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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.
It was discussed on slash previously in the following article:
Numbers Stations Move From Shortwave To VoIP.
liqbase
If you have a cheap short wave radio, even a "radio shack" one, you can pick up voice audio coded messages to spies that the CIA sends to agents. You will only find them by pure chance, but I have managed to find them and record them but I would say that for every 6 or 8 months of listening to short wave radio I will hear only 1 of these broadcasts. It's usually the same female voice. It's great fun when you find one, you feel like you hit the lottery.
As an avid Shortwave fan, there are less and less clear stations broadcasting to NA, as more and more world service broadcasts move to the Internet. (YEAH I'm talking about you BBC) I wonder how long until the only people who own shortwave radios are spies? Although propaganda stations are well worth the price of the radio. Listen to Cuba's hour loop of things we blame on the US today, and keep a straight face, I dare you.
I remember when I was 12 or so and heard one of these for the first time. A woman reading numbers in Spanish. Damned if I didn't feel like James Bond sitting there listening to it. I still have that radio, too. Too bad it doesn't pick up anything besides evangelical stations now. Yes, technology has advanced and the world has moved on. So have I. I accept that. But there was a certain thrill of finding that clandestine guerrilla propaganda station that just can't be replaced with web surfing.
With these stations becoming so popular, isn't it time to sell ads? After all, spy agencies can always use the extra cash, and the people who listen to these things probably constitute a solid geek demographic.
... why do I feel like I've missed a step there?
Or worse:
1) Create personal numbers station with especially intriguing sequences to draw audience
2) Sell ads on your personal number station
3) Profit!
It's quite likely they're broadcasting from here Google Satellite
That's Ayios Nikolaos. Supposedly part of the Echelon network. If you look to the north of the building, there's a large mast that might easily be a short-wave antenna.
If you are in the US military and go to the language school in Monterey, a big portion of your "lab" training is learning how to transcribe groups of numbers read in your target language. It's a big part of your "grade" in your coursework.
Now, it's hard to say if the US transmits numbers, but it's pretty clear that there appears to be some intelligence value in teaching the electronic warfare people how to listen to streams of numbers in other languages.
It's probably a great way to send one-way messages to the field. A simple AM radio can be modified work in different frequencies. With that and a normal-looking one-time-pad code book can go a long way to providing secure communication that is inconspicuous.
So, the CIA might not do it, but other countries and services probably do.
For those of you who like this sort of thing, check out 202-386-6909 and http://code-cracker.cerbumi.org. This is a test project that I developed for Cerbumi.org, a new and entirely non-commercial (no ads, fees, etc) website designed to help with real-world problem solving. (Think of it as a "Sourceforge.net" for projects like the "Open Prosthetics Project.") The first person to solve the puzzle and post the answer to the code-breaker project can choose where the Cerbumi.org team will make a $100 donation on their behalf.
:)
If this sounds like fun, please consider signing up for the Cerbumi.org site at http://public.cerbumi.org/goons (a "secret back door for a site that normally requires registration) and try to crack the code. Also, please consider checking out the main planning project at http://cerbumi.cerbumi.org and our Flash-based demo at http://cerbumi.org/flash. I'd love to hear your thoughts, too... just reply.
the main reason they still use short wave is the that some of "short wave" isn't so short... the frequencies that they use are the ones that carry long distances so that the origin of broadcast can be very far away from the agent. Also, the devices required to listen to particular frequencies can be made very small so that agents in difficult places can hide the devices. Finally and most importantly, the broadcast voice of the coded messages is distinctly American. Maybe another country could use the voice with an American accent but I don't see why it would be necessary. I think that the agency has faith in the quality of the method used to code the message. Voice messages were used throughout WWII without any enemy getting anywhere near breaking the codes.
Computer data requires equipment to receive and decode, even if it just a laptop. Short wave requires only a receiver that can be made almost arbitrarily small and can therefore be ditched or hidden in an emergency.
Yankee
Hotel
Foxtrot
You want your one-time pads to be very, very secret; that's why you can spread the actual cryptotext anywhere and not have to worry about a thing. If it were as simple as comparing one numbers station to another, any intelligence agency with a few computers to throw at the problem could check the numbers against each other and look for meaningful messages. While you might think that's oh-so-slightly unlikely, is it something you're willing to bet your security as an intelligence agency on?
The World Wide Web is dying. Soon, we shall have only the Internet.
Why couldn't it be replaced by websurfing? Maybe the codes are ultra subtle? Perhaps the .gif on the title bar of a certain webpage has it's pixels on one row manipulated in a very small way to give a massages, perhaps instead of being pitch black (0,0,0) it is (1,0,0) undectable to the human eye and perhaps seen as irrevelant to 99.999% people who do detect it but write it off as an artifact/noise introduced somehow in the making of the gif.
Or perhaps the action is on IRC.
Or maybe the first letter on every site gives a clue. The beauty is that these methods don't advertise themselves and are nearly undectable to anybody.
Shortwave radio is known so the thrill is somewhat gone from catching those fleeting messages.
Shouldn't it be possible to use a directional antenna or some similar technology, from several points around the globe to locate the source of the transmissions with a reasonably high degree of precision?
