Category Archives: Articles

Rijmenants’ paper sheds light on Cuban numbers stations

I’m always amazed by the remarkable talents and extraordinary knowledge of SWLing Post readers. Dirk Rijmenants recently commented on one of our Cuban spy numbers station postings:

[T]hanks for your work on this fascinating blog.

I have additional information on how and who used these Cuban numbers stations. I composed a paper based on FBI and court documents. “Cuban Agent Communications” can by found in the Papers section of my website.

Here’s the direct link (pdf):
https://www.ciphermachinesandcryptology.com/papers/cuban_agent_communications.pdf

Have fun reading!

Dirk Rijmenants
Cipher Machines & Cryptology

I’ve read Dirk’s paper, which does, indeed, shed light on the process of receiving and decoding numbers. Most of all, it exposes the vulnerability and fallacy of using anything other than one-time decryption keys and single-use pads. Why? Most of what the FBI has learned about Cuban numbers came from laptops that were used to help decrypt coded messages–an unnecessary procedure when numbers can simply be decoded on note pads that can then be burnt or destroyed.

But don’t take my word for it–download and read Dirk’s paper “Cuban Agent Communications” by clicking here. Also, be sure to check out Dirk’s blog and cryptology website; I’ve bookmarked both.

Thanks for sharing your findings, Dirk!

Global News Dashboard: BBG news networks share a front door

Vatican Radio: breaking news broken?

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Pope Francis I (Photo: Vatican Radio)

A few moments ago, Cardinal Jorge Mario Bergoglio of Argentina was elected Pope, becoming the first pontiff from the Americas, and taking the name Pope Francis I. When breaking news like this is happens, I often turn to shortwave radio to hear it “from the source;” what better station for news about the Papal elections than Vatican Radio? Right?

Hm. When I turned to Vatican Radio on 13.765 MHZ at 20:00 UTC today, here is what I heard:

After a little music and announcement confusion–including what sounds like at least three audio feeds coming in at once–Vatican Radio settles on an announcement program which states, in several languages, “Vatican Radio’s programming schedule is currently being modified to cover the election of the new Pope.”

It wasn’t until thirty minutes later (20:30 UTC), when the Vatican Radio service to Africa started in French on 11.625 MHz, that I heard any substantive news about the new Pope:

Of course, I can find information about the new Pope from any one of two million different online sources, but it did surprise me that Vatican Radio wasn’t better prepared for this event. I even wondered if there was a different broadcast running on a consecutive frequency, so I checked; all were identical, however.

Still, the radio archivist in me can’t help but experience some appreciation of the confusion on the airwaves. After all, this is a genuine piece of radio history and a fascinating thirty minutes of audio in the wake of a big decision.

In my mind, I envision the Vatican Radio staff frantically stirring to assemble news–for which they had no advance notice–regarding the new Pope. No doubt, the CNNs, BBCs, and Al Jazeeras of the world had pre-prepared material on each of the papal candidates. When the white plume of smoke announcing the election was first spotted, these broadcasters were likely more than ready to pull out the appropriate material and publish.

Perhaps this is not how Vatican Radio usually operates. Indeed, I suspect their live feed of events experienced a technical difficulty which they have, no doubt, since resolved. And for what it’s worth, their website was appropriately up-to-date.

History: sometimes bumpy, but always fascinating. Especially on the airwaves.

Zimbabwe: door-to-door search for radios

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FR160 (Source: SW Radio Africa)

On Friday police in Rusape went door-to-door to houses belonging to known MDC-T supporters, in search of shortwave radios. But the MP for Makoni South said they found nothing.

Pishai Muchauraya said the morning raids saw police officers go in groups of three to MDC-T homes in Gandanzara, ‘demanding radios distributed by Pishai.’

[…]Last week the police ordered a ban on the possession of shortwave radios, saying they are being used to communicate hate speech ahead of next month’s constitutional referendum and elections set to be held later this year.

Wind-up, solar-powered radios sets have been distributed by some NGOs to rural communities, where villagers have established listening clubs to tune in to popular independent stations such as Studio 7 and SW Radio Africa. The broadcasts are produced by experienced exiled Zimbabwean journalists based in Europe and the US.

