I visited in 2003, and volunteered to stand in the parlor of the mansion, as the docent told us of how a volunteer from each incoming set of recruits would stand with a loaded pistol leveled at their head as the Official Secrets Act was read out to the class. Visiting Bletchley Park was a tremendously moving experience, and I would encourage all to visit, and to support the Bletchley Park Trust. Greetings from Kentucky.
In the last five minutes of the film, the music is so loud that one either (a) cannot hear what's being said; OR b) music distracts from comprehension. A surprising beginner's error in a film made with a budget. The positive aspect is that is a v clear explanation.
An interesting feature of the Enigma machine is that it is “reversable”. As explained, when an operator types in a plaintext message, they get an encrypted (scrambled) sequence of letters. Now. If the recipient of this encrypted message sets their machine to exactly the same initial settings, then types in the scrambled letter sequence, the plaintext message emerges! Pretty cool, since it meant that the operator had both an encryption machine and decryption machine in the same box. This is why a code breaker’s main task was to discover the setup parameters. The “bomba” machines functioned by systematically disqualifying setups that would not have been capable of producing the intercepted encrypted letter sequence.
I think it’s interesting how at the beginning of each message a key (Spruchschlüssel) must be sent to seed that messages start rotor position. And how over time this procedure needed to change because it weakened the encryption. e.g. they would simply type a randomly selected 3 letter key but type it twice to avoid errors. But doing so created a relationship between the two sets of encrypted letters helping code breakers identify the correct rotor positions for the day.
The daily code sheet had an initial setting for the three letters visible in the rotor window. But the person sending a new message would first instruct the person receiving to change the window setting to an intermediate arrangement and with the rotors in that new setting the first operator would send a new set of letters in which the message would be encoded. The operators got sloppy and fell into using combinations of letters the code breakers could identify, like HIT & LER, BER & LIN, LON & DON, MAD & RID. So it was easy to guess from HIT the second set of letters was LER. Operators sometimes used their initials and their girlfriend’s initials. It didn’t much matter to the operators because, as they were told by their superiors, the Enigma coding system was unbreakable.
yes but i think that the real use was that operators used the same code eg Berlin everytime . You cannot guess Ber and get lin because the machine cannot be cracked incrementally (although statistics do help) I could be wrong but you cannot get tom and assume cat because tom on its own gets you knowwhere i could be quite wrong
Excellent video, on a very difficult subject. I have done a lot of reading about the Enigma machine, and this program does a good job of explaining the device. I knew Enigma machines were old when adopted by the military, but I didn't know how old.
What a fascinating machine! Thank you for this close-up look :) The Backgroud Music at 15:00 was a bit too loud in my opinion, but nevertheless a great video. Keep it up
Clearly explained, thank you. However, please 'be mindful of your likely audience' (who are probably of an age when hearing is not quite so clear) when using background music. It became frantic, intrusive and rather spoilt an otherwise excellent video. Probably not necessary at all. Will look forward to further Bletchley videos.
A suggestion "for the next presentation video"? Demonstrate a short example - maybe a sentence such as "Good morning, how are you?" Anything really. Demonstrate how the initial rotor settings would be set, how the code book interacted - and then demonstrate how it would be received, if possible. A short "tutorial", if you will.
Great question. If I recall correctly the 3 letter kenngruppen is used to send the operator's random 3 letter code too the receiver. They used too send it twice, then reset the rotors and start the message using there own 3 letter stating key.
@@zyamaha1 I found the answer after much spelunking on the Internet. Sometimes the radio operator delivered an enciphered message a bit late. The Enigma operator would have to determine what day the message was originally sent in order to reconfigure his machine for that day. The Kennegrupen were apparently in plain text in the message; the Enigma operator could cross-reference those letter groups on his code sheet to the key for a particular day of the month, then reset his machine for that day and decipher the message.
@@denvan3143 Kinda but kinda not. The Kenngruppen were simply indicators to tell the recipient which key sheet to look at. Suppose you were the signals unit somewhere on the coast of Northern France in 1944. You might want to communicate with : OB West in Paris Other units of Army Group B Luftwaffe - air support Supply - "we need more ammo !" Kriegsmarine - coastal defense or any of those might want to communicate with you. These would not all be in the same key network. So you need a key sheet for each one. If you're a small unit maybe you've only got a couple of key sheets. If you're Rommel's HQ signals unit you might have more than a dozen. The Kenngruppen tell you which key sheet is being used. If the key sheet shows hyd efr jjo poy as the 4 kenngruppen for today, on this particular key sheet, then you start your message GOYOP - ie two letters of junk and then one of the kenngruppen in any order. The recipient looks at the first five letter group in your message and recognises YOP as identifying this key sheet. Obviously one (very) subsidiary use might be identifying the date of a message but mostly it's a key sheet identification scheme. Which the Germans started phasing out round about late 1943 I think because they decided it was giving away too much information. If the enemy knows who is using which keys, then even without breaking your cipher, they get to learn quite a bit about your order of battle.
The first rotor turns once per key press, the second rotor turns once every 26 rotations of the first rotor, and the third rotor turns once every 26 rotations of the second rotor.
This is the first video / information that I've been able to find about how the daily settings were arrived at and communicated - this question has been bugging me for a while, so many thanks! Presumably if the day setting sheet was captured or made known to the allies this would completely defeat the enigma process - assuming the allies had the same version working model to use to decode. I then presume the German forces would need to re-issue and distribute new day settings to all users if / when they discovered the day settings had been captured / compromised.? I'd imagine if that ever happened it would be extremely disruptive. I'm not sure that I quite understood the bit about the individual user passwords that had to be thought up quickly and what the need was for them, other than to identify the user / coder / decoder sender / receiver? I really enjoyed this video and will be looking at the others. Thanks again.
The sender would give a three letter password to the receiver, which was the new three letter setting displayed in the rotor window. The sender would then transmit another three letter Setting for the actual message. The second set of three letters was in code; The receiver would decode it and use that as the actual window setting for the rest of the message. Without doing this all messages for that day for all senders and receivers would have the same encipherment And if the enemy broke the code they could read all messages sent by everyone that day. This way each code would have to be broken by the enemy.
