Rerun: TechStuff By the Numbers (Stations)

by the Numbers Stations. It's a pretty creepy one. Um, one of my favorite little topics, weird tech topics to talk about because it's a secret thing that's not outright hidden. The meaning is hidden, but you can discover these things if you just happen to have a short wave radio and some patients and you know, some good positioning. So

fun topic. Hope you enjoy tech Stuff by the Numbers Stations. Recently, Amazon canceled their television series truth Seekers, which I thought of as sort of a cross between Shaun of the Dead and The X Files. So in the series, a cable technician named Gus played by Nick Frost, is obsessed with ghost hunting, and he gradually indoctrinates his new partners as his name is Elton John. He's played by Samson Keo. Uh. Anyway, it's it's a cute show. It's a little odd in tone.

And the part that really applies to this episode, however, is that one of the things that Gus fixates on in the early episodes is a radio frequency playing a numbers station, and it's based off of an actual historical number station that folks call the Lincolnshire Poacher. And here's what it sounds like. Gree nine seven one five, Gree nine seven one hive, Gree nine seven one hive. So that's a real thing, or it was a real thing,

and it's not the only such station out there. There have been lots of numbers stations over the years, some using different jingles to signal an incoming series of numbers. Some of them have male voices, some use female voices, some used children's voices, Some of them are in more code, Some have people reciting not just numbers but letters and code signals. A lot of them are super creepy, which makes them really ideal for a show about paranormal investigation.

But while the supernatural stuff is fanciful nonsense, the numbers stations are actually anchored in our real world. And while tech stuff did do an episode about numbers stations many many years ago, I thought it would be good to use numbers stations as a way to talk about not just what they are, but also about short wave radio communications, the physics of radio in general, and the process of ciphering and encrypting information. So this is really gonna be

a big overview, catch all kind of podcast. So let's start off with radio itself. Radio waves are part of the electro magnetic spectrum. Uh. They are there along with stuff like my microwaves, visible light, X rays, and gamma rays. All of this is part of one big spectrum of electromagnetic radiation. You could actually think of it all as different flavors of light if you like. It's just that the slice of light that we can see is a

very small slice of the overall spectrum. Now, specifically, radio waves are in the long wavelength part of that spectrum. Electromagnetic radiation moves in waves all at the speed of light, because hey, really it is just light, just different flavors of it. But those flavors of light do have different wavelengths, which also means they have different frequencies. So what does that mean exactly, Well, let's start with wavelengths. Imagine a

nice smooth wavy line. The distance between two consecutive crests on that wave, so the very peaks at the top parts of our curve. In other words, that would be one wavelength from one crest to the next. A frequency just refers to the number of times a given cycle happens within a given amount of time, and we frequently use one second as the time unit. And with electromagnetic radiation, we talked about how many full wavelengths of a given signal pass a specific point in space within one second.

We also use the unit hurts to describe this relationship. A one Hurts frequency would have one cycle or one wavelength per second passing you know this given point in one second. A giga Hurts frequency has a billion cycles per second. Now, all electromagnetic radiation is traveling at the same speed, which is around three thousand kilometers per second in a vacuum. Because the speed actually changes depending upon the medium through which the radiation is traveling, that happens

to be the speed limit of the universe. Nothing goes faster than that, so the energy is traveling at that speed, but the frequency is dependent not just on speed but how long those waves are. In fact, because we know all these waves are traveling at that same speed, we can figure out the wavelength if we know the frequency, and vice versa. So the formula is wavelength equals the

speed of light divided by the waves frequency. Alternatively, frequency is equal to the speed of light divided by the wavelength. So as long as we know either the frequency or the wavelength, we can figure out the other one. Because the speed of light is a constant, it's not a variable. On the longest wavelength side of the spectrum are radio waves, which can measure more than a hundred meters in length.

