Zodiac Killer’s 340-Character Cipher Solved After 51 Years

A team of codebreakers has announced a solution to the Zodiac Killer‘s famous 340-character cipher received by The San Francisco Chronicle in 1969. The team needed to run months of solutions using sophisticated computer programs to crack the cipher, but ultimately found a clear, haunting message. One that talks about how the mythical Northern California murderer looked forward to the “paradice” of death.

The San Francisco Chronicle, fittingly, reported on the solution to the code. The three-person team that teased out the message consisted of Jarl Van Eycke, David Oranchak, and Sam Blake. They’re all computer programmers and codebreakers from Belgium, the US, and Australia respectively.

In the video above, Oranchak shows how he, Van Eycke, and Blake finally cracked the code. And even with multiple “fast and powerful cipher solver” programs, the task was extraordinary.

The Zodiac killer's infamous 340-character cipher

David Oranchak

The Zodiac Killer, who operated in Northern California in the late ’60s and early ’70s, taunted the Bay Area press during his active period with ciphers. (At least the active period officials know of, anyway.) The murderer, who claimed to have killed more than 30 people, sent four ciphers in total. This 340-character one is the last to be solved.

The cipher was exceedingly difficult because of the Zodiac’s use of transpositions of the encrypted symbols. While solvers only needed to figure out the key for the Zodiac’s other ciphers, for this one, a key was necessary as well as an unscrambling of the letters. The codebreakers’ programs had to sort through 650,000 possible reading directions to find the correct one for the cipher.

The Zodiac killer's encoded message

David Oranchak

As for the message? It’s as horrific as you’d imagine. The complete text is above. It includes the “same kind of attention-seeking junk from the Zodiac” he was known for, according to Oranchak. “I now have enough slaves to work for me,” the Zodiac writes, presumably referring to his victims. “Where everyone else has nothing when they reach paradice [sic] so they are afraid of death.”

Most notably, the Zodiac says that it wasn’t him “on the TV show” and that he’s not afraid of the gas chamber. This is a critical detail, as somebody who claimed to be the Zodiac had called into a TV talk show days before The Chronicle received the letter. Hence it being a sign the solution to the cipher is indeed valid.

As for acknowledgment of the validity of the solution, it seems authorities approve. The FBI in San Francisco even said on Twitter that it was aware that private citizens solved the cipher. Now if we can just figure out who the Zodiac Killer actually is, we’ll be all set.

Featured Image: David Oranchak