Dave Oranchak posted today about how he (along with Jarlve and Sam Blake) cracked the Zodiac Killer’s infamous Z340 cipher. Here’s his video:
Unsurprisingly (to me), it turned out that code breakers had been (kind of) close for some time, with the single largest tell (that never quite told) being the curious results you get if you examine every 19th character of the Z340.
So, the core of the cipher system turned out to be a combination of a “knight move” transposition (down one row and along two columns) plus the Zodiac Killer’s trademark set of reflected letter homophonic cipher shapes.
However, Zodiac – clearly stung by the ease with which his first major cipher had been cracked – threw in some extra confounding factors.
- At the end of the top line, he wrote the words “LIFE IS” in his homophonic cipher (not transposed)
- At the end of the bottom line, he wrote the word “DEATH” in his homophonic cipher (also not transposed)
- The rest of the bottom two lines were written in his homophonic cipher, but with the letter-order of some of the words reversed (e.g. the Zodiac’s signature word “PARADICE” was written as “ECIDARAP”)
- The remainder of the cipher was split into two nine-line blocks, where the order of the letters was transposed using knight’s move reordering.
There was also, annoyingly, a single row of ciphered letters in the middle that were out by a single column, which skewed all the text passing through it. It’s fairly easy to see that once you’ve got everything else right, though.
This was – I hope you’ll agree – a simply epic slab of codebreaking. Congratulations to David Oranchak, Sam Blake, and Jarl Van Eycke!!!!
More details (including the FBI’s statement) can be found here.
All in all, the Z340 plaintext reads:
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
WILL BE AN EASY ONE IN PARADICE
LIFE IS DEATH
As a chess player like yourself Nick, there’s a part of me that is annoyed I never thought of this! How often have we looked over this cipher, read an article, played around with some idea, then headed right over to play blitz chess online? While I’m half joking, there is an important point here with code-breaking, and innovating in general. I think you have to always keep alert to ideas, wherever they may come from. One of us could have spotted this connection. Sometimes I think we get too locked into tunnel vision, for example trying to navigate a grid using all the methods we use when working in software analysis mode. I’m sure the Somerton Man code can be solved by piecing together a few ideas that appear far apart without some lateral thinking.
I’m probably being unreasonably harsh on us all, but just wanted to make the point about imagination and getting out of our own analytical ways sometimes.
Thanks Nick!
We got REALLY luck!
Or lucky, even. Apparently I can’t crack the code of spelling.
Came here to see if you were onto that. Australia is claiming one of the mathematicians involved.
I think your bracketed word “than” in the 4th line should be “that”.
Richard Henderson: yup, well spotted, now fixed. 🙂
Dave: I think my definition of luck is somewhat different from yours. Plugging 650,000 transpositions into AZDecrypt is more Thomas Edison than lucky. 😉
Nick: We might all be ‘having lots of fun’ if we could make comparison with some of the better histerical solution attempts.
Simon: like a lot of other people, I once wrote code to try out a fair number of transpositions (though not even close to 650,000), including all eight knight move steps – but what with all the other factors to contend with, that was merely the starting point.
As far as the Somerton Man’s code goes, the inference that it is probably an acrostic (rather than a cipher) seems very strong – specifically, I don’t think anyone would now be surprised if it turned out to be the first letters of a (self-penned?) poem.
https://ciphermysteries.com/2015/08/13/my-life-is-all-but-over
https://ciphermysteries.com/2015/09/12/barry-traishs-backronymic-poem
Given Barry Traish’s relative lack of success in finding matches for all but the last line, I do now wonder whether his experiment should be rerun with a less rigid pattern match (i.e. assuming that one or two of the letters in each line were miscopied).
Nothing short of amazing, the collaboration of brilliant minds and the stepping stones well documented for each contributor to gain a step further to the solution.
Absolutely incredible and amazing work from the trio! The time of miracles is not over yet
And yeah I was totally wrong about the Bauer solution three years ago
Watching Oranchak’s video, I don’t quite understand why the first attempt to apply the deciphering method only produced fragments of the solution, the second attempt applying the very same method produced only gibberish and only the third attempt with the deciphered fragments locked in place produced the full solution. What’s going on?
JG: effective decryption of short homophonic ciphertexts is only possible thanks to large datasets of long-string statistics. And so even small disruptions to the ciphertext are enough to throw codebreaking programmes off the scent, because the long strings get slightly mangled.