So a radio wave with the wavelength of one would a frequency of about three mega hurts, meaning about three million wavelengths would pass a given point in a second, and each wavelength is measuring one meters between those crests. Again, the speed of the signal is still the speed of light. But let's say we get to the other end of the spectrum, towards the very very very tiny wavelengths on the electromagnetic spectrum, and when I say tiny, I mean

really tiny. Gamma radiation, which represents the smallest of the waves that we know about, are less than one hundred pico meters in length, and a picometer is one trillionth of a meter, so this is actually smaller than the nano scale. The frequency started out at around ten to the power of nineteen hurts or ten quintillion hurts. Now, I've talked about electro magnetic radiation in terms of waves, but we also know that it behaves as both a wave and a part nicle. There are a lot of

experiments that have shown this, and they're fascinating. But I don't want to get too far off track. Some of you out there might be screaming too late now, So we should also mention photons, the particles of light. A photons energy is directly proportional to the electro magnetic frequency of that wave. It's also inversely proportional to the wave length. So gamma rays pack a huge energetic wallop, while radio waves, by comparison, are whimps. So let's get back to the

radio spectrum in particular. We know that radio waves have the longest wavelengths in the electro magnetic spectrum, which means they also have the lowest frequencies and the lowest amount of photonic energy. Generally speaking, we group electromagnetic frequencies ranging from thirty hurts or thirty wavelengths per second up to three hundred giga hurts or three hundred bill in wavelengths per second. Obviously, this is a really big range, but

all of that are radio frequencies. Now, different countries divvy up this spectrum of frequencies for different uses, some of which depend upon the capabilities of those frequencies. So, for example, if you're looking at around thirty hurts, this is the extremely low frequency or e L f ELF range. You know, I used to play in ELF range in Dungeons and Dragons. Wait,

I'm thinking of something else. So these wavelengths are really long, and they are good at penetrating stuff like deep water, so it can be used for very basic communications with submarines. A M radio would be up in the medium frequency range for radio frequencies, and also the medium wavelength range. Just above that are the high frequency short wave radio bands, which are what we're really going to talk about a

lot today. These have a wavelength between ten and one, and frequencies that are between three and thirty mega hurts. Radio Waves in this band of frequencies have some really useful properties, and one of those is the broadcast range, as in how far these radio waves can travel. So higher frequency radio bands can essentially only travel by line of sight, so there is a limited range to them.

If you've ever listened to an FM radio station, because FM frequencies are in a band called very high frequency or VHF, then you might have had the experience of the station starting to give out as you travel away from the source. Depending upon the power of the broadcasting station, you typically have a range of around thirty to forty miles or fifty to sixty kilometers, but radio waves that are a bit longer can travel further thanks to a

layer in Earth's atmosphere called the ionosphere. Higher frequencies can move right through the ionosphere. They just punch right through and go into space, but lower frequencies, those having the longer wavelengths, aren't able to do that, so they actually bounce off the layer and come back down to Earth. By reflecting back down to Earth, these radio waves could travel much further than they would just by line of sight. Now, as the name suggests, the ionosphere is a layer of

our atmosphere that is host to ionized particles. Ionization is the process by which an atom becomes charged, either with a positive charge, meaning it has lost electrons electrons are the negatively charged particles. So then you've got an imbalance. You have more protons with the atom than you have electrons, and thus you have an overall positive charge, or it could become negatively charged, meaning that an atom has taken on more electrons. Now, this makes that layer of Earth's

atmosphere electrically conductive. It happens because our atmosphere is hit by ultra violet light from the Sun and it hits the atoms in this layer of the atmosphere. It energizes those atoms, and when the atoms get really energetic, the electrons move further out from the nucleus and they can

actually peel off if they have enough energy. Now you've got free electrons, and those free electrons are either reflecting radio waves if they have a long enough wavelength, or they can actually absorb them or otherwise allow them to pass through for shorter wavelengths. This works in both directions. By the way, not just radio waves coming from Earth, but also radio waves that are coming in from space,

because lots of stuff out there generates radio waves. I'm not talking about aliens, I'm talking about like solar activity and stuff like that. Now, the activity of the ionosphere changes throughout a day over any given spot on Earth. So during the daytime, that part of the Earth is facing the Sun, so the atmosphere overhead is being hit with a lot more ultra violet radiation, and thus the lower part of the ionosphere, the part that's closer to us,

