ABSTRACT
Imagine, in the midst of the cold world war, you are a clever math student with a good background in signal processing. Somehow, who knows how, you end up being contacted by your government to help with some transmissions they have started to pick up from “the other side.” The transmissions are in a short-wave radio frequency nobody ever noticed before and they look like random appearances of beeps and silences within some background hash. At rst you doubt there will be any useful signal at all in all these beeps, but your contact assures you-from his good sources-these are indeed critical signals that they urgently need to understand. To you it seems like an interesting challenge, kind of a game to test your math skills, so you decide to give it a go.
