I know that Harden’s solution was eventually published in the paper, but the tactics that the Harden’s used, specifically guessing that the killer would be with "I" and their assumption of double letters/symbols – were they ever described publicly at the time? Or did that only become known later on?
I’m curious to know if Zodiac read about how the Harden’s solved the 408 and specifically adjusted the 340 to account for it.
“Murder will out, this my conclusion.”
– Geoffrey Chaucer
Most of the articles at the time mentioned that they looked for patterns in the cipher, such as places where KILL would fit:
https://www.flickr.com/photos/seanutbutter/2462841231
Harden said he broke the code by looking for four-letter patterns which would fit in with the word "kill."
"We felt that ‘kill’ would be used more than once," he said.
In the message, the writer used "kill" once, but "killing" twice and "thrilling" and "killed" once each.
This one talks about Betty discovering patterns:
https://www.evernote.com/l/AAHEbmCED9BA … sH_Vw25EpY
I’m not sure where the "it starts with ‘I’" aspect originated. Maybe it’s a Graysmith-specific claim?
Come to think of it, I can’t find any references to Z408’s double letters except in Graysmith’s book.
Most of the articles at the time mentioned that they looked for patterns in the cipher, such as places where KILL would fit:
https://www.flickr.com/photos/seanutbutter/2462841231
Harden said he broke the code by looking for four-letter patterns which would fit in with the word "kill."
"We felt that ‘kill’ would be used more than once," he said.
In the message, the writer used "kill" once, but "killing" twice and "thrilling" and "killed" once each.
This one talks about Betty discovering patterns:
https://www.evernote.com/l/AAHEbmCED9BA … sH_Vw25EpY
I’m not sure where the "it starts with ‘I’" aspect originated. Maybe it’s a Graysmith-specific claim?
Come to think of it, I can’t find any references to Z408’s double letters except in Graysmith’s book.
So, it seems perfectly logical to assume that Zodiac read this in the paper and deliberately made sure not to repeat the same mistakes in the Z340. In retrospect, that kind of information probably should have been kept under wraps.
“Murder will out, this my conclusion.”
– Geoffrey Chaucer
The American Cryptogram Association also challenged Zodiac after the 408:
The killer wouldn’t dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar Allen Poe, that any cipher created by man can be solved by man. Zodiac has not told the truth in his cipher messages to the Examiner, the Chronicle and the Vallejo Times-Herald. Zodiac has not done this, because to tell the complete truth in relation to his name – in cipher code – would lead to his capture. I invite Zodiac to send The American Cryptogram Association a cipher code – however complicated – which will truly and honestly include his name.
That may have prompted Zodiac to make the "My name is…" cipher.
The link to Edgar Allen Poe is fascinating as per the following:
In 1841, Edgar Allan Poe wrote a series of articles in Graham’s Magazine, in which he solved simple ciphers sent by the reader. At the end of the series, Poe published two cryptograms sent by W. B. Tyler, who wanted to challenge Poe’s remark that human ingenuity could not contrive a cipher which human ingenuity cannot resolve.
The second W. B. Tyler cipher went unsolved for 160 years. This cipher appears to be a sequential homophonic (just like the 408 and as the 340 appears to be) with allot of errors (intentional or not) and AZdecrypt can barely solve it.
I couldn’t disagree more with Poe’s statement. Granted in his time there did not exist as sophisticated cipher methods as we have today. But it’s very easy to create a cipher that is impossible to decipher without access to the key. One time pad is the main example which comes to mind.