ends up getting more crowded with ions. Now that means that longer radio waves are going to hit the ionosphere at a lower altitude and then reflect off. But at nighttime, the Sun is on the other side of the planet, so the lower part of the ionosphere kind of calms down a bit, and now the longer radio waves will actually travel at a further altitude. They'll go higher up

before they hit the ionosphere and reflect back down. That also means that you can actually pick up longer wavelength radio signals from further away at nighttime because there's this different angle that allows the waves to reflect and travel even further. Now the history of radio, as in the technology that we use to leverage radio waves. This gets complicated because we call the technology the same terms as we call the the scientific phenomena that is in our

operating with the technology. But we'll we'll carry on. So the tech radio has a very long and complicated history, and it's full of some really serious drama. I mean not just radio dramas like soap operas, I mean like drama drama. Just get a couple of radio enthusiasts talking about Tesla and Marconi or Armstrong and DeForest and see

how things go if you want some entertainment. But we'll just cut to the chase and say that by World War One, people were figuring out potential uses for radio waves, like being able to send communications quickly across large areas if you know you're trying to coordinate numerous groups of

soldiers in different theaters of combat. For example, communicating by radio involves generating a carrier wave signal at a specific frequency and then modulating it, so, in other words, changing that signal in some way in order for it to carry information. A steady signal gives you no real useful information other than someone or something is generating this signal, But by creating a way to encode and decode information by altering that signal, do you have a way to

send more complex information. A M radio modulates a carrier signal by changing the amplitude of the wavelength, and this requires a good deal of power, and the long wavelengths mean you need big radio towers to beam out these signals. FM radio modulates signals through frequency modulation, altering the frequency

of the signal slightly. And radio stations, like the kind we tune into for entertainment purposes, these are fixed frequencies right like If they weren't, you would never be able to tune into your favorite radio station because you wouldn't know what frequency to go to. So this means they can't take advantage of the changes in the ionosphere. They're always stuck transmitting at a set frequency. See whether conditions are good for long range transmission or not. Shortwave radio

operators have a little more flexibility. They're working with a specific series of frequencies in the high frequency range of the RF spectrum, but they can swap from one of those sets of frequencies to another and thus take advantage of atmospheric conditions, so early in the day you might use one set of frequencies that are available to you, and late at night you might use a different set, because the actual radio waves will travel at different distances

as the day changes. But there's another aspect to communicating during wartime, which is that, generally speaking, you don't want the people who are fighting on the other side of the war to know what the heck you're talking about, so you have to come up with some means of of you skating the meaning of your message. This is particularly important with radio for a very obvious reason. See, there are a lot of different ways to send secret messages,

and some of them are more secure than others. If you and I are the only ones who know about a black, glassy rock near a trina field, you know, a rock that has no business being there, and I hide a message under that rock for you, there's a decent chance that you'll get to the message before anyone else does. I might not even need to encode the message at all, because no one else even knows that there's a rock there. If I were to send you a message through the mail, well, now there's a few

points where someone could intercept that message. Right. I mean, perhaps the batties check my mailbox. They see that I've put the little mail flag up, so they come and check it and they steal the message before I can even go anywhere. Or maybe they keep checking your mailbox on the other side, looking at incoming mail, and they

grab my message when it arrives at your mailbox. Or maybe they're super tricksy and they've infiltrated the postal service and Cliff the mailman is secretly a dirty old spy always suspected it. Well. Radio communications are out in the open. Anyone with a receiver that has an antenna that can tune into whichever frequency is being used can actually listen in on that frequency. So you have no control over

who can hear what you're sending out. So if you're sending something out in secret, you have to encode it in some way that makes it hard or impossible to determine what is being communicated. Now, when we come back, we'll talk about how this sometimes involves making creepy radio broadcasts. But first let's take a quick break. Let's say you

want to create your own radio station. You've put up a transmission tower, you figured out your power needs, to generate the signal necessary to claim a subsection of the r F spectrum set aside for broadcasts, and you're ready to go right, Well, no, not if you don't want to get shut down and find or worse. In order to make sure the spectrum isn't just a free for all, which would make communication difficult at least, governments have designated