At 8:18, you show a sample code sheet. What is the last column for? I translated the column heading as "characteristic groups", but that doesn't tell us how it is used.
The first 5 letters of every message has to be in this format ??xxx, where xxx is a scrambled version of any one of the four 3-letter groups in that column and ?? were any two letters chosen at random by the sender. These were transmitted 'in the clear' -- that is encrypted. The receiver then looked at the xxx part and decided by quick mental unscrambling which line of the setting sheet was being used by the sender. The scrambling was meant to be done differently for every message sent on a particular date.
@@James_Bowie I have watched a few more videos since I posted this question, and I think I understand now. If I've interpreted things correctly, the "ringstellung" numbers are the daily internal settings for the rings on the rotors (not the start position in the machine), and the "characteristic group" is suggested password for the start position for one specific message. Is that correct?
Great explanation. Thank you. Please tell me was the turnover position for each rotor different to each of the other four from manufacture? That is, at a fixed point on every rotor but at a different place for each of the 5 rotors?
Polish mathematicians Rejewski, Żygalski and Różycki cracked Eningam, the military version, in about 1932 and handed everything, including Enigma built by polish mechanics to British in 1939, few weeks before the II ww started. Read XYZ by Dermond Turing.
I wish they had better explained the "double stepping" of the middle rotor. As I understand it, this happens because the pawls-and-ratchets mechanism for advancing the Enigma machine's rotors differs from how the mechanical counter on an old car odometer works. I'm not sure of the exact reason it was designed this way; perhaps so as to be durable/reliable and allow the rotors to be easily removed and reordered? But as a consequence of this design, when a key press causes the middle rotor to turn into its turnover position, the very next key press will cause it to turn *again*, along with the rotor to its left. This means some combinations of rotor positions will get skipped. An analogy would be if an odometer counted "088," "089," "090" ... and then "101," "102," "103," etc.
Why doesn't Enigma use an odometer style movement, with pins and gears? I'd guess that, given the requirement to mount the rotors quickly and in any order and to have a simple, robust and reliable mechanism, the pawls, teeth and notch system was favoured. They couldn't tolerate a misaligned rotor as is occasionally seen in mechanical odometers as this would compromise the integrity of the electrical contacts route. Double-stepping arises because there are actually two ways the pawl levers can step a rotor: (i) by pushing on one of its 26 teeth to the right of the rotor (viewed from the operator), or (ii) by pushing on its notch to the left of the rotor. The 26 teeth on a rotor are mostly held away from the pawls by the notched ring or flange on the next rotor to its right. Obviously the fast rotor has no rotor to its right, so it steps at every key press. Notch positions in each rotor (Ringstellung) are changed daily as dictated by the codebook day settings. Consider a 3-rotor machine. Suppose the middle rotor is at a position one short of exposing its notch and the fast rotor has just exposed its notch . Suppose the rotor windows show AAA. Now a key is pressed. The fast rotor steps as usual to B and, because its notch is already exposed, the middle pawl drops into it, contacting the teeth of the middle rotor and stepping that rotor from A to B. The rotor windows now show ABB. So far it's mechanical odometer-like. But the middle rotor has now exposed its notch. So, at the next keypress, the fast rotor advances as usual, the middle rotor advances again, this time by the pawl in its notch (not its teeth). And, at the same time, the slow rotor advances one step (the pawl pushes its teeth, let in by the notch on the middle rotor). The rotor windows now show BCC (not the ABC that would be expected by odometer-style sequencing). That is double stepping: two rotors have both moved in two consecutive keypresses. As far as protecting against decryption attack is concerned, this double-stepping was probably a weakness.
I'm not sure which came first but, in addition to the plugboard, the extra two(totaling five) rotors were added to the complication. If Mr. Fryer said that; I didn't catch it and was waiting for it!
It’s complicated. According to the information I’ve found the German military’s Railroad K and the Swiss K Enigma machines were pretty much off the shelf, used only the original three rotors and had no plugboards. The G-312, used by the Secret Service (Abwehr) Used three rotors and the plugboard. The first to use the plugboard and five rotors was the Enigma I, also known as: • Enigma A • Wehrmacht Enigma • Heeres Enigma • Service Enigma • Army/GAF Enigma Rotors I through VIII were used in the M1, M2, and M3 (all generally referred to as “M3“), which all used the plugboard. The four rotor M4 which was used by the German Navy had the plugboard, all eight rotors plus rotors Beta and Gamma.
An excellent explanation and tour of the machine. Sadly most documentaries made about the code breakers focus on the people and the effects of their work and barely skim the surface of the amazing machines involved on both sides - machines that spawned developments which underpin our modern tech world. A Question: What are those wired gubbins inside the lid of the Enigma?
Why make it difficult to hear especially as you reaching the end of your presentation? I am very interested in this machine and couldn't quite catch all of it.
Captions are a poor "last resort". Great video, but those making it need to realize you don't add "background music" that makes it exceedingly difficult to hear what is actually being said. It's as if the people that made the video never listened to it all the way through when they were done.
Fascinating stuff. One thing I wasn't quite clear on. Was the encoding symmetric? (I.e. If a encoded as the n'th letter in the message became y, with the same starting configuration when y was entered as the n'th character in sequence the displayed output would be a again.) If not, was there a switch or something to convert the machine from encoding mode to decoding mode?
This was before the maths that allows for public key encryption and electromechanical devices only used symmetric. The maths that would allow for asymmetric encryption was done at Harvard in the 1970s. However, it turned out that GCHQ had been working on the problem in the 60s, had solved it in pretty much the same way, but had kept quiet about it! (It's more complicated than that, but that is the gist).
What i do not really understand is that a letter cannot be encrypted as its self surely if you press a b a b will come up sometime. Also spying is about deception and we will never know the truth for all we know wr were getting all the info from the generals cook via carrier pigeon.
Yes i have a feeling that the intelligence came from elsewhere and to disguise it all we needed were 8000 workers a few mathematical problems geniuses and a large country house. result we were all fooled all of the time.
