Internet Numbers Station
Stream Error! Please refresh the page.
How it Works
This station is backed by a true random number generator provided by Arbitrand. Once per second, we use the random number generator to generate random bits from quantum noise, and then turn 8 bytes of entropy into a digit between 0 and 9. In keeping with the history of numbers stations, we use these digits and a text-to-speech synthesizer to generate the stream of random numbers. Digits are transmitted timestamped, and everyone listening is hearing the same stream.
Despite the possibility, there are no coded messages in the stream, just random digits. We generate digits ten seconds ahead of time, to account for some variability between our clocks. In a sense, this stream is a form of public randomness.
History of Numbers Stations
Numbers stations are a cold-war era technology that was used to hide coded messages. A shortwave radio station would broadcast random numbers on a set schedule, sometimes 24/7, with a fixed time interval between each number.
Within this stream of random numbers, it is possible to hide coded messages. With a stream of random numbers, a known transmission time, and a one-time pad encryption mechanism, numbers stations offer a low-bandwidth communication medium that both hides the time of transmissions and offers unbreakable encryption on their content. Due to the use of one-time pads, messages are indistinguishable from random data.
Each station had a different protocol for encoding when messages and broadcasts were occurring. Some stations would broadcast only their random patterns, and other stations would mostly broadcast repeated sequences of numbers before switching to random messages. Some stations also had repeated codes that would indicate something about the content of the data stream, which could mean the start of a message.
Some of the earliest text-to-speech technology was used for numbers stations, and others would have operators that came on the air in shifts, reading off a list of numbers into a microphone for hours and hours.
Several numbers stations are still active today, although not nearly as many as in the cold war. As recently as 2010, the US has charged spies with the use of numbers stations to receive coded messages. Shortwave radio is still the most common transmission medium, due to its intercontinental range, but some of them use digital encodings now.
Encrypted Messages in Numbers Stations
Coded messages could be sent using unbreakable encryption based on one-time pads. One-time pad encryption uses a key of the same length as the plaintext, effectively providing perfect security. Since the one-time pad is random, the message being transmitted contains no information content about the plaintext, and even brute force attacks are useless.
The main drawback of this method is that you depend on generating and exchanging one-time pads securely. The perfect security of one-time pads depends on generating a large amount of random data without using cryptography to do it, which requires a true random number generator, and exchanging a one-time pad often means physically handing off a book or a flash drive.
More on Numbers Stations
Numbers Stations Research Center
A Good Press Article on Numbers Stations
Questions or comments?