[monocasa]

They're encrypted with a key that's shipped on every processor they ship. A combo of classic espionage and electron microscopes means that we should assume state actors can know the exact mechanism of microcode update changes.

[sillysaurusx]

Thanks! In that case, they seemed to have a good point: if it was an open source CPU, it seems like security might be an issue.

One way to do it: ship security updates using the same technique as intel, and don't release the source code for the fix until much later. I think I remember an open source project doing something similar. But of course, it seems pretty hard to manage that complexity: what if the fix introduces code changes that future commits depend on?

Interesting problem...

[klyrs]

I'm by no means an expert, but open design and verification of secure enclaves seems quite feasible -- keys would differ between different chip makers, I imagine. Folks could write patches, but perhaps not sign them for hardware they own. Though I'd expect most maintainers to work with the community to get bugs fixed.