at you for that matter. (so fair comments, but perhaps a bit harsh?)

candiddevmike 3y ago

What's the point of TPM-backed full disk encryption with no usability impact (meaning password/pin-less) for the average user who is more likely to get their device stolen vs some covert disk image shenanigan?

riedel 3y ago
Why go pin less? I like the fact that the TPM can restrict retry counts and I do not need a rediculously long password. The only thing I do not get is why this is not done by a simple SIM card like in any mobile phone. Then one could choose a TPM. Even more: I do not get why I cannot encrypt my android phone with my SIM card.
- lostmsu 3y ago
  I have many machines, some headless.
Nextgrid 3y ago
If the device is stolen it can still enforce OS-level authentication (including potentially phoning home, invalidating its access to remote resources, or erasing itself), except now you can't bypass it by rebooting and running chntpw. Will this stop a dedicated attacker? Probably not, although a fTPM with an up to date OS would require the attacker to find an exploit for this machine's early boot firmware (UEFI, etc) or burn a Windows zero-day, both of which are very costly. It does however prevent your casual thief from watching a YT video "how to reset windows password using linux live cd" and then getting access to your sensitive data (browser's saved passwords, etc), so it's a major improvement.
- vlovich123 3y ago
  I prefer to require entering a master password on boot manually and then configuring the OS to auto login to my non root user (with a different password than the disk). The longer and more complex your dependency chain for security, the more opportunity for it to be compromised. The encrypted “password on boot” partition then contains the keys to mount the other disks. I’d really like Apple’s model on my machine where the root image is just the stock OS image unencrypted and the co-processor owns the responsibility of managing IO (and done efficiently) using my master key. TPM seems like it misses the mark from that perspective.

hooverd 3y ago

While that's a very good use case, the desired one where you're not allowed to use the Internet unless you're using a big three approved device that can attest you're not using an ad blocker isn't so much.

md_ 3y ago
A core argument the post makes is that TPMs are insufficient for verifying full stack integrity and thus ineffective for FDE. (Eg by exploiting vulnerable drivers, an attacker can dump the disk encryption key from kernel memory.) But in such a scenario, an attacker can also use such an attack to bypass any remote attestation/DRM/etc! I guess you could argue that such attacks are too much work for consumers, and that low fences control big dumb animals…but I think, fundamentally, the same argument applies to consumer security functions like FDE! Tl;dr: I think it’s hard to argue that TPMs are both useless for practical user security and a threat to free computing. It’s gotta be one or the other!
Nextgrid 3y ago
> he desired one where you're not allowed to use the Internet unless you're using a big three approved device that can attest you're not using an ad blocker isn't so much. There's no reason to believe this will require a TPM or depend on the presence of one. As far as I know, Widewine and similar DRM schemes successfully achieved this without any hardware assistance. Yes, bypasses exist and all the major piracy groups have them, but the objective of preventing the masses from having access to a working bypass is clearly achieved and doesn't require hardware.
- lxgr 3y ago
  > Widewine and similar DRM schemes successfully achieved this Do you have any references to back that statement up? Software-only DRMs are ultimately always either plain obfuscation or some variant of white-box cryptography, which is also anything but proven to actually work.
- sudosysgen 3y ago
  Widevine and other schemes are trivially defeated as far as manipulating the results of what you see on the screen. The best they've been able to do is sometimes protect the compressed original stream, but they also routinely fail at that, and that's not the kind of security that can defeat an adblocker. The kind of security you're talking about would require some kind of TPM-like solution to attest you're running approved software and don't have root.

