Zodiac Killer Cipher

Team Rubik · Post by **Team Rubik** » 15 May 07 10:30 pm

For all those cipher buffs out there, the film 'Zodiac' is being released this week about a series of tragic murders in the US in the 1960s and 1970s. 
 
The killer released a series of ciphers to the media which would reportedly lead to his identity, only one of which has been solved. There are plenty of links on the internet, but this one provides some good info. To date the ciphers are still unsolved and the murderer has not been found. 
 

http://www.re-quest.net/mystery/zodiac/index.htm

Grank · Post by **Grank** » 15 May 07 10:42 pm

the murderer was probably lucky that he didn't mention a log book or an FTF prize ... he may not have been as safe as he thought

Zytheran · Post by **Zytheran** » 15 May 07 11:59 pm

As someone who knows a thing or to about ciphers I would like to point out that the story in the press doesn't hold any water.
"Using a simple letter substitution cipher made it easy to solve the Zodiac's July 1969 message" is a load of BS. What is shown is not a simple mono-alphabetic substitution cipher that can be easily solved by a teacher.
The clue about the double 'L' giving the game away is crap, he has used different symbols for each 'L', effectively hiding the the double letters.
If the assumption is used about "I" being the first letter then that isn't going to help find the "ill" set of letters in the cipher assuming the "kill" word..
I'd say the story was concocted to cover the fact the investigators were onto him and they needed a cover story to not give the game away.
Just my 2 cents worth..

Cached · Post by **Cached** » 16 May 07 12:07 am

When you look at it - you're right, there's nothing like a simple substitution in there.

I agree Z, sounds like they were attempting to say "bah, that was easy", when infact it wasn't.

What's the trick to this one?

Post by **CraigRat** » 16 May 07 8:32 am

Hmmm,
I ran it through my machine and I get some nonsense about "Liking Pina Coladas and gettin' caught in the rain....."

I need to lay off the coffee.....

Zytheran · Post by **Zytheran** » 16 May 07 1:37 pm

When you look at it - you're right, there's nothing like a simple substitution in there.

I agree Z, sounds like they were attempting to say "bah, that was easy", when infact it wasn't.

What's the trick to this one?

So you want me to solve the 3 unsolved ciphers and potentially nab a serial killer and solve a major unsolved crime..?

When I could be spending my time solving other ciphers and finding plastic containers with Maccas toys in them??

Priorities dude, priorities..

That image in previous posts is missing the unsolved last line.. if anyone solves a cipher I would be surprised you had a line unsolved, as opposed to random bits and pieces..

With the cipher set so large an alphabet and the text so small it isn't easy..
Even with that small sample above there are 7 symbols for e, 3 for t, 5 for a, 5 for o, 3 for n etc. etc.
With a few exceptions most symbols are only used 2 or 3 times.
As you progress through the cypher text new symbols appear for the common letters to make sure the count never gets too high for any existing symbol. The frequency spectrum of the 408 cipher is quite flat and this "solved" by the "teacher". However the 340 cipher which uses the same symbol set and displays more typical distribution hasn't been solved.

80+ symbols chosen to give a flat frequency and only 340 characters of cipher text..good luck.

BTW, the double LL does appear slightly more obvious later in the cypher but I story is still soooooo unlikely.. IMHO

TeamAstro · Post by **TeamAstro** » 16 May 07 2:43 pm

I wonder if they know there are really 13 Zodiacal constellations.

The 13th is Ophiuchus.

I wonder if......

Astro

Team Rubik · Post by **Team Rubik** » 16 May 07 7:02 pm

Zytheran wrote: The frequency spectrum of the 408 cipher is quite flat and this "solved" by the "teacher".

I would like to know the context in which you are questioning the term 'teacher'.

Cached · Post by **Cached** » 16 May 07 7:06 pm

Team Rubik wrote:
Zytheran wrote: The frequency spectrum of the 408 cipher is quite flat and this "solved" by the "teacher".
I would like to know the context in which you are questioning the term 'teacher'.

In the original article (link above), the article says:

Don Harden, a local high school teacher from Salinas, sat down with his morning cup of coffee and within a few hours he and his wife solved the cipher.

That context, I think.

Team Rubik · Post by **Team Rubik** » 16 May 07 7:21 pm

Sorry, I wasn't clear in my question. 
 
Why is there a need to put the word teacher in quotation marks? It is not necessary if you are using the term to describe one who teaches, so I was curious as to what he was in fact alluding to.

Cached · Post by **Cached** » 16 May 07 8:30 pm

I just noticed that the letters are different depending on the sound they make.

Like the silent E's are a round circle with a dot in it. Which is the tracking symbol for silent key/ gone home.

I think the letters are different depending on their sound.

Zytheran · Post by **Zytheran** » 17 May 07 12:38 am

Team Rubik wrote:Sorry, I wasn't clear in my question. 
 
Why is there a need to put the word teacher in quotation marks? It is not necessary if you are using the term to describe one who teaches, so I was curious as to what he was in fact alluding to.

Oh, I'm sure the guy was/is a teacher. I'd just like to know what else he knows because his story leaks like a sieve. Homophonic substitution ciphers are far from simple and the cipher text in this case is about half what it needs to be for successful crack. It really isn't the sort of thing you just nut out over a morning coffee.

Cached · Post by **Cached** » 17 May 07 1:20 am

Zytheran wrote:
Oh, I'm sure the guy was/is a teacher. I'd just like to know what else he knows because his story leaks like a sieve. Homophonic substitution ciphers are far from simple and the cipher text in this case is about half what it needs to be for successful crack. It really isn't the sort of thing you just nut out over a morning coffee.

I don't think anybody ever solves a zytheran puzzle over coffee...

I found a Don Harden on google that is a chem professor - wonder if the same guy?

"about half what it needs to be" - are there bits missing from this one?

Team Wibble · Post by **Team Wibble** » 17 May 07 8:37 am

[quote="Zytheran] Homophonic substitution ciphers are far from simple and the cipher text in this case is about half what it needs to be for successful crack. It really isn't the sort of thing you just nut out over a morning coffee.[/quote]

Nevermind nutting out a cipher over a morning coffee, I'm reading the forums over my morning coffee and I just read that as "Homophobic substitution ciphers"

Its too early in the morning....

Cached · Post by **Cached** » 17 May 07 1:52 pm

Curse you team rubik - this is a fascinating story and i've now spent wayyyy too many hours reading up on it.

I'm hooked. what a story.