AK Wilks, Subject: Is The Zodiac 340 A Two Part Cipher?   Sat May 12, 2012 2:21 pm

Lately I have been wondering more and more if the Zodiac 340, which has defied the efforts of FBI supercomputers, police and amateur code breakers for over 40 years, may be a two part cipher.

In other words, is there a code key for the first ten lines, and then a new almost completely different code key for the next ten lines?

Answer: I don’t know.

But it may be worth examining. Here are some things which may point to it being a two part code, with the most likely "cut" being between the 10th and 11th lines.

1. Dan Olson, the head of the FBI Cryptography Unit, noted that lines 1 – 3 and lines 11 to 13 had "distinct higher randomness" which was likely indicative of "homophonic substituion". Lines 1 to 3 would seem to be an opening and the start of a code key. Are lines 11 to 13 a new opening and the start of a new code key? That is one possible interpretation of what Olson notes.

2. The Raw Graysmith Proposed Solution, as interpreted and presented by Bullitt/Kite/Obiwan/Wilks and others, is very impressive in the first half, with clear English langauge sentences that either read correctly as is or with very minor anagram use, like HERB CAEN I GIVE THEM HELL TOO THEO SEE A NAME THESE FOOLS SHALL SEE MAIL LOOK. But lines 11 to 20 have very little coherent words and no phrases, and only by Graysmith resorting to extreme anagram use and forced solves does he manage to construct a solution that reads mostly like baby talk gibberish.

I am now tending towards the opinion that perhaps lines 11 to 20 of the 340 rely on a very different code key than lines 1 to 10.

3. ENTROPY gave his observation and opinion on the Graysmith proposed solution and over a dozen others that "The one thing ALL of these solutions have in common (besides being incorrect) is that they tend to unravel after the first 5 or so lines as the substitution patterns used in the first part are no longer sustainable."

I think there is merit to Entropy’s observation. One possible reason for it is that there IS a change in the code key, probably coming after line 8 or most likely line 10.

4. Looking at the raw unsolved 340, it seems that perhaps Zodiac calls our attention to the 10th line, which unlike any other line starts and ends with " – ". Is it perhaps meant to act as a cut off, a mark indicating that the 10th line is the end of something, and the 11th line a new start?

If this is true, then perhaps Doranchak can alter his excellent codesolver webtoy so that we can try different approaches on the 340 first ten lines as one code, and 340 lines 11 to 20 as a seperate code.

Ideas, criticisms, questions?

tahoe27, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sat May 12, 2012 2:40 pm

I posted this at Tom’s back in Jan. 2010–don’t know if it means anything, but it was something I noticed:

When looking at the three-part symbols that matched (IOF) and them being perfectly lined-up from top to bottom, I noticed they were exactly 8 lines apart. This reminded me of the three-part cipher as it was (in sections) 8 tall and 17 wide. Could this mean anything?

AK Wilks, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sat May 12, 2012 6:19 pm

That is interesting and there are patterns and repeats in several places. But because of what Olson said the two – by Z on the 10th and that Graysmith and every other solution tends to peter out after the 9th or 10th line my guess is the 10th is the cut line if there is one. The IOF on the 5th could be THE while the IOF on the 13th could be DOG as an example.

doranchak, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sun May 13, 2012 5:57 am

Nick Pelling also believes the cipher is split into two parts:

http://www.zodiackillerfacts.com/forum/viewtopic.php?f=11&t=1278

It may be split into two keys, but if so, why can’t codebreaking software such as zkdecrypto crack the individual halves? This has been tried many times. Maybe it’s because 170 characters is too short for heuristic search methods like zkdecrypto to work.

Anything’s possible, but I think the cipher is unbroken because something else is going on that is making the cipher difficult to break. Quill discusses some interesting possibilities here:

http://www.zodiackillerfacts.com/forum/viewtopic.php?p=24186#p24186

http://www.zodiackillerfacts.com/forum/viewtopic.php?p=24190#p24190

There have been many ideas about how the cipher might be constructed. Ultimately, the only way I can think of to rule out all these many different possibilities is to construct test ciphers that share many of the same statistical qualities as the 340 cipher, and that use whatever strange construction method you suspect Zodiac may have used in his cipher. Then, if the test ciphers are easily broken through cryptanalysis, and the same cryptanalysis still cannot break the 340, then that is evidence that the hypothesis is weak and can be ruled out. And, of course, if you’re lucky, then you might stumble on the right scheme.

doranchak, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sun May 13, 2012 6:05 am

I am still baffled by some of the unusual features of the 340, most notably the repeating intersecting pivots, and the IOF showing up in the same column. And why do a lot of these anomalies occur near the pivots?

http://www.zodiackillerfacts.com/forum/viewtopic.php?p=22570#p22570

The IOF trigram (noted in that post as |5F ) has an occurrence that is sandwiched right between the pivots, which are themselves connected by that "5-4-." pattern (filled circle, half circle, dot). Why? Is it pure coincidence, or is there something about the cipher construction that would make such patterns more likely?

morf13, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sun May 13, 2012 9:55 am

What if the cipher is meant to be folded, so that the IOF symbols touch each other? Or maybe, the IOF starts and ends the true message hidden in the 340?

Quagmire, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Sun May 13, 2012 6:23 pm

It might be a hoax or entirely unconnected but the 1990 Christmas card contained a photocopy of 2 keys – I’ve often felt this could be a clue from Z that the 340 needed 2 keys to solve it. If genuine, that card seems to have been the last thing that Z ever posted – maybe he was at death’s door and felt he had to send a final clue/taunt before "signing off" for good?

entropy, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 14, 2012 5:11 am

I’m honestly skeptical of even the first part of Graysmith’s solution. It does sound fairly coherent but it is, of course, much easier to come up with that for a short portion of the cipher. That said, it’s entirely possible that there is a change of key within the cipher… or part of it is double-encoded… or a gazillion other possibilities.

