Zodiac 340 cipher has been cracked

[DevilsAdvocate]

The Zodiac 340 cipher has been cracked by a private team who has been working on it for years using software algorithms. Not unexpectedly it doesn't say anything substantially different from the previous ciphers.

I haven't seen a report yet on how the cipher works, but a team member did mention that it involves something more than matching symbols to letters, which is what was expected.

It has long been questioned whether the cipher may be unreversible or simply random symbols, making it uncrackable. This could be an interesting breakthrough for cryptography.

 

[DevilsAdvocate]

A video is now available on how they cracked the code. Interesting stuff. They got a bit lucky in recognizing that one of the partial decryptions had enough interesting words to warrant further investigation.

It is a type of substitution cipher, like the previous ciphers. The first letter in each word forms a key that is mostly, but not exactly, alphabetic. The symbols are then arranged using a type of diagonal pattern. But in one of the lines the symbol from the end of the line is moved to the start of the line. Also, the first line ends with plain text that must be ignored in the pattern and then the plain text moved to the end of the text.

The decrypted text has some incorrect letters, either intentionally or due to encryption errors. I think they make one mistake in their letter correction. I think "I KNOW THAT MY NEW LIFE IS" is meant to be "I KNOW WHAT MY NEW LIFE IS".

 

[Blue Mountain]

An explanation of what the Zodiac 340 cipher is would have made your initial post more understandable.

FBI confirms Zodiac Killer's 340 cipher solved by trio of amateur math and software codebreakers [The Register]

A team of code breakers has solved a cipher attributed to the Zodiac Killer, a serial murderer known for a Northern California killing spree in the late 1960s who has still not been identified or apprehended.

David Oranchak, a US-based software developer, Sam Blake, a mathematician based in Australia, and Jarl Van Eycke, a programmer based in Belgium, managed to crack Z340, a 340-character cipher that's one of four such codes attributed to the Zodiac Killer.

Z340 was sent to The San Francisco Chronicle on November 8, 1969, and was provided to the FBI shortly thereafter. It remained unsolved for 51 years until Saturday, December 5th, 2020, when Oranchak, Blake, and Van Eycke submitted their solution to the US Federal Bureau of Investigation and had their solution validated.

 

[DevilsAdvocate]

An explanation of what the Zodiac 340 cipher is would have made your initial post more understandable.

FBI confirms Zodiac Killer's 340 cipher solved by trio of amateur math and software codebreakers [The Register]

Mea culpa. I should have provided some background.

The Zodiac killer was a serial killer in Northern California in the late 1960s and early 1970s who sent letters taunting the police and included four separate ciphers. The killer included unpublicized information and artifacts to confirm he was the killer. The killer has never been identified.

The first cipher (called Z 408 because it has 408 characters) was in three parts and was cracked without much difficulty by a school teacher in 1969. The killer claimed that if it was deciphered he would be caught, but when deciphered said, in part, that he would not give his name.

The third cipher (Z 13) cipher is 13 characters following "My name is ---". One theory is that it decrypts to "Alfred E. Neuman", the goofy mascot of the humorous Mad Magazine.

The fourth cipher (Z 32) came with a map with a compass drawn and some numbers indicating that the puzzle led to a bomb that would go off if not discovered. No bomb went off. A likely solution to puzzle was that it merely pointed to the location of two known previous murders.

This second cipher (Z 340) remained unsolved for over 50 years, until now. The killer had previously demanded one of two prominent lawyers appear on a talk show so that he could talk to them. One did appear and a person claiming to be the Zodiac killer called in but gave no information to confirm that he was the killer. The decrypted message says little different than what the killer had already said, but does say that he was not the person who had called into the TV show.

This is one of the most famous and longstanding modern ciphers to be decrypted.

 

[DevilsAdvocate]

I think that the error in "I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE" is including the plain text "LIFE IS" from the first encrypted line to the last decrypted line. I think the "LIFE IS" should be ignored in the plain text, just as it is in the decryption pattern. Giving "I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE WILL BE AN EASY ONE IN PARADICE".

 

[BillC]

I thought it might be "I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE WILL BE AN EASY ONE IN PARADICE. DEATH IS LIFE"

 

[DevilsAdvocate]

I thought it might be "I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE WILL BE AN EASY ONE IN PARADICE. DEATH IS LIFE"

I have looked into it some more and agree with others who have suggested that the best interpretation is that is it meant to be "LIFE IS DEATH". The plain text of the first line combined with the otherwise excessive word at the end of the decrypted text.

 

[caveman1917]

I have looked into it some more and agree with others who have suggested that the best interpretation is that is it meant to be "LIFE IS DEATH". The plain text of the first line combined with the otherwise excessive word at the end of the decrypted text.

This "LIFE IS DEATH" made me think the killer might have been from the neo-nazi milieu as that is a slogan which was adopted by the SS and is still popular in those circles. When I took a look at the video the original paper appears to have included a Celtic Cross at the bottom as well. Most likely all just a coincidence though.