Welcome to Stuff you missed in History Class from how Stuff Works dot com. Hello, and welcome to the podcast. I'm Sarah Dowdy and today I am joined by a very special guest, Jonathan Strickland. Hey there, So you guys probably remember Jonathan Strickland. He joined um. He joined both of us a few months ago as the Admiral for our Renaissance Festival episode. But this time he is here in his real life version, presenting on technology, which is your your specialty, my forte. As they say, there will be no hazas this particular episode. Maybe we could squeeze one and at the end or something. But Jonathan is the co host of tech Stuff is probably a lot of y'all know, and he also is a staff writer who specializes in technology articles and Deplina and I often talk about how you would like somebody like Jonathan and Chris to join us for technology related episodes sometimes when we really want something better explained than we're able to do. And we've actually covered a lot of the same topics as you and Chris too, Yes, that's true. We've We've covered several things, including Ada Lovelace, who I think got an enormous amount of praise on both of our podcast she was phenomenal, absolutely holomonal to be able to reach a point where not only was she able to write programs for a machine that did not yet exist, but recognize that numbers can substitute in for things and actually represent other forms of media like music or pictures at a time where there was no device to do that. On is beyond my imagination to do all that while being the daughter of Lord Byron. Of course, well you know, I would say that helps probably had a little dose of the crazy in there too, but no, absolutely phenomenal and other topics as well, But yes, and this is one that that I know that stuff you missed in history classes touched on related topics, and we at Tech Stuff have talked about some related topics, but we wanted to sort of look at the overall picture of what cryptography was like during World War Two. And this will be sort of the kickoff of a little series that I'm going to do with a few other How Stuff Works podcast co host who all focusing on something that's history related but also focused on their specialty. So that's why Jonathan has picked Codes Today, something that is tech related but has a really fascinating history behind it too, Yes, and that history stretches way back before World War two, of course. Uh. And I even had a little crash course in cryptography I wrote up so that we could kind of have a common language to work from. And it does come from a pair of Greek words. Essentially means hidden writing is what cryptography really boils down to, and it is the idea of hiding a message by encoding it and so way, and very common way is using a cipher where you are replacing letters within a message with some other letter or symbol or number, and you're using a very specific key so that someone who receives that message, the intended recipient, can take the encoded message, they take the key, and then using the key, they decode the message. But ideally anyone else who intercepts said message would just have a bunch of gibberish that they could not understand. Now, in reality, a lot of these ciphers don't remain secure forever, and we will see, right and there we have some very good examples of that. But there are a lot of different types of ciphers, and one of those, the most basic is the mono alphabetic cipher. That's where you use one symbol to replace each letter, and probably everybody is familiar with that one. It's what I used in my spy club as a kid. It's pretty straightforward. Maybe when you're eight it seems like it would be a breakable, but in reality it's pretty easy to crack right right. This would be when you might say, all right, let's shift all the letters over four letters, and no one will ever figure it out, right, So A becomes D and B becomes E and uh. It seems at first, when you are unaware of how to analyze cryptography that that would be be fairly secure. But just using something simple as a frequency analysis, which is typically the frequency that certain letter combinations appear in any given language. So if you know that the message was written in English, you know it's ciphered, but it's an English based language, you could start looking for letter combinations that would give away what the coded letters are. So look for double letters for example. Those could be ta s or l's, things like that, things word very short words exactly if you haven't. If you if you have your text actually broken up in the same grouping of of letters as your plain text, words are that's a dead giveaway, which is why a lot of ciphers are written in five letter blocks, so that you might even have two short words combined together or a very long word broken across a couple of blocks, and it makes it harder to detect, but even then pretty easy to figure out exactly the analysis. So another version of this one that's a little bit more complicated, is the polyalphabetic ciphers, and those substitute each letter with a different symbol based upon where the letter appeared in the message. So instead of a direct substitution, just it's the first letter, it's the second letter, and so on, it can be like that. Yeah, and there's there's a couple different methods of doing this where, for example, the first time the letter if the letter A appears in your message, it maybe in ciphered. I'm just