11 Famous Uncracked Code | Mysterious Ciphertexts

For thousands of years, cryptography has been used for secret communications. The ciphertext or codes are a confidential way of writing any sensitive information. During the World Wars, these types of code were widely used for transmitting crucial information over long distances.

But the development of cryptography has been paralleled by the advancement of cryptanalysis – the “breaking” of codes. It’s more like a ball game between these two: sometimes the code breakers get the upper hand, sometimes they didn’t.

We are listing some of those mysterious and famous Uncracked texts and code that are still under scrutiny.

11. The Somerton Man (Tamam Shud)

Taman ShudPhoto credit: Wikimedia

The case of Somerton Man was an unsolved mystery of an unidentified man found dead on Somerton beach in Glenelg, South Australia on 1st December 1948. From the dead body, police recovered a piece of paper with the words ‘Tamam shud’ a Persian phrase for “ended” printed on it. Later, it was recognized that the piece was torn from a copy of ‘Rubaiyat’ of Omar Khayyam.

Upon retrieval of the copy, intensive studies were done on a series of mysterious letters founded on the final pages of the book, but nothing seemed to help. In fact, the International authorities like F.B.I and Scotland Yard were unable to figure out anything meaningful. So far, this case has been considered “one of Australia’s most profound mysteries”.

10. Zodiac Killer’s Code

Zodiac Killer's CodesPhoto credit: Wikimedia

The ‘Zodiac’ was a mysterious serial killer who terrorized Northern California between the late 1960s and 1970s. There are nearly 37 killings on his name mostly in San Francisco Bay, the cities of Benicia and Vallejo.

He shot two high school students on December 20, 1968. A year later, the local newspapers received an anonymous letter from the killer in which he took full credit for the murders. The letter contained a 408-symbol cryptogram in which the killer hid his identity.

The publishers received another letter after a few months, but this time he addressed himself as the Zodiac. He then sent two more cryptograms, one of which was never decoded. It was never traced and there is no personal information about him, except the name Zodiac. The Zodiac murder case is still open in the California High Court (since 1969).

9. D’agapeyeff Cipher

D'agapeyeff Cipher

Alexander D’Agapeyeff was a Russian born English cryptographer who is famous for his still unsolved D’agapeyeff cipher. In 1939, he published the first edition of his book: Codes and Ciphers, an elementary book on cryptography.

At the end of the book, he mentioned a “challenge cipher” for readers. The code is still not decoded but upon asking D’Agapeyeff for a possible method for solving the riddle, he answered he has forgotten how to solve it.

Cryptographers and scientists believe that the code can never be solved as it contains numerous mistakes. Alexander was regarded by many as the most talented cryptographer majorly because his cipher remained unsolved for more than 70 years.

8. Shugborough Inscription

Shugborough_inscriptionPhoto credit: Wikimedia

The Shugborough inscription is regarded as one of the world’s top uncracked ciphertexts. It is a series of letters – O U O S V A V V between the letters D and M, engraved on an 18th-century monument in the ground of Shugborough Hall in Staffordshire, England.

What did fascinate historians and cryptographers is that the inscription is engraved just below the mirror image of Nicolas Poussin’s famous painting: The Shepherds Arcadia.

In 1982, the authors of the ‘The Holy Blood and the Holy Grail’ suggested that Poussin was a member of the Priory of Sion, and his panting and engravings contain hidden message(s) of great significance. There are many other theories related to his cipher but without any proof.

7. Chaocipher

ChaocipherPhoto credit: Viral nova

Cryptographer John F. Byrne came up with the Chaocipher in 1918. According to him, Chaocipher was simple yet unbreakable. Bryne was so confident that he offered cash rewards to anyone who could solve it.

The Chaocipher was created using two simple rotating disks and was small enough to fit into a cigar packet. In May 2010 the Byrne family donated the Chaocipher-related papers to the National Cryptologic Museum in Ft. Meade, Maryland, USA.

