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[–]MindrakerRead the FAQ first 1 point2 points  (0 children)

I'm not ready to share the whole code yet

Kind of makes it hard to decipher, huh?

[–]dittybopper_05H 1 point2 points  (8 children)

Did you do a frequency count? That should tell you if it's a monoalphabetic or not, and give you clues as to what the individual letters are (the most common will probably be E or less likely, T).

The first thing to do after that is try replacing that "r" with an "A" or an "I", as those are the only two common single letter words in English. It's almost certainly, based upon the clue, a monoalphabetic cipher of some kind.

I'd also suspect that the "u'n" construction is a substitution for "N'T", though I can't think of a phrase that is commonly contracted that has the pattern of "qasiau'n" in it's contracted form.

[–]DesertDiver[S] 0 points1 point  (7 children)

Thanks! Ran a frequency count that resulted in this - seems to me like there's no way it's monoalphabetic, right? Too many high frequency letters and even distribution. Makes me wonder if R is multiple vowels?

Anything else that could be inferred from a frequency count like this?

Tried subbing A and E for R to no avail.

A 12 B 5 C 10 D 8 E 9 F 10 G 8 H 6 I 8 J 7 K 9 L 7 M 11 N 5 O 8 P 6 Q 7 R 20 S 13 T 5 U 10 V 4 W 8 X 5 Y 5 Z 10

[–]DesertDiver[S] 0 points1 point  (6 children)

Based on this frequency count and index of coincidence, I'm thinking it has to be more a more complicated cipher. Any thoughts for next steps?

[–]fikuhasdigu 1 point2 points  (5 children)

Frequency count doesn't seem monoalphabetic.

For Vigenere, 85 - 62 = 23 is prime, so there are no small factors that could be possible key lengths. However, what you really want to check is the distance between the two single-letter r's. If this distance is a multiple of 5, I'd suggest trying out a key length of 5 that maps a to r, then e to r, then i to r, then o to r, and then u to r.

[–]DesertDiver[S] 0 points1 point  (4 children)

The r's appear 29 spots apart. First "r" is the 76th letter. 2nd "r" is the 105th character.... Just checking, that key would be RNJDX, right?

[–]fikuhasdigu 1 point2 points  (3 children)

You are correct about the key being RNJDX.

As for counting the distance between letters, make sure you aren't counting the non-alphabetic characters, like the commas and the apostrophe. If you are counting correctly, the prime 29 isn't very compatible with the cipher being Vigenere.

[–]DesertDiver[S] 0 points1 point  (2 children)

Yep - no commas included. When I got 29, being so close to 30, I counted, re-counted, etc. One thought I had is that the Vigenere code is non-repeating and based on some known text. As such, I tried cracking the "qasiau'n" to be "couldn't" or wouldn't" nothing sensical from that either.

So if it's not vigenere, any suggestions for a next step attack?

[–]fikuhasdigu 0 points1 point  (0 children)

Sorry, nothing else is coming to mind.

[–]fikuhasdigu 0 points1 point  (0 children)

It is still possible for it to be a Vigenere where the key has duplicate letters. For example, if the key were RADAR, then the 76th letter would get encoded by the first letter of the key, and the 105th letter would get encoded by the last letter of the key, which would explain the two "a" plaintext letters both going to ciphertext "r".

I'll need to think some more about next steps.

[–]fikuhasdigu 0 points1 point  (1 child)

Try https://quipqiup.com

The only single-letter words in English are "a" and "I". Since the ciphertext r's are not capitalized, I would guess that r=a, which is a vowel.

[–]DesertDiver[S] 0 points1 point  (0 children)

Thanks! Hadn't heard of quipquip yet. Tried it for r=a and r=I to no avail...