Hi!
The last couple of weeks I was not in the mood to work on z340. But yesterday I tried some ideas with pen and paper and asked myself „how would I have constructed z408 if I had only pen and paper?“. Would I write my plaintext right into a grid and substitute it into another grid? Or would I write the plaintext first on an empty sheet without any shape? I also remembered a posting where someone said that Zodiac maybe wrote the cipher symbols directly above the plaintext letters and then made a neat copy into the grid (which could explain the mistakes with the triangle symbols because of sloppyness or a thick felt pen).
Here are some images of one of my experiments. I think this approach is close to the method Zodiac used because it can explain the triangle errors as well as the broken cycles in the homophonic substitution (smokie treats call them cycle disruptors I think).
I think the .pdf is self explaining. If not, please tell me and I will explain in more detail.
Why I am doing this? Because I want to take one step back from my „digital“ perspective. I think that if Zodiac used a method like the one shown above he would also had used a similiar method for z340. With some variations of course.
In an earlier thread I wrote:
„Personally I don’t think that Zodiac transposed an already enciphered text since this would mean that he had to draw all those symbols twice. I don’t know…but I think this guy was lazy (that’s only an assumption). The crossed out „k“ in z340 confirms that he was not willing to write the whole cipher again after he made a mistake (I would have started again since I am pedantic).“
If Zodiac used the method shown above it would not be too much of extra work to create a transposed cipher. IF z340 is a transposed cipher created by the such a method, I don’t think it is a keyed cipher (e.g. double columnar) or any kind of cipher which needs an extra step. Some kind of way/path transposition would be easy enough to create.
I’ve documented another way to create a homophonic cipher. By using the following method it is possible to create the final cipher without a „draft“ and still keep perfect cycles:
I personally don’t think that he had used this method. Of course we will never know for sure. Anyway…I like to make experiments with pen and paper to find new ideas.
Your method works. However: Why not simply writing the alphabet A-Z with all the symbols used below of each letter? As many symbols as you have thought about, according to your (btw separate) frequency table? Then, after using each symbol once, repeating with the upmost symbol..later on shuffling the order? Here’s the key..Harden (or whoever sent the key) had written A-Z vertically, which doesn’t make any difference, imo.
What I do think, however, is that Z must have written down the amount of homophones used for each letter. Otherwise he probably wouldn’t know, e.g. after using four homophones for the letter I if he should add another (new) symbol) or if he had to repeat from the beginning. The amount of homophones is well-chosen thus I’m quite sure that he had thought about that in advance, e.g. listing the alphabet in combination with the amount of homophones, e.g.
A(4) B(1) C(1) D(2) E(7) F(2)…etc.
BTW, the letter ‘O’ in the 408 is quite strange as one homophone shows up no earlier than in the third sequence. It appears as if Z had corrected himself with regard to his frequency table, realizing that ‘O’ should be represented by 4 instead of 3 homophones. ‘Well, nobody is perfect‘, is what I guess he would have thought when realizing it..
QT
QT
*ZODIACHRONOLOGY*
Largo: I really like your re-enactment of the encoding process. Your disruptor hypothesis makes a lot of sense. Encoding all of A, then all of B, all of C, etc., would be much more time efficient, but also make it easy to skip the occasional plaintext. I also really like your transcription hypothesis, explaining how he may have used dots to keep track of his encoding diffusion.
I tried to re-enact the encoding process as well. I was trying to figure out why some symbols cycle together at the beginning of the message, and then the cycles become random in the bottom half of the message. It is the "check mark" hypothesis, similar you your "dot hypothesis."
See the 7th post down here:
viewtopic.php?f=81&t=2617&p=41045&hilit=check+mark#p41045
Or here:
By the way, I found the exercise very instructive. I did it by hand. If you make a key and encode by hand, putting a check mark by the symbols as you go, you get a real feel for how Zodiac must have encoded the symbols. I don’t know if he used multiple keys, and would like to dispense with that idea if possible.
But with the 408 and I suspect with the 340 he started out with perfect cycles that become more random as he went. My theory is that there is a very simple reason for that. He wanted to make sure that he used all of the symbols in a cycle at least once. Once all were checked off a few times, he started to randomize more and more. With high frequency letters, he would have had a lot of check marks on the symbols. There would have been so many that it would have been difficult to keep track of the exact order of symbol selection.
If his key was written on a small piece of paper, or a bit condensed, that would explain the randomization because the check marks would start to be very difficult to count and keep track of with high frequency letter symbols. They would have been very clustered together. The only way to cycle symbols perfectly is to make a big key, with the symbols spread out away from each other so that there is room for a nice, neat line of check marks that are easy to count. That would have taken a lot more effort. Thus the increased randomization of the cycles in the second half.
Maybe I should re-enact a route transposition.
