"He found that the Arethusa intercepts did not represent coded messages at all. They were simply the output of a particular mathematical function, a Riemann zeta function, which has many uses—one being that it is used in some cryptosystems as a random number generator. He proved that if you set up this function in a particular way, and then gave it, as input, a particular string of numbers, it would crank out the exact sequence that was on those intercepts. So that was all she wrote. And it almost ended Comstock’s career."