Expert Says NSA Have Backdoors Built Into Intel And AMD Processors

[joshcryer]

16. A backdoor can be discovered, but non-trivially.

Several ways:

1) If Intel is in on it, then you'd have to compare CPU operation of CPUs whose microcode is updated and who has its microcode off. You should be able to reverse engineer what the microcode is doing by running an instruction set test suite. This would at least tell you what is broken and what it is intending to fix. If you find something broken you can write your own software side work arounds, which while they won't be microcode level, at least then you have a working CPU, without having to have a signed microcode.

2) If Intel isn't in on it then you can check the microcode at boot time against the microcode that Intel provides, if there's a mismatch, then you're looking at microcode that may be compromised (and that would indicate that someone other than Intel has the 2048-bit RSA key, which would be a hell of a lawsuit right there).