Number Stations and Enigma Stations
sigidwiki.com
sigidwiki.com
Number Stations - https://news.ycombinator.com/item?id=30496873 - Feb 2022 (23 comments)
Gerät 32620: the machine that powered numerous number stations - https://news.ycombinator.com/item?id=24342120 - Sept 2020 (66 comments)
Using KiwiSDRs to locate HF radio transmitters and numbers stations - https://news.ycombinator.com/item?id=17414699 - June 2018 (9 comments)
There must have been more threads about these...
And it's not impossible to locate a shortwave listener (especially in the days when numbers stations were commonplace). At really short range it's possible to detect the local oscillator though modern direct conversion techniques make this harder.
In the 80s some countries were using this principle to identify people watching TV without a license.
Nowadays with a good digital receiver, nothing leaks from the receiving antenna.
Though I wonder if spies used SDRs (or other direct conversion receivers) earlier than the mainstream for this reason.. On the other hand I've heard spies usually shy away from special electronics because it's a lot harder to explain than a standard holiday shortwave receiver.
A what now? :) Are you sure that is a lot harder to explain away than literally any computer gizmo looking object? (Today, not in the 70ies)
Exactly, numbers stations were a big thing in the 70s-80s.
In those days carrying a SW receiver was pretty standard and almost every country had a world service radio station that people would actually listen to.
These days using the internet makes a lot more sense yes, both for tourists and spies. Because spies want to be where the mainstream is to avoid detection.
(and why does google give me a map of Latvia for an image search of "rule 34 russian woodpecker"? cf https://kartinkof.club/uploads/posts/2022-07/1657128790_10-k... )
(and in 10th grade, there was this girl I was crushing on who was really into microprinting, so I tried to play cool and wound up with a closet full of photoreducers, and wouldn't you know, that hobby stuck too...)
Well, I'm a licensed ham radio operator.
I won't speak to the methods the US uses now, but Russians are fond of ad-hoc wireless networks in public places.
I wonder if this popular 2001 rumination on the difficulty of source attribution in public local networks had any influence on said preference: https://www.youtube.com/watch?v=TVdoQ2fmIYs
I always appreciated that in the lore of the STALKER games the PDA network that allows modern communication within the Zone is a cooperative mesh network between every STALKER's gear.
I guess clandestine operations now use expiring dead drops in the form of IP addresses with some protections, but they may be using applications or other hide in plain sight methods like chats rooms in games, etc., which are not unheard of.
Considering governments and intelligence services love to run Tor exit nodes from time to time, they may have their own darknet servers, too.
There's no way to be sure how they operate, and I don't want to dig into that kind of rabbit holes, to be honest.
Maybe in Asia or America you can listen more number stations.
(Usual risks of the person setting the drop (and therefore the drop itself) being under surveillance apply, I guess)
1. You knew what to look for, though you shouldn't have. They'll either disappear you, or call you paranoid and forcefully commit to a mental institution (where the treatment regiment will surely make you suffer all kinds of mental ailments).
2. You didn't know what to look for, but you found a legit signal anyway. This means they've fucked up - but once they realize that you know, you'll get the same treatment as in point 1. There is no "responsible disclosure" when it comes to spycraft, and the only bounty will be on your head.
3. You're just paranoid and imagining things.
By the time the wider public learns about you, the three possibilities here are indistinguishable.
1/ In the above example the message was “one if by land two if by…” and the encoding base was hexadecimal. Does a message exist that encodes in a different base but looks like it is hexadecimal? For example the OP’s message decodes to utk"ol"h if the base was actually 17. We assume it’s base16 not base17 because only the digits 0-F are used. Is there a string of pairs of digits in the range 0-F (without G) that would decode to something meaningful in base 17 (0-G)?
2/ And what about a message that means two different things — something innocuous in base16, with the secret message in base17, say? Other bases might work: 15 feels like a good candidate too, but it is probably harder to make a readable message the more you deviate from the masquerade base.