TechStuff Ponders an Enigma

confusing some people. H The best part is see Jonathan hear from Europe. Jonathan never tells me what quote he's gonna do, and uh I didn't tell him. I was going to do the introduction in German. This time I actually switched my quote. Okay, so when you as I heard you speaking Germans like, oh no change, Uh, he changed the play on me. So anyway, today we're going

to talk about um. Something that actually came to mind when during the process of recording our episode on quantum computers, which were led to a discussion of quantum cryptography and cryptography is something that actually fascinates probably just about all of how stuff works dot Com considering UM, and it also comes to play it touches on another podcast topic that we tackled months and months ago, Mr. Touring. Oh yes, Alan Touring is gonna come up, and it's very important

in this discussion as well. We're talking about the specifically the Enigma machine, which was a cipher machine used by Germany during World War Two. Yeah. The funny thing is, UM, if you've watched any history or read any history about World War two and UH specifically the war between Germany and the Allies, UM, you have a sense of what

this machine meant to the German war effort. But the thing is, what I don't think comes across in a lot of those UM discussions is that there's no one Enigma machine, and it certainly wasn't unknown to the world before that because the the Enigma goes back years before the start of World War Two. It was actually a

commercial machine used to encrypt messages. And in fact, because it was a commercial machine, it gave some people a leg up on on figuring out how to crack the code because it was generally considered to be a practically uncrackable code if you were to follow the most careful security procedures possible. And we'll get into why that is. But before I think, before we jump into what the machine did and what how it did it, we need to talk a little bit just about cipher's in general. Please.

All right, So a cipher really, and in this case we're talking about creating a coded message, and uh, there are different ways of doing this, lots different ways. You can create a new alphabet, you can try and hide things and images. That's called agraphy, right where What you can also do it is hide messages within a file,

like like the code for a file. So I could send a seemingly harmless file to Chris, but if you were to actually look into the code of that file, hidden there, not displayed in any form of executable function, might be a message. So there are lots of different ways of getting secret messages across, but a very common one is using a cipher where you replace one letter of the alphabet with another. All right, So the very basic version of that is a mono alphabetic substitution cipher.

It means you're using just the one alphabet and that one letter is always going to represent another letter always in that cipher. Oh yeah, my friends and I used to do this back in you know, grade school. Yeah, you know we we would say, okay, so every letter, you know, the letter A is represented by the letter D and it just goes down the alpha that like that. You've just shifted the alphabet to the to the right a couple of places, sure, like that, and then you

just go from there. And so in order to to decode this, if you're not just trying to crack it, I mean, if you're actually decoding it, like you're the person who is supposed to receive this message, you would need to know which letter you know, how far over did the alphabet shift? Right, So if if A is B and B s C and C is D, then you know, all right, well it's a. It shifted one place, and so I know to shift all these letters back a spot so that I can decode this. All right.

That's your very basic mono alphabetic substitution. Now those are easy to crack. It's easy for anyone to crack, yes, all right, as long as you know some basic uh rules and and tendencies in your native language, you can crack these. For example, you can start looking for two letters that are like letters that are are doubled up. You start looking at those, and then you think, okay, which letters in the English language are the most frequently

paired together? Like two ta s would be an example. H. Two teas happen a lot, so that that letter there could represent a T. Let me see if that starts to fit other things. And you look for patterns, and you find these patterns and you can decode things. You can make this a little more difficult, actually a lot more difficult, depending on how sophisticated you get using a polyalphabetic substitution. All right, so there's this one kind of cipher called a Vignier cipher. Uh, this is a little

more complex. Now. In a Vineer cipher, you've got a grid. It's twenty six boxes across in twenty six boxes tall.

All right. On that top level of the grid, you have the alphabet spelled out normally A, B, C, D all the way to Z. And then on the next one you shift that letter over once, so now it's B through A. So the last the last one is gonna be A. And then you go the next lay up level down you shift it over against Now it's C through B and do this all the way down until you get to Z to A at the very bottom, all right, or not zo a zero zero y Um.

