What are number stations?
First classified by the ENIGMA group in the late 80's and early
90's number stations are generally accepted to be covert
transmissions to spies in the field of foreign countries. Appearing
at any time of day or night on the shortwave bands, number stations
have been calling out with their automated voices since at least
the first World War. It has not been confirmed by any government or
organisation what number stations really are, so we can only really
speculate as to their real purpose. There are three different types
of broadcast; voices reading groups of numbers or letters, Morse
transmissions and noise stations, transmitting noise and data. A
typical voice station transmission will begin with a piece of music
played for several minutes, a voice repeating the same number or a
repeating morse character. Then will follow the message header,
perhaps 2 then 3 numbers. This music is played and the message
header repeated to allow the intended listener to tune accurately
to the station. The message begins, usually the message consists of
groups of 5 numbers or letters or a mix. Some stations repeat each
group. At the end of the message there is an ending indicator,
perhaps the message header repeated again or some other shorter
group of letters/numbers. Morse stations are identical except that
everything is broadcast in Morse code.
The first account of a number station was reported in an ENIGMA
newsletter from the German Kurzwellenpanorama magazine dating from
WW1. The BBC were noted for sending messages to
people overseas which where coded messages to SEO agents during
WW2. From then on encrypted messages broadcasted with creepy
automated voices have been being sent with stations appearing and
dissapearing as political events changed over the last 60
Number stations offer a powerful advantage in our modern world.
Complete anonynimity. The recipient of the message can be almost
anywhere in the world and receive instructions without fear of
being traced through a phone call or internet connection. All the
recipient needs is a shortwave radio and to be in the right place
at the right time.
The coded messages sent are generally encrypted using a
technique known as a one time pad. In this system, two identical
sets of random numbers, printed on numbered sheets are generated
(the pad); one pad is kept be the sender and the other is kept by
the recipient. When a message is to be sent, the original plaintext
message is mathematically added to one of the random numbers on the
pad. The random number used is pre-determined by the sender and
recipient so that both are in sync. When the message is sent over
the air the recipient transcribes it by hand and then subtracts the
random number on her pad from the message she has just received.
The random number is then discarded. In her hands she now has the
original plaintext message, sent to her over an open channel with
zero possibility of enemy decryption. The only way that messages
sent with one time pads can be deciphered is if your enemy
retrieves your pad or the sender re-uses a pad.
What is ENIGMA naming system?
We are using ENIGMA naming system to call stations here. It's
first universal method for naming number stations - before it radio
amateurs were using their nicknames took from interval signals etc.
First letters mean language or type, numbers have ordinal value.
Alphabetical suffixes are given for different formats of some
- E - English
- G - German
- S - Slavic
- V - other languages not included above
- M - Morse code
- X - noise stations
- XP - polytones
For example station NNN in English, German, French, Hungarian
and Morse code carries designators E12, G12, V12, V18 and M02.