specific bands of frequencies for specific uses. See if multiple transmitters were trying to use the exact same frequency, everything

would get garbled. You would have tons of interference. If you've ever used a pair of walkie talkies, you probably know that it's standard for folks to say over when they're done talking because the walkie talkies switched between transmitter and receiver mode, and without the over you might have both parties trying to talk at the same time and no one can hear anything because you're both holding down

the transmit button. Well, when you think about all the radio, television, cellular, WiFi, and other signals zooming around out there, all of which are part of the RF spectrum, you quickly realize that you've got to make up some rules or else no

one would ever know who they're talking to. Now, way back in eighteen sixty five, the International Telegraph Union came into formation, and in nineteen thirty four it changed its name to the International Telecommunication Union, and it's part of the United Nations today, and one of its jobs is to designate specific slices of the RF spectrum for specific

uses to allow for seamless operations between the world. That way, the radio is made by a company in Japan will work in places like the US because the frequencies that we've set aside for terrestrial radio stations are the same, assuming that both US and Japan are following the suggestions from the i t U. Now it's up to the

governments of various countries to enforce these rules. In the United States, radio stations have to obtain a license from the Federal Communications Commission to get a permission to broadcast on specific frequencies within the A, M or FM bands of the ur F spectrum. There are other frequencies reserved for amateur radio operators, but if you want to operate your own amateur station, you have to get a license from the f c C, and passing a test is part of that process. Now, if you just want to

listen to radio. That's different. You don't need a license. In that case. You could have a shortwave radio set and as long as you're not transmitting, you're just listening, no licenses needed. But to transmit you gotta get permission first, and the f c C will even assign a call signed to you. Number stations are different. With commercial radio stations, you can do some research to see who owns and operates that station, but with numbers stations, there's a distinct

lack of information. This puts them in the realm of pirate radio stations. These are stations that have no identifying information associated with them, and they are operating without being registered with the FCC or similar agency in other countries. Now that doesn't mean that these agencies like the FCC don't know about them. There is a look the other way situation in which one part of the government is using stuff that the other parts just don't need to

worry about. You know, by the way, if you're wondering if people operate pirate radio stations, they sometimes do. But there are ways to triangulate signals and determine where those signals are coming from. So if someone is broadcasting without permission on a specific frequency. It's typically just a matter of time before the Feds come in and shut things down. Now, you could hop onto other frequencies, but unless your audience knows where to tune in, you would likely be talking

to no one or at least very few people. So, since we know that it's possible to figure out where a radio signal originates, and since numbers stations can remain in operation for years or decades, we have to draw the conclusion that these numbers stations have some sort of sanction from governments, otherwise they would get shut down. Now, some sources say that numbers stations, these radio frequencies that are sending out seemingly nonsensical information, got their start in

World War One. Others say it was actually closer to World War Two, and I tend to suspect that the ladder is more accurate. Radio was important in World War One, but it was also still pretty early on in the evolution of the technology. But at some time around World

War One. In World War Two, someone got an idea, and that idea was to establish a transmission on a particular signal, or sometimes a series of signals that would change throughout the day to take advantage of the ionosphere and the differences and signal propagation, and the signal would broadcast encoded information presumably two spies. So let's say you're

running a top secret spy organization like the m I six. Now, granted, you're spending a lot of time dealing with the fact that your top spy has a habit of introducing himself to any one in hearing range and then drinking his way across the world. But you've got a lot of other more responsible spy types out there too, and you

might occasionally need to send them orders. But if your operative is halfway across the world, deep in enemy territory and you can't rely on normal communication channels, you might want to send a coded message by shortwave radio. This has a huge advantage and that the radio signal goes out everywhere, so you know that your enemies will be able to detect the signal, but they won't know what

the message was or who it was actually for. If you were to call your operative, it's possible someone could detect the call and trace it to the recipient, the spy, and thus compromising them. So sending out a message by a radio means you give no information about who is supposed to receive that message. The operative knows to tune