I'm sitting here. I'm I'm mixing myself up now the way Vin your cipher's worked as you would have a key phrase or keyword, Okay, So it's something that you and the person you're writing to have both agreed upon in advance. So let's say that for for Chris and I, we sit there and we decide text stuff is our key phrase. You would look at your grid and you

would go down that first column. You go all the way down to the T column, the column that starts the alphabet begins with the letter T. And then let's say that my first word is to Chris is going to be how d I then look across the top of that grid for the H on the very top row.

All right, So I've got my finger on the t oh based on the first column, and I'm looking at the H column in the top row, and I find the intersection of those two so where the T row and the H column meet, and then that letter represents H. And then for oh, I go because my key phrases tech stuff. I go to the E column or E

row on the first column. So I look at that first column, which is again in alphabetical order, so it's A B, C, D E. So I go to the E row and then I look for the O in the top row, and I find the intersection of those, uh, the column of O and the row of E. But that and that becomes my Oh so Chris, because he knows that the key phrases tech stuff, he knows which road to look at, and then he looks at the

encoded letter. He finds that in the in within that row, looks up to see what column it is, and that's the letter it it decodes into. Now this might sound really complex. That's kind of the point. Well, you don't want the enemy to decipher your code, because then it will learn what you're up to and the element of

surprise is lost. So this um this method becomes less useful if you are starting to encode longer and longer messages, because that increases the chance that the enemy or someone who is not meant to read the code can figure out your key phrase or keyword. And if they figure out that keyword, then they've unlocked everything. That's all they need. They just need to create a Vinyer cipher graph or chart and then use that key phrase to decode what

you've said. Now, the Enigma machine takes and a similar approach to the Vignier cipher and complicates it on a massive scale and also automates it. Yeah, because, um, you know with any of these codes that the key uh is probably the most important part. Um. If you intercept a coded transmission and you have no idea how it has been enciphered, it's going to take you much longer

to try to break that code. Um. Whereas if somebody on the other end has the key to it, they'll be able to decipher it in no time or a little bit more than no time. UM. So that's that's one of the tricky parts, is I mean you can uh you know, during War two they were there were all kinds of different ways to send messages, including things like one time pads, which is a a pad used of paper used with a particular code this is the

one for this message. And uh. This would be used out in the field by agents who couldn't carry something like a rotor machine like the Enigma with them. Uh. You know. And the thing is if the if you lose, if the person on the other end loses the key for that particular pad uh, um, it's just gonna take forever.

But the Enigma was a way to automate this UM this process, and this machine, which was first patented nineteen nineteen, ended up being pivotal UH in World War Two, both for the Germans and well actually the the Axis because they did have a Japanese version that they used UM, but also for the Allies when they were able to figure out how the machine worked, and because it does have its own flaws. UM. So let's let's talk about what was in an Enigma machine and what it looked

like and and how it encoded letters UM. Each of the machines, going back to the very first one, the

Enigma A had rotor wheels UM and a keyboard. It looks a little uh if you've never seen one of these machines, and they all look a little different there, Like I said, uh, several different types of machines that evolved over time, but all of them had a keyboard on it UM arranged in more of a well, at first it was an alphabetic fashion and then turn into more the German keyboard style, but so kind of like

a typewriter. Yeah. And the very first one looked a little bit like one of the old timey cash registers. It was so big, um but yeah, I mean these had rotor wheels though, and so you would type a letter, let's say A, and depending on the way the rotor wheels were set, it would produce a completely different letter. Yeah. And the way it would produce it as it had lamps twenty six lamps, each one uh marked with a letter, and the lamp that lit up would be the encoded

letter for that particular key press. Yeah. They use were the ones used in World War Two. The earlier ones did not have lamps. Um. But yeah, I mean the ones that we're talking about specifically around World War Two. That made it easier for the operator to identify which letter was being used because these most of these machines had no printer. Yeah. Usually you would have two people working on both sides of this, both the encoding and

decoding side. You would have one person who would be pressing the keys and another person who would either be writing down the letter um, the encoded letter or writing down the decoded letter. Because an important part of the Enigma machine, and actually one of the reasons why it was eventually broken was that it was a device that if if you if you type the let's let's just say for for argument's sake, that if I type the

letter A, the letter Q comes up on the lamp. Well, if I were to take a second Enigma machine that was that was configured the same way as the first one,

