The paper on Trusting Trust is as much a thought experiment as anything. It's not really about compilers, and thinking of it as a "compiler hack" misses the poi

The paper on Trusting Trust is as much a thought experiment as anything. It's not really about compilers, and thinking of it as a "compiler hack" misses the point somewhat. The bigger point of that hack, is if a component of a system is integral and implicitly trusted, then compromising that component means that the entire system can no longer be trusted. It seems sort of obvious when stated that way, but Ken's demonstration pointed out a few significant details. First, that such an attack didn't have to be large, only two or three changes to the compiler. Second, that such an attack was practical to implement instead of just theoretical. Third, that once a system is compromised, it couldn't even be relied upon to tell you that it was compromised (his follow-up included a third compiler tweak to alter the decompiler), which was probably the scariest point of all. The type of attack that Ken described is still relevant, even if it's not the compiler that's the target. For example, if you could compromise Windows Update, you could do basically the exact same thing. That's why Windows Update requires crypto signatures.