Enjoyed it the enigma is not at one level a cerebral problem it is a practical machine which will be easily solved with a few bits of circular cardboard shuffled. can be cracked by most people easily but lets call it an enigma!!!!!!? And pretend its difficulty warrents a museum with a duck 🦆 pond. .
No, they mean literally NEVER. It is physically impossible for a letter to be encoded as itself. The key switches were two-way reed switches. When a key is not pressed its corresponding bulb is capable of being illuminated if the complex wiring route through the rotors, through the reflector (which is like a fixed rotor), and back through the rotors happened to go via that key switch. But, if the key is pressed, then there is no electrical route to that bulb -- the route is open circuited. Hence a letter can never be encoded as itself. This peculiarity was a key item in the breaking of Enigma traffic. If a 'crib' ever revealed a same-letter match with a possible decrypt, then the possible decrypt was wrong -- these rejections saved a massive amount of time.
@@frederickbowdler8169 As the chap said, it can't return as an A because there's no circuit. You only have a circuit if it returns as something else. So I think you're asking - how, apart from there not being a circuit, did the design of the machine ensure that the letter shuffling could never shuffle an A back to an A. And the answer is that - once the key is pressed - there's only 26 single wires that take the current from the keyboard to the Reflector. One for each letter on the keyboard. It's a unique path that gets A on the keyboard to say F going into the Reflector. Consequently the only path by which the current could get back to A on the keyboard switch before being sent to the lamp, is if it started off from the F connection at the Reflector. But the Reflector ALWAYS flips the incoming letter to a different one. The letters were wired up in pairs. Thus the current cannot leave the Reflector from the F connection if it arrived there. And since the F connection is the only starting place on the Reflector that could take the current back to A on the keyboard, and then the lamp, we know it can't be an A when it arrives back. The "solution" would be to have double wires throughout the machine so that the current could go back from the Reflector the same way that it came (but down a parallel wire) and to wire up the Reflector like the Plugboard so that it sometimes left a letter unchanged. But that would require doubling the wiring throughout the machine, and they obviously thought it woudn't be worth it.
@@leemoore5212 since I posted that I have found out a micro switch was underneath every key and when pressed the letter pressed was negated so I am pretty certain that the reflector has little to do with this aspect because later reels after the reflector could transpose it .I hope I'm correct.?
@@bigbeemerbiker yes I was confused as the mathematics professor stated that the reflector had something to do with this and he was mistaken. Thanks for the information .
What material were the rotors made from? Metal? Wood? Plastic? What kind of insulation did the wiring have to have to keep the machine from short circuiting?
There was no such thing as plastic in the early 40s, AFAIK. Maybe someone knows differently. If there were, the box would have been made of plastic to be lighter and water resistant.
I have known that the enigma machine‘s were produced commercially and sold to the public initially. What has never been explained to me is who the market was for this encoding machine. Was it government? was it business to business? Did they use a telephone line or telegraph line? Or was it on its own dedicated pair of wires?
Each of the two prong cables has two wires, just like an extension cord. There is no schematic of the plugboard because, if no cables are plugged into it, the letters pass through without being scrambled: A passes through as A, B passes through as B, etc. if you pause the video at the insert of the monthly code sheet you can see the plugboard arrangement for each day in the column marked “Steckerbindugen”, 10 pairs of letter substitutions.
I saw another video that showed that if there wasn't a plug inserted in the socket. the socket looped back on itself, no swap. With a plug inserted it pushed the loopback bar away, breaking the circuit. The cable instead swapped the return path with letter at the other end of the plug cable. .The plug on the other side did the same. Swapping the two letters The plugboard added a dimension of complication in that not all letters were swapped with another and was not in a fixed order like the rotors.
Did the British ever try later on to decipher those encrypted Enigma messages, that had caused so big problems during the early days, before Turing's Bombe really became successful, and during the dark periods? Those messages could still potentially have been of great military interest or of great historical interest after the war.
Excellent video but tbe music is extremely annoying. It gets louder and louder as the video progresses. Very distracting as I have to use headphones and the video becomes difficult at 14:30 and unwatchable at 14:38. Why did you ruin the video with music? Unnecessary.
The British used an Underwood typewriter and an untrained typist for the the encryption the result was the same except that the letter pairs were reversed inverted and halted when she stopped for the obligatory egg sandwiches.
I haven't found an answer to this question: Some Enigmas have numerals on the top row of letter keys and yet there is no 'shift' key to change from letters to numerals so how would these top row of letters become numerals?
It would be quite easy to see in a decrypted message that a random letter was in an appropriate place. If you know your decrypted message was TWENTYA then you know the A meant the percent symbol. If you decrypted message was "Are there any questionsh" then you know the H meant the ? symbol.
@@Nailzy1985 I accept that, but as I said there are some Enigmas with numerals on the top row of keys, as well as letters. The machine in this video does not have those numerals. For example the Q key also has the number 1 on the same key. So if you were using those, instead of typing TWENTY you would just tap two keys, probably WO (the top row of keys includes numerals 1 to 9 but not zero). How would the decryptor (and for that matter the intended recipient) know that the number twenty was transmitted and it wasn't just a distorted bit of morse receoved over a poor radio link, or a dozy morse opterator at the sending end or a befuddled listener interceptor? A simple number might be easy to interpret but what about a long number in the thousands? That could be dismissed as a garbled signal. What would happen if you sent a signal "SEND 520 SACKS OF POTATOES WE ARE STARVING"? If all of the message was received correctly it decrypted as "SEND TWO SACKS OF POTATOES WE ARE STARVING". The T key is also the 5 key. The W key is the same key as the 2 key. The O key is the same key as the 0 key. Would you send two sacks of potatoes or five hundred and twenty? The transmitting officer would have pressed the correct keys, and then the whole squadron would have starved to death because they only recieved two sacks of potatoes instead of five hundred and twenty. Or, if they only wanted two sacks and received five hundred and tweny, what would they have done with the surplus? Answer: probably make potato vodka!
@@gasgas2689 you make a fair argument on that. I'll be going to Bletchley Park again soon once it reopens from COVID - and I'll do my best to get you an answer!