into a specific radio frequency at a specific time. This is something that you have to work out beforehand, obviously, as most of us aren't aware of what's going on with radio waves all around us, or we'd have a lot of trouble concentrating on anything. You might set up a regular broadcast session using different frequencies throughout the day,

depending upon whichever one works best. And maybe some days you have nothing to report, so you might even send out a code for that, or it might just be gibberish. But other days you need to alert your operative to return home, or step it up and place a bigger bet in baccarat or whatever it may be. So these numbers stations typically have some sort of indicator at the top of the hour. The Lincoln Share Poacher, which we played at the beginning of this episode, is an example

of that. That little tune marked the beginning of a transmission, followed by the actual message. The message would be a sequence of some sort, typically numbers, sometimes letters. The voice might be a recording, or it might be read live on the air. It could be a man, a woman, or a child's voice. You might pick up a short wave signal with someone counting in another language. But what

do those codes actually mean? Well, that's the real question, and that's one that's kind of impossible for us to answer because the coded messages use an approach that is unbreakable assuming you don't get hold of the secret. So

this leads us to a discussion about cryptography. Cryptography, or the art of writing and or breaking codes, is ancient, and people have come up with a lot of interesting ways to hide important information even if it's in plain sight, and have it be indecipherable as it were to the

uninitiated at least. These range from the very simple strategies such as a rudimentary replacements for like the Caesar cipher, where you just substitute symbols for letters or just shift letters around, so, for example, you might say a B actually means C and a C means D. That's a very simple Caesar cipher. While these sort of ciphers might confound someone at casual first glance, they aren't particularly hard

to crack. If you happen to know what language was used to write the message, you can look for patterns in those symbols to indicate common letter combinations. So, for example, in English, the letters J, Q, X, and z are really pretty rare, but the letters A, E, O, and T are really common. So you can look for symbols that show up a lot and start to think, well, these most likely represent some of the most common letters.

And then you have letter pairs. In English, you get stuff like T H, E, R, O, N and A N a lot. You can also look for common double letters like T, T, S, S, E and so on. Knowing the rules of the language means you can start looking for clues as to what these symbols actually represent. Some ciphers take one little extra step, including some symbols for common letter pairings. Really, this is just taking a

page from other alphabets, including older English alphabets. So for example, the old English letter thorn represents the th h or the sound. So maybe you have symbols that can represent certain letter pairs or double letters or phonetic sounds, and that can make it a tiny bit more challenging if someone wants to break the code. Now. There are also ciphers that use clever means to change how letters are encoded in some predetermined way. Which is what the famed

Enigma machine could do. The Enigma machine was like a really complicated typewriter, only when you hit a given letter such as W on the machine, the machine would generate a different letter based on whatever its initial settings were. So let's say you hit W and you get G instead. You write that down for your encoded message. Then the Enigma machine would advance its mechanism so that the entire

encoding process changed. So if you hit W again, now the machine wouldn't produce G for the second W, it would produce something else, like maybe P. The Enigma machine was so complicated that it prompted Allied forces in World War Two to construct early computer systems. And had it not been for a couple of quirks with the machine, so, for example, the machine would never use the correct letter as a cipher for itself. Well, if it hadn't been doing those sort of things, the Allies might not have

ever cracked that code. And there are other methods to send information in a clandestine way. There's hiding information within some other message or inside a physical object. This is called steganography. So you can imagine a painting that has a hidden message incorporated in it so that anyone who's just looking at the painting just see's a painting, but someone who knows what to look for can read the message.

Steganography is fascinating stuff, and in our modern tech age, it can extend to stuff like files that are hidden within other files. So how do numbers stations keep information secret? Well's through one of the oldest tricks in the book, the one time pad. Using a one time pad properly is pretty much a guarantee that no one will ever be able to crack the code. It's a perfect cipher in that regard, though in other ways it has its

own drawbacks. Now, when we come back, we'll talk about the one time pad some of the famous number stations out there and speculate on what it all means. Spies. It means spies. We'll be right back, okay. So the beauty of the one time pad is that if you do it correctly, it is unbreakable. The reason for that

is two fold. One is that the key that you used to actually encrypt the message is a randomly generated key, So each letter of your message has an encryption method that is independent of every other letter in your message. So someone intercepting the message won't be able to look for those patterns in the symbols. And the other reason is that you use each randomly generated encryption key only once.

