All I know for sure is that FBI does believe there is at least a partial message in there and not just random.

I’m pretty sure that the best software developed that would be useful on this code are the ones that were created by Zodiac researchers, so to me that implies that the usefulness of other code solving programs in this case is not very much.

Take that to mean what you will about the message or lack there of.

I don’t see how the 340 can be a real code. With the deciphering software that exists today and the number of people who have reviewed the unsolved code. The other code was solved pretty quickly by ordinary citizens. What are the chances that the zodiac then came up with the code of the century? I believe it has to be goblygoop.

Amy

You may want to check out this one regarding the 340:

viewtopic.php?f=81&t=907&hilit=340

The ratio of the amount of homophones vs. cipher text length is more complex in the 340 than in the 408, which is why the 340 is harder to crack.

QT

Good point QT. My assumption is that there are programs to crack a basic homophonic cipher in like 2 seconds, and most of the advanced cipher programs are probably dealing with a different encryption method precisely because of how easy that is.

Z340 probably has a multi stage encipherment, one part of which is homophonic and the rest… that’s the hard part to guess. That’s why cipher programs have not cracked it.

Good point QT. My assumption is that there are programs to crack a basic homophonic cipher in like 2 seconds, and most of the advanced cipher programs are probably dealing with a different encryption method precisely because of how easy that is.

Z340 probably has a multi stage encipherment, one part of which is homophonic and the rest… that’s the hard part to guess. That’s why cipher programs have not cracked it.

Not necessarily a multi stage encryption..I even rather doubt it. Everything indicates that Z had encrypted all of his ciphers in a similar way – the my name is, the 408/340, button-letter ‘map’ cipher. All done in a similar way, e.g. no interruptions or blanks between the words. All with various but similar symbols, all in the same fashion.

My name is-cipher:
13 symbols / 8 homophones

Map-cipher:
32 symbols / 29 homophones

– short ciphers might require more homophones –
(e.g. if 24 alphabetical letters show up in such a 32-letter cleartext)

Looking at the 340/408:

340-cipher:
340 symbols / 63 homophones (average of 5.4 cleartext letters represented by each homophone)

408-cipher:
408 symbols / 54 homophones (average of 7.6 cleartext letters represented by each homophone)

Of course a cipher text is EASIER to solve if its text is LONGER. It also may be EASIER to solve if its cleartext letters are not scattered on to MANY homophones.

Both is the case with the 340: More homophones per symbols, with 63 homophones even 11 more than the 408 – although the text is shorter! This is why the 340 is way harder to crack, just due to its increased complexity. More homophones and less text simply makes it incredibly harder to crack the cipher.

But there is a trick…obviously the 408 can be solved by computer with a complexity of 7.6 cleartext lettters per homophone. Ignoring that the 340 is about 16.7% shorter than the 408, our target is now to reduce the complexity of the 340, at least to a level close to the complexity of the 408. But how to do that?

I’ve only found one way to simplify the 340 – let’s ignore some of it’s symbols! Of course, if we can choose (and yes, we can), we won’t eliminate the most frequent but rather the rare ones. E.g. those appearing only once in the cipher. This doesn’t ‘hurt’ the cipher too much, as it should still be solvable with one ‘blank’ or gap inside. However to eliminate one symbol is not enough. Personally I chose to eliminate all symbols appearing only once or twice. Of course our cipher now has some ‘blanks’ in it, however I’d say it is still better to have an incomplete cipher with some blanks in it than one which is too complex to be solved at all.

Eliminating those 9 homophones (representing an overall of 17 symbols in the cipher), I get an improved complexity ratio:

340-modified:
323 symbols + 17 blanks / 54 homophones (average of 6.0 cleartext letters represented by each homophone)

Please note that the higher this ratio is, the lower is the complexity of the cipher. So we now get an increased amount of cleartext letters per homophone, reciprocally decreasing the complexity of the cipher to a degree that it should become solvable. Please note that the amount of cleartext letters per homophone is not proportional to its complexity..therefore a 22% difference (6.0/7.6) of this ratio does not necessarily mean that it’s complexity isn’t still e.g. >50% higher.

