Zodiac Killer's cypher Solved!

[Headbandf1]

A hobbyist codebreaker believes he's cracked the Zodiac killer's last encoded message (above). It is, he claims, a Caesar cipher with some substitution stuff, though it's not really clear from the article. His solution identifies Arthur Leigh Allen as the killer:KILLSLFDRHELPMEKILLMYSELFGASCHAMBERAEIOURDAYSQUESTIONSABLEEVERYYWAKINGMOMENTIMALIVEMYPRIDELOSTICASTGOONLIVINGINTHISWAYKILLINGPEOPLEIHAVKILLDSOMANYPEOPLECANTHELPMYSELFIMSOANGRYICOULDDOMYTHINKIMALONEINTHISWORLDMYWHOLELIFEFULOLIESIMUNABLETOSTOPBYTHETIMEYOUSOLVETHISIWILLHAVKILLDELEVENPEOPLEPLEASEHELPMESTOPKILLINGPEOPLEPLEASEMYNAMEISLEIGHALLEN
With spaces, that reads "KILL SLF DR HELP ME KILL MYSELF GAS CHAMBER AEIOUR DAYS QUESTIONSABLE EVERYY WAKING MOMENT IM ALIVE MY PR IDE LOST I CAST GO ON LIVING IN THIS WAY KILLING PEOPLE I HAV KILLD SO MANY PEOPLE CANT HELP MYSELF IM SO AN GRY I COULD DO MY THINK IM ALONE IN THIS WORLD MY W HOLE LIFE FUL O LIES IM UNABLE TO STOP BY THE TIME YOU SOLVE THISI WILL HAV KILLD ELEVEN PEOPLE PLEASE HELP ME STOP KILLING PEOPLE PLEASE MY NAME IS LEIGH ALLEN".I always assume "multiple keys used for different parts of the ciphertext", "Bible Codesque frequency shenanigans", etc., with these things. And it contains no new information, just the prime suspect and generic pathos. Cynical, I know! Be sure to drink your ovaltine.

 

[H^2o2]

That would be awesome if its legit. The Zodiac was supposed to be like an ex navy guy I think. Was this dude? Creepy shit.

 

[merlot]

If the killer is/was Arthur Leigh Allen then he died in the early 90's.

Pity they didn't cipher the code 40 years ago.

 

[PhenoMenal]

I'd love for this to be solved as much as anyone, but there's quite a few points to consider before we jump to conclusions about this being solved (and lets not beat about the bush - it is still NOT solved) ...

* No reputable cryptanalysts are saying this has been cracked, just this one kid and a couple of newspapers. There's not a single mention of it at sci.crypt, for example.

* The FBI, NSA, you name it - they've all worked on it (it is after all multiple murder cases), yet to this day it has has not been solved.

* Numerous possible solutions have been put forward for this, none have ever been found to be definitive.

* IF it was cracked EVERY character in the decipherment would make sense. Especially in the case of mono/polyalphabetic ciphers, once you've got a "foothold" into cracking two or three characters ("cribs") it quickly becomes easier and easier to then go on and deduce them all. For example, if you've figured out that XAPPR = H_LLO you can easily deduce that A will decrypt to E. But that is not the case with this kids decipherment - a lot of it is just 'random garbage'.

* If this is simply a variation of the caesar cipher it wouldve been cracked days after its first publication (ie. decades ago). Even if it was a polyalphabetic cipher it would've been cracked very quickly.

* Consider the first 4 characters of the ciphergram... "HER>", which he claims decodes to "KILL". Caesar ciphers are monoalphabetic (one character always decodes to another particular character), therefore "HERR" could transcribe to "KILL", but "HER>" could not, under a monoalphabetic cipher.

* If it was a caesar-style monoalphabetic cipher then each letter is simply shifted by a fixed number, 3 in the case of the traditional Caesar ... ie A becomes D, B becomes E, etc ... yet to make his decipher even partially work he had to use a combination of 3,4, and even that alone wasn't enough.

* Also, while he says he used a Caesar shift of 3, then 4 (then repeat), he doesn't exclaim how this works in regards to the symbols ... (you can shift A to D, B to E etc, but what do you shift ">" to, for example?)

* A lot of his decipherment still doesn't make any sense ... even with his system a fair bit of it decodes to garbage

* So is it a polyalphabetic substitution cipher? If it was then surely this kid who claims to have cracked it would've said so, instead of claiming it's a caesar cipher.

* A classic Caesar cipher will generally include a large proportion of the characters of the alphabet, sometimes all 26. This has many more.

* The '340 Zodiac cipher' uses 25 letters (all but Q). That wouldn't be totally abnormal for a monoalphabetic cipher of this length although you'd still expect the number to be around 20ish given the rare frequency of certain characters.
However, it also ...
- Has 10 _reversed_ English letters
- 28 symbol characters, only 7 of which you'd find on a keyboard
- Most of the ciphertext itself is represented from these symbols, not regular characters.
- There are 63 different characters in total.

* Experts believe it uses direct substitution, alternate substitution, anagramming, and dummy characters scattered throughout. This is quite different and far more complex to crack than the classic caesar cipher decrypt that this kid uses.

* Do you really think the first word of the decipherment will be "KILL"? Come on. To me it seems that's where this kid has got himself bogged down - right at the very start, which is why the first 4 characters may fall into place but it immediately goes downhill from the 5th.

There are enough patterns in the ciphergram and the character distribution statistics also suggest that it is a legitimate cipher ... (not just random characters designed to waste everyones time, although such biases can still easily be created), but I don't think this pundit has cracked it, let alone come even close.

You may be thinking "but so many words in the decipherment sound like they're hitting the nail on the head" ... this page for example gives a completely different, yet equally as realistic, decipherment as the one mentioned in this thread ...
http://web.archive.org/web/20080206131017/http://www.dtm.ciw.edu/chris/z/340explain.html

 

[h^2 O]

I can't wait until it actually is cracked....will probably read "Satan commands me to spill the blood of the innocent" Hope its something cool like that

 

[KSP]

I remember that fack. I was a little kid and all the parents were freaked out he'd get one of us.

Now if we can just solve his gazintas.

 

[michael68]

I can't wait until it actually is cracked....will probably read "Satan commands me to spill the blood of the innocent" Hope its something cool like that

rofl.

 

[budbasket]

Lol

 

[Linenoise]

If/When this thing is ever solved, I will be sorely disappointed if it says anything other than: "If you can read this you are gay. Peace out bitches!"