osy 3y ago

> This sounds like the rant of a typical Linux fanboy Hi, it's me the Linux fanboy whose entire personality is making Hackintosh and VM apps for iOS. Just a friendly reminder that attacks on the author's credentials have no baring on the weight of the arguments. > The reason there is no explicit threat model defined in the TPM specs is because it defines a general-purpose hardware security module It sounds like you have zero experience in security :) > it defines a general-purpose hardware security module No it doesn't. I think you're hinting at HSM which is another beast I may write another fanboy FUD piece about at some point. But no, HSMs are not the same as TPMs. And TPMs are not HSMs. For one thing, and HSM defines something called a trust boundary where keys should never leave. TPMs will happily hand you the keys when you meet a certain condition. HSMs support key migration and provides a secure way to transfer keys from one HSM to another without leaving the trust boundary. I can go on and on... > TPM's security properties also depend on the rest of the system The argument isn't TPM versus no security. The argument is TPM versus the existing security you have on Windows. (Passwords, FDE, etc). Of course all this depends on the system. TPM doesn't add anything (* with the exception already listed in the article). > it at least opens the possibility of making it secure in the future once those vulnerabilities are discovered & fixed Nope. Architecturally flawed. But I'd just be repeating the argument from the article. > means a casual attacker can't just pull a drive or reboot the machine and run chntpw or steal sensitive data from discarded drives that haven't been properly wiped They can with a $80 FPGA. Read the appendix. > I like the fact that a rogue datacenter employee or intruder can't just pull one of my servers' drives out and get sensitive data. They can with a $80 FPGA. (Unless your datacenter uses Intel TXT and tboot and other prerequisites that were talked about in the article) > I like not having to worry about having sensitive keys on the filesystem somewhere If you use BitLocker, they are always in kernel memory > derived from the TPM doing remote attestation at boot That's not what "remote attestation" means :) > I like not having to worry about unattended reboots or entering LUKS passphrases remotely If you like that, just disable your password and you'll get the same result

lxgr 3y ago
> Just a friendly reminder that attacks on the author's credentials have no baring on the weight of the arguments. > It sounds like you have zero experience in security :) Seems like you're countering an ad hominem with an ad hominem here...? I don't know the TPM specifications in detail myself, but I do know that TPMs are in fact quite general-purpose HSMs, of which assisting in attestation/measurements for the purpose of trusted computing is only one (although certainly the most controversial) subfeature. If I can store my SSH keys on my TPM and just don't use trusted computing at all... How is that "zero practical security"?

alerighi 3y ago

There are two issues. One is a false sense of security. You think that you have the same level of security of a full disk encryption, but you don't. On a full disk encryption only who knows the password can access your data. On this system the disk is automatically decrypted at boot, so any flaw in Windows that permits a privilege escalation done by that PC can give access to your data. If somebody that wants your data steals your PC he will be likely to find a way to access your personal data. It's a protection against a casual thief that is probably not interested in your data and can't probably even figure out how to bypass the Windows password screen. But if this doesn't make harm, why not have it? Because having disk encryption enabled by default to a user that doesn't know that is enabled by default is not necessary a good thing. Let's face it: users don't do backups. I know even companies that have all their data on a single server with no backups. Now if the motherboard breaks and you don't have backup... you can't just take the disk out of that computer, connect to another PC and recover the data. You have lost your data! But wait, you say Microsoft tought about that, indeed if you signed in with a Microsoft account you can recover your Bitlocker encryption key from the Microsoft portal... wait what? Exactly. No security at all! Microsoft knows your encryption keys and it stores it on their servers... again: false sense of security is worse than no security at all! Finally, even if this system was 100% secure: do you trust the hardware? The same hardware produced by the same manufacturer of the products where nearly once in a year a big security flaw is discovered? The same hardware where we know that the NSA, and probably other government agencies, placed backdoors? Whatever, typing a password when booting up the computer (that is once in a day) is such a big deal?

dist-epoch 3y ago
> indeed if you signed in with a Microsoft account you can recover your Bitlocker encryption key from the Microsoft portal. ... No security at all! Microsoft knows your encryption keys and it stores it on their servers. This is complete disinformation. Microsoft gives you the OPT-IN OPTION to save your Bitlocker encryption key to your account. It's clearly labeled and you need to click on it to activate it: https://allthings.how/content/images/wordpress/2021/11/allthings.how-what-is-bitlocker-recovery-and-how-to-find-the-recovery-key-on-windows-11-image-13.png https://allthings.how/content/images/wordpress/2021/11/allth...
3y ago

cm2187 3y ago

Likewise, I am not too concerned about the NSA breaking into my laptop. I just want that if some kid finds it and tries to plug the SSD into his computer, my files aren't all there to be read.

mixmastamyk 3y ago

This "middle-brow dismissal" should be downvoted and flagged on the first sentence alone. Not be the top comment. The datacenter use case sounds useful—should have led with that.

Nextgrid 3y ago
I've edited my comment to hopefully clarify that I am talking about the piece and not accusing the author himself. My problem with the piece is that it reads like the usual knee-jerk pro-Linux FUD that typically originates around scare words like "Microsoft", "secure boot" and "UEFI".
- mixmastamyk 3y ago
  I didn’t read it that way. Was spirited, but no insults that I noticed. And it’s not like those “scare words” didn’t become scary for a reason. Your response starts with reverse FUD.