While we're on the topic of random numbers, etc., this is what I was told a long time ago about military OTPs. I don't know if this OTP generation was by NSA or by one of the military forces itself. And, as this information is at least 10 years old, who knows if this is how it's still done. And maybe it was disinformation, and never done this way. Anyway, there was supposedly a heavily shielded room which had equipment that used radioactive decay to generate random numbers. Apparently it was pretty automated and the thing basically spit out pairs of paper OTP pads that were already prewrapped in tamperproof packaging. To me, this makes more sense than Clancy's "atmospheric noise" hypothesis. But then, Clancy was generating entire CD's worth of bits, which would certainly need orders of magnitude more bits than actual paper pads.