We can all agree this dude would be the best grandpa. So many interesting stories.

The military Enigma rotors had different internal wiring to the commercial version rotors. It was the miltary rotor wirings that Marian Rejewski was able to work out purely by applying mathematics, using permutation theory, from just having a body of enciphered messages available to him and code book settings for September and October 1932. It took him just a couple of weeks to do this.

At last, a explanation that makes ring-settings clear. The various books are very ambiguous on this. This is the best explanation of the mechanism of Enigma I have seen

I want him to read a book to me... that voice is amazingly soothing

Thank you for mentioning Polish matematicians.

Alan will never get enough recognition for his role in history. Highly recommend watching "The Imitation Game"

Trotz des cleveren Designs der Deutschen haben die polnischen und britischen Mathematiker herausgefunden, wie sie den Enigma-Code brechen können. Danke, Professor und Team, für diese hervorragende Einführung! (Danke auch an Google und KZfaq)

I could let this guy tell me a bedtime story.

I love KZfaq precisely because it gives me content like this. Thanks for the video!

Great to see David Brailsford back on the channel.

Three Polish matematicians: Marian Rejewski, Jerzy Różycki and Henryk Zygalski cracked the Enigma in the first place using the cryptologic bomb.

I don't know if this was of much help for deciphering, but since Enigma lacks umlauts you could probably expect a lot of the combinations "AE" "OE", "UE", in places where you'd expect to find vowels.

Damn, this guy is an excellent teacher. He can explain anything. I understand everything that he's saying.

Is there any imformation about the guy or gal that invented enigma ?? Seems that person must have been years ahead of their time

It so interesting how all the "security measures" the germans had actually made enigma easier to crack. By adding rules (like dont put the same wheels in the same spot two days in a row, the wheels spin at different points and other i don't remember) they gave cryptographers outside constraints. If they had not done it then there would be no apparent system or logic. But the settings list had rules and the wheels were different.

Absolutely fascinating stuff, I could listen to this all day - I can't wait for a further installment!

This is the video I wanted to see from you guys from a loooong long time... love this!

It would be very interesting to see some explanation of how the cryptoanalytic process of deciphering such a contraption looked like in a bit more detail. Did the people at Bletchley Park use some specific mathematical approach helping understand the code ? Did any other electrical tools were used ? Can't wait for the next video!

Great repertoire. Love your simplistic account of all issues. Thank you.

I want to fix his collar

Hugely entertaining! Can't wait for the next EP!

The clearest explanation I've seen - especially that part about the ring settings vs. the rotor settings which is not explained elsewhere. Thanks!

This is brilliant and massively interesting. Thank you for this fantastic video.

aaaand above all of that they were speaking german. That is harsh.

Why mentioning Simon Singh only as the owner of Enigma machine, but not the author of "The Code Book", the best introduction to cryptography ever written, and - what's important - very well researched, unlike some error-laden movies ? Singh's account of Enigma history and techniques is both complete and simple to comprehend.

For those who are interested: Factorial (!) of 4 for example is 4 x 3 x 2 x 1 = 24 so 4 items of any kind can be arranged in 24 different combinations. Most calculators can only calculate 69! modern ones can go a bit further by having 3 digits in the exponent.

I've seen that movie (As I expect many have); But the way you have described it, makes it obvious now, why Turing proposed the computer. This looks/sounds like a perfect problem for a computer. Many factorials, and simple bit/binary math. Nicely done. |Thanks.

I've watched this entire series 3 times now but I still find it really interesting.

Great teacher, great energy, great voice!

This is the coolest video you guys have done in a while I'm really looking forward to the next one!

Personally, this isn’t Turings work that I find most fascinating, his paper “The chemical basis of Morphogenesis” is truly original and brilliant.

ABSOLUTELY FASCINATING!!!

I made a vb module for ASCII encryption. It can be "set" with any number of one-to-one character mapping arrays (tumblers), but it goes a step further with additional settings to programmatically determine which tumblers to use based on an ASCII sum of the character being encrypted along with its previous character which is already encrypted. Also, the process can be coded to happen any number of times for completely sloppy results. It remains the code of which I am most proud. The process of making a device as complex as Enigma boggles my mind, though.

