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PlayStation 3 hack - how it happened and what it means (The Guardian)

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 8, 2011 20:24 UTC (Sat) by dlang (✭ supporter ✭, #313)
In reply to: PlayStation 3 hack - how it happened and what it means (The Guardian) by Cyberax
Parent article: PlayStation 3 hack - how it happened and what it means (The Guardian)

no they don't

look at the tivo, it implemented TPM (signed bootloader, signed firmware, signed kernel, signed userspace) I've had mine hacked for over 10 years.


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PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 8, 2011 20:27 UTC (Sat) by Cyberax (✭ supporter ✭, #52523) [Link]

That's not TPM (aka Trusted Platform Module).

TPMs are hardware modules that can do signature validation and decryption. http://en.wikipedia.org/wiki/Trusted_Platform_Module

Working _around_ TPM is not a "TPM hack".

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 8, 2011 22:53 UTC (Sat) by dlang (✭ supporter ✭, #313) [Link]

on my tivo, what actually happens is the bios gets re-written to disable the TPM features.

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 9, 2011 0:30 UTC (Sun) by Cyberax (✭ supporter ✭, #52523) [Link]

Yep. That's "working around" TPM, it's certainly doable.

However, imagine now that you need TPM to decrypt the video stream and TPM module is built into the CPU. What are you going to do?

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 9, 2011 0:40 UTC (Sun) by dlang (✭ supporter ✭, #313) [Link]

that's a different definition of TPM than I am familar with.

TPM as i understand it concentrates of making sure that the system is running only 'good' software, by having the hardware validate the bootloader, the bootloader validate the kernel, etc. This chains the trust of the hardware up to the software.

using a piece of hardware to do the decryption of content does not seem to fall into this category.

having a piece of hardware that is locked down that does the decryption with the intent of preventing the user from accessing the content otherwise seems to fall in the definition of DRM.

TPM can be used to lock down a device that then implements DRM, but they are separate types of tools.

forgive me for being a bit pedantic here, but I believe that it is important to keep the definitions straight.

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 9, 2011 1:16 UTC (Sun) by foom (subscriber, #14868) [Link]

Yes, but the TPM could have "sealed" the keys the video is encrypted by, thus making you unable to decrypt your videos without the TPM enabled (and having verified your Tivo as running only "good" software).

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 9, 2011 6:27 UTC (Sun) by dlang (✭ supporter ✭, #313) [Link]

where could TPM have these 'sealed' keys? they can't be in the hardware (especially if that can't be modified after manufacture)

if they are in the software they are accessable, if by no other means than by letting it get decoded and then reading the ram directly.

PlayStation 3 hack - how it happened and what it means (The Guardian)

Posted Jan 9, 2011 9:47 UTC (Sun) by Cyberax (✭ supporter ✭, #52523) [Link]

>where could TPM have these 'sealed' keys? they can't be in the hardware (especially if that can't be modified after manufacture)

In the changeable part of internal memory. It's not like TPMs are _completely_ immutable.

>if they are in the software they are accessable, if by no other means than by letting it get decoded and then reading the ram directly.

They are not in software.

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