Nancy asked him how that was possible, since the stations were thought to use codes called “one-time pads”. Essentially, these are code systems that are used once, then discarded, never to be used again. If used properly, they are considered to be unbreakable.

Katsuhara replied that he expected, in all this tumult, for the stations and recipients not to have time to switch encryption schemes before transmitting a new message. He had managed to land two messages intended for the same recipient, unit 1471, and sent them off to his younger brother, who had substantial computing power at his disposal, to see if he could do anything with them.

Nancy reported that the Cuban station, which literally never broadcasted at this hour, was spewing out its typical letter-filled transmissions. She then surprisedly interjected that a new station—one she’d never encountered before—had started a simultaneous, interfering transmission.

We were deep in conversation when, an hour later, Bill logged on. He had an idea.