Well those fragments make where the scratched out letter replaced with the reverse K look all the more interesting since the first one ends at that letter.

Thanks for the dataset. I plotted each rectangle and overlaid this copy of the 340. Here’s the result:

(Ignore the zero followed by the horizontal red line)

Looks accurate except for the crossed circles, dots, and horizontal lines. Which image of the 340 did you use as the basis of your analysis?

In the notes that come with the data I mentioned that each position x and y are the bottom-left corner for each symbol. You have to add the symbol size x and subtract y. This is the crappy line I used in my freebasic program: circle((gr(i).px+(gr(i).sx/2))/30,(gr(i).py-gr(i).sy/2)/30),16,rgb(255,255,255)

I know it is not logical but I cba to change it right now. Sorry

Thank you for posting more on the intersecting trigrams, it is very interesting!

I’m going to take a closer look at all of it in a couple of days and I’ll get back to you.

More crap: line(((gr(i).px)/30)+100,((gr(i).py)/30)+100)-(((gr(i).px+(gr(i).sx))/30)+100,((gr(i).py-gr(i).sy)/30)+100),,bf

px and py are bottom-left corner position of each symbol and sx and sy are the symbol dimensions.

Generated this: https://www.dropbox.com/s/frz190lcgo5q7 … t.png?dl=0

It should be spot on.

One explanation for this could be the cipher author wrote out the cipher as a 34×10 block but then cut it up into 17-column chunks of rows to rearrange them into a 17×20 block. The resulting chunks may have preserved the gap distance of the rows they originally belonged to. But there’s no cutting and pasting evident in the cipher, so he would have had to re-write it, perfectly preserving the placements of symbols in the result.

Thanks for the distance data doranchak.

I like your idea very much! It does explain the differences between whole rows.

In the same way, he could also just made it 17×20 and then cut it up in different pieces and rearrange the whole thing like a patchwerk and trace it over on a ‘lightbox’. This may hint graphical design, publicity. I used them in that sector and people do not generally own these. Take another look at the pen on the dripping pen card.

Take another look at the pen on the dripping pen card.

Are you perhaps thinking of a parallel to the Rotring Rapidograph? Maybe you weren’t but I had posted on that in the past. Used, as you know I’m sure, in graphics as the mainstay when doing manual artwork it required washing every once in a while to prevent clogging of the fine nibs and general ink build up or when changing colors. There was a cleaning fluid for it but I just remember days when I was "washing my pens", literally, in the sink with hot water.

Anywho, don’t mean to interject off topic. Following this thread with interest.

Take another look at the pen on the dripping pen card.

Are you perhaps thinking of a parallel to the Rotring Rapidograph? Maybe you weren’t but I had posted on that in the past. Used, as you know I’m sure, in graphics as the mainstay when doing manual artwork it required washing every once in a while to prevent clogging of the fine nibs and general ink build up or when changing colors. There was a cleaning fluid for it but I just remember days when I was "washing my pens", literally, in the sink with hot water.

Anywho, don’t mean to interject off topic. Following this thread with interest.

Hey traveller1st,

No I mean as in a possible clue to a transposition scheme, patched up.

I owned a set of Rotring pens in school, thanks for reminding me of that! I do remember vaguely they needed cleaning. Reminds me I still use the cover of the box the pens came in, it is some sort of multi functional ruler.

I’m going to do the same for the 408. I’ll post the data/images once I have it, couple a days I guess.

I just finished the work on the 408 and here are the data and images. The images were generated with the data so it’s workable.

The 3 parts of the 408 are joined so ignore the space between row 8 and 9, 16 and 17.

408 raw symbol placement data: https://www.dropbox.com/s/uxs8k9p48dx9a … a.txt?dl=0

https://www.dropbox.com/s/cnzm6d44sdx6k … 4.png?dl=0
https://www.dropbox.com/s/61ls4gep9fbr6 … y.png?dl=0

https://www.dropbox.com/s/fwabhj66z5ivb … 6.png?dl=0

The extra spacing between certain rows/grouping of rows is also visible in the 408 and seemingly to a greater extent. I’m inclined to rule out most of my own thoughts of this relating to some sort transposition scheme with the 340 because of the 408 data. I don’t know what it could mean. It probably relates to how the cipher was written down, and not to how it was made.

