Six secret codes that remain unsolved: from buried treasure to 15th-century manuscripts

From the location of buried gold and a Second World War code to a sculpture that has stumped the CIA, these famous ciphers and puzzles remain unsolved

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Who doesn’t love a mystery? From the Loch Ness monster to the identity of Jack the Ripper, some enigmas have stood the test of time.

It’s the same in the secretive world of cryptology, where famously unsolved codes, ciphers and puzzles have kept cryptologists and amateur sleuths entertained — and frustrated — for centuries, as they seek to crack the code and discover what the creator was secretly trying to convey.

Here are six famous codes and ciphers from across the world that have never been solved.

The Voynich Manuscript

Having been carbon-dated to the 15th century, between 1404 and 1438, the Voynich Manuscript has been hotly debated by scholars, and has remained impervious to code-breakers for centuries.

The 240-page book was rediscovered by rare book dealer Wilfrid Voynich in 1912, although mentions of it date back to the 1600s.

The illustrated, handwritten codex is believed to be Italian in origin, owing to analysis on the paints, and uses a hitherto unknown writing system. It’s author, language and purpose remains a mystery. Illustrations inside include fictitious plants and fauna, dragons, castles and astrological symbols.

It's currently being held at Yale University's Beinecke Rare Book and Manuscript Library, and cryptographers, including American and British codebreakers from both the First World War and the Second World War, have tried and failed over the years to make sense of it.

Jan Marek Marci, a rector of Charles University in Prague, who came into possession of the codex wrote of it in 1665: “…for such Sphinxes as these obey no one but their master.”


One of the most famous unsolved codes in the world stands outside the CIA building in Langley, Virginia.

The four-part sculpture, Kryptos — from the ancient Greek word meaning “hidden” — was created by American artist Jim Sanborn and dedicated on November 3, 1990.

Since then, cryptanalysts from all over the world have attempted to crack the four codes chiselled into its surfaces, succeeding in breaking three of the four.

The sculptures are covered in ciphertext — including deliberate spelling mistakes and missing and additional letters — some featuring aspects of Morse code.

The first three were solved by members of the public, the National Security Agency and the CIA, but the fourth has never been cracked.

“A lot of the work [I do] deals with secrecy and the modus operandi of spies — how they operate, how they turn sources and things like that,” Sanborn told Wired.

The Dorabella Cipher

A code which remains unsolved to the present day was created by the acclaimed English composer Edward Elgar.

The creator of Pomp and Circumstance wrote an enciphered letter in 1897 to Dora Penny, the daughter of a reverend whose stepmother was friends with Elgar’s wife.

Consisting of 87 characters over three lines, the cipher appears to be made up of 24 different symbols made up of semicircles and dots.

The Dorabella Cipher got its name from an 1899 composition Elgar named for Penny, which he named Dorabella as the pair remained life-long friends.

Over the past century, a handful of people, including musicologist Eric Sams, and cryptologist Richard Henderson have claimed to have solved the puzzle. However, as both men achieved different outcomes, which ignored one or more of the characters, it is still considered unsolved.

The Tamam Shud Case

It’s a case that has baffled Australia, and the world since it first came to light in 1948.

On December 1, 1948, Australian police found the body of a man on Somerton Park beach, southwest of Adelaide, South Australia. His identity has never been discovered, and an ancient text he was carrying led to a cipher that has never been solved.

A scrap of paper found in the fob pocket of the man’s trousers read “Tamam Shud”, which translates from Farsi as “is over” or “is finished". Police eventually located the book from which the scrap had been torn, which turned out to be a copy of The Rubaiyat of Omar Khayyam by the 11th-century Persian poet and astronomer.

In the back of the book, they discovered faint indentations representing five lines of text, in capital letters, with the second line struck through. The top line reads: “WRGOABABD.”

The fact that the man has never been identified has lead to speculation he was a spy, and the encryption has never been solved.

The Beale Ciphers

For fans of tales of buried treasure, the unsolved Beale Ciphers has it all — buried gold, treasure maps and secret locations, only one of which has been solved.

The papers are a set of three ciphertexts, each detailing the treasure, location and list of owners and kin, dating back to 1885.

The story originated in an 1885 pamphlet called The Beale Papers, which contained details of a hoard of treasure found in a mine in New Mexico by a man named Thomas J Beale, who then buried it in a secret location in Bedford County, Virginia, around 1820.

Beale created three sets of papers filled with ciphertext, the second of which concerning the contents of the treasure — gold, silver and jewels — has been solved. Part of it reads: “The vault is roughly lined with stone, and the vessels rest on solid stone, and are covered with others.”

While some cryptologists have dismissed the Beale Ciphers as an elaborate Freemason hoax, it remains that the first and third ciphers have never been solved. The description of the treasure itself is estimated to be worth more than $43 million.

The final flight of carrier pigeon NURP 40 TW 194

Even the best brains at Britain’s Second World War former code-breaking headquarters of Bletchley Park have been stumped by a message attached to a military carrier pigeon’s leg, found in a suburban fireplace in England in 1982.

During renovations at their home in Bletchingley, Surrey, David and Anne Martin found the skeletal remains of a bird with a red plastic capsule attached to its leg which identified it as a Second World War military carrier pigeon. Inside the capsule was a coded message consisting of 27 groups of five letters with some numerals at the end, beginning: “AOAKN HVPKD FNFJU.”

In 2010, experts at Bletchley Park, while unable to crack the code, reasoned that because none of their classified MI6 pigeons carried coded messages during the war, that it contained information that would have been vital at the time possibly pertaining to the D-Day landings on June 6, 1944.

They also ascertained that it likely came from British military leader, Field Marshal Montgomery's headquarters. It remains unsolved.

Updated: June 05, 2022, 4:41 AM