Over forty years of frustration have passed since the Zodiac killer first sent his mysterious 340-character cipher to the San Francisco Chronicle. It only took a week for two teachers to solve his previous cipher. But many thousands of people, over four decades, have tried to crack the mystery of the 340-character cipher, to no avail. You may have seen many would-be solutions in news stories and on the internet. The 408-character cipher was solved with a definitiveness that defies any possible doubt, because it is impossible for the Harden’s key (Part 1, Part 2, Part 3) to produce such an easily understood plain text message purely by chance. No such solution yet exists for the 340, despite numerous claims to the contrary.
So, with so much failure and defeat confronting us, should we just accept the possibility that the killer, frustrated by the swift unlocking of his previous secret message, simply created a fake cipher to keep us all busy all these years?
True crime author Michael Kelleher recently asked me if there was a way to know for sure if the 340 had a real message hidden away under its mysterious symbols. Our conversation evolved into this article:
The short answer is: We don’t know if there is a legitimate message in the 340-character cipher. But the cipher text shows us many interesting and peculiar features that continue to draw us into its trap. Why would these features be there if there is no underlying hidden message?
If it was a hoax all along, then it was a really, really damned good one.