After you use it, you destroy the key. Since you don't repeat the process, you avoid giving code breakers enough information in order to crack a message. If the code never repeats, you can't establish any patterns. Now, the downside of this is that you do have to make sure that everyone you're communicating with has a copy of the

encryption keys. So whenever you generate that random key, you have to make sure the person or people that you're sending messages to have exact copies that they are able to keep safe. Going back to the Enigma machine, if the Germans had followed the procedure of changing the machine settings for every single message, it would have made the code even more difficult to crack. But an actual practice, doing this was very hard to keep straight and could

result in miscommunication. So for the sake of convenience and clarity, the Germans often wouldn't change the settings as frequently as they were supposed to, and that gave the Allies a foothold and figuring out what was actually going on. Generating a coded message requires a few steps, and since we're talking about numbers stations, I'll go with numbers first. But keep in mind, it's not just the way numbers work, it's just it's the easiest way to explain it to

you guys. So your first step is that you create a simple substitution cipher for all the letters in the alphabet, plus any symbols that you plan on using, for example, any punctuation. You assign numbers to each of those letters and symbols, So you could go just as simple as numbering the English alphabet from one to twenty six A

to Z, but that's pretty simplistic. So you establish your basic cipher, and you make sure everyone who needs it has that they know that if they see a one, that means a two means to be for ciphered text. But that's just one step. Next, you generate your encryption key. Now, this should be a string of random numbers, with each number ranging from zero to nine. Typically you group them in blocks to make it easier to trans it and receive. The most common one I've come across is blocks of

five digits each. Now this is really important. Your encryption key has to be as long or longer than whatever message you intend to send. So if your message is one forty characters long, you need one hundred forty randomly generated numbers, and you create a whole bunch of these for the purposes of communication, with each encryption key taking up a single page out of a path of paper.

If you were to look at one of these sheets of paper, all you would see are a bunch of digits divide up into groups of five, and just no apparent pattern to them because they would be randomly generated. So when it comes time to encode a message, let's say your message is extract asset. That's what you want to tell your operative. You would write down your message in English, So you write down extract have a space asset, and then you would use your cipher method to change

each letter into its corresponding number. So we'll go with the very simple substitution of A is one, b as two, and so on, but we would probably use something different in the field. We're gonna use zero as an empty space. A lot of real number stations use a different method UH in order to make it easier for people who are receiving the messages to actually decode them, but you

get where I'm going. So using our substitution cipher, we see that the first letter of our message, the E in extract, would be the fifth letter of the alphabet. So our first ciphered note is five. The second letter of extract is X. That's the twenty four letter, So then we have to write to four. So this actually takes up two digits in our our cipher text. When we're done, are simple substitution cipher would look like this.

This is extract asset. If we were to write it all out by numbers, it would be five two four to zero, one eight one three two zero zero one one nine one nine five to zero. But this is not encrypted yet. It's just enciphered, which means that if someone were to intercept this message, they could potentially suss

out what it means pretty quickly. I mean, for one thing, if you listen to that, even though it's broken up into two different blocks of of digits, you do have a repeating one nine one nine in there that could indicate a double letter, and in this case it actually does. Those are the two s. Is an asset, So now

you have to encrypt this mess age. This is when we take one of those randomly generated encryption keys, the ones that are at least as long, but preferably longer than the messages we plan to send, and we've grouped the encryption key into blocks of five digits, but again these digits are each randomly generated. We grab the first key off our pad. Let's say that this key starts with a five digit block that says zero eight to

three nine. Now we would probably just hold onto those first five numbers, not use them for encryption, because those first five numbers will alert our agents in the field which of the encryption keys they need to use, because remember they have a whole pad of these things, and each one is different, so they have to look in their pad and say, all right, well, let's look for the encryption key that starts with zero eight to three nine.

