Just a thought

What if zodiac wrote like this

We refer to this as a period 2 transposition.

right , I mean I guess what lead me to this wasn’t really the idea of period 2, but more a period 2 where the 2nd half is written right to left – I rushed my thoughts and example during my lunchbreak …

Should have been:

jtuhsgtuaoth

I just feel sometimes that there’s interesting left / right hints at symmetry in 340 or some kind of interleaving transposition that isn’t a straight period transposition…

anyway, I’m a novice that loves pen and paper!

right , I mean I guess what lead me to this wasn’t really the idea of period 2, but more a period 2 where the 2nd half is written right to left – I rushed my thoughts and example during my lunchbreak …

If the cipher is transposed this way in one block then it would not complicate decryption much. But if Zodiac took it sentence by sentence (or part by part in a aperiodic way) then it is probably very difficult to decrypt, even without the 2nd halves written right to left.

You can try to make a 340 sized plaintext with your scheme and then I will encode it for you and feed it to AZdecrypt’s transposition solver and see if it can figure it out.

anyway, I’m a novice that loves pen and paper!

Allot can be done with it. Just a slow computer.

I just feel sometimes that there’s interesting left / right hints at symmetry in 340 or some kind of interleaving transposition that isn’t a straight period transposition…

Do you know about the period 19 observation in the 340?

Hi Jarlve,

Yes, I’m aware of the spikes for period 19, but I’ve always thought this is pointing not to a periodic-grid-transformation, but to something about the underlying encipherment structure, like use of a scytale or a certain rythym to the substitutions…

Or a rythym to the plaintext that somehow creates that spike…

I think there’s an assumption that the plaintext is like the 408 – a letter / prose.
For example it could instead be a list like "kill, kill, kill, etc" – which is just to say that 1-it’s not the type of plaintext anyone would really look for – or that 2 – the structure of the plaintext itself could be contributing to weird spikes…

I dunno – I’m just spitballin’! But it’s fun and intriguing.

Try this

I know people think this relates to 340 but I personally don’t. Nor do I think the Halloween card bears any clues relevant to it.

I think the pivots are the most curious thing about 340 – plus all the structures surrounding them. There’s some order here we just don’t know what it is a shadow/projection of yet.
That and the way some symbols seem exclusive to certain parts of the cipher.

For example it could instead be a list like "kill, kill, kill, etc" – which is just to say that 1-it’s not the type of plaintext anyone would really look for – or that 2 – the structure of the plaintext itself could be contributing to weird spikes…

I have to counter a bit.

The 340 is not like the 408 or it would have been solved ages ago.

A repetitive list like that is impossible to hide, and if not so repetitive it would just solve normally. Can you come up with a meaningful plaintext of a type that not anyone would look for?

Some possibilities for meaningful plaintext no one would look for:

(please note I’m only answering the previous question – I’m not saying this is what I think is in the 340)

1. Another language (spanish, french, whatever.)
2. A sort of steganographic plaintext – like ascii art
3. A plaintext that excludes vowels (or you could invent any number of variants on this)
4. Phonetic spelling
5. What if it decoded to another famous already cracked code or one from a book?
6. It could decode to something that relies heavily on abbreviations like a calendar, key to a map, technical manual…

(bonus) 7. Could be encoded twice – if he did a simple caesar shift before a homophonic sub, then it would only decode back to the shifted version – then you’d have to decode that…

Anyway, for the record I think it’s none of the above – I just think it’s good to keep an open mind about what we might be missing for lack of imagination.
I’ve always felt it’s a message about the Lake Beryessa attack.

I think it was probably encoded in a fairly simple way – but has two steps and possibly a mistake. He could have also ready a chapter about one-time pads and not understood that they basically couldn’t be decoded (it seems to me he didn’t understand this when he sent his short codes – because I do believe he wanted them cracked.)

(bonus) 7. Could be encoded twice – if he did a simple caesar shift before a homophonic sub, then it would only decode back to the shifted version – then you’d have to decode that…

No, that actually would decipher to the original plaintext. A Caesar shift would have no effect at all.

-glurk

Hi Glurk – are you saying that some of the programs running through 340 are actually decoding once, (homophonic sub into gibberish, then decoding that gibberish (a second time) through a caesar shift or other scheme?

I’m not sure how layering on a 2nd scheme to the encoding would not have an effect on the decoding efforts, as it would require you to solve two codes, while having absolutely no clue that the first have of your decoding was on the right track.

I’m happy to be corrected. Here to learn!

Hi. What I mean is this. If a plaintext were enciphered with a transposition scheme, for example, and then homophonically encoded, that would make a difference. But a Caesar shift, specifically, is just a simple form of a substitution cipher. And a homophonic cipher is a substitution cipher.

So, the Caesar shift would have no effect, it would just decode normally. Imagine you take a plaintext and Caesar shift it, then Caesar shift the result again. It does nothing. It’s just a different Caesar shift, same as if you had done that one to begin with!

In other words, it would just be substituting the substitutes, and have no effect.

-glurk

Some possibilities for meaningful plaintext no one would look for:

(please note I’m only answering the previous question – I’m not saying this is what I think is in the 340)

1. Another language (spanish, french, whatever.)
2. A sort of steganographic plaintext – like ascii art
3. A plaintext that excludes vowels (or you could invent any number of variants on this)
4. Phonetic spelling
5. What if it decoded to another famous already cracked code or one from a book?
6. It could decode to something that relies heavily on abbreviations like a calendar, key to a map, technical manual…

(bonus) 7. Could be encoded twice – if he did a simple caesar shift before a homophonic sub, then it would only decode back to the shifted version – then you’d have to decode that…

Anyway, for the record I think it’s none of the above – I just think it’s good to keep an open mind about what we might be missing for lack of imagination.
I’ve always felt it’s a message about the Lake Beryessa attack.

I think it was probably encoded in a fairly simple way – but has two steps and possibly a mistake. He could have also ready a chapter about one-time pads and not understood that they basically couldn’t be decoded (it seems to me he didn’t understand this when he sent his short codes – because I do believe he wanted them cracked.)

Thanks Fisherman’sFriend,

I appreciate your fresh thinking.

1. Probably not, tested by me in 2017: viewtopic.php?f=81&t=3242&p=51214&hilit=languages#p51214
2. Possible but not something like ASCII since that is usually very repetitive.
3. Good hypothesis, we need to test some basic variations. Here is a cipher without vowels:

W5]4Q,$;/&BZDO0[@
(ZN=%9")JWP:;5[QN
5E%6XBUK?"GLWD$>
M)/3O2<1B(5[-N4C%
"ZW,$Z0X!&*B7:[]8
6QE^HI;WUN-B'&(D
9"FA%W>]JB2(4JCF^
Q^J"/&O2Q0UA:,AW
;9BWJ,$R/6X9P[N#%
J$O@.69VNZ%BQ0=H]
K:;*4(X5J[,R"+I?]
^6;W]ADW9N@!)84/0
#6,.B-O0UCQ0XF[8N
/;,OQ*/:^TX^A?;.O
6[42?(0,8Q:.;NLY
S1F]E/+&#D>%"O)"/
4OU/6BH<(O0?]Z,X=
4ONB:5(>9Z6ULQ/%K
R$"2O7X2W,J?LCZ0
O[*R(NPFC^Q"W/O;8

4. If the phonetic spelling would be consistent then it may be unlikely.
5. Double encryption?
6. Probably to repetitive and therefore impossible to hide.
7. See glurk’s comments.