Unfortunately, when you allow for changing keys, it can become a convenient way for some folks to create a seemingly sensible solution using iffy methodology. I’ve seen a couple of "solutions" which simply changed keys at whatever random points the previous key stopped working. A "solution" which changes keys seven or eight times at random points in the cipher will likely sound really nifty but is utterly unverifiable. A solution with just one or two key changes or one using some kind of coherent system of key changes would be interesting to consider.

tahoe27, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 14, 2012 11:12 am

I’m honestly skeptical of even the first part of Graysmith’s solution.

Me too. I don’t think it reads or has anything to do with Herb Caen. It’s just what our eyes see in a sense.

AK Wilks, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 14, 2012 1:21 pm

I’m honestly skeptical of even the first part of Graysmith’s solution.

Me too. I don’t think it reads or has anything to do with Herb Caen. It’s just what our eyes see in a sense.

Keep in mind, since I think most of Graysmith’s "solution" is garbage, I am talking about two things – the first stage "raw translation", which I think may be largely or at least partially correct, and Graysmith’s forced attempt to derive a "solution" from this, which is a failure.

So I think the raw translation of I GIVE THEM HELL TOO SEE A NAME THESE FOOLSHALL SEE is probably correct. Part of that raw translation is:

HERCEANB

Now Graysmith "solves" that as HERB CAEN. And maybe he is right – the letters fit and it is only a very mild anagram. Jack the Ripper started a famous letter as MR LUSK FROM HELL.

But he may be wrong. That first line reads as is HERCEAN BIGIVE THEM HELL TOO. Which could read as HERCEAN BIG/I GIVE THEM HELL TOO.

A big daunting task – like solving this cipher – can be called HERCULEAN. Here we have HERCEAN BIG. So even if Zodiac never heard of Herb Caen, this may well be the right RAW TRANSLATION, even if Graysmith SOLVED it wrong. Also, an SF area serial killer and Zodiac suspect signed a letter as HERCULES and that entire first line Caesar shifts to his name, and only about 1% of 17 letter sequences do that.

See http://zodiackillersite.forummotion.com … ysis#28449

So for me that raw translation of HERCEANBIGIVETHEMHELL is very likely correct, regardless of whether it was meant to refer to or be a play on the name of a local SF columnist.

And when you solve the other lines as SEE A NAME, etc., you get most of the letters for the HERCEANB sequences.

ENTROPY – I agree with you, if you start getting into 3 or 4 or 5 keys, it is too easy to just make stuff up. I am proposing a possible TWO KEY code (hmm like the 1990 picture as Quag mentioned), with the statements from FBI code analyst Dan Olson about the higher distinct randomness on lines 1 to 3 and 11 to 13 pointing to the cut off being line 10, which Zodiac himself draws attention to with the starting and ending " – " marks, and what you noticed, that the Graysmith proposed solve and most others fall apart at best by the 9th or 10th line.

I do think the 4th line SEE A NAME matches very well visually to the 4th line of the unsolved 340, perhaps the one little assist Zodiac gives us, and that the first line decode also probably correct. See below. Maybe I will start a seperate thread on the Raw Graysmith as interpreted by Bullitt/Kite/Obiwan/Wilks.

AK Wilks, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Fri May 25, 2012 1:37 am

http://www.zodiackillerfacts.com/forum/ … =50&t=1426

I see the idea about the 340 being a two part cipher, with the cut line being the 10th line, is starting to catch on.

This guy takes it a step further and suggests it could be a four part cipher, using the Halloween Card "Paradice Slaves" cross as a clue, noting the " – " at the start and end of the 10th line as I did, but then saying the " + " at the center could be extended to divide the cipher into four parts. Not sure I agree, I think it is more likely a two parter, but certainly an interesting idea and worth exploring.

The mystery of the 24 " + " symbols in the cipher is a big issue. Yes common doubles are EE, SS, TT, but look at the words we KNOW that ZODIAC USED:

KILL, KILLING, THRILLING, COLLECT, SHALL, WILL.

The " + " solves as an "L".

Even under this four quad theory, I would be very confident that + is an L in the upper left and upper right quadrants. If we want to try a variation, I could explore the + as an E, S or T in the lower left and lower right quadrants. All for the simple reason that the + as L seems to clearly work in the upper left and right, but not so much in the lower left and right.

Here is the Unsolved 340 in four quadrants from the center + and the Raw Graysmith Proposed Solution in four quadrants. I added the circles around the three "09" ‘s that happen six lines apart. 3 09 6.

Some of the words and phrases in the Raw Graysmith seem to somewhat fit the quadrants. Arguably anyway. It gives a different read –

HERCEAN HELL TOO SEE A NAME THESE FOOLS.

Then it reads –

GIVE THEM THEO SHALL SEE.

Then there must be a largely new cipher key for the lower left and lower right quads? In the lower left almost all the words are vertical – DUEL SIR BARS LEASH.

zodio, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 28, 2012 3:43 am

On Tom’s site someone (forgot who) posted it could have the by knife, by rope by gun, by fire- paradice slaves in it. You can see "by" in each quadrant. Thought it was quite interesting. Also may have Berryessa in there.

onewhoknows, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 28, 2012 12:58 pm

On the Postal Keys from the 1990 Eureka Card did anyone ever track down the numbers
on the front of the keys to a specific postal box? I would guess somewhere in California,
most likely the Bay Area.

AK Wilks, Subject: Re: Is The Zodiac 340 A Two Part Cipher?   Mon May 28, 2012 1:04 pm

One of them traced back to Montana and the iron ore magnet sperator is also perhaps a clue to mining areas of which Montana has many.