The Numbers Stations Analyzed, Discussed

GMontag wrote to mention a Washington Post article about the always-intriguing 'number' radio broadcasts. The numbers stations, as they are known, are 'hiding in plain sight' spycraft. Random digits broadcast at little-used frequencies are known to be intelligence agencies broadcasting their secrets in encrypted form. The Post article gives a nice run-down on the truth behind the transmissions, and touches a bit on the odd community that has grown fascinated by them. From the article: "On 6840 kHz, you may hear a voice reading groups of letters. That's a station nicknamed 'E10,' thought to be Israel's Mossad intelligence. Chris Smolinski runs SpyNumbers.com and the 'Spooks' e-mail list, where 'number stations' hobbyists log hundreds of shortwave messages transmitted every month. 'It's like a puzzle. They're mystery stations,' explained Smolinski, who has tracked the spy broadcasts for 30 years." This article made me recall a great All Things Considered story from a few years back about Akin Fernandez's 'Numbers' CD, a CD compilation of some of the most interesting strings of randomly read numbers reaching out across the airwaves.

Comments

1258965

[TechnoLust]

1258965

1258965

1258965

There was a BBC radio programme about this...

[terrencefw]

There was a BBC radio programme about this a few months ago:

http://jamesholden.net/2005/04/23/the-lincolnshire -poacher/

Conet Project MP3 Download

[3mpire]

You can download the mp3's for free: http://irdial.hyperreal.org/the%20conet%20project/

Re:locating

[Technician]

shouldn't it be fairly straightforward to locate the origin of these transmissions?

Yes. Automatic radio direction finding is common and was often used in the cold war. The spectrum is constantly monitored and when a new broadcast pops up, it is automaticaly DF'ed and logged. When several DF sites pickup the same broadcast, triangulation to the source is a simple task.

Here is what a typical DF site looks like. Both the US and Russia have them.

http://www1.shore.net/~mfoster/FLA_Wullen.htm

Re:Time Bomb.

[Detritus]

A quantum computer is useless against a message encrypted with a properly constructed one-time pad.

Re:Time Bomb.

[spaceyhackerlady]

In ten years someone who has been recording them for thirty years will have quantum breakers to decode them with.

No.

Decrypting one-time pads isn't hard because there isn't enough compute power to throw at it. It's hard because it can't be broken, no matter what you do to it. Given a message to decrypt, the best an enemy cryptanalyst can do is random chance. There are better ways of compromising secrets.

This is a well-established result in encryption and there is no point in arguing about it. The only time one-time pad encryption has ever been broken was when the agents misused their one-time pads. The Venona decrypts are a good example of this.

(Wow! First time I've ever linked to the NSA!)

...laura

HF, VHF, UHF...

[Kadin2048]

You're correct, but just in the interests of preventing confusion, the idea of what was a "long wave" in the early 20th century was very different from what an electrical engineer might think of today. What are today rather low frequencies for radio communication were at the time rather high, hence the term 'short waves.' The preferred frequencies for communication at the time are now barely used by anyone, with the possible exception of naval communication with submarines and the like. Their data-carrying capacity is just too low, and the antennas they require are obnoxiously large.

Of course, by calling things in the 1-30 MHz range "high frequency," those engineers forced us to use such terms as "very high frequency," and "ultra high frequency" when equipment finally became capable of transmitting at those wavelengths.

Re:Time Bomb.

[FooAtWFU]

There's a couple ways to generate one-time pads. The first I read was described at HotBits. They take a little radioactive bit of cesium, and a radiation detector which can detect atomic decay:

What we do, then, is measure a pair of these intervals, and emit a zero or one bit based on the relative length of the two intervals. If we measure the same interval for the two decays, we discard the measurement and try again, to avoid the risk of inducing bias due to the resolution of our clock.

You can find more at Wikipedia's article on hardware random number generators:

There are two fundamental sources of practical quantum mechanical physical randomness: quantum mechanics at the atomic or sub-atomic level and thermal noise (some of which is quantum mechanical in origin). Quantum mechanics predicts that certain physical phenomena, such as the nuclear decay of atoms, are fundamentally random and cannot, in principle, be predicted. (For a discussion of empirical verification of quantum unpredictability, see Bell test experiments.) And, because we live at a finite, non-zero temperature, every system has some random variation in its state; for instance, molecules of air are constantly bouncing off each other in a random way. (See statistical mechanics.) This randomness is a quantum phenomenon as well. (See phonon.)

Because the outcome of quantum-mechanical events cannot in principle be predicted, they are the 'gold standard' for random number generation. Some quantum phenomena used for random number generation include:

• Shot noise, a quantum mechanical noise source in electronic circuits. A simple example is a lamp shining on a photodiode. Due to the uncertainty principle, arriving photons create noise in the circuit. Collecting the noise for use poses some problems, but this is an especially simple random noise source.

• A nuclear decay radiation source (as, for instance, from some kinds of commercial smoke detectors), detected by a Geiger counter attached to a PC.

• Photons travelling through a semi-transparent mirror, as in the commercial product, Quantis from id Quantique SA. The mutually exclusive events (reflection -- transmission) are detected and associated to "0" or "1" bit values respectively.

Thermal phenomena are easier to detect. They are (somewhat) vulnerable to attack by lowering the temperature of the system, though most systems will stop operating at temperatures (e.g., ~150 K) low enough to reduce noise by a factor of two. Some of the thermal phenomena used include:

• thermal noise from a resistor, amplified to provide a random voltage source.

• Avalanche noise generated from an avalanche diode, or Zener breakdown noise from a reverse-biased zener diode.