@@Nailzy1985 Good luck, I was (and in theory still am) a steward there, and no one I have met there knows! In the end it must just have worked logically, the receiver would guess the number. It just leaves open the possibility of a mistake. The nearest I can get it that somewhere I read the transmitting officer put a X at the start of a number, and for some unknown reason a double X, XX at the start and end of an important person's name. Other than that you just had to type out the whole number. I should have asked my dad when he was alive, but he only told me he was intercepting the signals about three years before he died. Then I didn't know about the Enigmas with numbers as well as letters. I don't think my mother ever knew what he did.
How did the codebreaker know when one of the wheels turned over? They see (as I understand it) the message as a series of letters on a crib sheet and never see the machine. What in the actual encrypted message indicates that the wheel has turned?
The right-hand wheel turns one position after each letter. After one complete rotation, the middle wheel moves one position and after one complete rotation of the middle wheel, the left wheel moves one position. You can see this nicely in the videos of the bomb.
He's a true genius on the subject, but a poor communicator. That poor girl struggled valiantly getting every tidbit of information from him that she did - kind of like trying to learn the Enigma in the first place.
Sorry but I have to vent a little bit. I absolutely love the videos about the Enigma. But why-oh-why must video creators put such annoying music in their productions?? I see later on down the comments this has, unsurprisingly, been brought up already and the creator has indeed responded to the commentor. Thank you.
i dont think the plug board made it that much more complex, at the end of the day all it did was do a direct substitution, without any scrambling like the rotors did
We see the same camera problems from poor camera operators. 1st the machine is the main character and the 2 humans are the question and answer part of video. When filming information video keep the camera on the subject which is the machine not the 2 asking, informing etc. Maybe in the near future a true process could happen such as machine operator is handed a message, he/she types. So what happens after that? Someone had to copy the encrypted message, then send message by Morse code. Someone received and entered into machine to get the message! 😮
"Very few of them left." "When you say, 'very few' - ten, twenty?" "Maybe three-hundred-and-fifty". ??????? I believe the wrong rotor settings were used when defining and translating "very few".
Any presented hire machines, are not presented basic requirements for purpose intelligent ketchup messages - like not visible super receiver. 3 wheels, wooden boxes without any protections from military damage possibility and whether - looks like simulatory for training, not for military part biggest deadly WAR in global history. Serious explanation naive theories how to connect 2 machines is lack of basic knowledge in many areas, transmission & receiving, for simple function is missing attached extra necessary equipments - they not released ready ridible message? From Bletchley Park? - well, day after signed capitulation, everything looks like paper burned in Bletchley Park. Simply question WHO WIN WWII - like always PROPAGANDA, process are still pending. Germany with Volunteers country, in global history, build-up the biggest WAR MACHINE, takeover large territory on intercontinental stealing. And build-up BIGEST NETWORK - ENIGMA.,with different geopolitical areas & tims. The number required ENIGMAS? - you needed know about structure German Army, where country or territory they covered. Now biggest "professors" please choose only one German Enigma - for free conversation, powodzenia. For that specific purpose intelligent operations, on huge network Enigma - was answer, by POLISH interceptor BOMBA.
I visited in 2003, and volunteered to stand in the parlor of the mansion, as the docent told us of how a volunteer from each incoming set of recruits would stand with a loaded pistol leveled at their head as the Official Secrets Act was read out to the class. Visiting Bletchley Park was a tremendously moving experience, and I would encourage all to visit, and to support the Bletchley Park Trust. Greetings from Kentucky.
Cool biker jacket 👍🏼
In the last five minutes of the film, the music is so loud that one either (a) cannot hear what's being said; OR b) music distracts from comprehension. A surprising beginner's error in a film made with a budget. The positive aspect is that is a v clear explanation.
An interesting feature of the Enigma machine is that it is “reversable”. As explained, when an operator types in a plaintext message, they get an encrypted (scrambled) sequence of letters. Now. If the recipient of this encrypted message sets their machine to exactly the same initial settings, then types in the scrambled letter sequence, the plaintext message emerges! Pretty cool, since it meant that the operator had both an encryption machine and decryption machine in the same box. This is why a code breaker’s main task was to discover the setup parameters. The “bomba” machines functioned by systematically disqualifying setups that would not have been capable of producing the intercepted encrypted letter sequence.
A key problem was it could NEVER encrypt a letter as itself. If you saw an A you straight away knew the letter was not A
I think it’s interesting how at the beginning of each message a key (Spruchschlüssel) must be sent to seed that messages start rotor position. And how over time this procedure needed to change because it weakened the encryption. e.g. they would simply type a randomly selected 3 letter key but type it twice to avoid errors. But doing so created a relationship between the two sets of encrypted letters helping code breakers identify the correct rotor positions for the day.
The daily code sheet had an initial setting for the three letters visible in the rotor window. But the person sending a new message would first instruct the person receiving to change the window setting to an intermediate arrangement and with the rotors in that new setting the first operator would send a new set of letters in which the message would be encoded. The operators got sloppy and fell into using combinations of letters the code breakers could identify, like HIT & LER, BER & LIN, LON & DON, MAD & RID. So it was easy to guess from HIT the second set of letters was LER. Operators sometimes used their initials and their girlfriend’s initials. It didn’t much matter to the operators because, as they were told by their superiors, the Enigma coding system was unbreakable.
yes but i think that the real use was that operators used the same code eg Berlin everytime . You cannot guess Ber and get lin because the machine cannot be cracked incrementally (although statistics do help) I could be wrong but you cannot get tom and assume cat because tom on its own gets you knowwhere i could be quite wrong
Excellent video, on a very difficult subject. I have done a lot of reading about the Enigma machine, and this program does a good job of explaining the device. I knew Enigma machines were old when adopted by the military, but I didn't know how old.
What a fascinating machine! Thank you for this close-up look :) The Backgroud Music at 15:00 was a bit too loud in my opinion, but nevertheless a great video. Keep it up
Thanks your your feedback - We'll take this on board. We're glad you enjoyed the video!
The music tended to overpower the voices and it was hard to follow the conversation.
Nicely done Ms Munro. You brought this all together. Thanks
We're glad you enjoyed it!