grabbing the letter at random with L. And the second time the letter A appears, it may be the letter D. And it all depends upon the specific set of rules you have set down for that key the algorithm, if you like, that's the specific protocol the you follow, and that does make it much more difficult to break because you can't guarantee that every time you see a certain cipher that it's going to translate to the same letter. Moving on from there, we get a little bit more complicated and have polygraphic ciphers. Those use a combination of letters, numbers, or symbols for each quoted letters, so we don't have this direct translation anymore. It's not going to be something that you can just break out into the original words in the plane text to the cipher text. That's right. You. It's very confusing when you first get one of these messages because you can't be sure how many characters represent one single letter, and by doing that you really make it more difficult to break the code. And then I think the last one we have here is the transposition ciphers, which it's kind of like a word jumble, where you've taken the letters of the of the message, the plane text message, and you just mixed up the letters. So you're not replacing any letters here, you're mixing them up according to a in a prearranged code. So you might say, all, right, letter of this message should appear first, then the fifth letter of the message apers second, and you just follow that key and as long as the other person has the same key, they can unscramble it, but of course that's not terribly safe either. People with a lot of imagination can piece us together, sort of like Sunday Morning. Not for your top secret message. Yeah, a hobbyist could could crack that with enough ingenuity and time. So another element in here, and one that we're going to be talking about quite a bit in our second episode on this uh this subject is codebook. So code books, of course contain a list of phrases that linked to specific code words. So if you were just reading them, they might be familiar words, but they don't have any meaning to you. You can't you can't decipher it. You can't into it what the word might represent in any way unless you have the book right. So you could possibly break a cipher and you know that this next word is hawk, but you don't know what hawk means. It could it could mean a bird, but it might actually stand for something else, probably does in the case of wartime, And you know, you might be able to make some guesses, but you're not necessarily going to know. So codebooks were also very very important on both sides during the World War Two, And if you combine that with ciphers, you are getting a pretty tough code. Finally, and then a related technique to cryptography is called steganography, which is hiding a message within an image or some other kind of medium. Right, this is really super cool stuff. This is where let's say, Sarah that I met you on the street and I handed you a postcard and the postcard just said hey, how are you doing? And it has nothing else on there's no other message there, and you think, oh, well, that's just completely innocent. But on the flip side of the the postcard, where the picture is, which looks like this nice little landscape, you could maybe actually noticed that along the edge of a lake, there's really a message that's in there. And you look more carefully and you see that there's something hidden and it's hidden from plain sighte uh. And it can get a lot more complicated, especially with today's technology, where you can hide things in u R L, you can hide things within a QR code. It's it's lots of different ways of hiding a message, but it's done in such a way that from the casual observer's perspective, no message even existed. I like this one, although it doesn't sound quite as practical as the others, especially for wartime communications. You're not really thinking romantic spy sort of stuff. Yes, exactly, all right, So now that we've gotten a background on cryptography, we can start talking about how it was used in World War Two, which is sort of the heyday almost it seems, of cryptography. It's it's really I would say World War Two is probably the foundation for modern cryptography. The developments that were made during that era leading up to World War Two, but really uh intensely built upon during the years of World War Two that has led to to the way we use cryptography today. So it's it's an important time in history as far as this whole development of science is concerned. It is. And we're going to start by talking about the axis powers use of cryptography, partly because we want to start this whole thing off by talking about the Enigma machine. It's probably the most famous example of cryptography in World War Two, I would say, and something that we have both talked about on our podcast. Deplena and I talked about it in our Alan Touring episode. You and Chris talked about it in your Alan Touring episode. It's something that I think most people out there are they've at least heard of it. Yes, And if you were to look at one of these things, it would look like it was a typewriter and a whole bunch of lightbulbs and some plugs going every which way, and you might wonder what was the purpose. Looks like a mad inventor thought. It really doesn't. And the person who actually thought it up was not a mad inventor. He was he was quite He was ingenious in his own