It was in “News at 8” tonight by NPO1 – the “Dutch BBC One”.
https://youtu.be/U0jLHOR_2W0
Does the spelling of “Paradice” give a clue to the author and therefore the Zodiac killer?
Are there other linguistic peculiarities or style which give a clue as to the identity of the killer?
Who was it on the tv show?
David, sincere congratulations to your and your colleagues, and I’m sure it took more than luck (luck is when preparation meets opportunity).
Well done!
Was thinking along similar lines Mark. Seem to recall that early punters came up with th assumption based on modus operandi that Zodiac’s sharp memory, that he was possibly a casino card counters or roll pattern (craps) numbers man. Might the last word of Z340 decryption therefore refer to ‘pair a dice’ (paradice). Now that the tumult and the shouting has died, guess search for an identity will gain some renewed interest and we’ll no doubt be having lots more fun trying to catch the basket.
The San Francisco Police Department, like the FBI, was short on reaction Friday to the cipher s solution beyond acknowledging the code had been cracked. The Zodiac s last victim, taxi driver Paul Stine, was shot to death by the Zodiac in October 1969 in San Francisco. And like any homicide, it s still an open case until it s solved. However, former city Homicide Inspector Gianrico Pierucci, who oversaw the Zodiac case for several years before retiring in 2017, said the new solution probably doesn t advance the investigation much. The difficulty of the code indicates the murderer was intelligent, but the bragging about slaves and the misspelled word paradise were already present in other Zodiac writings.
I agree that the substance of the message doesn’t seem, on its face, to add much to the investigation – although any newly intelligible content is progress. As for intelligence of Zodiac, if we assume he intended the message to be read in the near term, he seemingly was at least ignorant of the overwhelming confounding results of his inconsistency in encoding. It was the combination of the transposition being broken into parts, the insertion of plaintext outside the transposed message, and what appears to be errors that completely undermined that assumed goal. That’s not enormously intelligent to me.
I must confess that I don’t know much about the Zodiac killer, but my understanding is that there are other letters yet to be deciphered, maybe deciphering of this message and the techniques used to do so will lead to the decipherment of the other letters. Ultimately it seems obvious that the hope has to be that the decipherment of the letters will lead to clues to the identity of the killer; I am not sure to what extent this decipherment has provided any clues.
Well that didn’t work out as Planned. I think I knew in 1969 that the Zodiac was just turning the crank on everyone. But we tried to crack it anyway. Never came close lol. But I have to say after rooting around on the internet i can see where the case is solved. They Have DNA from the Bloody Gloves, They have 2 DNA samples from Chery Jo Bates. One is from the 90s, yeah scratch your head on that, from a lump of flesh, blood and hair collected from under her nails, Plus the new one just collected By the History Channel. Have they been compared? Who Knows, Better yet have they been given to the Team that caught the GSK. Who Knows again.
David Oranchak says he solved the last 16 lines of Z340. He did not. He put the date 2/23 a day after you printed. However, I had solved the year before and sent to LE and DOJ and they sent me letters back. I waited and waited. You do not have the solved correct date. As I told you, they are not honest. I have everything to prove date solved including letters and emails.
David Oranchak says he solved the last 16 lines of Z340. He did not. He put the date 2/23 a day after you printed. However, I had solved the year before and sent to LE and DOJ and they sent me letters back. I waited and waited. You do not have the solved correct date. As I told you, they are not honest. I have everything to prove date solved including letters and emails.
IMHO the easiest way to identify the Zodiac is to widely circulate the fact that the Zodiac had a fascination with collecting slaves for paradise. I think it is a reasonable assumption that the Zodiac would have mentioned these nutty ideas to others, and that these people would remember even after fifty years.
Byron Deveson,
While we’ve got you on board with your SIP thoughts on the ever facinating Zodiac killer Byron, are you going to reconsider your original thoughts on Maxwell John Beumont as detailed in the S.A. Police Gazette. It seems to have been an honest gaff and you can’t be held responsible for any mistaken identity which if so was quite a coincidence imo.
Have noticed something Z340 is solved vertically as well. Theres a line above “Gyke” – the word “because”, you drop the be, type cause space gyke. – it is the language Friesen – upper pennisula of the Netherlands and where he is from, it says GOOD LUCK. I wonder how many times he hid words and it has to be done a second time to get the vertical messages. Just like he did when he hid messages behind misspellings. HMMMMMMM Actually it said “cause” by Z, and David added the Be- which is part of the reason you just dont change things arbitrarily and say the coder did it wrong. In this case the solver did it wrong or we would have seen it before.