The 51-year-old Zodiac Killer cipher has just been cracked by an Aussie mathematician

After 51 long years, the unsolvable 340-character zodiac cipher has just been solved by Australian mathematician Samuel Blake.

The ‘Zodiac’ killer, a San Francisco murderer responsible for 5 stabbings and shootings in the late ’60s, was never caught for his acts – but the recent codebreaking might finally bring him to justice.

It doesn’t surprise me that code-cracker Samuel Blake and two other cryptologists struck their breakthrough at the University of Melbourne. With the strict curfews and lockdowns in Melbourne due to COVID-19, Dr Blake took boredom to a whole other level, undertaking the trial and error of approximately 650,000 combinations whilst attempting to crack the code.

zodiac code solved
Image: Bettmann Archive, Getty Images

The killer sent the coded message to newspapers during his killing spree of 1968 and 1969. With 5 homicides under his belt, the murderer was never identified nor charged, and the code remained unsolved for half a century.

zodiac killer drawing
Image: News.com.au

Using Melbourne University’s supercomputer “Spartan”, Dr Blake, along with the help of cryptologist David Oranchak and software programmer Jarl van Eycke, solved the cipher after stumbling upon a combination which contained the word “Gas Chamber”, and subsequently detecting an error in the key.

“During the year we tested, by trial and error, around 650,000 different reading directions through the cipher. This search turned up — more or less — nothing,” Blake described on social media.

“However, one of these searches uncovered a surprising combination of words: GAS CHAMBER. That such a macabre phase should pop up in a sea of noise warranted further attention.

“From this fragment, David, Jarl van Eycke and I reworked the key and corrected an error Zodiac made in his diagonal enumeration of the second vertical segment of the cipher. 

“Jarl’s fantastic program, azdecrypt, was essential in this process.”

Associate David Oranchak even offered a video on YouTube to explain how the code was solved.

Ultimately, the code was decrypted to read:

“I hope you are having lots of fun in trying to catch 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 on in paradice death” 

For someone who created a code which remained uncrackable for 51 years, you’d think that, surely, he could’ve spelt “paradise” correctly.

Although the code has not yet revealed the identity of the killer, the FBI has confirmed that the investigation will continue, and with 2 more messages from the killer which have also remained unsolved until now, a name might not be far behind.