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A comment on AMD PSB Vendor Locks EPYC CPUs for Enhanced Security at a Cost. Parent comment

Re:AMD PSB Vendor Locks EPYC CPUs for Enhanced Security at a... by caf on Wednesday September 09, 2020 @03:52AM (#24418453)
I don't think this is supposed to secure against someone with physical access.

If they have physical access and are replacing the BIOS, they could just replace the CPU at the same time with a fresh unlocked one that will lock itself to the replacement's signing key on first boot.

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Re:AMD PSB Vendor Locks EPYC CPUs for Enhanced Security at a... by mcosta on Wednesday September 09, 2020 @08:16AM (#24420170)
Can these CPUs sign with its key from software? If they can, then that system can not sign with the original key, and it is trivial to catch it.
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Re:AMD PSB Vendor Locks EPYC CPUs for Enhanced Security at a... by caf on Wednesday September 09, 2020 @08:31PM (#24427630)
The key in question is a public key, it's not a secret. The CPU uses it to verify the BIOS, not the other way around.
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