Stuck.

Meanwhile I am 340-blind.

Quiztime.

After some analytical issues, I nevertheless got stuck with the 340…and therefore would like to know about your opinion regarding the following issue:

Let’s assume that Z had used the same encryption method as in the 408. Let’s further assume that he was supposed to distribute a certain amount of homophones (symbols) for each letter of the alphabet. Now I end up with a double letter occurring three (3) times in the 340, which actually is one more double letter than any letter would usually occur. Not a problem yet, as this might have been caused by one more word containing such a double letter. Nevertheless I got a problem and would like to know how you think about it. Here are my theories:

Talking about the ‘+’ symbol. The repeated use of a double letter somehow indicates it is represented by only one single symbol (otherwise another symbol would occur and the double would not be viewable). However such a letter with only one single symbol would sually not occur three times as a double letter and would it also be expected to have an overall frequency of ~3% or less. The ‘+’ symbol however repeats, is present >6-7% and is occuring three times as a double letter. Now what can be the reasons?

a.) Z had used one symbol for a letter with an expected frequency of ~3% or less, however this letter accidentially – in his cleartext – had occured 3x as a double letter and had an unexpected high overall frequency of 6-7% instead of some 3% or less (e.g. as the letter P could do).

or

b.) Z had modified the amount of homophones by purpuse, as normally 3-5 homophones would be expected for a letter with the frequency of 6-7%, he therefore did reduce the amount of symbols to only one symbol for the alphabetical letter, to somehow irritate or position a ‘blender’ and subconsequentyly using the homophones for other letters of the alphabet

or

c.) Z had in fact used the correct (expected) amount of symbols/homophones, however the letter represented by ‘+’ is not only represented by ‘+’ but also some additional 3-7 symbols which mostly would occur between the various ‘+’ symbols, leading to an overall frequency of ~9-14%

Somehow I am sure that at least one of the events above had taken place. The problem is, depending on each scenario, the double letter represented by ‘+’ is either a.) an exotic one (e.g. P) or b.) one with an adequate frequency (e.g. the letter ‘L’ or ‘S’) or finally c.) a letter with an expected higher frequency (‘E’ or ‘T’).

Depending on the scenarios mentioned above, it might be a next step to continue with digraph reversals such as ED-DE for the symbols O+ / +O, which in fact do occur.

Appreciate to hear about your opinions,

QT

You continue to skip over your (Quicktrader) correct original study and the fact that Zodiac had a particular personal vocabulary, which used "L" and "LL" much more than the average person.

Glurk’s study shows that TT, LL, SS and EE are the most used in English writing, with LL being the second most used.

So off the bat we have reason to consider ++ as LL.

In the first Zodiac Code he used "S" 24 times. Only once was there a "SS", and that happened in the phrase "it iS So much fun". Zodiac neved used a word that has "SS" in it, not once. Compare that to the number of words he used in the first code that had "LL" – SEVEN different words! And they are words we might think it is likely he also used in the 340 code. They were:

Zodiac also used these words with a single "L". – like, people, wild, girl, slaves, slow, animal, afterlife.

By my rough quick count, the letter "L" appears 33 times in the 408 code. About 8.1% of the letters are "L", which is about double normal usage, as it happens that many words Z liked to use have either L or LL in them. So if Z used "L" 8.1% of the time in the 408, it seems to me that 9.7% use in the 340 code is within normal deviation, really only two more uses of a word like kill, killing, collecting, etc., would do it. And if we strike the untranslated last 18, leaving us 390 translated letters, the 33 uses of "L" amount to 8.5%, which is even closer to my proposed 9.7%. in the 340 code.

I’ve done a small bit of work on this, and I’m going to have to say that as far as Zodiac’s use of the doubled letter "L," he did in fact use it a lot.
More than would be expected in normal writing. Even in words that, properly spelled, would not have the letter doubled.

