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Random numbers, Persian code: A mysterious signal transfixes radio sleuths

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Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#31
If anyone is interested in further reading, this group are the world's leading experts on number stations (outside of intelligence services of course). They've done a detailed article on the new station, including recordings, technical mishaps, and analysis of why they believe the station is CIA run. https://priyom.org/number-stations/other/v32

> Considering the topical interest in this station, the Priyom team shares its further expertise regarding V32's attribution, beyond being transmitted from a US military facility. While this remains unconfirmed speculation, and not facts, a prime candidate for the operator of this station would be the CIA. Contrary to popular belief, US intelligence has not entirely moved away from numbers stations. Sources in the intelligence community indicate that the CIA provides extra training about numbers stations and one-time pads to clandestine agents assigned to locations with a very hostile operating environment, such as Iran or North Korea: it is envisioned as a last-resort means of communication with high-value sources. So according to this, numbers stations are actually still an institutional part of the CIA playbook. The war in Iran, and the Internet blackout installed by the regime, fulfill the very circumstances for which the CIA would have planned this.

> We already know that the CIA has a significant presence in Iran and involvement in the war, having provided crucial intelligence tracking Iranian leaders that enabled the assassination strikes that kickstarted the war. They most probably have had a network of infiltrated assets already in place and organized, ready to be reached through a numbers station if need be right when the war started - which makes the CIA a candidate for running V32 consistent with a legitimate intelligence operation. However, what we've observed from V32's operations - technical quirks and shifting formats - suggest that the technical deployment of the numbers station and shortwave transmissions themselves may have been a little rushed by the circumstances.

> Another noteworthy feature of V32 is how all its transmissions take place on the same frequency. Most other numbers stations in general are comprehensive operations targeting many different recipients in different countries, and making use of many different transmission times and frequencies suited to the particular signal propagation needs corresponding to all those areas. In contrast, the fact that V32 always uses a single, same frequency, at always two given times of the day, would be consistent with an operation that only needs to target a single geographical area: Iran.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#32

Earlier quoted context omitted.

Shortwave radio is more challenging than you might imagine. Near to the transmitter it's received by ground wave, further it's scattered off the ionosphere. In-between it's undetectable due to the skip zone. This might also explain why Amelia Earhart went missing [1] Coverage is obtained from multipath and reflections. Leading to variable strength and timing. Not as bad as DXing on HF with low power but much harder t…

My father regailed tales of his college years where it was a game to have a HAM radio operator start broadcasting and to have teams try to find where they were hiding, first. More challenging? Not really. It does require multiple boots on the ground to do it.

[deleted]

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#33
post #29

Earlier quoted context omitted.

If you can receive a shortwave signal, you can triangulate the source.

Reflections will pose a problem though. Two receivers of the same signal may not be from the same proximate source. One could from the original antenna the other from a reflection. Both could be reflected but by different reflectors. Even if the proximate source was the same for both the receivers, triangulation might yield the location of a virtual image of the original source. BTW I am just going by geometry and ma…

Exactly I have friends who have had voice contacts reflecting off aurora at VHF

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#34
post #29

Earlier quoted context omitted.

Reflections will pose a problem though. Two receivers of the same signal may not be from the same proximate source. One could from the original antenna the other from a reflection. Both could be reflected but by different reflectors. Even if the proximate source was the same for both the receivers, triangulation might yield the location of a virtual image of the original source. BTW I am just going by geometry and ma…

Exactly I have friends who have had voice contacts reflecting off aurora at VHF

That made my day. Thanks for the laughs.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#35

I wonder why they keep using a dedicated numbers station instead of embedding the code in a regular radio broadcast on a traditional channel? I'm sure that even before LLMs one could find a way to create a story where certain numbers / code words would be embedded without altering the underlying story too much. And they could probably get BBC / whatever station to air it. It would be a bit less inconspicuous to liste…

regular AM/FM stations are not broadcasting on shortwave bands

There are still quite a few shortwave radio stations broadcasting.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#36

I wonder why they keep using a dedicated numbers station instead of embedding the code in a regular radio broadcast on a traditional channel? I'm sure that even before LLMs one could find a way to create a story where certain numbers / code words would be embedded without altering the underlying story too much. And they could probably get BBC / whatever station to air it. It would be a bit less inconspicuous to liste…

I can't find it immediately, but I've read about something even sneakier than this. A standard broadcast station was modified such that its carrier signal was modulated by a PSK signal. The intended listener would use e.g., a PSK-31 modem to listen to the carrier signal and would be able to obtain the encoded digital data. Everyday listeners would hear the regular broadcast. The station involved _might_ have been a BBC station, but I don't recall.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#37

I wonder why they keep using a dedicated numbers station instead of embedding the code in a regular radio broadcast on a traditional channel? I'm sure that even before LLMs one could find a way to create a story where certain numbers / code words would be embedded without altering the underlying story too much. And they could probably get BBC / whatever station to air it. It would be a bit less inconspicuous to liste…

who's to say they aren't doing both? They may not even be sending anything over the number station; these stations will continue on a schedule even when there is nothing to say and nobody is listening because it makes it harder to eek out a foothold in the event of a weakness in the encryption.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#38
post #15
post #5

This reminds me of UVB-76[0], a shortwave military radio in Russia. It would be interesting know why they're using this method to communicate covertly rather than beaming down messages to a phone via satellite or something. I'm not an expert on radios, though, so maybe it's not as clunky as I'm imagining where an undercover asset is hauling around bulky equipment. 0: https://en.wikipedia.org/wiki/UVB-76

Like the article says, satellite messages can be traced while radio is broadcast to everyone so it's impossible to find out who's listening. Shortwave radios are also cheap and widespread, so it's easy to get one anywhere in the world and if your house gets searched, it won't be suspicious if you have one.

Satellite unicast receivers also can't be located. Iridium pagers were (maybe still are?) a thing, for example.

However, carrying one of these is probably highly suspicious compared to a world band radio receiver.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#39

I wonder why they keep using a dedicated numbers station instead of embedding the code in a regular radio broadcast on a traditional channel? I'm sure that even before LLMs one could find a way to create a story where certain numbers / code words would be embedded without altering the underlying story too much. And they could probably get BBC / whatever station to air it. It would be a bit less inconspicuous to liste…

Shortwave propagates better and also its just a one time pad being distributed so embedding doesn't matter as much as long as the one time pad is longer than the intended message to send. There is no way to decrypt it because once you encrypt a message using a one time pad it is impossible to decrypt without the exact one time pad that it was encrypted with.

Re: Random numbers, Persian code: A mysterious signal transfixes radio sleuths

#40

I wonder why they keep using a dedicated numbers station instead of embedding the code in a regular radio broadcast on a traditional channel? I'm sure that even before LLMs one could find a way to create a story where certain numbers / code words would be embedded without altering the underlying story too much. And they could probably get BBC / whatever station to air it. It would be a bit less inconspicuous to liste…

regular AM/FM stations are not broadcasting on shortwave bands

Sure, but that would be a benefit, I would think. Most old cars come with an AM/FM radio, most cheap phones now have FM (? I don't know about AM, don't think so) and so on. So it would be more inconspicuous to listen to a regular radio than to a special station on special hardware. You don't even have to broadcast from EU, you could probably purchase some Radio Quatar Classical Rock or something :)
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