way, as Dr Arthur Sherbius, And that was in nineteen twenty three, and he was inventing this not as a means for the government to pass along secret messages to various branches of the military or intermilitary messages. It wasn't meant for that at all. It was meant for corporations to try and send secret messages so they could keep corporate secrets, so that other competitors wouldn't steal corporate information, private information private. But of course the German government quickly realized that this could be a useful tool for very secret communications, and so in nineteen the German Navy started using a modified version of the Enigma machine and and from there it sort of picked out the German Army followed in nineteen The Air Force started using one in nineteen thirty three. We should say, though they were all modified, they were all a complicated version of this commercial machine, right, and they even evolved during the course of World War Two somewhat. Now, if you want to know what the basic sheen is, you have to imagine imagine a disk around wheel, all right, and it's thick, It's about maybe half an inch thick, and on either side of the wheel are contacts electrical context that an electrical UH current can pass through. Along the outer edge of the wheel, where if it were a tire, this is the part that we make contact with the ground. Along that outer edge are letters that represent positions. Now you have three of these in a basic Enigma machine, all right, and you the way you set these, how you set them determines the pathway the electricity takes when it comes in on one side and goes out the other. Now, uh, you can change the orientation of these reels in multiple ways, so that makes it very complex. So this pathway could take lots of little criss cross the ways. And what it boils down to is the typewriter part with all the keys. When you press a letter, it sends an electric signal into the rotors. It goes through this complicated pathway that's determined by the orientation of those rotors. When it comes out the other side, it lights up a light bulb representing a different letter when you So when you press the letter A, perhaps the letter Q yes. And so it takes two people to do this. Someone has the normal message, the message that is supposed to be encoded, and they press a key. There's a second person who watches the light bulbs and writes down which letter lights up. And after you press that A, the rotor, the first rotor on the left rotates one position. So that means the pathways for the that electric current to follow through have changed from the first letter to the second. That's right. So if the first two letters were A A for some reason, and you pressed A and the Q lit up, the second time you press A, perhaps the M lights up, and every time after that's gonna light up differently. So you already have so many possibilities just from that simple disc option. But there's a way to make it even more complicated, right there. There are two things that make this even more complex. One is that once you go through a certain number of of moves with that first rotor, the second rotor can rotate, which means you've just added a whole new set of variables. And with the German Navy they had four rotors in their Enigma machines, which means that once the third one would rotate, it just made it even more complex. And this allows you to have a key that does not repeat. It does mean that whoever has the recipient, whoever the recipient is, they have to have a machine set up the exact same way that your machine was set up. Now, the other thing that made this complicated was they had plug boards, so unfair really, the plug boards, and what the plug boards did was you were you would attach a cable that would swap the input of a certain key with another key. So let's stick with A. Let's say that you have a plug in the A and a plug in the H, which means every time you press A, it's as if you had pressed H on an unaltered machine. So that makes it even more complex. And the plugboards were added a little later. That was an evolution of the Enigma machine. And the Germans were so confident that this machine was uncrackable that they never ever worried about anyone intercepting their messages because those ciphered messages would be impossible to decipher. They were a little too confident, though, because there were a few problems with the whole thing, one being that the machine couldn't encode a letter as itself. So you've been using the example A A could never be A no matter what combination of rotors you were using, no matter how many cables were involved, A just couldn't be A. That's a pretty big clue. I mean, it doesn't sound like it reduces your your options that much, but it really does if you're thinking about it in terms of probability. Right, Yes, that's that was one of the things Touring jumped on right away was he said, well, if this machine cannot in code a letter as itself, that removes one option out, and by removing one option you have given us a foothold. That was definitely a weakness. Another was that in order to make this work again, you had to have two machines and you had to have them both set up the same way, which meant if someone were able to get hold of a machine and the codebook so they you could see which which set up was needed for any particular day. You know, everyone had to know how to set their machine up once they received the message, then