How South Korea communicates with spies in North Korea

“Attention number 521, attention number 521, Please receive a telegram.”

by Martyn Williams , May 10, 2013

     

   

Tune the shortwave radio bands around midnight and you’ll hear all sorts of signals in the air above the Korean peninsula. The late night hours are primetime for radio stations that target North Korea because its one of the few times of the day that prospective listeners can hide away in secret and listen to news and information from overseas.
But between the international broadcasters and static, there are other signals attracting a much smaller audience.
The most mysterious of these is only on the air for a few minutes each time, and the broadcasts come just a few times each night. If that’s not enough, the content of the programming is even stranger.
After a North Korean popular song, an announcer comes on and broadcasts a string of numbers. And then it shuts down.
“Attention number 521, attention number 521, Please receive a telegram.”
And then a string of numbers is read out.
It’s a so-called “numbers station.” They have been mysterious fixtures of the shortwave broadcasting bands since the cold war, sending strings of numbers that are widely believed to be coded messages for spies overseas.
This particular station has been dubbed “V24” by radio monitors that follow such broadcasts – they are still a relatively common method of communications – and it’s the only regular one on air in Korean.
Sending such messages over radio brings both advantages and disadvantages over other methods of communication.
On the down side, the radio broadcasts are one-way only. It’s not possible to send back a reply.
But on the up side, the broadcast can be received over a wide geographic area, so it doesn’t matter where someone is. And unlike other communication methods, like a drop of documents or a meeting, the only thing that has to be set up in advance is the time and frequency.
I’ve picked it up numerous times, both in South Korea, Japan and the western coast of the United States, but no one has probably done more monitoring than a user called “Token.”
Based in the Mohave Desert, Token has published the most authoritative schedule of V24 to date.
It shows V24 is on the air every day of the month and there are usually only three or four broadcasts each night, according to a schedule drawn up by a radio monitor in the U.S. When V24 does come on the air, it’s either on the hour or half hour in slots from 10pm to 1:30am local time.
It currently switches between four frequencies: 4900, 5115, 6215, 6310 kHz.
The broadcast begins with a song and the identity of the recipient, then numbers read in groups of three and two. For example: “238-89, 561-45, 573-22 …” and then the same numbers but in groups of two and three. For the example above, the second group would be: “23-889, 56-145, 57-322.”
The break between the five numbers is probably changed to improve readability in the case that the signal is bad.
Here’s a recording:
So, what’s going on here?
The numbers are, of course, the message that’s decoded by the agent in the field.
The decoding method might be a dedicated codebook or the numbers might point to letters in a real book – something that could sit on a shelf and draw no suspicion, but with the right knowledge could be used to unlock the code. For example, “238-89” might mean page 238, line 8, character 9.
But perhaps more interesting is the source of the broadcasts.
While a scratchy shortwave radio broadcast might seem likely from North Korea, most long-time number stations listeners think V24 is coming from South Korea, broadcasting to spies in the North.
The South Korean government has never confirmed this and there is little evidence to point either north or south, but the rationale is based on a few pieces of history.
The most convincing is that Radio Pyongyang, North Korea’s international shortwave broadcaster, used to transmit numbers during its programming. There wasn’t any doubt about the source of the transmissions, but monitors say they ended in December 2000.
And as far as circumstantial evidence, North Korea’s much tighter social controls hint that radio broadcasts might be a better way to route secret messages.
One other interesting thing about the broadcasts – while I have never heard it, occasionally listeners have reported hearing the Windows XP closedown sound right before the transmission goes off air.
While V24 transmits in speech, four times a month one of the same frequencies carries a similar transmission in morse code. The station, dubbed M94, is on the air at 11pm local time on the 10^th, 11^th, 26^th and 27^th on 5115 kHz.
Picture credit: Si’ilk...

Media freedom faces "greatest challenge since the Cold War"

Latest update: 06/05/2013 

- Press Release

Media freedom faces "greatest challenge since the Cold War" - 03/05/2013

A group of leading International broadcasters – gathered in the DG5 consortium – declared today that media freedom faces its greatest challenge since the Cold War with Internet blocking, satellite jamming and the return of shortwave jamming.

 

The statement issued on behalf of the representatives of Audiovisuel Extérieur de la France (AEF), Australian Broadcasting Corporation (ABC) [Australia], British Broadcasting Corporation (BBC) [United Kingdom], Broadcasting Board of Governors (BBG) [US], Deutsche Welle (DW) [Germany], Nippon Hoso Kyokai (NHK) [Japan] and Radio Netherlands Worldwide (RNW), said: “The jamming of satellite broadcasts has become a regular occurrence as regimes seek to block certain services from the being received. This jamming affects area stretching from Northern Europe to Afghanistan and as far south as Northern Africa. We have also seen internet blocking of services and cyber-attacks on media organisations of all over the world, shortwave jamming and disruption and interference with FM broadcasts. Media Freedom has not faced such a concerted campaign of disruption since the end of the Cold War. ”
The broadcasters called on all nations to recognise the legitimate role played by international broadcasts in offering free access to global media and coverage of events.
During the cold war the jamming of radio broadcasts to East of the Iron Curtain was common place. European and US broadcasters worked hard to overcome this in a game of cat and mouse. From the late 1990s digital satellite broadcasting has flourished delivering a wide range of programmes in many languages to communities across the globe. Audiences have been able to benefit from international broadcasts that provide a different perspective on news and cultures.
Increased satellite jamming of FRANCE 24 broadcasts to Iran and Syria stepped up significantly this year and this marks an unwelcome increase of the oldest method of interrupting programmes. The deliberate satellite interference is both extensive and powerful. This is contrary to the international regulations that govern TV satellite broadcasts. RFI’s shortwave broadcasts to Iran in Persian continue to be jammed intermittently, and access to RFI websites continue to be blocked in China.
The AEF is heavily involved in pooling resources with fellow broadcasters and lobbying the satellite industry to stop deliberate interference and achieve media freedom worldwide. This involves seeking both long term and short term technical solutions in order for our content to continue to be received during major political events and crises. Like all the other leading international broadcasters, we are working with the ITU (International Telecommunication Union) and other UN bodies to spread the word about the profound influence that jamming is having on audiences and the industry.
About DG5:
For fifteen years, the DG5 consortium meets once a year and gathers the presidents of the five major international media groups from the Western States (AEF, BBC, BBG, DW, RNW). NHK (Japan) and ABC (Australia) joined the group as observers in 2012. Meetings are also held several times a year between media experts to discuss the wave interferences, the Internet blocking, audience researches, strategies and international distribution.
Watch and listen to the world:
The group in charge of French international broadcasting services comprises three media: the trilingual news TV channel FRANCE 24, the international radio station RFI and the Arabic-language radio Monte Carlo Doualiya. From Paris, they broadcast to the world in 14 languages. The group’s journalists and its unique network of correspondents offer viewers and listeners comprehensive coverage of world events, with a focus on cultural diversity and contrasting viewpoints via news bulletins, reports, magazines and debates. The group has a combined weekly audience of over 90 million listeners and TV viewers and its new media platforms attract 25 million visits a month. The group is also a shareholder and partner of the French-language general interest TV channel TV5MONDE.