> Those are not sufficient conditions for a one-time pad. The entire pad, not just some "seed" has to be random. Well that seems a bit pedantic, but yes, you'r

> Those are not sufficient conditions for a one-time pad. The entire pad, not just some "seed" has to be random. Well that seems a bit pedantic, but yes, you're right. The difficulty I was focusing on however is the randomness itself, not how far it has to be extended. Ostensibly once you've incorporated a non-deterministic seed (which is necessarily external) into your process, you can extend it to the pad itself. The pad itself will just be a stream of that data, like a non-deterministic stream cipher. I get the impression you're aware of this already though, so I won't belabor it. > One time pad systems are used regularly for high-security embassy-to-State Department communications. Since there are also secure couriers between those locations, there's a way to distribute key material. With today's storage densities, carrying key material around is easy. Fair enough, I'll concede they have practical uses in situations where there are couriers and extremely high security requirements. That's about all they're practical for, though :)