they could intercept a message and then interpret how to decipher it. Um, you just had to know the day the message had been sent. You had to know the day the message was sent, so and you had to have a corresponding codebook that would tell you the right setting for that day. But even without that, once they started learning how the actual machine worked, they were able to start thinking, how can we simulate this by building something of our own that can take this information and perhaps decide of it. So if we intercept a message, we can if if even if we don't know what the original settings were, perhaps we'll be able to create something that can run enough simulations through where we can crack the code. And Polish mathematicians got a toe hold in this by intercepting an Enigma machine, so they could see a little bit what what they were dealing with and what kind of machine would need to be created to possibly break this code. Yes, and they ended up sharing that information with Bletchley Park, which a famous famous institution there during World War Two. That was that was codebreaker central for the British a manor house, and I should take this opportunity to I think one time we said it was in London. It's outside of London. That was the whole point, because it was more secure being away from the city. But yeah, with this information that the Polish mathematicians had with their intercepted Enigma, the teams at Bletchley Park started working on building these early computers called bombs to a eventually simulate the Enigma machine and figure out how it worked and figure out how to break it. But what I think is interesting is that this was I was talking to you about this earlier, and it's kind of hard for me to wrap my mind around. But they're working by process of elimination. Rather than like, Okay, what was it set on? It's more what was it? How was it not set? Yes? Yeah, By eliminating all the potential factors, they narrow it down to the one that it actually was. Uh. It really reminds me of quantum computing. Actually, I'm not going to go into it, don't get there. But but I'm just saying a similar thing. You're eliminating all the all of the possibilities to get down to the one reality. And it is pretty amazing. The bombas that the Polish mathematicians had created ended up informing the British when they started creating the the bumba b O m b E. I always like to say the bum and uh and yeah that was that was a huge, huge jump in of crypto cryptanalysis and just the British war effort in general. And one thing about all of these these codes and decoding them is there's so many different names. There's the name of the machine, there's the name that the opposing force usually calls the code, and then the name of the machine that is able to decode it. But in this case, the Allied efforts to decode the German messages was known as Ultra. Yeah, it was known as Ultra, but you never said it ever, Ultra. I just didn't say anything at Fletchley Park, like it's all done through semaphoreign mime. Uh No. Ultra was such a secret term that you were not supposed to utter it to other people. Ultra was just a general term that referred to intercepted and deciphered messages. And because it was such secret information, you could not you could not reveal that to anyone who was not already classified to know it so much so that there were people who lost their jobs, who were court martialed because they refused to deliver sources of information because it fell under the umbrella of ultra. And so there are people who are discredited during the war because they were maintaining this level of secrecy, which is pretty phenomenal, and they had a huge burden, which is the flip side to cryptography. If you've intercepted a message and you've successfully deciphered it, and you now know what that information is, how do you act on that? Because if you act on it in a way that reveals to the enemy that you have understood what their messages are, they are going to take efforts to change the way that they are encoding things, thus putting you back to square one. As long as your enemy feels that their code is unbreakable, you're in a great position because they're not going to take any more precautions with it. Otherwise they can just develop a new machine, developed a more difficult code. And yeah, like you said, you're back at square one, then yes, and it is. I mean, it's just it's it's hard to think about because you know that a lot of these messages had life or death consequences exactly, and they had to take very careful consideration of how to act on it so that they could preserve as many lives as possible without tipping their hand. Was it information that could have been procured from some other sources aside from breaking the code or how important was it? Fortunately for the Allies, the Germans were extremely confident that the Enigma code was unbreakable. And I think the only way that they would have I think, I think what their normal routine was the Germans this is would be that if they felt that the code was endangered, they would issue new codebooks and they would have a new set of codebooks go out to the field rather than scrap the system and start with something new, so they'd stick with the system. They would just say, oh, well, what's what is at risk? Here are the physical codebooks that tell people what settings they need to have the Enigma machine on. And I didn't really