I've been moving with the bodies that move to a different sound

[sovay]

I just taught my niece a simple substitution cipher and within ten minutes she had correctly deciphered a short message I had written to her. I could watch her make the connections, exclaiming as she recognized individual encrypted letters without having to refer to the key. Then she drew a picture at the bottom of the page to make it clear she had not just copied out but understood. Morse code, Playfair, one-time pads, here we come.

Comments

[yhlee]

I once jointly taught Playfair to a group of fellow student teachers as part of an interdisciplinary team (two history teachers and me in math)! Super fun, and crypto is great for those two subject areas. :D

Will you work her up to a Vigenère? ;)

[selkie]

THAT EDITOR SAID ARIE HELLER WAS NOT A REALISTIC CHILD
I'MA LOCK THAT EDITOR IN A ROOM WITH CHILD AND CHILD, RESPECTIVELY
AND A ONE-TIME PAD AND SOME PUTTY EXPLOSIVES AND A TRINITROTOLUENE CAP

[sovay]

AND A ONE-TIME PAD AND SOME PUTTY EXPLOSIVES AND A TRINITROTOLUENE CAP

SHARE THE FRUITS OF ALL OUR LABOUR

[sovay]

I once jointly taught Playfair to a group of fellow student teachers as part of an interdisciplinary team (two history teachers and me in math)!

Oh, that's cool!

Will you work her up to a Vigenère?

I might have to work up to a Vigenère, but if she wants to, I will.

[nineweaving]

How absolutely wonderful! May I recommend the bi-literal cipher?

Nine

[sovay]

May I recommend the bi-literal cipher?

She was already suggesting combinations instead of one-for-one substitutions, so she may take to it!

She figured out her own ciphered name from the first three letters and then seeing two of the same letters—still encrypted—later on in the word. By the end of the message, she knew it ended with my name even before she deciphered it because of context. It was like I could watch her working out the first principles of cryptanalysis in front of my eyes. I told her that it is not the only thing I love her for, but she should know that she is really, really smart.

[sorcyress]

I don't know how you feel about mid-century boy's books, but "Alvin's Secret Code" by Clifford B Hicks is, I feel, the gold standard for "child learns about cryptogruffy" (misspelling intentional)

Some of the adventure story plot is a little unrealistic, but the background cryptography lessons are *fantastic*. You and she could make scytales!!!

~Sor

[sovay]

I don't know how you feel about mid-century boy's books, but "Alvin's Secret Code" by Clifford B Hicks is, I feel, the gold standard for "child learns about cryptogruffy"

I grew up on a lot of mid-century children's books of assorted genders, but I don't think I read that one, so I will check it out! Thank you for the recommendation.

(I don't know where I learned about scytales, though.)

[vass]

That's a great age of nibling to have.

I did that too when my niece had a copy of... I forget the book, but it was a modern version of one of those old-fashioned activity books, and it had a substitution cipher in it.

So I sent her a note in that cipher, saying "If you can read this, I owe you a Mars bar" and left the promised chocolate in her grandparents' fridge for safekeeping.

[sovay]

That's a great age of nibling to have.

I really, really like her.

So I sent her a note in that cipher, saying "If you can read this, I owe you a Mars bar" and left the promised chocolate in her grandparents' fridge for safekeeping.

Aw! That's lovely.

[minoanmiss]

I meant to reply to this with delight all weekend, but/and am still glad I reread it today.

[sovay]

I meant to reply to this with delight all weekend, but/and am still glad I reread it today.

Yay!

Links of interest

[nodrog]

I may be the only one here who knows what a “one-time pad” is.  Tho’ maybe not.  (Here's a tip:  Use pi.  Pre-arrange how many places in you start.  The Julian date is good; every day the same message would look entirely different!)

Me, I'm all set - I have my "Dick Tracy Secret Code Maker" built by Lawrence Engineering in 1939.

https://sliderules.nl/media/slide_images/Lawrence_Code-Maker_Beich.jpg

(That image printed and scissored would make your own.

LawrenceCodeMakerBoxOpen_Kenneth%20Lewis_med.jpg

-Likewise:  The gift set.)

https://sliderulemuseum.com/Manuals/M102_DickTracySecretCodeMaker_Inst.pdf

I'll tell you what, you can cook up a mess with that thing!

https://www.dcode.fr/slidefair-cipher

[“uncopyrightable” is the longest English word with no repeating letters.]