Clearly explained, thank you. However, please 'be mindful of your likely audience' (who are probably of an age when hearing is not quite so clear) when using background music. It became frantic, intrusive and rather spoilt an otherwise excellent video. Probably not necessary at all. Will look forward to further Bletchley videos.
Thank you so much. I have plans to visit Bletchley Park as soon as we are clear of Covid.
Make sure you visit the computer museum to see the colossus which is on the same site but not part of the ‘Bletchley park’ admission
A suggestion "for the next presentation video"? Demonstrate a short example - maybe a sentence such as "Good morning, how are you?" Anything really. Demonstrate how the initial rotor settings would be set, how the code book interacted - and then demonstrate how it would be received, if possible. A short "tutorial", if you will.
Great explanation. However, have I missed the function of the 3-letter sequences identified as Kenngruppen in the settings sheet?
I am also looking for the answer to this question
Great question. If I recall correctly the 3 letter kenngruppen is used to send the operator's random 3 letter code too the receiver. They used too send it twice, then reset the rotors and start the message using there own 3 letter stating key.
@@zyamaha1 I found the answer after much spelunking on the Internet. Sometimes the radio operator delivered an enciphered message a bit late. The Enigma operator would have to determine what day the message was originally sent in order to reconfigure his machine for that day. The Kennegrupen were apparently in plain text in the message; the Enigma operator could cross-reference those letter groups on his code sheet to the key for a particular day of the month, then reset his machine for that day and decipher the message.
@@denvan3143 Kinda but kinda not. The Kenngruppen were simply indicators to tell the recipient which key sheet to look at. Suppose you were the signals unit somewhere on the coast of Northern France in 1944. You might want to communicate with :
OB West in Paris
Other units of Army Group B
Luftwaffe - air support
Supply - "we need more ammo !"
Kriegsmarine - coastal defense
or any of those might want to communicate with you. These would not all be in the same key network. So you need a key sheet for each one. If you're a small unit maybe you've only got a couple of key sheets. If you're Rommel's HQ signals unit you might have more than a dozen.
The Kenngruppen tell you which key sheet is being used. If the key sheet shows hyd efr jjo poy as the 4 kenngruppen for today, on this particular key sheet, then you start your message GOYOP - ie two letters of junk and then one of the kenngruppen in any order. The recipient looks at the first five letter group in your message and recognises YOP as identifying this key sheet.
Obviously one (very) subsidiary use might be identifying the date of a message but mostly it's a key sheet identification scheme. Which the Germans started phasing out round about late 1943 I think because they decided it was giving away too much information. If the enemy knows who is using which keys, then even without breaking your cipher, they get to learn quite a bit about your order of battle.
The first rotor turns once per key press, the second rotor turns once every 26 rotations of the first rotor, and the third rotor turns once every 26 rotations of the second rotor.
This is the first video / information that I've been able to find about how the daily settings were arrived at and communicated - this question has been bugging me for a while, so many thanks! Presumably if the day setting sheet was captured or made known to the allies this would completely defeat the enigma process - assuming the allies had the same version working model to use to decode. I then presume the German forces would need to re-issue and distribute new day settings to all users if / when they discovered the day settings had been captured / compromised.? I'd imagine if that ever happened it would be extremely disruptive. I'm not sure that I quite understood the bit about the individual user passwords that had to be thought up quickly and what the need was for them, other than to identify the user / coder / decoder sender / receiver? I really enjoyed this video and will be looking at the others. Thanks again.
The sender would give a three letter password to the receiver, which was the new three letter setting displayed in the rotor window. The sender would then transmit another three letter Setting for the actual message. The second set of three letters was in code; The receiver would decode it and use that as the actual window setting for the rest of the message. Without doing this all messages for that day for all senders and receivers would have the same encipherment And if the enemy broke the code they could read all messages sent by everyone that day. This way each code would have to be broken by the enemy.
This is the exact explanation I use when I get busted by the girlfriend smuggling new tech into the house.
At 8:18, you show a sample code sheet. What is the last column for? I translated the column heading as "characteristic groups", but that doesn't tell us how it is used.
The first 5 letters of every message has to be in this format ??xxx, where xxx is a scrambled version of any one of the four 3-letter groups in that column and ?? were any two letters chosen at random by the sender. These were transmitted 'in the clear' -- that is encrypted. The receiver then looked at the xxx part and decided by quick mental unscrambling which line of the setting sheet was being used by the sender. The scrambling was meant to be done differently for every message sent on a particular date.
@@James_Bowie I have watched a few more videos since I posted this question, and I think I understand now. If I've interpreted things correctly, the "ringstellung" numbers are the daily internal settings for the rings on the rotors (not the start position in the machine), and the "characteristic group" is suggested password for the start position for one specific message. Is that correct?
Great explanation. Thank you. Please tell me was the turnover position for each rotor different to each of the other four from manufacture? That is, at a fixed point on every rotor but at a different place for each of the 5 rotors?
Do you have any pictures of how the rotors moved the settings? Thanks! Interesting stuff!
Congrats for the amazing video
Thank you!
Polish mathematicians Rejewski, Żygalski and Różycki cracked Eningam, the military version, in about 1932 and handed everything, including Enigma built by polish mechanics to British in 1939, few weeks before the II ww started. Read XYZ by Dermond Turing.
Blimey that guy with the hat is hard work. Getting him to answer questions is like extracting teeth.
Yeah, this is an interesting first draft of a vid. It’s worth a proper coherent do-over.
Yes, like when he asked, early on, "should we open the box?"
He appears to be an engineer; getting information from them can be somewhat arduous.
Getting information out of Mr. Fryer, is like getting Enigma to give up it's secrets.
I wish they had better explained the "double stepping" of the middle rotor. As I understand it, this happens because the pawls-and-ratchets mechanism for advancing the Enigma machine's rotors differs from how the mechanical counter on an old car odometer works. I'm not sure of the exact reason it was designed this way; perhaps so as to be durable/reliable and allow the rotors to be easily removed and reordered? But as a consequence of this design, when a key press causes the middle rotor to turn into its turnover position, the very next key press will cause it to turn *again*, along with the rotor to its left. This means some combinations of rotor positions will get skipped. An analogy would be if an odometer counted "088," "089," "090" ... and then "101," "102," "103," etc.
