Shafe Shifter Just another guy on the internet.

Number Stations

For more than 30 years the Shortwave radio spectrum has been used by the worlds intelligence agencies to transmit secret messages. These messages are transmitted by hundreds of “Numbers Stations”.

Shortwave Numbers Stations are a perfect method of anonymous, one way communication. Spies located anywhere in the world can be communicated to by their masters via small, locally available, and unmodified Shortwave receivers. The encryption system used by Numbers Stations, known as a “one time pad” is unbreakable. Combine this with the fact that it is almost impossible to track down the message recipients once they are inserted into the enemy country, it becomes clear just how powerful the Numbers Station system is.

These stations use very rigid schedules, and transmit in many different languages, employing male and female voices repeating strings of numbers or phonetic letters day and night, all year round.

The voices are of varying pitches and intonation; there is even a German station (The Swedish Rhapsody) that transmits a female child's voice!

One might think that these espionage activities should have wound down considerably since the official “end of the cold war”, but nothing could be further from the truth. Numbers Stations (and by inference, spies) are as busy as ever, with many new and bizarre stations appearing since the fall of the Berlin wall.

Why is it that in over 30 years, the phenomenon of Numbers Stations has gone almost totally unreported? What are the agencies behind the Numbers Stations, and why are the eastern European stations still on the air? Why does the Czech republic operate a Numbers Station 24 hours a day? How is it that Numbers Stations are allowed to interfere with essential radio services like air traffic control and shipping without having to answer to anybody? Why does the “Swedish Rhapsody” Numbers Station use a small girls voice?

These are just some of the questions that remain unanswered.

[Here are Some Bits From A Wired Magazine Article]
As shortwave is abandoned by public broadcasters in favor of satellite and the internet, these curious stations continue to broadcast, seemingly unaffected by the end of the Cold War or the development of new technologies. But even listening to the signals is illegal in some countries.

No government has ever acknowledged a numbers station, but the British Department of Trade and Industry told London's Daily Telegraph in 1997 that there was no mystery and that the stations were not "intended for public consumption."

Number station signals are not low-powered, which would suggest in-the-field broadcasts by clandestine operatives. Rather, they come from powerful transmitters with global reach, requiring massive masts that are not easily hidden.

Wired News has a good article on the subject.
http://www.wired.com/news/technology/0,1282,65698,00.html

Salon's Article On Number Stations
http://www.salon.com/people/feature/1999/09/16/numbers/

Wikipedia's Numbers Station Page
http://en.wikipedia.org/wiki/Numbers_station

If you want to hear what one of these things sounds like you can check out this real audio clip. It's a bit eerie.
(Audio Clip of A Numbers Station Broadcast - Real Audio): http://home.freeuk.com/spook007/CYNMARK.ra

More audio clips here: http://home.freeuk.com/spook007/