and that's really important. We'll talk more about why that is in a minute, and I typed the letter Q, the letter A would light up, and then all I would have to do, essentially is take my coded message that was sent to me, type it out on my Enigma machine that is configured the same way that the encoded message machines was configured, and then have someone else write down which lamps let up, and I have the decoded message, except that the people in England were saying, no,

this is gibberish. It's use and someone says, no, you idiots in German. Anyway, the I thought I would make you laughing. I thought about that last night and I was just waiting to unleash it. Um. So the cool thing here is that, all right, So imagine that each of these roters. Think of it like a cylinder. Okay, So imagine a cylinder and on the the on the ends of the cylinder are rods and contact points. So there's rods on one side and contact points on the other. Okay,

this is where an electrical current can flow through. Now there are twenty six rods and twenty six contact points, so there's one for each of the letters the alphabet. Now, if you were silly, you would just wire these straight across, so a would all position one would would also would be a straight wire from the rod to the contact and position one. Now, of course that's not the way the Enigma machine works. What happened was they wired it so that position one would go to a different contact

on the other side. So position one might go ton like Rod one might go to contact twelve. Rod two might go to contact twenty three. Rod three might go to contact one. That kind of thing. And you had this massive wires inside the rotor that determine which ones went to what, And then the rotor would fit inside the Enigma machine, which would uh electricity from a battery would come through, and depending on what key you pressed, that would allow the pathway to go through to a

certain rod. The the electricity would go through the wire in the rotor come out the side of the contact that again is not directly across from the position of the rod. And that's the basic idea of how it

would substitute a letter. Now if it if the rotor did not turn, or if there were not more rotors, you would just have a mono alphabetic substitution, like every time you type A, the letter Q would light up if nothing else changed, if that all it did, in which case it would have been a useless machine because people would have been able to break that without ever having to spend more than a couple of hours on a on a on a message. Now, a lot of

the machines, UM, we're using three rotors. UM. Now here's here's where this makes it more complex. Uh. These machines came with five rotors uh named numbered with Roman numerals UM and every here here again here's part of the key. UM. The German command would send out the monthly use of wheels. So you might put the wheels in for one two, so four would be in the leftmost position, one would be in the middle, two would be in the right most position, and every time the operator presses a letter,

let's say J the third. Actually, think of this if you've ever seen a car odometer that measures the distance. The rotor on the right moves one notch every time the operator presses a button. So the operator press is J, the rotor on the right turns one notch. The operator presses N, the rotor turns one notch, and then the middle um. Every so often, the middle rotor moves one notch, and then again with the leftmost it moves more slowly, so as the operators typing the message out, the rotors

are turning to incipher the message more thoroughly. The idea being that you're not repeating the same alphabet to frequently. In fact, you it would take you, it would take you an incredibly long message to be able to repeat pete such an alphabet ah. And that's one of the tricks. Eventually it could happen, which is why the Germans limited

their message length to two fifty characters. So to to explain this even further, if I press let's say that I just have the one rotor in there, just for simplicity sakes, So I've got one rotor in there, and if I press the letter A, the letter Q lights up because that's just the way the wiring is in that rotor. After I pressed the letter A, the rotor

turns one notch. I pressed the letter A. Well, Q is not gonna light up because what's just happened is that there's a new rod where the electricity makes contact with that rod. It's in position A. The first rod was in position one. Now that the rotor has turned one notch the rotor, the rod that's in position for the letter A is rod too. So instead of Q

lighting up, maybe J lights up. So you could just keep pressing A and a different letter is going to light up every time, except for one other exception we should point out, which was again something that helped the Allies break the Enigma code. They the Germans had decided foolishly, as it turns out, that no letter would ever incipher

to itself. So B can never b B. Yes, so if you saw the letter B in a message, you automatically knew it wasn't B. So you've just you've just and that sounds like it's menace fuel that you've only eliminated one option, But that was huge. I mean, without that, it would have been so much harder to to decode these messages. Now when you add that second rotor in uh so, let's say that again, we're gonna go with

the positions. So the so we have the rods in the twenty six positions and the contacts on the other side of the cylinder in twenty six positions. Electricity comes in through rod one and it's going out through contact twelve. Then you have your second rotors. So the second rotor, Rod twelve is accepting the electricity, but it's contact that the second rotors, Rod twelve is connected to contact UH seven. So you've got now something that's going in through contact