Awesome video! I did a school project on Bletchley Park!

You know, I don't understand half the stuff this guy talks about, but his voice is so engaging.

Truly magnificent fellow that Professor Alan Turing.

Welp, my brain is jello. It's amazing that Bletchley Park ever figured this out. Truly speaks volumes to the intelligence of the folks that broke Enigma.

Second part please! Im loving this

You could have mentioned his collar to him at some point.

Amazing explanation sir.

I'm unclear on two points: 1 - The alphabet ring on the rotors could be set to any one of 26 positions but did not interfere with the wiring, this was fixed inside the rotor. This was an offset was provided although no alterations were made to the wiring. 2 - I was led to understand in the past that the commercial Enigma's 3 rotors had different wiring from the military version, even with only 3 rotors. This was one of the breakthroughs Hans-Thilo Schmidt's information gave to the Poles, who had access to the commercial Enigma.

Thanks Professor!

He is making my head spin , I am seeing stars in the middle of the afternoon

Good video professor, thanks for uploading! :)

I also love the raspberry pi teddy bear on the desk, so cute and iconic!

Love these videos!

The enigma machine has already been broken (in early 1930) before the war even started. So who played a major role Alan Turing OR Marian Rejewski OR Tommy Flowers? Rejewski use mathematics to show what makes the Enigma ticked and demonstrated some of the ways to decipher it and Turing mechanised it while Flowers digitised it (well using punch tapes).

Both "The imitation game" and the movie " enigma" weren't actually filmed at bletchley Park. I live 6miles away from it and my grandfather was stationed there during the war

*C.S.E* (Casual : Snooper's Enigma) : I admire - the woodwork *_R > G_*

looked at some photos of the paperwork that accompanied these machine, almost looked like a predecessor to ASM. Hearing it had a vuln though, useful. Suppose thats like an system built by people though..... perfect way to begin the morning.

idk why but hearing his story makes me both heartbroken and happy

I'm so glad that someone's finally addressed the rings on the rotors. So many books, documentaries, and KZfaqrs seem to shy away from them. I'm still a little bit confused though. Does changing the ring position on a rotor effectively, and rather crudely, create a "new" rotor (i.e. one that has different wiring)?

The Polish Cipher Bureau doesn't get nearly enough credit for its early work on Enigma.

amazing, I am loving it!

this guy is amazing at explaining

Nicely done. Would like to know the specifics of the battery as power source. Also, the lighting mechanism for the buttons in the days before LEDs.

There's one thing that doesn't seem correct: The Ringstellung (positioning of the ring) does *not* change the wiring of the contacts. It did *not* make an 'offset' there or alike. There was *no way* to change the wiring or which contact connects with what other contact, at all. This was just impossible, because they were fixed parts that could *not* move or rotate in any way. So, what did the changing of the Stellring actually do then? It changed the point, were this special rotor caused the rotor next to it, to move a step, as well. The Stellring is the only part of the rotor that could be rotated - all other parts are fixed. And only the Stellring itself moved (no contacts, wirings, whatsoever). But the Stellring had a little recess on it. (In the case of some rotors, it had two, as you mentioned.) So, if you moved the Stellring and fixed it in a different spot, you could determine, when exactly the rotor next to the first one would move, as well. Say, you start with the rotor in position "A" (shown in the little window), and it's Stellring is set to position "B", then this rotor would move ONE step alone, but when it moves again, it would cause the rotor next to it, to move, as well. And, if you changed the Ringstellung to position "E" (but again begin with the rotor in position "A"), the first rotor would move FIVE times alone, before it would cause the next rotor to move, as well. That's what the Ringstellung does.

What about the number 12 is significant to Turing's implementation of the Enigma problem? Is there a mathematical principle which explains why he needed 12 machines and not 10? Thanks for any suggestions.

James Grime explains this much better. Very clear understanding of the machine after watching the numberphile video.

It is so cool to see how some engineers invented and evolved an encryption-machine on the one side. Meanwhile their enemys found the weak point with very smart ideas.

i keep hearing voices in my head repeating everything i read but i have no idea who it could possibly belong to

Well done!