talk about but the recipient of the message. To to de cipher a message from the the coded one, you would give the the ciphered message to a typist who would have their own Enigma machines set up just like the first one, they pressed the first letter, so if that A was a QUE, they would press Q and the the A light bulb lights up and so then you would have a second person taking down the flat text message exactly. UM. And I kind of was interested that the secrecy for all of this really extended beyond the war to the the BOMBA machines were all destroyed on Churchill's orders. After the war. I read one account of one of the women who had worked on the machines at Bletchley Park and talking about how her crew just happily destroyed them because they were so temperamental. They were just glad to see them go. That's an unusual story either. There are a lot of stories about destroy void cryptography machines because it was just considered to be too dangerous to let that information out further technology that could still be useful. Although today, of course, most of these machines have been rebuilt. You can see a lot of them if you visit Bletchley Park, which I think is cool that they've They've gone to the trouble of illustrating these because if you watch a video of one, it's a little easier too to comprehend than if you're just trying to read about it or hearing about it too, to see exactly how they were right. And there's some software out there as well that simulates a lot of these different machines so that you could type in a message and it would come out as a ciphered message. And again you have a friend who has that same software running, and you tell them, all right, set your software to this setting and run this message through and see what you get. And it might say, you know, you are a poopy head. It's all the messages I get from Chris all the time. It's really worth worth coding. Yeah, it takes a lot of effort to get that across. Another thing, though, is Enigma kind of gets all the glory. I'd say, you know, it's the only with if we were saying earlier that it's probably when most people are familiar with, and it might also be the only German code that people are familiar with. Sure, and it's not the only German code by a long shot. You wanted to speak specifically to the Lawrenz machines, which the Lawrence machine was interesting. It was a steam powered machine, so a little bit different and also the kind of old school little steam punky, little steam punky. Uh. It actually would send a message over telephone wire, over a telegraph wire, um, and you would have two machines set up where you would type in a message onto one machine. It encodes it using an ex or algorithm. And I to to explain that would probably take an entire podcast on its own, but just just to say that each letter is a symbol assigned a certain binary value, and then there's a key that also has a binary value. You add those two values together, it creates a third value that becomes the ciphered text. So as long as the other machine again has the right key, uh, then you can decipher it. And again the Germans were very confident about this. They thought, well, we've got this. The key is is this this role of tape. Essentially that both sides, both the sender and the recipient, they have identical strips of tape that have these values in it. The h the coded message gets sent across the wire, they run the tape through the receiving machine and then they get the plain text information. Thinking that no one in between would ever be able to crack that code, so there wasn't a whole lot of fear about intercepting those messages either on the side of the Germans, but there should have been. There should have been, I mean Lorenz who have used for just the most important information. It was reserved for high command for Hitler. Kind of ironic if you think about how they were so confident with Enigma that they wanted this extra code, but it was eventually broken by the machine. Colossus and um Letzley Park had a quote, and I kind of wanted to get your opinion on this. They called it the world's first practical electronic digital information processing machine, a forerunner of today's computers. Yes, it was the first of that nature. Uh, you can look at any act which was not yet built. It was not finished until um and all the other preceding computers were electro mechanical, meaning that there were actually gears in parts that moved, not just electronic circuits created by either wires you know today we think of microchips. Back in the day, we're talking about actual physical wires running to and fro and everywhere. That's why these machines tended to be the size of fairly sized room. Colossus is an apt term. Yeah, there were there were ten of them and they were huge. Um, yeah, that's perfectly accurate. It is definitely a predecessor to today's computer. And of course, just as you would imagine today's computer, the computer that's on your desktop, perhaps the computer that you have in a pocket or in a bag near you right now, far more powerful than Colossus. And I watched the video of Colossus, you know, recommending these two folks to to check them out and kind of get a better feel for how these things look and how they work. It reminded me almost of a workout machine, partly because of the tapes all wrapped around the little reels, and that combined with a wall of electronics, it really does take up an