A while back, I noticed a recurrent pattern of similarity between the layout of the QWERTY keyboard and the key to the Z408. While the entire key doesn’t follow the pattern, many of the plaintext letters (in blue) are represented by their nearby neighbors (in yellow), reflections of their nearby neighbors (in red), or the Greek equivalents of their nearby neighbors (in green). Take a look at the images I’ve attached; I threw these images together hastily, so please forgive any minor mistakes, but they do capture the general idea. For obvious reasons, these images don’t include symbols in the Z408 that don’t appear on the QWERTY keyboard.
I’ve never seen anyone mention this property of the Z408. I thought it might help others come up with new ideas for the other unsolved ciphers, or help further characterize the man behind the crimes (for one, it might suggest that he had familiarity with typewriters at the time).
Finder
These are fascinating observations. I think it would be useful to run an experiment that makes letter/symbol assignments completely at random. The experiment would help estimate how often "keyboard adjacencies" can be expected to occur by chance (by running the test thousands of times, say). This can then be compared to what we see in the 408’s key.
Somehow, I always think I will catch on to what you Guys are talking about, but I never do 
Anyhow, good luck with the research project
There is more than one way to lose your life to a killer
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http://zodiackillersite.blogspot.com/
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Somehow, I always think I will catch on to what you Guys are talking about, but I never do
Maybe this way of explaining will make more sense.
Let’s say I’m creating the 408 from scratch. I see the letter "A" in my message. I need to replace it with a symbol. I look at my typewriter, and there’s an "S" right next to the "A". So, I use the "S" to replace the "A" in my message.
Later, I see the letter "B" in my message. I look at my typewriter, and there’s a "V" right next to the "B". So, I use the "V" to replace the "B" in my message.
Then I see the letter "D" in my message. On my typewriter, there’s an "E" next to the "D". So I use the "E" (but this time, I flip it horizontally).
"G" is close to "R". "H" is close to "M". "I" is next to "U". "U" is next to "Y". "V" is next to "C". Etc.
The actual solution to the 408 seems to reflect some of these kinds of choices!
Somehow, I always think I will catch on to what you Guys are talking about, but I never do
Ditto , dumb it down a bit finder
Right. It at least opens up an interesting hypothetical about the 340 – Could Zodiac have done something similar with the 340? Maybe using keys two spaces away or some other variation?
MODERATOR
These are fascinating observations. I think it would be useful to run an experiment that makes letter/symbol assignments completely at random. The experiment would help estimate how often "keyboard adjacencies" can be expected to occur by chance (by running the test thousands of times, say). This can then be compared to what we see in the 408’s key.
I agree. If you’d like to collaborate on a model (constraints, randomization mechanism, how to tally a given key’s "score"), I could code the test if/when I’ve got the time.
Right. It at least opens up an interesting hypothetical about the 340 – Could Zodiac have done something similar with the 340? Maybe using keys two spaces away or some other variation?
Exactly.
Doranchak — correct me if I’m wrong, but if we were to impose a "soft" adjacency constraint (of course, I don’t have all the logistics worked out, but I think you follow) on the key to the 340, wouldn’t that dramatically reduce the key space? And thus improve the odds that a genetic algorithm could crack the 340?
Ultimately, even if the 340 doesn’t rely on the QWERTY layout, understanding how he developed the 408’s key may still help us get into Z’s mindset and come up with new ideas for how he might’ve developed the 340’s key, or the map code, etc.
That’s interesting. I’m not sure what to make of it yet. It reminds me of another observation which is that the person who typed the confession letter started out putting two spaces between sentences. Then, around 1/3 to 1/2 through, he stopped doing it and reverted to one space between sentences.
This suggests some superficial knowledge of typing, IMO. Being old enough to have actually learned how to type on a typewriter, I can say two things. (1) Typists were taught to put two spaces between sentences. (2) If you learned in a formal environment and typed long enough, it became second nature. These two points in conjunction with the confession characteristics suggest to me that the person who typed the confession had some type of nontrivial exposure to typing, but did not type on a regular basis. He knew he was supposed to have two spaces between sentences; but once he got going, we was no longer paying strict attention to the semantics of typing and lost track of it.
If the QWERTY aspect of the encoding is correct, it would be an additional indication of exposure to typing.
Very interesting Guys! Good Luck, and thanks for the explanation
There is more than one way to lose your life to a killer
http://www.zodiackillersite.com/
http://zodiackillersite.blogspot.com/
https://twitter.com/Morf13ZKS
Since this pertains directly to the ciphers, and some of our best code people don’t always go to other sections, I moved this thread over to CIPHERS and resized the graphics so we can continue the discussion there!
I moved it here: viewtopic.php?f=81&t=2419
MODERATOR
Doranchak — correct me if I’m wrong, but if we were to impose a "soft" adjacency constraint (of course, I don’t have all the logistics worked out, but I think you follow) on the key to the 340, wouldn’t that dramatically reduce the key space? And thus improve the odds that a genetic algorithm could crack the 340?
AK moved the thread so my reply is here now: viewtopic.php?p=33646#p33646