Why doesn't Enigma use an odometer style movement, with pins and gears? I'd guess that, given the requirement to mount the rotors quickly and in any order and to have a simple, robust and reliable mechanism, the pawls, teeth and notch system was favoured. They couldn't tolerate a misaligned rotor as is occasionally seen in mechanical odometers as this would compromise the integrity of the electrical contacts route.
Double-stepping arises because there are actually two ways the pawl levers can step a rotor: (i) by pushing on one of its 26 teeth to the right of the rotor (viewed from the operator), or (ii) by pushing on its notch to the left of the rotor. The 26 teeth on a rotor are mostly held away from the pawls by the notched ring or flange on the next rotor to its right. Obviously the fast rotor has no rotor to its right, so it steps at every key press. Notch positions in each rotor (Ringstellung) are changed daily as dictated by the codebook day settings.
Consider a 3-rotor machine. Suppose the middle rotor is at a position one short of exposing its notch and the fast rotor has just exposed its notch . Suppose the rotor windows show AAA. Now a key is pressed. The fast rotor steps as usual to B and, because its notch is already exposed, the middle pawl drops into it, contacting the teeth of the middle rotor and stepping that rotor from A to B. The rotor windows now show ABB. So far it's mechanical odometer-like. But the middle rotor has now exposed its notch. So, at the next keypress, the fast rotor advances as usual, the middle rotor advances again, this time by the pawl in its notch (not its teeth). And, at the same time, the slow rotor advances one step (the pawl pushes its teeth, let in by the notch on the middle rotor). The rotor windows now show BCC (not the ABC that would be expected by odometer-style sequencing). That is double stepping: two rotors have both moved in two consecutive keypresses.
As far as protecting against decryption attack is concerned, this double-stepping was probably a weakness.
I'm not sure which came first but, in addition to the plugboard, the extra two(totaling five) rotors were added to the complication. If Mr. Fryer said that; I didn't catch it and was waiting for it!
It’s complicated. According to the information I’ve found the German military’s Railroad K and the Swiss K Enigma machines were pretty much off the shelf, used only the original three rotors and had no plugboards. The G-312, used by the Secret Service (Abwehr) Used three rotors and the plugboard. The first to use the plugboard and five rotors was the Enigma I, also known as:
• Enigma A
• Wehrmacht Enigma
• Heeres Enigma
• Service Enigma
• Army/GAF Enigma
Rotors I through VIII were used in the M1, M2, and M3 (all generally referred to as “M3“), which all used the plugboard. The four rotor M4 which was used by the German Navy had the plugboard, all eight rotors plus rotors Beta and Gamma.
An excellent explanation and tour of the machine. Sadly most documentaries made about the code breakers focus on the people and the effects of their work and barely skim the surface of the amazing machines involved on both sides - machines that spawned developments which underpin our modern tech world.
A Question: What are those wired gubbins inside the lid of the Enigma?
Thank you! Very interesting video. 🥰
Brilliant expose. Thank you so much
Thank you - a good explanation (marred only by intrusive and unnecessary music towards the end).
Why make it difficult to hear especially as you reaching the end of your presentation? I am very interested in this machine and couldn't quite catch all of it.
Did you use the captions?
Captions are a poor "last resort". Great video, but those making it need to realize you don't add "background music" that makes it exceedingly difficult to hear what is actually being said. It's as if the people that made the video never listened to it all the way through when they were done.
Fascinating stuff. One thing I wasn't quite clear on. Was the encoding symmetric? (I.e. If a encoded as the n'th letter in the message became y, with the same starting configuration when y was entered as the n'th character in sequence the displayed output would be a again.) If not, was there a switch or something to convert the machine from encoding mode to decoding mode?
The way you described it is correct. This video gives some more information: ruclips.net/video/G2_Q9FoD-oQ/видео.html
This was before the maths that allows for public key encryption and electromechanical devices only used symmetric. The maths that would allow for asymmetric encryption was done at Harvard in the 1970s. However, it turned out that GCHQ had been working on the problem in the 60s, had solved it in pretty much the same way, but had kept quiet about it! (It's more complicated than that, but that is the gist).
What i do not really understand is that a letter cannot be encrypted as its self surely if you press a b a b will come up sometime. Also spying is about deception and we will never know the truth for all we know wr were getting all the info from the generals cook via carrier pigeon.
Yes i have a feeling that the intelligence came from elsewhere and to disguise it all we needed were 8000 workers a few mathematical problems geniuses and a large country house. result we were all fooled all of the time.
Enjoyed it the enigma is not at one level a cerebral problem it is a practical machine which will be easily solved with a few bits of circular cardboard shuffled. can be cracked by most people easily but lets call it an enigma!!!!!!? And pretend its difficulty warrents a museum with a duck 🦆 pond. .
i think that when they say "a letter never transposes into its self " they mean very rarely possibly once in a message.😊
No, they mean literally NEVER. It is physically impossible for a letter to be encoded as itself. The key switches were two-way reed switches. When a key is not pressed its corresponding bulb is capable of being illuminated if the complex wiring route through the rotors, through the reflector (which is like a fixed rotor), and back through the rotors happened to go via that key switch. But, if the key is pressed, then there is no electrical route to that bulb -- the route is open circuited. Hence a letter can never be encoded as itself. This peculiarity was a key item in the breaking of Enigma traffic. If a 'crib' ever revealed a same-letter match with a possible decrypt, then the possible decrypt was wrong -- these rejections saved a massive amount of time.
@@bigbeemerbiker yes so i press an A but this prevents A BEING ILLUMINATED SO WHICH LIGHT LIGHTS UP IF IT RETURN S AS AN A
@@frederickbowdler8169 As the chap said, it can't return as an A because there's no circuit. You only have a circuit if it returns as something else.