I did not do exact word counts, sorry, but in a quick study I’ve found:

ALL, ALLREADY
AWFULLY
BILLIARD
BILLOWY
BULLET
BULLSHIT
CALLED
CELLING
COLLECT, COLLECTING
CONTINUALLY
FILLING
FULL
HELL
HILL, HILLS
HOLLY
KILL, KILLED, KILLER, KILLING
PULLED
REALLY
ROLLED
SHALL
SMALL
SQUEALLING
TELL, TELLING
THRILLING
TITWILLO
UNTILL
VALLEJO
WACHAMACALLIT
WALL
WELL
WILL

This should be all of them, I think, unless I missed something… I probably did miss something…
I don’t, however, believe that the 340 is simply a homophonic cipher like the 408. But I also don’t have any doubt at all that Zodiac often used "LL" in his writings. He clearly used it more than would be expected.

-glurk

Here are some others:

ALLEY (confession letter)
ALLEYS (confession letter)
ALLWAYS (1971-03-13-times)
BALL (confession letter)
BELLI (1969-12-20-melvin-envelope)
CALL (confession letter, 1969-11-09-chronicle, 1970-07-26-chronicle)
CELL (1970-07-26-chronicle)
FALL (1970-06-26-chronicle-cipher)
FELLOWS (1970-07-26-chronicle)
FOLLOWED (confession letter)
UNWILLING (desktop poem)
SPELL (1974-02-14-sla)
SPILLING (desktop poem)
WILLING (confession letter)
WILLINGLY (confession letter)
YOULL (1970-10-05)

Here are some others:

ALLEY (confession letter)
ALLEYS (confession letter)
ALLWAYS (1971-03-13-times)
BALL (confession letter)
BELLI (1969-12-20-melvin-envelope)
CALL (confession letter, 1969-11-09-chronicle, 1970-07-26-chronicle)
CELL (1970-07-26-chronicle)
FALL (1970-06-26-chronicle-cipher)
FELLOWS (1970-07-26-chronicle)
FOLLOWED (confession letter)
UNWILLING (desktop poem)
SPELL (1974-02-14-sla)
SPILLING (desktop poem)
WILLING (confession letter)
WILLINGLY (confession letter)
YOULL (1970-10-05)

Thank you very much Doranchak…the bold ones indeed match the double ++ in the third but last line..the others rather on other cipher parts..thanks,

QT
Today I realized that there is water in my trunk and a small lake behind the passenger’s seat…why did I buy exactly THIS car again…?

Today I realized that there is water in my trunk and a small lake behind the passenger’s seat…why did I buy exactly THIS car again…?

Lol. Fish smuggling?

This is IMO excellent work and a small example that message board discussion, criticism and exchange of ideas can actually break a little bit of new ground. Or at least lead to a new working hypothesis on solving one symbol (+), the most used symbol, in the 340. It seems it is not a regular cipher and at least one other stage is needed – but I like the idea of trying to reach a first stage solution (which has eluded us for 40 years), and then seeing where that gets us and where do we go from there.

Thanks to QT, glurk, doranchak and the many others who have worked on this still evolving study and debate.

To encapsulate, read the first post with QT’s study then this:

AK WILKS:

First look at QT’s correct original study and the fact that Zodiac had a particular personal vocabulary, which used "L" and "LL" much more than the average person.

Glurk’s study shows that TT, LL, SS and EE are the most used in English writing, with LL being the second most used.

So off the bat we have reason to consider ++ as LL.

In the first Zodiac Code he used "S" 24 times. Only once was there a "SS", and that happened in the phrase "it iS So much fun". Zodiac neved used a word that has "SS" in it, not once. Compare that to the number of words he used in the first code that had "LL" – SEVEN different words! And they are words we might think it is likely he also used in the 340 code. They were:

Zodiac also used these words with a single "L". – like, people, wild, girl, slaves, slow, animal, afterlife.

By my rough quick count, the letter "L" appears 33 times in the 408 code. About 8.1% of the letters are "L", which is about double normal usage, as it happens that many words Z liked to use have either L or LL in them. So if Z used "L" 8.1% of the time in the 408, it seems to me that 9.7% use in the 340 code is within normal deviation, really only two more uses of a word like kill, killing, collecting, etc., would do it. And if we strike the untranslated last 18, leaving us 390 translated letters, the 33 uses of "L" amount to 8.5%, which is even closer to my proposed 9.7%. in the 340 code.

