The Zodiac Killer Cipher: An Unsolved Mystery

The Zodiac Killer remains one of the most infamous unidentified serial killers in American history. Alongside his extensive murder spree throughout Northern California in the late 1960s and early 1970s, the Zodiac Killer taunted the authorities and the public by sending encrypted messages, known as ciphers, to local newspapers.

The unsolved Zodiac Killer ciphers have intrigued amateur and professional codebreakers for decades. In this blog post, we will delve into the background of the Zodiac Killer, examine the different types of ciphers sent by the killer, and explore the attempts made to decode them.

The Murders and the Zodiac Killer

Between December 1968 and October 1969, at least five known murders in the San Francisco Bay Area were attributed to the Zodiac Killer. The killer targeted couples, whom he attacked while they were parked in isolated locations. Often sporting a distinctive hooded costume, the Zodiac Killer committed the crimes with a handgun or a knife.

Throughout his crime spree, the Zodiac Killer sent a series of taunting letters and ciphers to local newspapers. These letters were filled with cryptic codes, symbols, and threats. Letters sent by the Zodiac Killer contained claims of responsibility for additional murders. The killer signed his letters with a distinctive symbol consisting of a circle with a cross through it.

The Zodiac Killer Ciphers

The Zodiac Killer made multiple attempts to encode his messages, adding an extra layer of mystery and challenging professional codebreakers. Four main ciphers have been associated with the Zodiac Killer:

The first cipher, known as the “Zodiac Killer Cipher 1” or the “408 Cipher,” consists of 408 characters arranged in a 17×17 grid. This cipher was sent to the Vallejo Times Herald on July 31, 1969. Despite the efforts of numerous codebreakers, the 408 Cipher remained unsolved for over 50 years.

The second and third ciphers, referred to as “Zodiac Killer Cipher 2” and “Zodiac Killer Cipher 3,” were both sent to the San Francisco Examiner in August 1969. These ciphers are commonly known as the “340 Cipher” and the “32 Cipher.” The 340 Cipher contained a total of 340 characters, while the 32 Cipher consisted of only 32 characters.

The fourth and final cipher, named “Zodiac Killer Cipher 4” or the “LBE Cipher,” was mailed to the San Francisco Chronicle on November 8, 1969. Unlike the other ciphers, Zodiac Killer Cipher 4 included a diagram of a bomb and claimed that if the cipher was not published on the front page of the newspaper, the Zodiac Killer would “crash a plane into the city.” The solution to this cipher remains unknown.

The Attempts to Decipher the Ciphers

Over the years, numerous individuals and organizations, including professional codebreakers and dedicated hobbyists, have attempted to decipher the Zodiac Killer ciphers. Although the 32 Cipher was solved shortly after its publication, the 408 Cipher and the 340 Cipher remain unsolved to this day.

In December 2020, an international team of codebreakers, led by software developer David Oranchak, managed to crack the 340 Cipher using advanced computer algorithms. The decrypted message, written by the Zodiac Killer himself, revealed his motivations: “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 [sic] ALL THE SOONER… YOU WILL NOW HAVE CRACKED THE CIPHER WHICH WASN’T TOO HARD TO DO.” Despite this breakthrough, the killer’s identity and the solution to the 408 Cipher remain elusive.

The Legacy of the Zodiac Killer Cipher

The Zodiac Killer’s use of ciphers has captured the public’s imagination. The intriguing nature of the unsolved ciphers has been the subject of numerous books, documentaries, and films.

As of today, the true identity of the Zodiac Killer remains unknown, and the unsolved ciphers continue to spark curiosity and speculation. The encoded messages are a testament to the killer’s desire for attention and his skills in cryptography. With the advancements in technology and the dedication of amateur codebreakers, there is still hope that one day the Zodiac Killer’s remaining ciphers may be deciphered, shedding light on one of America’s most perplexing mysteries.