In the age of the Internet, radio transmissions of secret code messages have become all but extinct. After all, it’s too easy to encode secret messages on the Internet – in audio files, in forums, in backend code, even embedded in graphical images (i.e. steganography). But on Friday, July 15, 2016, a North Korean short wave radio system abruptly, and inexplicably, returned to the airwaves.
News of the North Korean broadcast came as Pyongyang is angrily reacting to the planned deployment of an advanced US missile defense system in South Korea.The strange transmissions began around 12:45 PM and began with a female announcing:
“From now on, I will give review work for the subject of mathematics under the curriculum of a remote education university for exploration agents of the 27th bureau.”
The announcer then continued with:
“On page 459, question number 35, on page 913, question number 55, on page 135, question number 86, on page 257, question number 2…”
The bizarre string of page and question numbers went on for fourteen more minutes. Prior to this message, the North Korean station had remained silent for more than two decades.
Generally “numbers stations” follow a basic format beginning with a prelude that identifies the sender and the intended recipient. The prelude can take the form of a code name, a characteristic phrase, or sometimes musical sounds. After the prelude there is usually an announcement of the number-groups in the message supplying the page to be used from the one-time pad or other pertinent information. Finally, after all the messages have been sent, the station will sign off in some characteristic fashion (e.g. a sequence or zeroes or some specific musical sound).
Some believe the messages are encoded directives to agents to begin terror attacks (Pyongyang recently called for terrorist attacks against South Korea and their allies). Given that the messages were transmitted over shortwave frequencies, the intended recipients could be anywhere on the planet.