Aussie cracks Zodiac serial killer code
An Australian mathematician working with a team of three has helped crack the coded message sent more than 50 years ago by the infamous San Francisco Zodiac Killer.
The serial killer has never been caught over five murders in the Northern California area in the late 1960s and early 1970s but became known by his pseudonym in taunting letters sent to the San Francisco Chronicle newspaper.
Some of the notes came in the form of a code, including the complex 340 cipher that has remained unsolved until now.
Melbourne mathematician Samuel Blake worked in a team with codebreakers David Oranchak and Jarl Van Eycke to crack the enigmatic code.
"We tried several hundreds of thousands of indirect ways of solving the cipher and just by chance we happened to stumble upon a fragment of how it could be solved," Dr Blake told ABC News on Saturday.
"Using that fragment we reverse engineered the entire solution and got the entire message out from the Zodiac."
The decrypted message reads as follows:
I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME THAT WASNT ME ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT ME I AM NOT AFRAID OF THE GAS CHAMBER BECAUSE IT WILL SEND ME TO PARADICE ALL THE SOONER BECAUSE I NOW HAVE ENOUGH SLAVES TO WORK FOR ME WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE DEATH
Dr Blake, a visiting fellow at the University of Melbourne, said the message does not reveal the killer's identity but could help authorities track down who he is.
The university's supercomputer, Spartan, helped solve the message after processing more than 600,000 possible solutions.
Dr Blake revealed the cipher had multiple symbols and was written in a different way to normal codes, which made it more difficult to crack.
"The reading direction we are normally used to is left to right and top to bottom on a page," he said.
"Whereas what the Zodiac did in this cipher was write it diagonally.
"He went one row down, two columns across, wandering down, two columns across.
"To write it out and try to stumble across that correct enumeration was one of the main difficulties here."
No-one has been charged over the Zodiac case but speculation has been rife for years as to the killer's true identity.
In a statement, the San Francisco division of the FBI said the Zodiac Killer case remains an ongoing investigation and declined to comment further out of respect for the victims and their families.
"The Zodiac Killer terrorised multiple communities across Northern California and even though decades have gone by, we continue to seek justice for the victims of these brutal crimes," a spokesman said.
Originally published as Aussie cracks Zodiac serial killer code