MY 340

[sincos Profile]

I do not think it was a bad idea. E.g. the Caesar shift would have kept nr of repeated symbols oer row. I dont think that Vigenére does it. If I remember it correctly bith z340 and z408 have similar repeated symbols per row.

[doranchak Profile Website]

You're right; that makes total sense, since the cipher symbol mappings to the Caesar shifted text preserve the mappings between cipher symbols and original plain text.

Proof that it is easy for me to over think these things.

[4on4off Profile]

So does this mean that we can rule out both Vigenere and Caesar shift?

4

[sincos Profile]

Regarding Caesar shift I would say we could rule it out, as Zkdecrypto could have deciphered it. Regarding Videnere and homophonic cipher I dont think ZKD can solve it as it needs N number of keys. Vigenere would have decreased the repeated nr of symbols per row, e.g. with key length of 2 would decrease it by half. I suspect IoC should also reveal a hint about the key length. So Caesar yes and Vigenere 95% yes.

Column transposition would keep the repeated number, so I thinls that is a good idea. Row transpositions would also keep it, but I assume zkd could handle it. Some spiral transpositions would also keep it to some extent.

sincos

[ALisowsky Profile]

Doranchak:

Thanks for posting those ZKD stats for me! I am really surprised at the outcome, especially that we can still clearly see the key length even after a 63 symbol homophonic sub was applied.

I don't think the idea of a caeser shift is necessarily worth giving up on, as there is still a possibility that a shift occurs several times in the message. Perhaps each '+' sign indicates a change in shift, therefore eliminating the chance of a straight decryption from homophonic substitution. But I have no idea how we would test for this.

Also, has anyone had any experience in fairplay ciphers? Is there a way to detect if a fairplay is used?

Thanks!

Adam

[glurk Profile Website]

Adam-

I'll assume you mean the Playfair cipher, I've never heard of the "fairplay cipher":

http://en.wikipedia.org/wiki/Playfair_cipher

It's a nasty little devil of a cipher, in fact, and is not easy to break even IF it is not further homophonically enciphered. Here's an example Playfair, using text from known Zodiac writings, and the key itself directly relates to the text. I did not use any further homophonic methods on it, it's just a simple Playfair cipher on it's own. I wonder if anyone can decode it.

RM AG QV GL MR EL ED IN TH UA OD AF DQ ZR GL IF EL DP ZR GL BK MV BT MA BQ LQ QC GM HP FI RO LA FI HL AL DB YP LM ZD RY TK EN RY TV IL ZT OD OE AB AN RO IQ TL QA PL VA RX AW ZM QL PV YN GX HT OS FH IQ DZ BN MZ TP IA MZ TP TL HK RD ZP MO LO HI NC BD OS HZ HI FD HG TH NF FD MD LM ZE BL BL IH ZH QV BE LB DK DP TH ZH IH PN VY LV GN CT IQ ZR GL DH LN MU UR VL CQ LG LV UN LM DB AC DF PS LE DE DM AD FD PS HI GF PL YN RB FD QA XL

-glurk

(I expect this will be solved, and probably fairly quickly. There seem to be many very capable cipher folk here. I like that.)

[ALisowsky Profile]

Yeah, sorry I did mean Playfair, sometimes that dyslexia kicks in, makes me feel like I am drownding in a sea of ciphers.

I have not had much experience with them, but after digging in to your cipher Glurk, I really hope this wasn't used by zodiac on the 340.

Is it worthwhile for me to encode my340 with playfair, followed by homophonic to explore with ZKD? It could yield some kind of signature, who knows.

LETTER FREQUENCY OF GLURK'S CIPHER:


After I correctly deciphered the playfair square, I thought there would be some correllations between the square and the resulting ciphertext letter frequency, either that the letters on the borders would be highest, or that the letters used in the key would occur more frequently, etc. However, I am not seeing any of that. So that everyone can have fun with the cipher, I won't post up the square.

Adam

[doranchak Profile Website]

Got it. But I'll keep it to myself so others can have a chance to crack it.

[sincos Profile]

I got a new POI. I see 'IA MZ' in glurk's cipher...

[ALisowsky Profile]

I got a new POI. I see 'IA MZ' in glurk's cipher...

lol

More probable:
IA MZ TP TL HK RD
I AM STARLIPER