Like many of you, I presume, I became interested in the Zodiac Killer through the feature film. I watched the movie several times and left with the impression of “OK, so how is it that ALA is NOT the Zodiac”. This is how I came to this site, and of course now I have a very open mind with regard to the many suspects that have been suggested.

I find the ciphers particularly interesting, and of course now regard the 340 cipher as a challenge. Even if they catch this guy through familial DNA or something, he will still win at some level if this cipher continues to perplex humanity. This is why I joined the forum. I want to explore a particular theory about the 340 cipher, and because I am not a trained cryptology analyst, I will likely need critiques of my theory and/or help. I will lay out more about my theory in a future post in the appropriate forum section, but in the meantime I’ll state my beliefs about how this may unfold if I am right:

1). I believe that the cipher is a homophonic substitution cipher, that like the 408 cipher, requires some degree of rearrangement before a key is applied.
2). While the 408 rearrangement was relatively simple – only 6 possible combinations of the 3 parts, or perhaps 12 if you consider they could have theoretically been arranged horizontally – the 340 is more complex.
3). While there are many possible ways to rearrange the 340 cipher, subsequent Zodiac communications offered clues that could narrow the possibilities.
4). Once the proper arrangement is found, the cipher can be cracked by an “amateur” as the Hardens did with the 408
5). Like the 408, the solution to the 340 will not contain the name of the Zodiac

See you all on the boards