[confounded]

The author’s writing style makes them a little difficult to follow, but the details I can find seem to check out.

Does anyone know which Google/ChromeOS features this chip is used for, or what the justification for it is?

[puzzle]

It's the new TPM? The old one had a (now patched) firmware bug, which newer Chromebooks like the Pixelbook don't seem to be vulnerable to:

https://www.chromium.org/chromium-os/tpm_firmware_update

Edit: this is what Chrome devices use it for https://www.chromium.org/developers/design-documents/tpm-usa...

[asciilifeform]

Cr50 has replaced the old Infineon TPM, which the above link concerns.

[duskwuff]

Seriously. The hardware aspects are interesting, but the author's insistence on interpreting the situation as some sort of grand conspiracy theory, and using derogatory terms like "open sores" at every opportunity, makes the article nigh-unreadable.

[puzzle]

Beyond the rethoric, the substance is not very different from RMS' arguments against TPMs, which must be some 15 years old now. You'll have a hard time buying a device today without such a chip.

[pgeorgi]

I think it's worth noting that the TPM plans of 2003 differ a bit from TPM-as-of-2018.

What was called Trusted Computing, Palladium, TCPA, etc. in 2003 and became known in geek circles as "TPM" is now implemented as TPM + Intel Boot Guard + Intel SGX + Authenticated Code Modules + various other things (and other vendors' equivalents).

The TPM is the most benign part of it all: a slow, passive crypto chip with a small storage that it can hide away from the CPU unless the right system state and keys are presented (although the presented system state might be 100% fake).

[asciilifeform]

The Cr50 does not limit itself to user key storage.

It turns the USB-C ports into always-on NSA-keyed backdoors (anyone in possession of the private RSA key, can reflash all three flash ROMs in the machine with whatever he likes, via the external ports, which cannot even be cemented shut, as the machine charges exclusively from USB-C.)

[asciilifeform]

Cr50 is quite different from the Infineon et al TPM item commonly found in x86 boxes. It is able to rewrite AP and EC firmware, overriding the advertised write-protect feature; access the microphone; etc.

No reason to take my word for it: I recommend to read Google's source, I have linked to the most interesting routines.