Argentina, France — Fayçal Ziraoui loves a good challenge. As a teenager, he designed 3-D animations. In 2018, he completed the Ironman Race. Recently, he developed virtual reality software that allows people to experience life in a space capsule.
“I’ve never set limits on what I’ve learned,” Mr Giroui, 38, a French-Moroccan business consultant, said in an interview at his home in the Argentine suburb of Paris.
And so, when Mr. Ziroui stumbled across a article in a french magazine Saying in December that no one had ever solved the two ciphers responsible for the Zodiac killer who terrorized the San Francisco Bay Area in the 1960s and ’70s, he wondered, “Why can’t I?”
Ciphers had long confused cryptographers, law enforcement agents, and amateur investigators with a penchant for ciphers with unknown serial killers. Half a century of unsuccessful research had led many to believe that the identity of the Zodiac killer would forever remain a mystery. Many detectives have claimed to have uncovered the mystery through various techniques for decades, but have refuted their theories.
But two weeks after launching his search, Mr. Giraui said, he had cracked the two remaining ciphers – including revealing the identity of a killer – using an encryption key that only came to light in December, and creative code-cracking techniques.
In excitement, he began posting messages and Video online on some of the dozens of forums called “things like”Zodiac Killer – Unsolved and Forgotten“Where thousands of amateur keyboard sleuths track and debate the details of one of the most infamous serial murder mysteries in American history – involving two ciphers known as Z32 and Z13.
It didn’t take him long to cause a stir in the large, and now angry, online community devoted to the matter.
One of his posts was removed by a moderator on one site, on others his theories were condemned by people questioning his credibility and conclusions.
“I don’t believe it for a second,” commented someone Zodiac killersite.com, a popular platform. “When he says it took two weeks to crack the Z32 and an hour for the Z13, I think that explains it very well.”
In the end, Mr. Giraui realized that he was brazenly a little tactless in a tight-knit community presented as a surefire solution.
“He came in and told them ‘the end of the game,'” said his brother and Yusuf Jirouei, a journalist in Morocco. “But these guys don’t want the game to end.”
And it’s unclear whether the case – which has consumed police detectives for decades, generated dozens of stranger-than-fiction claims and inspired a blockbuster movie – will ever be resolved. The FBI and the San Francisco Police Department, to which Mr. Giroui sent his findings, declined to comment, citing the ongoing investigation.
Born and raised in Morocco, Mr. Giroui studied in France, where he graduated from the cole Polytechnique and HEC Paris, the country’s top engineering and business schools, and where he now works as an independent business consultant.
Mr Jiroui initially thought that solving codes would be a fun activity during the coronavirus lockdown. At the time, he knew nothing about the Zodiac killer, who was suspected of five murders in the late 1960s, but who himself claimed 37 murders.
The killer’s identity was a series of four ciphers using letters from the alphabet and symbols, which he sent with warnings to media outlets from July 1969 to April 1970, and technically, promised his identity.
The first 408-character cipher, in which the killer said he liked to kill people, was broken soon after being sent.
Many Zodiac enthusiasts consider the remaining ciphers – Z32 and Z13 – to be insoluble because they are too small to determine the encryption key. An untold number of solutions could work, he says, making verification nearly impossible.
But Mr. Jirouei said he thought suddenly. The code-crackers who solved the 340-character cipher in December were able to do so by identifying the encryption key, which they put into the public domain when they announced their success. What if the killer uses the same encryption key for the two remaining ciphers?
So he said he applied it to a 32-character cipher that the killer had included in a letter as the key to the location of a bomb that went off at a school in the fall of 1970. (That never happened, even though the police failed to crack the code.)
This produced a sequence of random letters from the alphabet. Mr. Giraui said that he then a . worked through half a dozen steps Including letter-by-number substitution, identifying coordinates in numbers and using a code-breaking program he created to crunch jumbles of letters into coherent words.
The work consumed his thoughts, waking him at night and leaving him in a state of constant anxiety as he learned the gruesome details about the murders.
“I was obsessed with it, 24 hours a day, that was all I could think of,” said Mr. Giraui.
After two weeks of intense code-cracking, he deciphered the sentence, “Find Labor Day 45.069 Norte 58.719 West.”
The sequence zeroed in on a location near a school in South Lake Tahoe, a California town that was referenced in another postcard believed to have been sent by the Zodiac killer in 1971.
An excited Mr. Giraui said he immediately turned to Z13, which allegedly revealed the killer’s name using the same encryption key and different cipher-cracking techniques.
After about an hour, Mr. Giraui said that he came up with “KAIR”, which he felt resembled the last name of Lawrence Kaye, a salesman and career criminal living in South Lake Tahoe, who There were suspects in this case. Mr Kaye, who also used the pseudonym Kane, died in 2010.
The typos were similar to those found in previous ciphers, he observed, possible errors made by the killer when encoding the message. The results that were so close to Mr. Kaye’s name and South Lake Tahoe’s location were too much to be a coincidence, he thought.
Mr. Kaye A. were the subject of report good by Harvey Hines, a now-defunct police detective who was convinced he was the Zodiac killer but was unable to convince his superiors.
On January 3 at around 2 pm, a tired but excited Mr. Ziroui posted a message Titled “Z13 – My Name Is KEY” on the 50,000-member Reddit forum dedicated to the Zodiac killer.
The message was deleted within 30 minutes.
The forum’s moderator wrote, “Sorry, I’ve removed this as part of the general policy against Z13 solution posts, arguing that the cipher was too small to be solvable. Refused to interview.
Similar dismissive comments were made on other forums. Many comments went down the mysterious, and sometimes nonsensical, rabbit hole; Others said Mr. Jiroui’s methods Was very confused.
David Oranchak, the leader of the team that cracked the 340-character cipher, said in a written exchange that he was skeptical of Mr. Giroui’s solution, noting that “hundreds of proposals for Z13 and Z32 solutions” already exist. , and that “it is practically impossible because of the brevity of the ciphers to determine whether any of them are correct. Others also approached Mr. Kaye as a possible suspect through circumstantial evidence.”
but David Nakache, a cryptographer and professor at the cole Normale Supérieure in Paris, and Emmanuel Thome, a cryptography expert at France’s National Institute for Research in Digital Science and Technology, said Mr Giroui’s code-cracking methods were correct and that police investigators should consider it.
Another cryptographer, remy geraudo, also disagreed with the cole Normale Superior, saying that Mr. Ziroui had made arbitrary choices in his work.
Looking back, Mr. Jiroui said he realized he had “came like a bull in a china shop” by openly challenging decades-old theories about the case on online forums.
Mr Oranchak said the Zodiac community “groups around favorite suspects,” influencing the way they evaluate code-breaking claims.
“They are generally friendly to people who are cordial when presenting their ideas, but once they start acting they are 100 percent sure they have broken the code or matter, The community becomes rather hostile.”
Five months after he first posted his solution online, Mr. Giraui has now disappeared from the Zodiac forums. He has stopped responding to comments saying he doesn’t have the “skills to play” in the charged environment of online forums.
“My brother used to tell me: ‘Brother, what you did here is the very easy part,’ Mr. Ziroui said with a smile. “‘Actually, convincing people is the hardest thing to do.'”