That's our starting point. So we've got our ciphered text and beneath those numbers of the ciphers, so our first block was five to four to zero. Beneath that we would write the second block of the encryption key, and then we would do the third block of the encryption key, then the fourth block, and then the fifth block to correspond with the four blocks of five numbers that represent extract asset. Now again these are randomly generated digits from

zero to nine. Then we do quick subtraction digit by digit. We take the encryption key number for each corresponding digit of our ciphered text, and we subtract the encryption key from the ciphered key. So I remember our first five numbers of our cipher text are five to four to zero. Let's say that our randomly generated encryption key is two seven. Well, if we're subtracting digit by digit, that means our first pairing would be the five from our block of cipher

text and the two from the ccryption key. So five minus two gives us three. This is the beginning of our encrypted text. But our second subtraction is seven that's from our encryption key, from two that's from our cipher In this case, you would make the two a twelve for the purposes of subtraction, and your answer would be five and so on. So you subtract each encryption key digit from the ciphered message digit to create the encrypted message.

So our first block of encrypted five digits would be three, five, three, three five. Remember we started with five to four zero. That in turn stands for the letters e x T. Anyway, you do this encryption method for your entire message, you turn it into blocks of numbers. Then you can broadcast those blocks of numbers through a number station. The agent tunes into that specific frequent see and agreed upon time.

They listen for that first block of five numbers, they grab the sheet out of their pad that corresponds to that. They write down the message that's being broadcast, number by number. They match each new number to the next digit in the encryption key, and then they just add those two numbers together to get the ciphered version of the message. Then they convert the ciphered version to the original message,

so they're just reversing the process. It's pretty elegant, and because that encryption key is random, it is impossible to crack. This is also why if you listen to a numbers station broadcast, the speaker typically will repeat a block of five numbers a couple of times, maybe several times, before moving on to the next block of five numbers. This gives the listener enough time to make sure they are transcribing each digit correctly, otherwise their decryption process isn't going

to work. Now, this key is impossible to crack as long as that encryption key remains random. But generating random numbers is actually trickier than it sounds now. One way to do this would just be to take a ten sided die and roll it a bunch, and then write down each of the results of your roles as you go.

The number of times you roll the die depends on how long you're encryption key is going to be, but keep in mind you want that encryption key to be at least as long as the messages you're planning to send preferably longer. So if your key has twenty blocks of five digits each, you would be rolling that die one d times and writing down the results, and the first five digits of your new key typically aren't used

as encryption, but rather identification. You can use other means to identify which pad or which page and a pad you should be using, but that's a pretty common one. There are computer programs that are supposed to generate random numbers. You know, you've probably heard of r n g s A random and umber generators, but what these really do is that they generate pseudo random numbers. They're not true

random numbers. Computers have to follow rules. Now, those rules can be really complicated, but they're still rules, and randomness sort of falls outside of the rules category. So computer

random number generators typically aren't truly random. Now to mere mortals, it can seem random, but in most cases, a person who knew the rules that the program was following in order to generate the numbers could create another program to duplicate that result, and that means the numbers aren't really random at all, and that could put an encryption key at risk. For that reason, a lot of spy agencies don't rely on computers to generate random numbers. Typically they'll

use other methods. Numbers stations really proliferated in the years after World War Two and throughout the Cold War, presumably because you had spies all over the Ding Dang during place with American spies in Russia, you had Soviet spies in America, and so on. The numbers stations declined in well number over the years, but there are still a

few out there broadcasting digits to whomever is listening. Some of them may still be connected to espionage, but others might be connected to non governmental activities, you know, like drugs, smuggling. Some of the numbers stations are shall we say, executed in a less than professional manner, which suggests that they are not backed by, you know, state backed operations. It's also possible that some numbers stations are broadcasting out meaningless

numbers just to obvious skate what's really going on. If you flood the airwaves with nonsense, you keep your opponents guessing at what you're actually up to. Now I've already played for you a bill of the Lincolnshire Poacher Numbers Station, which may have well been connected to the Seek Intelligence Service of the UK. But there was also the Swedish Rhapsody, which would begin with a jangly little tune that sounds

like it came straight from an ice cream truck. There was the Gong, which began with a series of low pitched percussive tones as if bells or gongs were being struck, followed by someone reading out numbers in German. There were tons of others, and there's still several in operation today. A Keen Fernandez, a short wave radio enthusiasts, became fascinated with these numbers stations and released a set of CDs containing recordings of various Numbers stations from around the world.