So what is obvious is that we still have to deal – assuming such an identical encryption method – with various circumstances:

– the 340 is shorter than the 408 and therefore harder to crack
– the modification / elimination of rare symbols leads to an even shorter cipher text (323 symbols)
– the modification also leads to ‘gaps’ or blanks in the cipher, making its cleartext harder to read
– although its complexity is getting reduced by the modification, the 340 has still a lesser average amount of cleartext letters per homophone than the 408 (meaning still having a higher complexity)
– the complexity of the 340modified may still be disproportionally high, although the ratio is now getting closer to the 408
– elimination of rare symbols may lead to a shift in e.g. vowel-/consonant ratios, e.g. if the rare symbols mostly represent consonants (which we don’t know yet)

Regardless those circumstances, I still prefer to try cracking the cipher through such a modified cipher rather than to deal with a 29% (5.4/7.6) less amount of average cleartext letters per homophone. This mostly because I expect its complexity to be disproportionally higher than using an incomplete cipher text with an average of at least 6.0 cleartext letters per homophone.

Due to those considerations, it is obvious that the 340 is – already by its nature – harder to crack than the 408. So IMO there is at least no need to assume (!) that Z had chosen a different or a multistage encryption method – all he had to do to was simply to make the cipher harder by using a higher amount of homophones (which he actually had done). "By the way have you cracked the last cipher I sent you?"

QT

I guess it depends on how we define "real". There are several ways in which Z could have made a "real" cipher, i.e. one which contains a genuine communication. The least likely way, to me, is that he came up with a logical, coherent system which just happened to be so complex that it continues to baffle code buffs and FBI experts to this very day. I find that extremely unlikely – I don’t think Z was a genius, far from it.

A more plausible way is that he came up with an illogical, more or less random system which still baffles us – as such a system may easily do when it’s based on the whims of its creator more than anything else.

And then there’s this new theory, mentioned by Morf in the other thread – which I find quite interesting:

http://zodiackiller.fr.yuku.com/topic/7 … R-SOLUTION

It’s very striking, to say the least, that the passage in question contains 340 letters minus the punctuation – it’s hard to brush this off as coincidence, I think, not least given that Z himself points to this passage and stresses that it’s significant – more so than the rest of the letter.

However, my initial reaction to it is not that this discovery will lead to a proper key to unlocking the true meaning of the 340. I think it’s far more likely that the communication contained in the 340 is, simply, identical to the section in the BB letter – and that what Z did wasn’t to construct a new, brilliant cipher at all: he just wrote down 340 symbols, choosing them from an "alphabet" or a selection of symbols which he had gathered in preparation for making the 408 cipher.

If this is the case, the 340 is "real" in the sense that it does contain an intelligible communication – but it’s not "real" in the sense that it’s a new and more complex cipher.

I believe 100% its real. Why would the Zodiac Killer correct line 6 if it were fake, unless you buy the double bluff. Also the Zodiac Killer places two dashes on the extreme edges of the 10th line, and a cross or plus sign exactly in the center of this line, and a Zodiac crosshair dead center of the bottom line. You could almost draw a large crosshair within the 340.
The Zodiac Killer sent us his complex 340 Cipher, but ever the egotist, it was possible, one of the keys he used within the cipher, was his own moniker, Zodiac. And it was to be placed alongside the only apparent reference to his name, on the 20th line of the 340 Cipher. Shown here below.
If we then count alphabetically, the numerical difference between the columns, ZOD produces no difference at all, ie; 000.
The IAC element produces 888. The Zodiac Killer possibly took the 000 and 888 and incorporated these elements, in the form of three circled 8’s into his following 13 Symbol Cipher on April 20th 1970. Even the crossed circle and inverted Aries were carried forward.

The 340 Cipher may also have inspired the Exorcist letter.
In the image below I have moved the two symbols on the extreme left of the Exorcist Letter to the right side as shown without altering their position on the vertical axis, then I have turned the extreme right symbol 90 degrees clockwise to form the new arrangement, shown bottom right and compared it to the most interesting part of the 340 cipher ie: the area where Zodiac appears to have corrected himself.
Five of the six symbols now bear a noticeable similarity to this area of the 340 cipher.