This is the sound of E03, also known as the "Lincolnshire Poacher" because of the use
of a short piece of the aforementioned folk tune that introduced it. This is one of the
best-known examples of a numbers station, something which reached its peak in the cold
war but since its end and the rise of the internet has died down a lot but hasn’t
not gone away. The "Lincolnshire Poacher" was believed to
have been run by the British secret service and first broadcast from Bletchley Park before
being transferred to Cyprus and Guam, continuing to broadcast up until 2008 sending encrypted
messages in the shortwave radio band as blocks of spoken numbers to agents out in the field
but we don’t know for sure because very few governments and no security services have
ever admitted to using them. So what is a numbers station and in this day
and age of end to end internet encryption, why are they still in use and why are the
existing ones as busy as ever?. This video is sponsored by Brilliant.org
If you have ever listened to short wave radio you may have come across some weird broadcasts
with no normal talking, just maybe a short tune or other repeated sounds and then repeated
sets of numbers being spoken with synthesized voices, then music or sounds to end it before
starting all over again. Other variations of this theme are stations that send the data
as morse code or as just musical tones. These are the numbers stations and they have
been around since the second world war but their activity rose dramatically during the
cold war. The languages spoken include English, German, Spanish, Russian, Slavic, Chinese
& Korean and they are located around the world. Initially, they were a mystery, they used
powerful shortwave transmitters yet no one claimed to own them and unlike illegal pirate
radio stations they weren’t shut down, they just went on and on and on, some for over
30 years, this makes it impossible to rule out government involvement.
By using the shortwave band, the range they can cover is from hundreds to thousands of
kilometres as the signal bounces off the ionosphere and ground to propagate its way around the
earth. The range increases dramatically a night as the suns effect on the ionosphere
is removed as many radio listeners can attest to.
Over time these strange broadcasts attracted the attention of radio enthusiasts who started
logging their broadcast frequencies, their schedules, types of transmissions, languages
and sounds and music used. This led to the equally strange names they
were given like the aforementioned "Lincolnshire Poacher”, “Spanish Lady”, “Gongs or
Chimes”, “Swedish Rhapsody” and “The Bored Man”.
Although few governments have admitted to using them with the exception of Poland, Sweden
and the former Czechoslovakia, it’s pretty much an open secret that they are used to
communicate with spies in the field. A UK government official said to the Daily
Telegraph that "People shouldn't be mystified by them. They're not, shall we say, for public
consumption" which is about as close as we have gotten to an explanation.
In the US as recently as 2009, a foreign agent working for Cuba for 30 years was convicted
and sentenced to life for espionage after receiving and decoding messages from a numbers
station. The thing about these stations is that they
are far from hidden, anyone with a shortwave radio can tune into them and listen to the
messages but only the person for whom the message is intended for can decrypt what they
contain. The system these spoken number stations use
is called a One-Way Voice Link so the agent or spy only receives orders but never transmits
back to the same station. The spoken messages could only be decrypted
with a OTP or One Time Pad, so called because the encryption key or password used to decrypt
the message was written on a paper pad is only used once and then destroyed.
The beauty of this system is not only is it very simple to use, it requires nothing more
than a pen, a piece of paper and a radio receiver, all everyday items that wouldn’t raise any
suspicions. The only thing that could, is the One time Pad itself but they could be
made very small and easily passed from person to person in the palm of your hand. Some suspected
agents have been found with OTP’s hidden in things like a bar of soap or written on
the back of a postage stamp. Because of the way the message is encrypted
and the use of the The One Time Pad, If correctly used it is considered perfectly secure against
any form of cryptoanalysis, no matter how powerful the computer used and or how much
time is taken, even a quantum computer would be unable to successfully reveal the intended
message. Because the encryption key is as long as the
message and if its was truly randomly generated, such as based on quantum events like electrical
noise instead of a computerised random number generator, any attempt to brute force decode
the message will just produce every possible plaintext combination the encoded message.
Even though the real message would be revealed by a brute force attack it would be just one
of billions of others, all with equal probability of being the true message.
To be correctly used, it’s assumed that the random number key used on the OTP is truly
random, the pad must securely be transferred to the agent it is intended for and never
shared and once the message has been decoded the key that was used must be destroyed and
never used again. The KGB used flash paper for some of their
OTPs which burned extremely quickly and left no ashes while others used rice paper or even
chewing gum that could be eaten or chewed to destroy the evidence.
So whilst this might be perfectly secure under ideal conditions with today’s tech being
far more easy to use and still being highly secure, why are numbers stations still used.
Nobody knows because no one will admit to using them, maybe they are sending dummy message
to keep those listening on their toes and in a constant guessing game or maybe its to
make those who are listening in think they have a large network of spies and agents even
if they have none at all. Sometimes the number stations are jammed by
foreign powers, the North Korean foreign language service “Voice of Korea” began broadcasting
on the E03 Lincolnshire Poacher’s old frequency in 2006, though E03 had moved to two other
frequencies and was broadcasting from Cyprus and Guam by then but this seems that jamming
is common occurrence in the world of number stations.
It's not just governments that could use them, anyone with access to a powerful radio transmitter
could do the same, from corporations to drug dealers, criminal gangs to terrorists. Anyone
wanting to communicate over long distances with complete anonymity and avoid the modern
digital world and the tracking and surveillance that accompanies it could do this very easily.
You simply can’t track a handheld radio and therefore you have no idea where the agent
could be operating. It’s believed by some that governments keep
number stations as a backup of last resort in the case of a countrywide shut down of
the phone and internet services in foreign countries and that the very highest level
of government communications use one time passwords which are still delivered in person
to avoid any possible electronic tracking, though they are more likely to be on a USB
key than a paper pad like the old days.
Now while the One Time Pads may be perfectly secure, our current encryption technology
is getting better and better and the security business is getting busier and busier so if
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