Re:Let me ask a "stupid" question (Score 3, Informative)

(since crypto relies on N being a very large number, large enough to where it's not worth it to spend NP time breaking the encryption, but where P allows for realtime encryption/decryption.)

If by "N" you mean the "N" in "NP", then I think you've got it wrong. The N is not a number, it stands for "non-deterministic", meaning that problems in NP can by solved by non-deterministic turing machine (which we don't know how to build) in polynomial time (the "P" stands for polynomial). Problems in P can be solved in polynomial time by a regular (deterministic) turing machine.