Jarlve-

Interesting work, and it brings up a topic I have wondered about before. The Z408 and the Z340 ciphers both share the same 17 column width, and so does the Z32, or "bomb cipher," even though it could have been squared off as 16×16. The Z13, or "My Name Is" cipher is obviously less than 17 symbols in length, so it doesn’t count…

I have wondered why this is. Personally, I like the "light-table" idea a bit. I don’t think that Zodiac had any particular affinity for the number 17, or anything like that, but perhaps he had (or created) some sort of grid that he used in writing them.

I don’t want to get off-topic, but I’ve never seen a good answer to "why always 17 columns." What do you think?

-glurk

Personally, I like the "light-table" idea a bit. I don’t think that Zodiac had any particular affinity for the number 17, or anything like that, but perhaps he had (or created) some sort of grid that he used in writing them.

I don’t want to get off-topic, but I’ve never seen a good answer to "why always 17 columns." What do you think?

Some very cool analysis was done on that very topic… http://crack-proof.com/zodiac-killer/projection-devices/

Very good site, IMO. The analyses are easy to understand and well referenced.

Thanks for the link up2something,

I can see what may have happened, simplified. He had or made some sort of grid on the paper to be traced with the plaintext written on the grid. The paper he was writing the cipher was on top of it, with or without a piece of glass between it (see up2somethings link). He was able to see-through the grid lines and plaintext. He saw the plaintext letter and then referenced to a sheet or sheets which held and managed all the symbols and cycle. He then wrote down that symbol.

Then what I think happened is that from the friction produced by writing, one of the surfaces would gradually move out of place and he would have to realign it on sight. This could explain some of the data I mined about the placement of the symbols but not all.

I don’t want to get off-topic, but I’ve never seen a good answer to "why always 17 columns." What do you think?

Hey glurk,

It was one of the first questions I had when I first started work on the ciphers. Obviously you can’t have 5 or 100 columns, just trying to say that he could have arrived at the number just as, hey this looks about right and then sticked to the system he created. Or maybe he had already had a system/device/grid/paper that held this format. Or it is a reference to something about him, or a ‘mathematical’ reason like using evil numbers: 17, 20, 24, 54, 63, 340, 408. Or maybe these were the closest factors that fitted the plaintext length and would make sense visually, he created a system and sticked to it. Or a combination of any of those.

Take a pick.

I also think it is a bit strange that the z32 is formatted to 17 columns. But it may be a consistency thing. For instance, in your post you mention the z32 and z13, two lesser known ciphers. Therefore you used the -z prefix, and since you want to stay consistent you also use the prefix for the 340 and 408. Which people normally quote without. (maybe you always use the prefix but that’s what I would do or ponder about)

I always thought it was interesting that if you have a grid with half-inch squares, then two sheets of standard-sized 8.5"x11" paper would yield exactly 17 columns and 44 rows.

The 408 cipher was 24 rows, and the 340 was 20 rows, fitting 17 columns and 44 rows exactly.

I always thought it was interesting that if you have a grid with half-inch squares, then two sheets of standard-sized 8.5"x11" paper would yield exactly 17 columns and 44 rows.

The 408 cipher was 24 rows, and the 340 was 20 rows, fitting 17 columns and 44 rows exactly.

Would that mean the 340 and 408 were made in one go or that just the same papers were used? That he made an easy and a hard cipher in one go perhaps?

I guess either of those possibilities could be true.

I have seen some speculation that the 18 symbols of filler at the end of the 408 have some undiscovered connection to the 340. Could the cipher author have started a new substitution key there, continuing it into the 340? Maybe, but the high number of symbols copied into the 18 symbols from the earlier rows of the 408 make them seem that they are only filler.

I also wonder if more plaintext is missing from the 408. Between the 2nd and 3rd parts, there is a break in continuity of the plaintext: [e I have killed will become my slaves]. The 3rd section of the cipher has more broken/interrupted homophone cycles (see this visualization), so it makes me wonder if restoring a missing section could fix up some of those interrupted cycles.