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Mar 22Liked by Brandon Hendrickson

Aaah, ciphers! How nice to see them here. Something I really like about them is that you can, depending on your preferences, break them either mathematically or linguistically or a combination of both. The mathematical kid will at some point figure out that Caesar (and Vigenère) are a kind of "adding"; maybe you can then tell them that mathematicians call this "modulo 26". One consequence of this is that if you don't have a Vigenère table to hand, you can just use your cipher wheel - figuring out how (to both encrypt and decrypt) could be a fun challenge by itself. For more on this topic, I recommend The Code Book by Simon Singh (the guy who also wrote the book on Fermat's Last Theorem).

The more language-arts oriented kid might note that only "a" and "I" are valid one-letter words (ok, sometimes "O" too), and work things out from there. Or notice patterns in words, because you can get a lot out of an encoded word with some letter WJUJYNYNTS. The first historically recorded case of this is from the Persian scholar Al-Khwarizmi, who apart from inventing like half the modern elementary math curriculum, once was faced with an encrypted letter and guessed that it began "In the name of Allah ...". And so the code was revealed.

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Wait, did you just tell me something about Al-Khwarizmi — a native of Uzbekistan, a leader in the House of Wisdom, the coiner of “al-jebra” (Arabic: “the re-setting of bones”), the man for whom the algorithm is named, a sporter of a really rockin’ beard — that I DIDN’T already know?!

Thanks for classing this place up! (Also, I was just wondering where “The Imitation Game” picked up the little non-historical detail of how the trick to solving Enigma was to recognize that “Heil Hitler” was likely to come up a lot. Now I suspect I know!)

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Mar 23Liked by Brandon Hendrickson

German Enigma messages mostly followed strict military communication protocols, including keeping your messages as short as possible by leaving out articles, prepositions etc. wherever this did not make the meaning ambiguous. If someone had wanted to demonstrate "patriotism", they would presumably have used the abbreviation HH or SH.

There were however lots of repetitions that Bletchley Park could use to attack the system, including a real example where a U-boat out in the Atlantic had the job of observing and reporting back the weather at 6 o'clock sharp every morning. These messages always started WETTER NULL SECHS (weather [at] zero six [hours]).

There was also thing where for each message, the Enigma operator had to pick a three-letter random combination and repeat this twice at the very start of the message. This was, ironically, part of a scheme supposed to make the cipher stronger. But humans are terrible random number/letter generators, as anyone who has studied password use in leaked data breaches will tell you (the most common one, if allowed, is always 123456. Always.) I think it is plausible that some operators were originally using HHH or similar, because we know during the war instructions went out that "from now on, all three letters must be different". Bletchley Park called repeated combinations that helped them break Enigma "cillies" with a C, and one theory is that this comes from one operator always using CIL as their three random letters. Others picked their "random" letters from the keyboard, coming up with the ever-popular QWE.

I don't believe there is any historical document showing that Bletchley Park ever used the particular "crib", as they called portions of guessed text, that the film references.

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ChatGPT-4 deciphered the "Why" section on the first attempt, which makes me uncertain that the idea can work in the future when every child has an access to an even smarter AI

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And, in truth, MUCH of schooling can now be solved by GPT-4, and one can only imagine what the models a decade from now will be able to do. This is one reason to not put grades or rewards on them; it also raises big questions about what sorts of tech to invite into (or ban from) the classroom.

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N zxji htij gwjfpnsl fhynanynjx ns rd Gntqtld htzwxj -ktw jcywf hwjiny-2 utnsyx ts f yjxy ktw ymj knwxy lwtzu xtqansl ny. Ymj ljsjynh htij bfx "ijhnumjwji" ymwtzlm xtrj jcujwnrjsyx ymfy fwj jcfhyqd qnpj ymtxj zxji bmjs ujtuqj ijhnumjw htijx-knlzwnsl tzy xufhnsl, zxnsl izuqnhfyjx fsi htrrts xyfwyx fsi jsix. Xyzijsyx sjajw xjjrji yt mfaj fsd inkknhzqynjx wjrjrgjwnsl mtb ymj ljsjynh htij bfx ijhnumjwji.

...and it opens with a single letter...must be an A or an I

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