faulTPM: Exposing AMD fTPMs' Deepest Secrets

Post by antegamisou » Tue, May 02, 2023, 3:08 PM UTC

netheril96 wrote: post #26

drakythe wrote: post #17

Earlier quoted context omitted.

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.

Post by hoffs » Tue, May 02, 2023, 3:11 PM UTC

bo1024 wrote: post #44

cwerling wrote: post #18

Earlier quoted context omitted.

One of the authors here. This attack is relevant if your machine is physically exposed to attacks, e.g., in an office environment or while traveling, and if you don't use any additional pre-boot passphrase to protect the disk (but rely solely on AMD's fTPM). When TPMs became popular, dedicated TPMs were mainly used, being a separate chip on the mainboard connected via the SPI or LPC bus. These were prone to (relative…

This is important because one purpose of TPMs is to prevent the owner of the machine from doing certain things (as in Digital Rights Management). And the owner of the machine presumably has physical access.

Post by dathinab » Tue, May 02, 2023, 3:12 PM UTC

taraharris wrote: post #13

Why not simply abandon TPM and focus on making simple, trustable, massively parallel general-purpose hardware without backdoors for spy agencies and corporations? Whose computer is this, anyway?

Post by als0 » Tue, May 02, 2023, 3:15 PM UTC

mastax wrote: post #36

salawat wrote: post #22

Earlier quoted context omitted.

ARM that are microsoft certified will specifically not give you that option. You are probably largely using x86_64 which come with the option to do so, but there has been a lot of push around moving to things like ARM for energy efficiency reasons.

> there has been a lot of push around moving to things like ARM for energy efficiency reasons There has? Where? Specifically for Windows PCs, not chromebooks or apples.

Post by Mindwipe » Tue, May 02, 2023, 3:24 PM UTC

bo1024 wrote: post #44

cwerling wrote: post #18

Earlier quoted context omitted.

One of the authors here. This attack is relevant if your machine is physically exposed to attacks, e.g., in an office environment or while traveling, and if you don't use any additional pre-boot passphrase to protect the disk (but rely solely on AMD's fTPM). When TPMs became popular, dedicated TPMs were mainly used, being a separate chip on the mainboard connected via the SPI or LPC bus. These were prone to (relative…

This is important because one purpose of TPMs is to prevent the owner of the machine from doing certain things (as in Digital Rights Management). And the owner of the machine presumably has physical access.