GLURK:

I’ve done a small bit of work on this, and I’m going to have to say that as far as Zodiac’s use of the doubled letter "L," he did in fact use it a lot.
More than would be expected in normal writing. Even in words that, properly spelled, would not have the letter doubled.

I did not do exact word counts, sorry, but in a quick study I’ve found:

ALL, ALLREADY
AWFULLY
BILLIARD
BILLOWY
BULLET
BULLSHIT
CALLED
CELLING
COLLECT, COLLECTING
CONTINUALLY
FILLING
FULL
HELL
HILL, HILLS
HOLLY
KILL, KILLED, KILLER, KILLING
PULLED
REALLY
ROLLED
SHALL
SMALL
SQUEALLING
TELL, TELLING
THRILLING
TITWILLO
UNTILL
VALLEJO
WACHAMACALLIT
WALL
WELL
WILL

This should be all of them, I think, unless I missed something… I probably did miss something…
I don’t, however, believe that the 340 is simply a homophonic cipher like the 408. But I also don’t have any doubt at all that Zodiac often used "LL" in his writings. He clearly used it more than would be expected.

-glurk

DORANCHAK:

Here are some others:

ALLEY (confession letter)
ALLEYS (confession letter)
ALLWAYS (1971-03-13-times)
BALL (confession letter)
BELLI (1969-12-20-melvin-envelope)
CALL (confession letter, 1969-11-09-chronicle, 1970-07-26-chronicle)
CELL (1970-07-26-chronicle)
FALL (1970-06-26-chronicle-cipher)
FELLOWS (1970-07-26-chronicle)
FOLLOWED (confession letter)
UNWILLING (desktop poem)
SPELL (1974-02-14-sla)
SPILLING (desktop poem)
WILLING (confession letter)
WILLINGLY (confession letter)
YOULL (1970-10-05)

Quicktrader, in exploring this idea keep in mind that Z frequently misspelled words with double letter combinations. Whether you believe this was genuine or feigned, it is a consistent hallmark of his misspellings throughout the letters.

coupple
untill
originaly
sqealling
Christmass
comitt
efect/efective
bussy
dissapeared
rubed
allready
aprox
dificult
posibly
triger
teritory
butons

Best of luck…

It’s getting better.

Thanks to Windecrypto tool, I got access to a better dictionary. http://www.blisstonia.com/software/Decrypto/

With the Dictionary Editor import function, it is easy to extract them to notepad, then use it with ZKD software. The advantage is you get more word results, also longer ones, and can see how many longer words are found. Also the 408 is still solved inbetween seconds.

So I now get 10-20 words with 5+ letters with each try, temporary even got the word ‘Afterlife’. Problem is ‘temporary’ and are there still so many possibilities:

340 / average length of 5 letters = 68 words to put into the cipher. Besides contact analysis, individual settings and especially the homophone init key, this goes into direction of a 68-digit-bruce force attack, but with words instead of letters (argnnn…).

Best setting for the init key, so far, however appears to be:

ABCDE..
51127212501415510455111110

Finding longer words, such as ‘everyone’, ‘afterlife’, ‘another’ or even short phrases can now be found. No final solution yet, though.

(line 6-9)

QT

Yeah, I’ll go on with it..a new approach.

I tried to delete some symbols to reduce the complexity of the cipher. The 408 had 54 different symbols in it, therefore a cipher complexity of 7.55 letters per symbol (in average). The 340, however, with 63 different symbols has a complexity of 5.4 (340/63), which is way more complicated.

To reduce its complexity, I therefore tried to ‘eliminate’ a certain amount of symbols. Most likely the less frequent ones, although ‘loosing’ information by that. When ignoring all symbols that have a frequency of less than 3, you get an overall of 54 symbols or complexity of (340-21)/54=5.9.

This is much better than trying to solve it with 63 different symbols (or 5.4). It’s still worse than the 408 (7.55), but I guess the chances to solve it become higher. Some reasonable results may appear, however no solution yet. But as you can see it could make sense..