The good professor should have been a computer historian. The guy has a way of putting computing history in a dichotomy of the atmosphere of J.R.R. Tolkien. Guy is bloody brilliant.

Bletchley park is well worth a visit to see a running Bombe!

So what role did the first British computer by the name of Colossus, and the first American computer by the name of ENIAC play in breaking the Enigma codes? I've watched the Numberphile videos on the Enigma, but these machines weren't mentioned at all, while here in Germany it's always written and told that the Enigma code breaking was done by using these computers?

12:09 Some modems use the same concept to enable wires to connect without having a "plug"

did the ring setting add a Caesars code per rotor?

The Polish army was the first to decypher enigma but it was quickly changed. The British army was able to do it because the Luftwaffe was very unprofessional in the use of the machine and they didn't take precautions.

Where can I get hold of the document at 7:34? It's not in the links.

Enigma was not "ultra, ultra safe." Now there's some inside humor for you! 1:45

Once the button is pressed to produce a number, there is no path, right at the switch, for a signal to come back to light up its own light. Independent of reflector or anything else.

David Attenborough bit at the end :) Loved it, great video.

Left handed computer scientist using line printer paper, classic ! Thanks for the introduction.

Heer's a qwestion: Coold intenshunal typos maek an endoced massage harderer to brake?

1:48 "Not Ultra safe". Indeed.

Surely it would be possible in theory for the Enigma machine to encode to the same output letter or is that simply unfeasible?

Another video about the evolution of ciphers after Enigma would be interesting.

This guy gets it. Explanation......done

Happy birthday, Turing! (He’d be 109 years old today, June 23, 2021)

Computerphile exists? Is this the -phile series ?

10:27 I feel Doenitz' face was too small for his head.

What was the name of the similar mechanism that the Japanese used during the war?

Amazing! :]

4:56 , what happens when the third rotor reaches its turn over point, does it do nothing or does it move on the middle or right hand rotor ?

4:31 wow that car goes fast jeezus how fast is that thing going mach 11?

~ 8:30 5! over 3! is 10 ? or 20? 5! / 2! I'm rusty on maths, but am I wrong? or does he mean [ 5! / (3!)(2!) ] where 2! represents the 2 unused rotors.... I would assume its already used in determining 3! .

Not really important here, but a mechanical speedometer/odometer is typically driven from the end of the transmission on a vehicle, sized (and usually color-coded) for the gearing that comes after it, in the axle itself. The diameter of your tires is also a part of the gearing, but you simply suffer a slightly erroneous speedometer/odometer reading if changing tire sizes from OEM. A steel cable with a spring made to rotate runs from the rotors in your dash to the gear attached to the tailshaft of a transmission in a typical rear-wheel drive vehicle. On a motorcycle the principle is much the same, but with the input usually coming from the front wheel. The reason it wouldn't work directly on the engine is because of the transmission and axle gears changing the ratio all the time. Engine revolutions per minute (RPM) rarely actually equals wheel RPM, let alone accounts for the distance in a mile.

where is the link to part 2?

At 10:58 he says choose 3 from 8 and arrange them in any order is 336. And 8*7*6 = 336, but that's just the picking of the wheels, with the 6 ways to arrange them you'd get 2016 possibilities.

Couldn't one put a voltage monitor on the wires and track which ones are transmitting when which buttons are pressed?

I got 99 problems but a cipher aint one.

BRAVO!

Fascinating

I want more videos on algorithms!!!

met simon singh at Imperial - related oe of the "errors" of the germans - in front of witnesses - also from the audience

Love that sweater. Love dave.

I still had trouble seeing how the message was recreated, until I realized (I think) that the character map "pairs" letters. If E was mapped to Y, then Y maps to E. Without this the plain text wouldn't be recoverable if Y had mapped to some other character. It's not so much random mapping as random pairing, many times.

I've never understood. We smuggled an Enigma machine out but they must have had books that told them what settings to use on a given day. How come we never managed to access those? Does anyone know?

its like 5 am why the f am i watching this?

I wonder if a personal computer (with software) would have been helpful?