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Comment by goolz | Hacker News Reader

To anyone with a bit more breadth on this topic: is this as terrible as it sounds or more just in the realm of academia and nation-states?

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TPM based disk encryption is mostly useful as theft protection, so that companies, education facilities or government agencies can provision 100,000 devices without having to match smartcards/fobs/disk passwords to devices and users. (Which often leads to terrible security practices, like backup passwords shared between devices etc.)

So cracking it in 3 hours by amateurs is pretty bad, because now even not too sophisticated thieves can start looking for crypto wallets or sensitive data to ransom.

> Bitlocker's TPM- only protector - can be defeated by an attacker with 2-3 hours of physical access to the target device

That sounds pretty practical.

Indeed it does, and this is just done by a team of researchers. Imagine what the NSA and their goons could get up to with 1000x more resources.

This is why you need to evaluate your threat model. Is the NSA out to get you? If so, I hope you aren't relying on HN for your security strategy. Are you worried about theft? Add a passphrase to your encrypted volume and don't rely on TPM. Worried about your coworker or family snooping on your computer and seeing your emails to your mistress? TPM is fine.

Well, considering I am 008, my threat model is quite high indeed! But ya, I was being hyperbolic. And HN has provided plenty of worthwhile info on the topic of OpSec over the years, do not be quick to discount. I would be a fool to reveal too much about my threat model but the reality is there exist many people who have reason to fear the NSA. Am I one of them? Nice try, NSA!

The popularity of hyperbole in HN discussions makes it easier for people to discount HN, both in drowning out useful information and in weakening discourse. Please reconsider in the future.

Perhaps, a counterpoint, the popularity of patronizing comments on HN make it... well, easy to discount what is actually quite good advice. Reconsider?

Not an expert, but I think the biggest exposure most consumers might face is lost/stolen devices where it's conceivable an adversary could have physical access.

They have a voltage fault injection attack on the SP. That's game over, never mind the fTPM.

Mostly academia and nation states. Physical access will always be king and this provides one more avenue for adversaries to bypass encryption more easily.

> Physical access will always be king

No. Your wording suggests that once attackers gain physical access, all is lost. It is not true. With a passphrase based full disk encryption, if the passphrase is strong and the machine is powered off, physical access doesn't imply data access.

You still have to defend against cold boot attacks or very sophisticated hardware implants:

https://www.bloomberg.com/news/features/2018-10-04/the-big-h...

Attach a microphone to the device while they are not looking, decode the keys they are pressing from the sounds, figure out what keys are the password, done.

This is _trivial_ for any mildly sophisticated attacker.

You don't even need to attach it, other placements are sufficient as well. An example of how an attack can be performed: <https://github.com/shoyo/acoustic-keylogger>

Room bugged = keyboard keylogged

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