rod one and coming out contact seven. Once it gets through the second rotor, you had a third rotor in. That makes it even more complicated. So it's like you've just added a huge mass of wires to this device and it gives it's even more complex. I'm sorry, did you say huge massive wires like the scheker Brett. Yes, So here's where the massive wires also comes in. There was a plugboard that came with many of these Enigma machines,

not all, but many. Yeah, do you remember if you think back to images you've seen of old telephone operators when they had to connect a call, they would physically take a wire and connect one person and plug it into the slot for the other person to make the connection. Well, on the Enigma machine, uh they had wires and plugs

that went from that basically connected the letters. Yeah. So in other words, you might connect the letter A and the letter J together with A with a wire, which means every time you press the letter A, it's acting as if you press the letter J. So that add added yet another layer of encryption on top of this device. Uh So, No, you're no longer send a message to contact one, because that would be the one for A. You're sending it to different or not contact but Rod,

you're seeing it to a different rod. Uh so maybe so. By setting the alphabet position on each rotor, setting the rotors in the particular order, choosing you know which rotor you want. Because these rotors, by the way, we're not um alf they if you were to look at a rotor and turn it and it had the letters on it, it would not be an alphabetical order. They mixed up the order of the letters to They wanted to make

it as complex as possible. So depending upon the the rotors you choose, the order you put them in, and the plugs that you plug into the plug board, that would determine what would happen if you pressed any particular key at any particular time. Plus, it's in German and you're probably transmitting it in morse code, so that's the level that you have to get through in order to

get to that original message. In addition, UM, the German Men's tended to break up messages into regular patterns of UM five characters at a time, so you know, a F B Q G space, you know, so the message wasn't written out, and so you wouldn't say, okay, well this this word has three letters and they're only you know, yeah, there's only so many word that would have three letters, and they broke it up so that once you know, there was really no way to tell how long the

word was. So a single word, and remember this is German, so these words could be you know, seventy three characters long. So a single word might might spend multiple five letters segments, so you know, it might begin on letter four of this five letter group and then finished three groups later down the line, and that might have just been the

word for I don't know like car um. So uh yeah, it just made it made it more difficult, obvious, skated the meaning of the original phrase as much as possible. So how would you ever decode such a message? Now? If you've got it really set up so that everyone knows how the how to set up their own particular Enigma machine based upon a codebook, you would have to

have like a codebook that was um given out by leadership. Right, you'd have to have someone in charge saying, on this day, for all messages that we send out, this is the configuration you have to use, because if you didn't have it, you wouldn't be able to decode it. Right. The German command would specify the wheel order and the ring setting and the the steckering the crossing Stecker means plug, so they called it a plug board. It was Stecker bread UM.

But the thing is the cipher clerk would uh would basically turn the three wheels to a position at random whatever he wanted it to be, and then they would twice put in the own randomly random text setting or message setting UM. And this was the indicator, which is six letter character UM. And then you set your wheels at that three letter text setting and it would give you the UM, the the code that the person who would on the other side is supposed to know to

get through it. UM. The thing is it would always have This is another thing that that boggles in mind to me, UM, with something with a device this capable. UM. They would transmit some things in clear text, like the preamble basically say the time of day, the number of letters in the text, and things like that that was sent and clear. I guess it was necessary, but it made it easier to figure out exactly what was going on and when it was set. And that turned out

to be important later. UM. And they would tell you, you you know, certain things, UM, you know, and everything came out in five letter groups and the indicator, which was in six letters. They changed that let later, which made it more difficult for the Allies, but still at that point it was too late. Yeah. And Uh. It also didn't help that, you know, the Allies new to look for certain words that would be used over and over

again in messages. They called them cribs. They would look for these cribs or possible cribs and uh, based upon just letter groupings and they could, you know, eliminate cribs from certain groups of letters. Again, because if a certain letter appeared at a certain part of a word and it was the same letter that should have been, you knew it wasn't that word, right, because of course I letters never going encode as itself using an Enigma machine.

So um, yeah, using these basic rules, it sounds like it's astronomical, like the number of things you would have to eliminate, and really it is pretty it's a pretty big number. But that's where folks like Touring came in. They they knew a bit about the Enigma machine already because the Enigma, the whole rotor based cryptography device, as Chris said, predated World War Two. Yeah, it's not that the trick is not getting your hands on a machine.

