[gcb0]

the very arguments the article gives to shun off this attack is what i think makes it very possible and the best option. Scale.

NSA demand backdoor on CPUs. other States figure out how the backdoor works and how access to it is allowed on the silicon. Instead of attacking ever changing firmware and whatnot, just develop something that will work on that authentication component of the always-present backdoor. The backdoor interface won't change so often as it is dictated by the NSA and likely designed by a committee.

Done. Now the economies of scale allow you to just place that one component, which will work all over the place, for a very low price/complexity (all you really have to do is to place it in the input signal for the CPU and all it have to do is to filter a very specific pattern. the rest is just visual and camouflage).

This also gives you the benefit of not having to work a payload for your attack depending on capabilities. You will always have the same capabilities. It makes perfect sense. And makes it extremely cheap!