:)
I don't have any shortwave equipment myself, but it seems that would be a very interesting project.
It would be quite exciting, say, to discover signals originating from a mountain in Wyoming
This is pretty sweet. It's a very interesting strategy. Shortwave receivers are easy to come by, do not arouse suspicion, and no one can detect that you are listening in.
You definitely can, it's (as you stated) usually called "moonbounce" or EME, for Earth-Moon-Earth. I'm not sure that it's really a particularly useful form of communication, but that doesn't stop hams from doing it just for the hell of it. (Though I've wondered if there are some 'Mad Max' style disaster scenarios where EME would conceivably be useful...)
To do it right you need a very directional beam antenna. There are particular regions of VHF that are known to be good for EME, because of the way they penetrate the Earth's atmo/iono/magnetospheres. However, people have done it on virtually all bands, from 6m into the microwave. (There is a neat page on 6m EME here, he claims that as of 2002 only 30 or 40 people have ever had successful QSOs, so if you want to be on the bleeding edge of amateur radio, that's where you go.)
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
Take the old Radio Moscow transmitter in East Berlin, for example. You are quite right that such HF broadcasts would often end with a looping tape containing info on what freq(s) the site would be transmitting next. Well and good.
Eventually, though, the tape ends and the transmitter shuts down. Fine. Now all you're listening to is a whole lot of nothing but white noise, right? STAY ON THE FREQ FOR ANOTHER 5-10 MINUTES. Suddenly another carrier comes up, and a woman's voice starts. On the Radio Moscow freq she would always start with "Achtung, achtung," then proceed to read-off a long string of number groups (NOT freqs!). When done, she would finish with "Ende," and the carrier would immediately drop.
Still sound like a freq change notice to you?
Regards;
Lest you think all these secret stations are foreign, here's the story of Yosemite Sam, a station that transmitted "I'm a gonna get you, you varmint!" followed by a quick digital BRAP sound, and how it was traced by enterprising hams to a US military-industrial facility.
Because you have something sensitive to say later.
But why not just use the same secure channel later?
No, there has to be another reason. I mentioned the most common reason -- that the secure channel is too slow. There can be others, of course, such as that the secure channel is only temporarily available, or that it can only be used a limited amount, or that it is one-way, etc..
A secure channel is required to be able to use an OTP, but it must be deficient in some way (other than its security) or it doesn't make any sense to bother with an OTP.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
The ionosphere bounce is most often like a flat mirror in the sky much like seeing the sky reflected on a hot road in the desert (looks like water on the road). Even though the direction of the wave appears to be from a few degrees above the horizon, the azmith is not skewed much most of the time. Most of the CDAA antennas have the delays set to focus not on signals from the horizon, but from a few degrees above the horizon. The more antennas you have which are spread out increases the antenna apature and much of the drift gets averaged out providing a reasonably accurate line of bearing. The sky wave is dynamic. The longer a signal is present, the more samples can be integrated also increasing the accuracy. With many coordinated stations, the circle you get on the map that may contain the source of the transmission becomes quite small.
I have done some HF amature radio hidden transmitter hunts in the 28 MHZ range. The bearing you get as you get close is pretty good. A couple guys working together sharing information can locate the final area very quickly. It is a lot of fun to see how many people you can beat to the hidden transmitter.
The truth shall set you free!
Years ago, some friends of mine used to find sport listening to "Numbers Stations". One in particular, during the Soviet era, used to identify itself as "The Moscow Radiotelephone Station." They would get on the air and proclaim "This data is for Testing Purposes Only, from the Moscow Radio Telephone Station, Book xx, Page yy, Group zz..." and then proceed with five letter cipher groups in perfect english phonetics. (Substitute xx, yy, and zz with whatever numbers of book, page and group they were sending at the time).
They were once reputed to have closed their broadcast on New Year's Eve with "and greetings to our friends in the CIA." Who says spies have no sense of humor?
Nearly fifty percent of all graduates come from the bottom half of the class!
>I'll just add to my previous comment that it was once widely believed that long wave radio signals propagate the longest distance, then for a while that idea was less well believed....
Terms such as "short wave" and "long wave" have largely passed into disuse, replaced by High Frequency (roughly short wave) and Medium Frequency (roughly long wave), and then for mostly point-point communications, VHF, UHF, and above.
Except for the exotic moonbounce and tropospheric ducting mentioned, all long distance radio communications on this planet uses various layers of the ionosphere, and depends on ionosphereic reflection and refraction, and is thus dependent on the state of the Sun, which has an 11-year up-down cycle. We're going to reach rock bottom in 2007, and then things will start looking up again.
If you want to see what frequency is best for reliable communications around the globe, check out this site and look at the map closest to you. These maps are compiled using ionosondes, and represent hourly experiments. They will tell you what frequency in the HF has the best chance of bouncing off the ionosphere and reach the destination. The NVIS map at the top is for transmitting straight up and having your signal come down in a ~250 mile radius. The maps below that, centered on cities around the world (San Francisco, Sydney, etc.) will show you what you need to do to get a signal to or from those cities. There's no quality info, but if you want current solar conditions, see the Propfire plugin, which will tell you.