So I think you're asking - how, apart from there not being a circuit, did the design of the machine ensure that the letter shuffling could never shuffle an A back to an A. And the answer is that - once the key is pressed - there's only 26 single wires that take the current from the keyboard to the Reflector. One for each letter on the keyboard. It's a unique path that gets A on the keyboard to say F going into the Reflector. Consequently the only path by which the current could get back to A on the keyboard switch before being sent to the lamp, is if it started off from the F connection at the Reflector.
But the Reflector ALWAYS flips the incoming letter to a different one. The letters were wired up in pairs. Thus the current cannot leave the Reflector from the F connection if it arrived there. And since the F connection is the only starting place on the Reflector that could take the current back to A on the keyboard, and then the lamp, we know it can't be an A when it arrives back.
The "solution" would be to have double wires throughout the machine so that the current could go back from the Reflector the same way that it came (but down a parallel wire) and to wire up the Reflector like the Plugboard so that it sometimes left a letter unchanged. But that would require doubling the wiring throughout the machine, and they obviously thought it woudn't be worth it.
@@leemoore5212 since I posted that I have found out a micro switch was underneath every key and when pressed the letter pressed was negated so I am pretty certain that the reflector has little to do with this aspect because later reels after the reflector could transpose it .I hope I'm correct.?
@@bigbeemerbiker yes I was confused as the mathematics professor stated that the reflector had something to do with this and he was mistaken. Thanks for the information .
If you do not know the rotor and reflector wire setup... Wouldn't that like explode the number of possibilities even without the plug board?
Yes, but they didn't want to take a chance.
What material were the rotors made from? Metal? Wood? Plastic? What kind of insulation did the wiring have to have to keep the machine from short circuiting?
There was no such thing as plastic in the early 40s, AFAIK. Maybe someone knows differently. If there were, the box would have been made of plastic to be lighter and water resistant.
exciting stuff
We are pleased you enjoyed it!
Fascinating, nice vid!
Two of the most popular words used were: BER LIN and HIT LER (you were supposed to use 3 letters at the beginning and 3 at the end)
WHEN YOU CANT HEAR THE Dialogue BECAUSE OF STUPID USE OF MUSIC, ITS AN ENIGMA
I have known that the enigma machine‘s were produced commercially and sold to the public initially. What has never been explained to me is who the market was for this encoding machine. Was it government? was it business to business? Did they use a telephone line or telegraph line? Or was it on its own dedicated pair of wires?
The commercial ones weren't like the ones used during the war. They were modified I believe. Example they never had plug boards
Does each of the two prong cables have one or two wires in it? Is there a schematic somewhere?
Each of the two prong cables has two wires, just like an extension cord. There is no schematic of the plugboard because, if no cables are plugged into it, the letters pass through without being scrambled: A passes through as A, B passes through as B, etc. if you pause the video at the insert of the monthly code sheet you can see the plugboard arrangement for each day in the column marked “Steckerbindugen”, 10 pairs of letter substitutions.
I saw another video that showed that if there wasn't a plug inserted in the socket. the socket looped back on itself, no swap. With a plug inserted it pushed the loopback bar away, breaking the circuit. The cable instead swapped the return path with letter at the other end of the plug cable. .The plug on the other side did the same. Swapping the two letters The plugboard added a dimension of complication in that not all letters were swapped with another and was not in a fixed order like the rotors.
3:24 - Why are there four columns of "start position" for each day? How was that degree of freedom exploited?
Did the British ever try later on to decipher those encrypted Enigma messages, that had caused so big problems during the early days, before Turing's Bombe really became successful, and during the dark periods?
Those messages could still potentially have been of great military interest or of great historical interest after the war.
See "The Code Book" by Simon Singh (2011) for much more info and history
Amazingly not found and captured by Yanks from a Submarine :) Great content guys :)
Thank you Philip, we are so glad you enjoyed it!
Gracias por los datos!
How did they decide which rotational position to put the rotors in when first inserting them?
Excellent video but tbe music is extremely annoying. It gets louder and louder as the video progresses. Very distracting as I have to use headphones and the video becomes difficult at 14:30 and unwatchable at 14:38. Why did you ruin the video with music? Unnecessary.
The British used an Underwood typewriter and an untrained typist for the the encryption the result was the same except that the letter pairs were reversed inverted and halted when she stopped for the obligatory egg sandwiches.
Long may leather elbow patches be used :)
I haven't found an answer to this question: Some Enigmas have numerals on the top row of letter keys and yet there is no 'shift' key to change from letters to numerals so how would these top row of letters become numerals?
It would be quite easy to see in a decrypted message that a random letter was in an appropriate place. If you know your decrypted message was TWENTYA then you know the A meant the percent symbol. If you decrypted message was "Are there any questionsh" then you know the H meant the ? symbol.
www.alamy.com/enigma-machine-in-the-bletchley-park-museum-uk-image6965741.html?pv=1&stamp=2&imageid=C9592A9A-D269-4923-8E1E-21309DD12C59&p=6659&n=0&orientation=0&pn=1&searchtype=0&IsFromSearch=1&srch=foo%3dbar%26st%3d0%26pn%3d1%26ps%3d100%26sortby%3d2%26resultview%3dsortbyPopular%26npgs%3d0%26qt%3dturing%26qt_raw%3dturing%26lic%3d3%26mr%3d0%26pr%3d0%26ot%3d0%26creative%3d%26ag%3d0%26hc%3d0%26pc%3d%26blackwhite%3d%26cutout%3d%26tbar%3d1%26et%3d0x000000000000000000000%26vp%3d0%26loc%3d0%26imgt%3d0%26dtfr%3d%26dtto%3d%26size%3d0xFF%26archive%3d1%26groupid%3d%26pseudoid%3d%26a%3d%26cdid%3d%26cdsrt%3d%26name%3d%26qn%3d%26apalib%3d%26apalic%3d%26lightbox%3d%26gname%3d%26gtype%3d%26xstx%3d0%26simid%3d%26saveQry%3d%26editorial%3d1%26nu%3d%26t%3d%26edoptin%3d%26customgeoip%3d%26cap%3d1%26cbstore%3d1%26vd%3d0%26lb%3d%26fi%3d2%26edrf%3d%26ispremium%3d1%26flip%3d0%26pl%3d
@@Nailzy1985 I accept that, but as I said there are some Enigmas with numerals on the top row of keys, as well as letters. The machine in this video does not have those numerals. For example the Q key also has the number 1 on the same key. So if you were using those, instead of typing TWENTY you would just tap two keys, probably WO (the top row of keys includes numerals 1 to 9 but not zero). How would the decryptor (and for that matter the intended recipient) know that the number twenty was transmitted and it wasn't just a distorted bit of morse receoved over a poor radio link, or a dozy morse opterator at the sending end or a befuddled listener interceptor? A simple number might be easy to interpret but what about a long number in the thousands? That could be dismissed as a garbled signal. What would happen if you sent a signal "SEND 520 SACKS OF POTATOES WE ARE STARVING"? If all of the message was received correctly it decrypted as "SEND TWO SACKS OF POTATOES WE ARE STARVING". The T key is also the 5 key. The W key is the same key as the 2 key. The O key is the same key as the 0 key. Would you send two sacks of potatoes or five hundred and twenty? The transmitting officer would have pressed the correct keys, and then the whole squadron would have starved to death because they only recieved two sacks of potatoes instead of five hundred and twenty. Or, if they only wanted two sacks and received five hundred and tweny, what would they have done with the surplus? Answer: probably make potato vodka!
