The Enigma Code

There are LOTS of lectures/vids on Enigma, but this is the BEST to understand the real decoding process.

This guy is a trooper, holding his tie up for an hour.

This is quite helpful. I have read and seen a great deal about the cracking of the Enigma; this video helped me to understand the challenges and the breakthroughs of Turing and his colleagues.

Excellent talk. Thank you David Perry. Good on ya mate. And thanks for posting this lecture.

Cryptologic mathematician at the NSA. Clearly very clever indeed. But doesn't think to simply clip the microphone further up his tie. It's interesting how great minds work!

There was one more variable in the Enigma. The operator also had to set up at which rotor position would it advance the next rotor. Not necessarily Z moves the next rotor but maybe A or G, etc. Maybe that was in one of the improved versions of the Enigma but either way it added a whole lot more keys to it.

Brilliant explanation, I have wondered for a long time how these machines work, most videos I’ve seen don’t go as in depth. Thanks for uploading.

The Powerhouse Museum in Sydney has an Enigma machine, and 20 odd years I was able to visit the storage area and have a closer look at it - as a WW2 buff, it was a great thrill!

Good job David Perry.

This is an awesome explanation! Only things missing (which are important details) are the ring-settings which determine when a rotor steps and the double-stepping mechanism. A normal odometer triggers the next ring after it gets to zero again, so at the 10th click (starting at 0). Using the ring-settings of an Enigma rotor you can change when this triggering of the next rotor starts, which makes for even more combinations. Apart from that we also have something called double-stepping which is a flaw of the mechanical setup of the rotor rotation mechanism using ratchets and pawls. When the second rotor rotates a click, the first one will too and the same is the case for the third rotor (near the reflector), so basically there are a few ring-settings less (for instance: if the second rotor steps, the first will too, but that means the possibility of only the second rotor is stepped is not there DURING encryption. In initial setup that setting is there). You need to have an actual Enigma mechanism to understand this. The number of non-used ring-settings is very small, so you can basically neglect it, or maybe not? Maybe, you can even find out the ring-settings because of this double-stepping flaw. Each flaw is a potential attack vector. I love the Enigma and basically all mechanical encryption devices. I dont like digital encryption, for the sake of liking a specific type of technology. Digital encryption is mechanical too in a sense, as a switch is an implementation of an abstract mechanical principle basically, a seesaw mechanism. As a transistor is a switch, we can conclude that a processor is mechanical. The fact the seesaw mechanism is driven by electrons and doesnt make it any different. Wait for quantum encryption where we really have non-mechanical concepts, like a situation where a switch can simultaneously be in a on and off position, this is not possible for an abstract switch definition being either on/off, hence our current computers are simply fast mechanical systems and the real next leap and change is quantum mechanics (where as I stated, mechanics is not a correct term, I would use quantum system for instance).

Super course! Have been waiting for this.

Oh man - you didn't even mention the other big weakness: no letter can ever possibly map to itself. That was very important too.

I thought he was joking when he said that he would be going to hold his tie up during that whole lecture

The U-571 mentioned and listed on the board was the name of the eponymous U-boat in the movie released in 2000. However the real U-571 was never captured by the Allies, nor was her Enigma Machine ever taken. The events in the film are loosely based on the British capture of U-110 and her Enigma and cipher keys.

Awesome video, it was very well explained. Thanks for sharing!

Thanks for sharing.Very informative.

This was amazing, thank you so much. And thanks for keeping the mood very light, it made your explanations that much easier to follow

@Channellock12 the best - and slower and complicated - was the One Time Pad. The rotored Enigma was improved to become the Type X machine with 5 rotors and plug boards. Then, the Rockex machines, one regular tape en clair but coded by a second tape. Today they mostly use a sort of teletype with scramblers.

Thanks very much, I thoroughly enjoyed that.

That bloody tie! Why didn`t he just move the mic higher?