It takes a certain kind of person to enjoy working on puzzles. They lay on the table, you might spend a day or two finding a single piece, and that’s ok.

I imagine it takes a whole other type of person to keep trying on a puzzle that has been stumping super smart minds for five decades.

But that’s exactly what happened – and why we’ve finally decoded the second cipher from The Zodiac.

In 1968 and 1969, a series of high-profile murerrs rocked the San Francisco Bay Area, with anywhere from 5 to 49 people losing their lives.

They became famous largely due to the publicity brought to the case by the perpetrator himself – The Zodiac.

He sent many messages to newspapers that included ciphers and cryptograms that he claimed led to his identity, his victims, or both.

The first message that was decoded was a 408 symbol cryptogram known as Z408. It only took four days, and the “winner” was a middle aged couple from Salinas, CA.

https://twitter.com/CnsprtrlRprt/status/1552609467585495040

The second message was not cracked for another fifty years.

“On December 5, 2020, the FBI received the solution to a cipher popularly known as Z340 from a cryptologic researcher and independently verified the decryption.”

The FBI continued their statement on YouTube.

“The cipher was first submitted to the FBI Laboratory on November 13, 1969, but not successfully decrypted. Over the past 51 years CRRU (the FBI Cryptanalysis and Racketeering Records Unit) has reviewed numerous proposed solutions from the public – none of which had merit.”

https://twitter.com/PopSci/status/1784039742935326809

Then software developer David Oranchak, applied mathematician Sam Blake, and warehouse operator Jarl Van Eyke – three hobbyist cryptographers  – finally cracked it.

They did have a bit of help from the FBI, and the pieces they had put into place over the years, says Oranchak.

“We couldn’t figure out the part that says, ‘soo her,’ but their cryptanalyst called me and said she thinks it’s supposed to say ‘sooner’ instead.”

This was the end result:

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME

THAT WASNT ME ON THE TV SHOW

WHICH BRINGS UP A POINT ABOUT ME

I AM NOT AFRAID OF THE GAS CHAMBER

BECAUSE IT WILL SEND ME TO PARADICE ALL THE SOONER

BECAUSE I NOW HAVE ENOUGH SLAVES TO WORK FOR ME

WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE

SO THEY ARE AFRAID OF DEATH

I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS

LIFE WILL BE AN EASY ONE IN PARADICE DEATH

https://twitter.com/BenjiLikesMyths/status/1337545873304264706

Now the trio has released a paper that describes the process that they went through in over a decade.

“The decryption success reported herein was preceded by the authors’ many years of failed experiments, dead-end ideas, and efforts to summarize what was known about the Zodiac case and ciphers.”

There is an extensive list of experts and amateurs that attempted to make even the smallest of inroads into cracking Z340.

They think the Zodiac didn’t like how quickly his first cipher was cracked and so put a lot more effort into the next one.

“It is clear that the complications introduced by Zodiac led to much delay in its solution. If the cipher were simply one of the well-understood classical systems, such as homophobic substitution, transposition, or polyalphabetic substitution…then traditional cryptanalysis and application of powerful cipher solving tools would have broke it.”

The cipher wasn’t just rectangular, but diagonally, and the message was split into four uneven sections. That made it difficult to use a decryption algorithm to help decode the text.

The spelling errors didn’t help, either, but eventually they came up with a few tools that did help crack the code.

The main one was the knowledge on the case that had accumulated across the world.

“The online community drew a wide variety of people eager to crack the case and its ciphers, which brought many different approaches and viewpoints. …As users on online forums discovered interesting details about the ciphers, Oranchak endeavored to preserve them online. This allowed other researchers to use the information as a foundational source of factual details to build upon.”

The internet is, of course, a mixed bag. That meant wading through suggestions from more than a few amateurs who didn’t have the experience to really move the needle on this case.

Computer automation has also come a long way, and it helped them go through thousands of potential transpositions far faster than they could have done it by hand.

Oranchak said that, in the end, the author’s own pride was what made it possible to crack this cipher. His comments about the “tv show” and the “gas chamber” helped them nail some of the words and phrases, and the rest fell into line from there.

https://twitter.com/data_rep/status/977893752634204160

The identity of The Zodiac is, of course, still a mystery.

Still, Oranchek and others believe knowing what this cipher says could help lead to an indentification one day.

“Either he knew codes, or had a good intuition about how to make them. He definitely reacted to the Hardens’ solution and made it much harder.”

The remaining two messages also need to be solved, but the trio who solved this one don’t expect them to be easy to crack. They’re short and there’s no guarantee they were encrypted via the same process as the others.

Which is to say, unless something big changes, we may never learn his identity – and our kids may be in the grave before all of the messages are finally cracked.

If you thought that was interesting, you might like to read about a second giant hole has opened up on the sun’s surface. Here’s what it means.