Read the full report on the website of clandestine radio station, SW Radio Africa.

Bill helps with low-power, license-free broadcasting

How to decode that RDFT in numbers station HM01? Roland explains

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A few weeks ago, I published a post with a recording of the Cuban numbers station HM01, a “Hybrid Mode” numbers station which interchangeably broadcasts both voice and a digital mode called RDFT with each transmission. I had suggested using an application called “DIGTRX” to decode the data bursts.

I then received a comment on that post from the author of the DIGTRX program himself, Roland. He has actually created a page in English which describes in detail how to decode the RDFT in HM01. Note that this page was originally in Roland’s native Portugese, and he kindly translates it into English for us: http://www.qsl.net/py4zbz/eni.htm

[While this means that we can decode the transmissions, it doesn’t mean we can necessarily decipher them, however. At least, not yet.]

Imagine that a spy numbers station is using an application you, yourself, authored to send coded messages. What are the odds? This apparently happened to Roland, when he discovered that HM01 was, in fact, using his application DIGTRX. What?!?

Actually, it makes sense to me that numbers stations would use DIGTRX. After all, it’s open source. Operatives in the field can download the application without raising awareness. If it were a proprietary application, either commercially or of their own design, it would add to the complication of downloading and using it (on both ends). As you’ll read in Roland’s tutorial, HM01 has built in robust redundancies by using RDFT and DIGTRX. Very interesting.

Thanks, Roland, for sharing!

China appears to be jamming the BBC World Service (and the SWLing Post)

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Structure of a Denial of Service attack. (Image: WikiMedia Commons)

No doubt, in publishing this, The SWLing Post will be hit with another barrage of denial-of-service attacks. If you notice the site loading slowly, or completely off-line for periods of time in the near future, you’ll know why…

A few weeks ago I mentioned various upgrades to the SWLing Post web server. Part of this is due to our increased traffic and part is due to the fact that we were moving to a more secure server.

You see, recently I posted an article with a recording of Firedrake along with a follow-up from Post reader, Mark. Two days later, The SWLing Post was hit with denial-of-service attacks from IP addresses, all of which appeared to originate from China. It almost brought the whole server down–however, my intrepid web host, CloudWeb, scrambled to block the offenders, and they did an amazing job. You may note that I had to temporarily remove the Firedrake posts (they’ve since been re-published). I don’t consider this to be a conciliation, but rather a victory: for free speech, and for its power on shortwave radio.

Anyone who follows the SWLing Post with regularity will know that I’m a strong believer in access to and freedom of news and information, so I’m a bit annoyed by the DoS attacks that attempt, however unsuccessfully, to mute our voice in China and throughout the world. No doubt, The SWLing Post is already behind the “great” firewall, anyway.

If our site does go down, follow our updates on Twitter and Facebook.

With that preamble behind me, I owe my thanks to Andy Sennitt for bringing this article to my attention:

Reuters-Logo1 (Source: Reuters)

Radio broadcasts in English from the BBC World Service are being jammed in China, the British broadcaster said on Monday, suggesting the Chinese authorities were behind the disruption.

“The BBC strongly condemns this action which is designed to disrupt audiences’ free access to news and information,” the BBC said in a statement.

China, which enforces strict restrictions on its domestic media, has been accused by several prominent foreign media of seeking to stop their news reports reaching Chinese audiences.

“The BBC has received reports that World Service English shortwave frequencies are being jammed in China,” said the London-based public service broadcaster.

“Though it is not possible at this stage to attribute the source of the jamming definitively, the extensive and coordinated efforts are indicative of a well-resourced country such as China.”

A duty officer at China’s foreign ministry had no immediate comment.

[…]”The jamming of shortwave transmissions is being timed to cause maximum disruption to BBC World Service English broadcasts in China,” said Peter Horrocks, director of BBC Global News.

“The deliberate and coordinated efforts by authorities in countries such as China and Iran illustrate the significance and importance of the role the BBC undertakes to provide impartial and accurate information to audiences around the world.”[…]

Click here to read the full article by Estelle Shirbon; with additional reporting by Lucy Hornby; Editing by Tom Pfeiffer at Reuters.com

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