- cross-posted to:
- cypherpunk@infosec.pub
- cross-posted to:
- cypherpunk@infosec.pub
A substitution cypher, a very predictable one at that.
Plaintext
he who must not be named
I don’t have the faintest idea what a substitution cypher means 😂
Found this system in Reddit - been using it once in a while for fun!
Probably Voldemort.
All substitution ciphers are weak. When I was 10, I was on a camp where we “discovered” an encrypted page in a night game and the next day, a game of searching for scattered “clues” (substitution pairs) took place. In the meantime, I had deciphered the message using frequency analysis and guesswork so the pissed-off organizers created another page with the same cipher for our team to solve. I was grounded for “spoiling the fun” while others were playing, and our team came last because they had to wait for their page.
Frequency analysis at 10? Lol sure.
I’m sure it showed up in Hardy Boys. It’s not that unbelievable.
I was a nerdy kid, and I played numerical crosswords. I had read Kjartan Poskitt’s books including Codes: How to Make Them and Break Them (in Czech, of course). I only remembered the first few vowels and one consonant from his list of top characters but that was enough because
- I had enough time for guesswork (took me about 90 minutes, I could do it in about half the time now with more experience)
- there were recurrent words relating to the theming of the camp
- Czech letter frequencies are more lopsided than English (we barely use F, G, Q, W, X)
- one page is good enough to get good statistics, and the two or three top letters did match expectations
- I could technically somewhat accurately recreate Kjartan Poskitt’s (actually the translator’s) frequncy table using a Harry Potter book I had (turned out not to be neccessary, it would have been time-consuming)
Some cipher creators actually preserve diacritics. Seeing a symbol like έ, ≗ or ⊔̌ would be a giant giveaway because we only have the following diacritics: ČĚŘŠŽ (+ rare ĎŇŤ), ÁÉÍÝ (+ rare ÓÚ), Ů. The organizers had converted the plaintext to ASCII before encrypting it but this is still weaker than treating letters with diacritics as completely separate.
I don’t think my story is too unbelievable. Some kids just learn things faster/slower than others. I learned to write in all caps before I could wipe my butt (I’ll leave it to interpretation if I was an early writer or late-ass wiper).
Hmm. Cool.
Well. I didn’t mean to make a difficult puzzle anyway - something to fill a minute I suppose! 😄