Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "Another Roof" channel.

13:05 Where's the "My Mental Health Story" video?
2
@AnotherRoof Oh, I guess you meant the video titled "Why Am I Completing 24 Maths Exams in 24 Hours?". I didn't understand that the thumbnail screenshot in this video referred to that one.
2
@LMB222 Since the nonce was to setup the machine and could be sent in plaintext, they could have used D20 filled with letters and use 6 letter initialization code to have 20^6 different nonces for every day to use in messages. Of course, due birthday paradox there would still be 50% change for at least collision after around 8000 messages so maybe make the nonce 8 random characters (no repetition of the nonce in encrypted form but feel free to send it twice in plaintext) and it would take 160000 messages per day to have a random collision. Without a single nonce collision, breaking the encryption would have been really really hard.
1
12:40 I think the movie was trying to make a point here that if you declare some human behavior (e.g. homosexuality) illegal, you'll always get unwanted side-effects, too, such as inability to disclose a Russian spy. Did it happen in reality? Nope. Did that undermine the point movie was trying to made? Nope, again.
1
The terminology is indeed hard. I would argue that the thing called "proof by induction" in mathematics is closer to deduction than induction using the the terms in this video. If you want to be pedantic, you should always use terms like "deductive reasoning" and "inductive reasoning" instead. That said, this video is hands down the best video I've seen on this subject matter.
1
8:00 If Germany had distributed D20 dice to every operator and told that operator must throw dice 6 times to get the initial 6 letters (sent without repeation), Allied forces would have never broken the encryption during the WW2.
1
If they had distributed D20 dices with letters to operators and said "start every message with 6 random rolls of dice to create nonce" it would have been impossible to break with the technology available at the time. The biggest weakness of the Enigma was that it couldn't convert letter to itself and that would have always been the way to break the encryption but it would have required more computing power than Allied Forces had during the WW2.
1
@Rokaize Correct Enigma usage required creating nonce and then setting the rings to match the created nonce which would have been used to encrypt that specific message. Operators failed to do this and used a single non-random nonce using the same nonce for multiple messages. I guess they were just lazy because it was easier to operate the machine this way. The correct operating procedure was (1) use wiring diagram and shared 3 ring daily configuration. (2) create nonce and send it twice using the daily configuration, (3) reconfigure all the rings to match the nonce you just sent encrypted, (4) send the actual message. You can skip steps 1, 2 and 3 for all messages for the day if you just re-use the same nonce for all messages! And you can also skip typing the first 6 letters so you can simplify the step 4, too. If the operator didn't understand that they undermine the security, it would be simply stupid to follow the official instructions because you can make the "same job" much easier with constant nonce. This still had the problem that nonce was sent twice which would make it easy to break with modern computers but would have required so much computational power that it would have been impossible to break using the WW2 tech. If random nonce had been used, only the messages that fully identical 6 first letters in encrypted form could have been used to find shared words. And even after that, you would have reversed the ring combination for those messages and you would need to reverse the daily encryption key from that.
1