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I'd been searching for a while to try and learn something about the microcode updates - what they did etc. No wonder I didn't find much, Intel have them locked

I'd been searching for a while to try and learn something about the microcode updates - what they did etc. No wonder I didn't find much, Intel have them locked up very tightly. Fantastic reading.

userbinator 12y ago
Intel have them locked up very tightly. Not surprising, because of all the implications that bad microcode updates could have (and some of the DRM technology in newer models, like TxT, also relies on microcode); I've heard rumours that no single person at Intel has knowledge of the entire microcode update mechanism. There's probably several layers of obfuscation applied too, and despite there being very good evidence that e.g. RSA-2048 or some hash function is used, it's possible that it was deliberately a diversion from the actual checking that goes on. Transistors are cheap enough to Intel that embedding a complete separate CPU core inside (with a different architecture) to do things like this would be very easy. On the other hand, I wonder how much government agencies know about this mechanism and ways they can make use of it; reverse-engineering the actual process from inspection of the die might take so long that it would never be practical. This is really security through obscurity, but it looks like Intel is betting on processors being so large and complex (and superseded relatively quickly) that reverse-engineering becomes infeasible.
- Igglyboo 12y ago
  Who would even have the knowledge to reverse engineer something like a modern intel processor other than ex-intel engineers? Would they even be able to do it in a reasonable timeframe(<5 years)?
  - ianlevesque 12y ago
    The people hacking the Intel engineers' computers.
  - AlyssaRowan 12y ago
    Yes, there are a few people: I could not do it myself but I've worked with one or two who definitely could. You very probably cannot afford them, or their labs. And I doubt they would want to post or share their results openly, so though I am curious, I do not think I shall ask. Why would someone? Perhaps a competitor wants to know if their design is being ripped off, or if a patent is being violated? Perhaps it is for other reasons sometimes. One simply does not ask about clientèle, you understand. I gather it is mostly incremental work: as vendors seldom do from-scratch redesigns, most of the reversing is not from-scratch either.

I'd been searching for a while to try and learn something about the microcode updates - what they did etc. No wonder I didn't find much, Intel have them locked up very tightly. Fantastic reading.

userbinator 12y ago

Intel have them locked up very tightly. Not surprising, because of all the implications that bad microcode updates could have (and some of the DRM technology in newer models, like TxT, also relies on microcode); I've heard rumours that no single person at Intel has knowledge of the entire microcode update mechanism. There's probably several layers of obfuscation applied too, and despite there being very good evidence that e.g. RSA-2048 or some hash function is used, it's possible that it was deliberately a diversion from the actual checking that goes on. Transistors are cheap enough to Intel that embedding a complete separate CPU core inside (with a different architecture) to do things like this would be very easy. On the other hand, I wonder how much government agencies know about this mechanism and ways they can make use of it; reverse-engineering the actual process from inspection of the die might take so long that it would never be practical. This is really security through obscurity, but it looks like Intel is betting on processors being so large and complex (and superseded relatively quickly) that reverse-engineering becomes infeasible.

Igglyboo 12y ago
Who would even have the knowledge to reverse engineer something like a modern intel processor other than ex-intel engineers? Would they even be able to do it in a reasonable timeframe(<5 years)?
- ianlevesque 12y ago
  The people hacking the Intel engineers' computers.
- AlyssaRowan 12y ago
  Yes, there are a few people: I could not do it myself but I've worked with one or two who definitely could. You very probably cannot afford them, or their labs. And I doubt they would want to post or share their results openly, so though I am curious, I do not think I shall ask. Why would someone? Perhaps a competitor wants to know if their design is being ripped off, or if a patent is being violated? Perhaps it is for other reasons sometimes. One simply does not ask about clientèle, you understand. I gather it is mostly incremental work: as vendors seldom do from-scratch redesigns, most of the reversing is not from-scratch either.