6. The Voynich Manuscript

The Voynich ManuscriptPhoto credit: Wikimedia

The Voynich manuscript is a handwritten book in an unknown script. It is named after Wilfrid Voynich, a Polish book dealer who bought it in 1912. The manuscript has been carbon-dated to the early 15th century around 1404-1438 and may have been originated from Northern Italy.

The book has around 240 pages filled with illustrations and diagrams. Over the decades, many top code-breakers and cryptographers have tried to solve it but they never got succeeded, though they have made some remarkable discoveries.

More to read: Biggest Unsolved Mysteries in Physics

5. Dorabella Cipher

Dorabella CipherPhoto credit: Wikimedia

The Dorabella Cipher is an enciphered letter written by a British music composer, Edward Elgar to his friend Dora Penny. The cipher consists of 87 characters spread over three lines and they look like numeric semicircles written in one of the 8 directions.

Written in 1987, the letter has never been solved. In 2007, the Elgar Society organized a Dorabella competition and offered a big prize to the person who solves it. Many entries were received and some were very impressive but none was found satisfactory.

4. Linear A

Linear APhoto credit: Wikimedia

Linear A and Linear B are names given to the two scripts used in Ancient Greek civilization. Sir Arthur Evans was among the first archaeologists to discover both sets of writings in various excavations.

In the 1950s, Linear B was widely deciphered mostly by Michael Ventris, an English linguist, and architect. Building upon Linear B, language scientists and cryptographers are still trying to understand its much more complex predecessor Linear A.

Linear A has hundreds of signs. They are understood to represent syllabic, ideographic, and semantic values in a similar manner to Linear B. While a considerable amount of those syllabic signs are similar to ones in Linear B, approximately 80% of Linear A characters are unique.

3. The Beale Cipher

Beale CipherPhoto credit: Wikimedia

The Beale cipher originates from an 1885 pamphlet announcing a secret treasure buried by a person named Thomas J. Bealle in a location near Bedford County, Virginia. The cipher is divided into three parts, one of which allegedly contains the location of a buried treasure of gold, silver, and jewels worth over $64 million. Out of these three, only one has been successfully solved while the other two remain a mystery.

Some experts consider Beale ciphers as an elaborate hoax. Some articles written in the 1980s reveal that there is a strong possibility that these ciphers may not have been written in the 19th century. Also, historical records of the city of Virginia cast serious doubts upon the existence of Thomas J. Beale.

2. The Phaistos Disc

The Phaistos CipherPhoto credit: Wikimedia

The Phaistos Disc is just another jewel of ancient Greek civilization. In 1908, an Italian archaeologist Luigi Pernier discovered a disc of about 15 cm in diameter, consisting of stamped symbols from Phaistos on the island of Crete, Italy.

The Phaistos disc consists of 45 distinct signs, which were more likely to be made by pressing “seals” into a disc of soft clay in a clockwise sequence spiraling towards the center of the disk. After years of studies, archaeologists, historians, and cryptologists have come to the conclusion that the writings cannot be deciphered until more references are found in this context.

1. Kryptos

Kryptos - Famous Uncracked CodesPhoto credit: Wikimedia

Recommended: 10 Unsolved Scientific Mysteries | Unlocked Answers

Kryptos is an encrypted sculpture located just outside the headquarters of the Central Intelligence Agency (CIA) at Langley, Virginia. Since its inauguration on November 3rd, 1990, there have been many speculations about the message it carries.

The name kryptos comes from the ancient Greek word for “hidden”. The sculpture consists of 869 characters, of which 865 are letters and 4 are question marks. It is divided into four parts, one of which is still un-deciphered and it’s also famous as one of the popular unsolved codes in the world.

Written by
Varun Kumar

Varun Kumar is an experienced science and technology journalist interested in machines, AI, and space exploration. He received a Master's degree in computer science from Indraprastha University. To find out what his latest project is, feel free to directly email him at [email protected] 

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