As this is not a valid solution, it must be assumed that the cleartext can still be completely different from this example. Also it appears that it doesn’t make sense to eliminate more symbols, as they are more freqent (3 or higher) and the cipher as a whole gets sort of lost then.

QT

And another quite obvious explanation might be that the "+" is not an homophonically substituted single character.
Apologies if someone’s already said that.

Some more news. It’s hard to proceed with that cipher, but still might be possible. With a new dictionary behind ZKDecrypto, results become amazingly interesting – sometimes 5 words of length=5+ or more in it – however no valid solution yet. All that based on a reduced amount of symbols so a better quota of homophones/letters might lead to a solution. But still a dead end.

There do exist many digraphs, however, such as AL, AS, TH etc.. Some of them are more frequent than others, which is hard to say which ones might be correct for digraphs in the 340.

Actually 3 different digraphs occur in the 340 with a frequency of 3. Assuming a frequency of e.g. 1.52 for a TH frequency, this is well what we may expect (340×0.0152=5.16 THs in the 340), considering the various homophones for letter T and H that still may occurr.

But now here is a clue: Zodiac liked the word ‘Thing’. In fact, in about 25 letters, Z used the word thing at least 16 times. This happened every third, if not even every second letter he had written.

Therefore, words like ‘anything’, ‘thing’, ‘nothing’ or ‘something’ may occurr in the 340, too. And, with three different types of (frequent) digraphs, one might assume to find this ‘thing’ word in connection with one of those digraphs.

M+, however, will probably not represent TH. Because then, the double symbol combination ++ would occur three times as ‘HH’ in the cipher, which would be rather coincidencial (due to its frequency and double letter frequency currently we assume + to either be L, T, E or S).

therefore, one of those, would represent ‘TH’ for two reasons:

1. No other high-frequent digraph available in the cipher
2. Possibly the word ‘thing’ occurring in any form with a 30-40% chance

Please be aware that there is no proof about it, but it appears to be somehow likely. A digraph frequency of 3/340 represents a 0.88% frequency, not considered any homophones yet (which would and probably will increase the digraph’s frequency).

So if I’d search for TH in the 340, I’d do it preferrably there.

QT

Good work, QT, and it spurred me to check this out. I think you had the right idea. But if I am right Z mixed it up just slightly to avoid using the same two symbol combo three times. But he does use it twice, and another time uses one of them.

In my 340 Solution (based on the Raw Graysmith, as worked on by Kite, Ed, Obiwan and others), I checked for TH combos. I think you right, Z liked the word THING, he also, like most human beings, used the word "THE" a lot. In the Raw GS I count TH as appearing 4 times, as THEM, THEO, THESE, THE.

Breaks down as:

1st line, 14&15 columns T and G solve as TH.

3rd line, 11&12 columns circle with vertical line (0) and circle with horizontal line (o) solve as TH.

8th line, 1&2 columns circle with vertical line (0) and G solve as TH.

15th line, 15&16 columns circle with vertical line (0) and circle with horizontal line (o) solve as TH.

So:

TG=TH ……………Solved as I GIVE THEM HELL TOO
0o=TH ……………GS solves as SLEUTHEO, AK solves as THEO—SEE A NAME
0G=TH ……………Solved as THESEFOOLSHALLSEE
0o=TH ……………Solved as THE

QT based on your previous work I think you showed why the "+" symbol likely solves as "L". Using that, and your idea on TH with my application of it, and my solve of S99 as SEE, this what you get.

I think this has the weight of both your statistical analysis and some word solves, and would provide an interesting starting point for someone to try to take it a step further, either through computer applications or pen and paper. Not saying this is absolutely right, but gotta start somewhere, and this has some solid justifications to at least be a working hypothesis.

AK, where is there a 340 cipher tool that you can fill in the boxes? I see Dave’s 340 webtoy site is not working.
By the way, if you guys are correct, the TH almost has to be followed by a vowel(provided Z didnt have an odd spelling error)