But the gap between demonstrating the vulnerability of a cryptosystem in the abstract, and actually breaking a bunch of messages written in that cryptosystem, is as wide, and as profound, as the gap between being able to criticize a film (e.g., by slotting it into a particular genre or movement) and being able to go out into the world with a movie camera and a bunch of unexposed film and actually make one. Of these issues the Cryptonomicon has nothing to say until you tunnel down to its oldest and deepest strata. Some of which, Randy suspects, were written by his grandfather.