You can find the recordings available online for free, and lots of musicians have actually incorporated parts of those recordings into their own works. One of the brilliant things about number stations is that, well you might figure out where the broadcast is coming from if you have the equipment to triangulate a signal. Like I said before, you have no way of knowing who those messages are intended for. They're just broadcast out into the world, so anyone could

be the intended recipient. But there have been a few cases in which authorities caught spies and uncovered their involvement with Numbers stations, but not because they had some magical way of finding out who was getting the messages. So, for example, in two thousand one, U S authorities arrested Anna Mantez Montez had secured a position with the US Defense Intelligence Agency, which, y'all, that's impressive for a spy to infiltrate an organization that you know spies on people wowsers.

And actually that happens, not like super frequently, but way more frequently than I would have thought. I figured, if you're the experts on spying, you should be pretty good at picking out ones that are trying to infiltrate your organization, but as the Mission Impossible movies tell us, that's not always the case. Anyway, the authorities suspected her of acting on behalf of another country. They searched her home and they found a code sheet for encrypting messages, plus a

short wave radio. It turned out she was spying for Cuba, and in eleven German authorities arrested a married couple named Hydron and Andreas Anschlag, both of whom were spying for the Russians and had been for years before the Berlin Wall had come down. During the raid on the couple's home, Hydron was actually in the middle of receiving a short

wave transmission. In the United States. In the mid nineties, the FBI identified possible Cuban spies in the United States and they managed to break into the home of one of those spies. They found a computer there with a decryption program on it. Essentially, it was a computer with the one time use pad programmed into it, so it had the codes used by numbers stations, and the FEDS just copied the key and they used it to decipher incoming messages that allowed them to build a big legal

case against numerous spies. But again, if done correct, this approach is unassailable. It just requires that the spies remain you know, undetected through other means, and that they keep a tight grip on their decryption keys. Otherwise the jig

is up. And while the number of stations continue to be creepy and a suitable fit for films and TV series about paranormal stuff or aliens or whatever, the truth of the matter is that they're probably telling operatives overseas to knock it off with all the martinis and extract assets stuff like that. Fascinating things. By the way, you

can find lots of recordings of numbers stations online. You can also find websites that allow you to use a software that lets you tune into different shortwave radio frequencies around the world, which is really really cool that it lets you actually listen in two different shortwave broadcasts which may or may not be number stations. I mean, there are a lot of people using shortwave radio to just chat with each other like amateur radio operators, but occasionally

you can actually find operating numbers stations. There are lots of resources online if you are interested in looking into that. You can also always invest in short wave radio equipment, although that kind of depends on where you are, like it may not, you may not be able to pick

up really interesting broadcasts depending on your location. You also typically have to use really super long antenna that need to be you know, elevated a pretty good distance to pick up broadcasts from really far away, so your mileage

may vary with physical shortwave radio setups. But as I say, there are websites where you can tune into someone else's short wave radio and use special software that lets you tune into different frequencies, being able to really listen in on whatever is going on that's being picked up by that particular radio set. So if you are int said, make sure you do some more research and check it out. Very cool stuff, all right. That wraps up this episode

of tech stuff. In our next episode, who knows what I'll talk about, I don't, but I'm looking forward to it. If you guys have suggestions for topics I should cover in future episodes, let me know. It could be a technology, a trend in tech company, a person, really, anything that's related to tech I'm eager to look at, examine and then report back to you guys. But let me know on Twitter the handle there is tech Stuff h s W and I'll talk to you again really. Sion Text

Stuff is an I Heart Radio production. For more podcasts from My Heart Radio, visit the I Heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.