It's figuring out how what settings the machine is being used to encode so that you can break the message. Although it did help because if you got your hands on the machine, you could at least find out what the wiring was, yes, and you could you could then start to eliminate various combinations because you're going to say, okay, if it's if it's a Roman numeral one, rotor then this position is always going to map to this contact

and you could start to eliminate things that way. Uh. The the over in Poland, there were cryptographers who are breaking these codes before World War two broke out, Yes, unfortunate, and they had a machine that they would use to do that called the Bombay and uh and someone set

them up the bomba. Yeah. Actually they when war broke out and it became obvious that things were uh, that it was going to be discovered that they were able to do this, the machine was destroyed, which is some of the Some of the code breakers made their way over to England and helped the English code breakers by adding to the level of knowledge about what the Enigma

machine was and how it worked. They also had some breakthroughs that stemmed just from from luck and and uh and bravery really because we're talking about uh times where where Allies captured a German group that had an Enigma machine, often something like a submarine. Um they would capture that and if they were able to, they could get the machine and the codebook, which would essentially tell them pretty much everything they needed to know. But uh, meanwhile, Touring

was working on his own BOMBA. Yes, he was UM. Yeah. Before we go into UH into that, I want to point out that we left out there. There's more to the Enigma machines UM than we really went into, and I would recommend if you're interested in learning more UM, there's a website for UH, the Crypto Museum, which is in the Netherlands. It's a virtual museum, but crypto Museum dot com UM will tell you probably everything you ever wanted to know about the Enigma machines and UH and

more UM. But we wanted to talk about the the attempts to break that the Navy, by the way, that was the three rotor machine was the one used by the Army Air Force. The Navy had a four wheel machine, yes, which was even more complex, and the the Secret Service UH, the people who were in the the high Intelligence groups used a completely different machine. Were not completely different, but UH used even more difficult machine to crack UM than that,

and they all had different variations on that. And in general, the Navy tended to practice better security measures and UH made it. It made it much more challenging to break that code. The Army and Air Force, by contrast, were not as as careful and so their codes were broken

faster than the Navy's UM. It's you know, part of part of decoding the the Enigma machine came into figuring out the wiring of the system, and part of it came from, you know, more traditional cryptographic approaches where you're looking for patterns and you're looking for a key phrases, and you're looking for uh things that could indicate that

UM that you've stumbled onto something. So if you if you receive several coded messages, I think a lot of problems is that we think of of decoding as you get one message and you're trying to figure it all out based on that one message. There were hundreds of

messages sent. So if you have hundreds of messages sent and you're working under the assumption that everyone has is using the same basic layout for their Enigma machine, you start looking for patterns, and if you find enough patterns, you might say, oh, all right, well, look these these two messages here start with the same essentially the same UH patterns. So that may suggest that they're both starting

with the same word. So let's start working back. And it may even be when I'm talking about patterns, I'm not even necessarily talking about the same ciphered letters. Because again if if if German A has set rotors to a certain alphabet setting to start off, and German B has chosen a totally different set, Uh, you're looking again at the actual pattern of of letter occurrence, not which

letters they are. Yeah. It also helps to have a thorough knowledge of German, much more than my one year and in high school enabled me to UH fake my way through that greeting. UM. No. They also look at contact analysis, which is basically how frequently one letter will be next to another in a language. So if you know UH German, then you're able to know certain things about the way UH certain words are more common than

other certain letter formations. So I think in a lot of ways, UM, until the Allies were able to get ahold of UH, you know, more thorough UM code cracking materials. I think the traditional code breaking tools like cribs and UH and contact analysis were probably very helpful to them. UM. But what's really funny to me is in in doing my research, I was reading about John Harrible UH, the Cambridge mathematician. He was twenty one years old, UM, and he was looking to UH to get into the cipher

known as red UM that the Germans had used. And what's funny to me is he actually stumbled upon something that we look at on that we've actually sort of talked about on the show, and we've talked about passwords. UM. He figured that at some point UH, they were going to get lazy and stop changing things and stop changing the keys that people would use for their u UM, the codes that they would use at the beginning of