entire room. So that's amazing to to think that that is a computer predecessor. Yep, yep. And again it was there to simulate these Lorenz machines and try and crack what those codes were, and it was a phenomenal achievement as far as technology is concerned. Okay, so we've probably discussed Germany pretty thorough lead by now, so we're gonna move over to Japan. And one thing that I found really fascinating was that Japanese communications had been monitored by the United States long long before World War Two began, right, more than a decade before, and Japan was not aware of that for quite a long time too, But that that tends to be the best way. That's usually how it happens, if you're doing everything correctly, if you're doing things how you should. So, yeah, the American said started screening Japanese telegrams between diplomats in November nineteen one. And these were really simple messages, so nothing like what we've been talking about with the Enigma. They were easy to break, and they gave the Cipher Bureau, which was the name of this UM code breaking organization in the US at the time and its director, Herbert Yardley, access to a lot of useful information. So it's diplomatic information, it's not military, but still gives you some helpful stuff if you're negotiating treaties, you know, that sort of thing. Definitely a little inside peak, some insider trading on a grand scale, that's what this is. But by the late nineteen twenties, this uh to do this, they relied on domestic cable companies in information, which is something kind of relevant to this. But by the late nineteen twenties, use of that information and plus monitoring of airwaves started to become kind of distasteful, frowned upon, and so eventually the cipher Bureau dissolved and Yardley, out of work trying to make some money during the Great Depression, decided to write a book and write a series of articles for the Saturday Evening Post on codes and code breaking. His experiences experience monitoring the information coming out of Japan, and it sets some shock waves going through the world that this information was so easily available. This this kind of proves why it's important to keep that secret parts secret because once once it got out that this was very easy for them to break the codes. The message that sends is we need to look at how we are ciphering our messages, how we're encoding things, and try to introduce as much randomness as possible. And randomness is what makes codes so difficult to break. You know, once you start being able to detect patterns, it's game over because it's just a matter of time before you can start, before you have to before that code gets cracked. So you want to avoid patterns as much as possible and have as much randomness in there as possible. But here's the trick. Random is hard. Computers are not truly good at producing random numbers. They are pseudo random because they're still following a set of rules in order to create random numbers. And on top of that, there needs to be someone else out there who has the same set of random data so they can decode the message you send them. So there's going to be at least one copy of whatever random, quote unquote random message you create or random key you create in order to cipher a message. But that was what really got countries around the world thinking, how can we create more of a random feel for our encoding technology, the random Yeah, if we don't, then our messages get cracked. We might as well just be sending plain text. It would be a lot easier and a lot faster. And so that did sort of lead to a shift in adopting these more complex mechanical machines, like we've talked about already with the Enigma, which was from the twenties, adopting machines more like that rather than these old style codes right right, And the Japanese chose a slightly different approach. Their machines did not look like the Enigma and did not. While they were able to generate randomness in a very similar way that the Enigma machine did, so the outcome was very similar, the actual mechanics were different. To explain, you want to know how Okay, So it's an electro magnetic device and it's called it's a step switching device as opposed to rotors, but very similar in that if you encode a character, there is a step switch that moves the encoder one step further so that the next key you press gets coded to a different one than it would be if it had been the first key. That sounds really complicated, but really again, well, we'll stick with the a's and the a's right that that you're coding two a's in a row. Obviously this would not be the case with the Japanese typewriter. But if you press the letter A, then the first step would be to encode that to whatever the setting has it. So we'll go with H and then the second that that would then step up the code a step. You press A again, it would then code to a different letter so z and very much the same way as the Enigma machine, but the actual parts didn't move the same way. Whereas the Enigma had these rotors. The Japanese typewriters used this this electromantic step system, and and they had interesting code names they did. So. The first of these electromagnetic code machines created by the Japanese was called the cipher Machine Type A. It was known as red to the U s, and the code it produced was known as red um. That code was fully broken though in nineteen seven, with a clue from one word the Japanese