The hidden world in short-wave.
I was interviewed a few weeks back for my website priyom.org [Javascript recommended] which is a community that tracks and logs Numbers Station and military radio stations from all over the world.
The article on The Daily Beast can be found here: http://www.thedailybeast.com/articles/2016/03/06/the-stupidly-simple-spy-messages-no-computer-could-decode.html
When I was 10 years old, I found a shortwave radio in a crumbling old leather trunk where we kept family photos and other memorabilia. As I spun the dial, tinny, modulating noises, like the song of an electronic slide whistle, emanated from the radio's small speaker. Staticky cracks and pops competed for airtime. The sounds swished and swirled, unintelligible and unremarkable. But then, emerging through the clamor, was a voice.
I might have run right over it with the dial, but the voice's rhythmic, steady pacing caught me up short. It wasn't a deejay. Nor a commercial. And he wasn't singing. He was just speaking. The same line, over and over again.
"7...6...7...4...3." Pause. "7...6...7...4...3."
I don't remember if those were the exact numbers. But they were numbers. A repeated sequence which had no obvious meaning, and was entirely devoid of context. To find him here, amidst the screeches and howls of the shortwave frequencies, was like coming upon a man standing in the middle of a forest, talking out loud to no one.
How long had he been here? Who was he talking to? He had that officious tone of the recorded telephone operators who chastised you for dialing a wrong number. "Please hang up, check the number, and dial again." And the same distracting static I'd heard in those messages filled the background. I wasn't sure if he was speaking live, or if he'd been recorded and set loose to play into the air.
It's well-written and a good introduction into the world of number stations and short-wave. I think the Soylent community will enjoy the article, maybe prompt some of you to dig a radio out of your attic and have a listen. Alternatively, you can listen to some stations online. Different stations broadcast at different times; check out the listings on the station schedule page (Javascript required).
Some other resources to check out on the scene:
Enigma 2000 group http://www.brogers.dsl.pipex.com/enigma2000
Simon Mason's website http://www.simonmason.karoo.net/
[Ed. addition.] These stations apparently depend on previously-distributed one-time pads:
In cryptography, the one-time pad is an encryption technique that cannot be cracked if used correctly. In this technique, a plaintext is paired with a random secret key. Then, each bit or character of the plaintext is encrypted by combining it with the corresponding bit or character from the pad using modular addition.
(Score: 0) by Anonymous Coward on Friday April 29 2016, @12:10PM
SSDD ran a similar one-time pad on 1 April [poisonedminds.com]