the message to tell you which rotor settings. Basically, people would start using UH the name of their dog or their girlfriend to start encoding the messages, and they were going to start leaving it there. Once the first message of the day was sent. They're not going to change it for every message anymore because they're in a hurry or they're lazy and they're not going to change it. And at first UM apparently this didn't They were abiding by the rules, they were doing things the way they

were supposed to. But as soon as people became complacent and started leaving that setting throughout the day, once they had cracked the first message of the day, they were set and they were able to they could identify this and they basically asked for all the messages sent across all of the machines for the first one of the day. And once they were able to do that, um, they were able to crack read and basically identify what was

going on for the entire days communications. And that happened around or so um, which was fairly early four I mean it was before the Americans got involved, but of course Europe had been embroiled in war for a while at that point. Um. But that's a pretty that's one of those things where we tell you not to be careless with your passwords, and you know, even back then,

it's just sort of ironic to me. Yeah, it's interesting. Um. The you know, it's you're talking about a device that once you start to encode the message, that's a very time consuming process, you know, setting your device the proper way and then starting to actually encode it and to confirm that you know, you that the letters you are writing down are indeed the correct ones based upon that configuration. It's the longer the messages, the longer it is going

to take to encode. And that means that the greater the span of time between when the message was written and when the message is received becomes and that that all of that I think leads to that sort of lazy behavior because you don't want to uh uh, you know, suffer problems because you were too slow. So yeah, I mean there were a lot of different reasons why this happened, and I think a part of those just because it's such a huge pain in the butt. But that's the point.

I mean, if cryptography wasn't a pain in the butt, then there will be no secrecy there. You have to make it difficult enough so that the message remains safe. So once we started getting tired of going to those pains,

there's no more safety. Yep, yep um. But yeah, we we talked about Alan turing Um and he invented a machine known as the the van Barismus Um, which I don't know why I called it that um, but yeah, Basically it was able to identify patterns in the text messages and that just made it faster for the Allies

to be able to track things down. Yeah. I think his machine was capable of decoding a Enigma message within something like fifteen hours, which sounds like it's a long time, but when you're talking about eliminating all those possibilities, it's pretty incredible, especially you're talking you know this is this these are the developments that led into computers, and that this predates computers, but these devices sort of became the

precursor to the computer. And you know, it's one of the reasons why we talked about touring being a father of of computing and computer science because it's this sort of stuff that that led to computers in the first place. Yeah, they I think. Also one of the misconceptions is said that the machine known as Colossus was used in breaking

the Enigma ciphers, and that actually is not true. UM. Colossus is frequently were referred to as one of the first electronic computers UM, but it was actually used to break the Lorenz cipher system, which is another a different machine UM that was used by the German Army High Command UM and Lorenz is the name of a company and they basically had been working on a completely different type of machine UM that did not use the Enigma codes. UM, but yeah, they used UM. The British used Colossus to

uh figure out the Lorenz system. UM. But yeah, that that actually is the machine that we talked about back in our UM chip Tunes podcast when pixel hate was had been allowed into the Bletchley Park Museum to record the mechanical relays. And of course, uh, today's computers uh, in terms of processing power could do the work that these machines did in scant a fraction of what the time needed to do that then, but um, and can

more thoroughly encrypt messages. I mean, even the freeware tools that you can get now to encrypt email are more thorough than than these machines were. But still very fascinating stuff. Yeah, yeah, and um, yeah, it was really I would love to actually get a chance to to see one of these devices, and there aren't quite a few of them, many in museums and things like that. Um, but I've never actually, I mean I've seen plenty of pictures, but I've never

actually seen one of these devices. Uh, you know, kind of curious, want to play with one a little bit, kinda kind of I don't want to lie, you can interesting. I don't know that I could write it in German, but anyway, the Yeah, it's a neat, neat device, and it really kind of speaks to human ingenuity on both sides, both to try and keep messages secret and the determination to to find out what that secret message actually is. Really kind of interesting, So I guess that kind of

wraps up this discussion about the Enigma machine. If you guys want to know more about either the the the Enigma machine, or perhaps some other topic of very specific device that you just think needs its own episode, let us know. Send us a message on Facebook or Twitter. You can find our handle there it's Text stuff HS double you, or you can send us an email that addresses tech stuff at how stuff works dot com and Chris and I will talk to you again for really soon.

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