word for and essentially was enough of a enough of a hint for them to break code red. Yeah. Again, it's one of those things where they're looking for repetition and patterns, and if it's a word that's used a lot, and if you're if you don't have enough steps there, if you're key repeats fairly frequently, then you run the danger of someone using frequency analysis on your message and figuring out what it means. That was one of the things that the Enigma was so good about was that because there were so many possible combinations, that unless your message was incredibly long and i'm talking novel length, then you're not going to have to worry about the pattern forming because you are not going to run out of those variations. Well, and another problem too is that the Japanese were sending several standard messages with their messages, so well we should go back to So they did decipher the code sent out by RED, and by that point, though by night messages through RED announced that there was another machine. That's probably a mistake too, to announce your new machine through your old one that has been compromised. And that new announcement was for the alphabetical typewriter, which was codenamed Purple. That's probably the more famous of the two. Yes, Purple is definitely more famous. And I read although from a source that I consider questionable, so this could be apocryphal. I want to proceed my my message with that that the reason why I was called purple is because that was, in fact the color of the binders that the United States used to hold all the intercepted and deciphered messages. A good story, yeah, I mean it seems legit. As they say on the interwebs. I do have to say, well, researching this though code read code Purple, I just kept on getting a lot of information on air quality. Yeah, but also very fitting for Atlanta. It is uh and they the the United States was able to crack these codes too. Um. The purple codes were not as sophisticated as the Enigma machines were. Uh. And the United States cracked them. And again, these are mostly diplomatic messages, they're not military messages. But the United States is keeping tabs on what's going on in the in the Pacific, and they called their interception and deciphered messages. Uh. Magic, because that's what it seems like when you're able to decode something. I guess very tinker tailor soldier spy. Yes it is. Yes, Gary Oldman would have had a lot of work during this time, and it took him a while to decode it. That we shouldn't make it sound like it was just an easy tak No, it took quite some time. It took more than a year a year and a half of hard work to crack the code. But they were able to figure that out. Um. And Uh, it's interesting the person who discovered the correlation was someone that you might not consider it first considering the time period. Right, so we're in the middle of it was in September n So World War two is is going on. The Americans are not really they're just really monitoring at the moment. The person who who discovered the correlation in a in a couple of messages which was enough to allow us to break the code, was Genevieve Grossian. So a woman was the one who discovered the correlation. And again, it's one of those things where we often overlook the people who first make these these uh discoveries, because you know, the big story about breaking the code is interesting, but sometimes we lose sight of the people. And I thought, well, that's someone that we should know about clearly, because this is someone who was able to find the first stepping stone that allowed us to crack the code. Alan Turing's getting his moment. There's plenty to go around. Um, so you know the timeline. By this point, you're probably thinking, well, if Purple was cracked in ninety, um, what about Pearl Harbor? How much was known? They were diplomatic messages, so there's no evidence that they were receiving information about Pearl Harbor. That doesn't mean though, there wasn't some pretty important information that was gained from understanding Purple. Yeah, there was. There's still some confusion and there are plenty of conspiracy theories about how much information was gleaned from Purple that could have prevented, could have at least prevented or at least prepared everyone in Hawaii for this attack. And uh, there was no specific message ever intercepted and decipher that had anything to do with a specific attack on Pearl Harbor, according to all official records. And again, conspiracy theorists might disagree with that ben In here, maybe we have to go with what history gives us, right, and what history says is that there was no way of knowing directly through the intercepted messages about the attack on Pearl Harbor. History would have unfolded a very different way. I'm sure had there been. What's ironic is that some of the most important information that was gleaned from these messages was about Germany rather than Japan. Ironic because of how how proud they were of the Enigma. All this information was really getting out through Purple anyway, that probably would have made the Germans a little kind of upset. Yeah. The Japanese ambassador to Berlin, a man named hiroshi Oshima. He was pretty descriptive while talking about what was going on in Germany and what the Nazi defenses were like and all that information was being picked up through through magic um, so a lot of information that ultimately helped prepare for