@@gasgas2689 you make a fair argument on that. I'll be going to Bletchley Park again soon once it reopens from COVID - and I'll do my best to get you an answer!
@@Nailzy1985 Good luck, I was (and in theory still am) a steward there, and no one I have met there knows! In the end it must just have worked logically, the receiver would guess the number. It just leaves open the possibility of a mistake. The nearest I can get it that somewhere I read the transmitting officer put a X at the start of a number, and for some unknown reason a double X, XX at the start and end of an important person's name. Other than that you just had to type out the whole number.
I should have asked my dad when he was alive, but he only told me he was intercepting the signals about three years before he died. Then I didn't know about the Enigmas with numbers as well as letters. I don't think my mother ever knew what he did.
Never explained how enigma excludes letter negation into same letter
At the risk of being churlish very few vids claiming to show how an Enigma works (including this one) actually do so.
Do you have a Telegraph Machine?
towards the end, the music becomes louder than the voice, can't hear what they say
I still don’t understand how the hell this thing works! I’m just not smart enuff I gess…😢
How did the codebreaker know when one of the wheels turned over? They see (as I understand it) the message as a series of letters on a crib sheet and never see the machine. What in the actual encrypted message indicates that the wheel has turned?
The right-hand wheel turns one position after each letter. After one complete rotation, the middle wheel moves one position and after one complete rotation of the middle wheel, the left wheel moves one position. You can see this nicely in the videos of the bomb.
Background music is a nousy distraction and far too loud
Get a pro in
That man needs mental care😂😂😂
He's a true genius on the subject, but a poor communicator. That poor girl struggled valiantly getting every tidbit of information from him that she did - kind of like trying to learn the Enigma in the first place.
@@dmartin4414 I couldn't understand him first time I watched the video,had to watch another time.
Yes. Why the goofy, "dramatic" music toward the end? Worried viewers were getting bored?
Sorry but I have to vent a little bit. I absolutely love the videos about the Enigma. But why-oh-why must video creators put such annoying music in their productions?? I see later on down the comments this has, unsurprisingly, been brought up already and the creator has indeed responded to the commentor. Thank you.
i dont think the plug board made it that much more complex, at the end of the day all it did was do a direct substitution, without any scrambling like the rotors did
Nice talk, but the music annoyingly covered some of what was being said :(
Why use the music? - and why at such a high volume?
It was especially bad towards the end of this otherwise great video 🙄
Why does it not have German letters ß, ü, ä and ö?
These can be written as ss, ue, ae, and oe w/o the need for the extra keys.
@@ltcterry2006 Thanks for the reply, two years after I asked the question 🤭 Better late than never.
My nan worked there during ww2
Have you had a look to see if your Grandmother is on our Roll of Honour? bletchleypark.org.uk/roll-of-honour
Bletchley Park yep I found something
And didn’t the German Navy add a 4th rotor?
This was tip of the iceberg.
We see the same camera problems from poor camera operators. 1st the machine is the main character and the 2 humans are the question and answer part of video. When filming information video keep the camera on the subject which is the machine not the 2 asking, informing etc. Maybe in the near future a true process could happen such as machine operator is handed a message, he/she types. So what happens after that? Someone had to copy the encrypted message, then send message by Morse code. Someone received and entered into machine to get the message! 😮
if there is a fee to look around i think the money should go toward veterans welfare instead of back into the govt purse
"Very few of them left."
"When you say, 'very few' - ten, twenty?"
"Maybe three-hundred-and-fifty".
???????
I believe the wrong rotor settings were used when defining and translating "very few".
Haha, but there were THOUSANDS of these manufactured of the numerous models.
Wheres my nuast gang at
😂
The background music obscures the dialogue. Very annoying and defeats the purpose of the video.
Any presented hire machines, are not presented basic requirements for purpose intelligent ketchup messages - like not visible super receiver. 3 wheels, wooden boxes without any protections from military damage possibility and whether - looks like simulatory for training, not for military part biggest deadly WAR in global history. Serious explanation naive theories how to connect 2 machines is lack of basic knowledge in many areas, transmission & receiving, for simple function is missing attached extra necessary equipments - they not released ready ridible message? From Bletchley Park? - well, day after signed capitulation, everything looks like paper burned in Bletchley Park. Simply question WHO WIN WWII - like always PROPAGANDA, process are still pending. Germany with Volunteers country, in global history, build-up the biggest WAR MACHINE, takeover large territory on intercontinental stealing. And build-up BIGEST NETWORK - ENIGMA.,with different geopolitical areas & tims. The number required ENIGMAS? - you needed know about structure German Army, where country or territory they covered. Now biggest "professors" please choose only one German Enigma - for free conversation, powodzenia. For that specific purpose intelligent operations, on huge network Enigma - was answer, by POLISH interceptor BOMBA.
I just wonder how anyone who works at Bletchley can know so little about Enigma, or was she playing dumb?