> Have dedicated hardware compute a hash from the content of program ROM How do you check the circuit of that hardware? How do you know the ROM you are readin

> Have dedicated hardware compute a hash from the content of program ROM How do you check the circuit of that hardware? How do you know the ROM you are reading is the ROM the CPU is executing from? How do you know the CPU is the architecture you think it is and the program means what you think it means? > You have to trust the hardware to some extent. No, you don't, and you shouldn't. You can do all of that calculation by hand. And at the very least you can check a random selection by hand. > Just keep it as simple as possible to minimize confounding complexity that an attacker can hide in. In other words: Don't use electronics. You can't get simpler than pen and paper.