the D Day invasion. So Pearl Harbor is off the table, possibly unless we're going to go conspiracy theory on it. But d JA so still an important code to have broken. Yeah, it's uh, it's amazing to me when you look at some of the mistakes that were made, because often mistakes are the only reason why certain codes were ever broken in the first place. Either there were mistakes and procedure where someone has set up a really secure system, but the people part of the system isn't so secure. My favorite example of that is somebody making a mistake in the typing of the message and instead of resetting everything so that the code is secure again, just typing out a corrected message on the same setting, right, which makes for just very slight differences between the two messages, right, And that that was huge. That was an enormous help. I mean, the protocol for that was if you were to send a message and you made a mistake while in ciphering it, that you were supposed to set it to a new whatever machine was involved, you were supposed to set to the next start over, start from scratch, Start from scratch with a new setting, so that all the message is going to be completely different because that way the Allies don't know that it's the same message. But by setting it back to the setting that was for the first time you try to transmit it, that means two copies of this message go out and that's enough for the Allies to say, wait a minute, this was in coomat. We can figure this out and we can start working on what has gone wrong for them and right for us. So human error is a is a big part of these codes ultimately being cracked. It seems ultimately yes, I would say that things everything from using common salutations or a common prefix to whatever the message is, that would often give the the analysts enough information to work on to start cracking a code. Even a weather report. The standards between a weather report the numbers or directions of wind might be different, but it's going to have a lot of the same vocabulary and that weather report information. That's also a good point because one thing that the British thought of while they were trying to capture Enigma machines so they could get Enigma machines and codebooks so that they be you know, the Enigma machine was was fairly portable, fairly in the sense that you could put one on a ship with much The Lorens not portable. Uh, And the Purple machines were not terribly portable either. In fact, uh, they just it was once you once you built one, that's pretty much where it stayed. But the Enigma machine was different. You could actually move those around with effort. They were not It wasn't a laptop, but it The British figured out that the Germans were probably using Enigma codes not just on official military craft, but also on things like ships that were taking weather measurements, so weather research ships that are not military ships. And they thought, well, why are we focusing on capturing a German navy vessel when we could capture one of these weather ships and get hold of the code books that way. And in fact, that's what a lot that's how a lot of the codes were broken. They found code books that were accurate for that that time period and we're able to start cracking codes. So that's another instance of a mistake where you know, you have to balance out who gets access to your secret message at different levels of codes. Yeah, yeah, it was because, again, if the machines had worked exactly correctly, and that all the people had done what they were supposed to do perfectly, and if the codebooks had remained perfectly secure, the Enigma code was uncrackable. Next time, though, we are going to be talking about some truly uncrackable codes. We'll be talking about the Allies use of cryptography during World War Two, So it'll it'll take us full circle from this discussion of Enigma and Purple and Lawrens and get into some codes that aren't based on machines, which is a pretty huge difference. Indeed more portable for sure, So that'll be next time. I don't know, do you have any other comments were for the use of codes by the Axis. I think I think we've really covered it pretty well. What central thing to me is something that I'll talk about more in our next episode about how this sort of technology has evolved in how we use it today. But that will be a good bookend. I think that it will be how we wrap things up. So if you want to let us know your ideas about the access use of codes or just codes and spies and all sorts of things during World War two. You can email us. We're at history podcast at how stuff works dot com. We're also on Twitter at Misston History, and we are on Facebook and gosh, I'm sure we have articles on codes, don't we. Oh yeah, I wrote one. Did you write one? Well, then you go ahead and find us off. Oh yeah. So go to how stuff works dot com and look up code breaking because that was one of my earliest articles. And I've been here for nearly six years and started the same week. Yeah and uh, And to this day it remains one of my favorites because it was just such a fascinating world. And I even include in that article a code that you can break, so fun, get out your your um cereal box sort of decoders and go for it. All right, pretty much all you need. So How Code Breaking Works by Jonathan Strickland at www dot how stuff works dot com. M for more on this and thousands of other topics. Is it how stuff works dot com.