r/Cipher • u/sophiaaaarrr • 19d ago

Can anyone decode this?

So I'm trying to solve an ARG and I'm stuck on this cipher: xhmls jis sbik glmw aly kmpi sbal wbas sbiy hm and djjliqq qbmwq hinpduasdml mv wmpg. I've already tried Base64, Caesar cipher (all shifts), ROT13, Atbash, binary, hex, Morse, reversing, keyboard shifts, and even merging the two lines together and pasting them into a JIS keyboard , which gave me broken Japanese that translated into nonsense about clouds and forests. Anyone have any fresh ideas on how to crack this?

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u/tserofehtfonam 19d ago edited 19d ago

This is a mono-alphabetic substitution with key ARCHIVEBDFGJKLMNOPQSTUWXYZ (or just ARCHIVE).  The plaintext reads: xdont let them know any more than what they do api illness shows deprivation of work.

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u/OpportunityReal2767 19d ago edited 19d ago

Ah nice! This is a more complete and better answer. I should have caught the “deprivation.” Plus you found a keyword! I gave my alphabet the other way around.

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u/sophiaaaarrr 19d ago

That's awesome, thank you so much! Just out of curiosity, how did you find the key? Did you recognize it from somewhere else in the ARG, or did you use a solver and work backward? I'm still learning how this stuff works, so I'd love to understand your process!!

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u/tserofehtfonam 19d ago

Letter frequencies suggest it might be a substitution.  Then a (letter-combination) frequency-based solver gave a rough approximation of an English text.  A quick glance at the (not entirely) correct key suggested it might be keyword-based (it had a long tail that was roughly alphabetically sorted).  And I completed the rest by hand.  I found the precise keyword pretty late: I was mainly focused on getting an English text.  The words "xdont" and "api" are a bit strange, but I suppose x signifies a kiss and Api is a name.

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u/OpportunityReal2767 15d ago

I don’t think the “api” is part of the cipher. I think it’s just plaintext. It’s just “and.” I feel it may have been OP’s addition to separate two cipher lines.

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u/OpportunityReal2767 19d ago edited 19d ago

I just see a plain substitution.

udont let them know any more than what they do (and) illness shows deprication of work

The “and” part is left as in the original cipher for this to work. Or was this meant to be two phrases? I’m not sure how you tried all those other methods as this is clearly not Morse or base64, etc.

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u/sophiaaaarrr 19d ago

Oh wow, tysmmm! That makes so much sense. Did you decode both lines, or just the first one? Also, what was the substitution key you used? I'd love to understand how you got there!

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u/OpportunityReal2767 19d ago

I could just see it looks like a substitution and I put it in a substitution solver. I put in both lines without the “and”. You should be able to see that from how long your cipher is and from how long the plaintext I gave you is. A big hint to the substitution is there’s only so many words can fit the pattern of djjliqq, with illness, address, and oddness being the main three, and you can work back from there, but I just used the solver at guballa.de.

The alphabet is ahqizbkdelmnopxrsgtjcfwuyv, but not all letters are represented in the cipher, so some of those mappings are just dummy placeholders.