In an era of strict cybersecurity and top-notch digital surveillance, it is usual to assume that every secret can eventually be cracked. However, some cryptic codes remain unsolved, posing challenges to codebreakers, cybersecurity experts, and amateur cryptologists for centuries.
According to experts, these mysterious symbols are nothing but time capsules of forgotten languages, secret missions, and probably lost civilizations.
Let’s uncover the top seven unsolved codes that remain mystery—with causes into why they remain out of bounds for even the sharpest minds on Earth.
Hordes of linguists tried to analyse it umpteenth attempts through artificial intelligence were made to crack the code, but all attempts remained unsuccessful. According to some, it’s an elaborate hoax while others believe it’s a medical alchemical treatise. Written in a lost language, the Voynich Manuscript continues to baffle codebreakers and conspiracy theorists to date.
1. The Voynich Manuscript, A Book of Unknown Language
This 15th-century codex, discovered in 1912, is written in a mysterious language with strange botanical illustrations, astrological symbols, and female figures. It is named after rare book dealer Wilfrid Voynich and remains one of the most mysterious ciphers in human history.
2. The Zodiac Killer’s Final Cipher (Z13)
The Zodiac Killer haunted California in the late 1960s. The person taunted police through letters. A portion was encoded. The Z340 cipher was cracked in 2020, but the shorter Z13 cipher remains unsolved still. It consists of just 13 characters but none could identify the killer’s name or intent from it.
Once cracked, it could solve the Zodiac case, succeeding in solving one of the most chilling cryptographic mysteries in criminal history.
3. Kryptos Sculpture at CIA Headquarters
The Kryptos sculpture, which is situated just outside the CIA’s Langley headquarters by artist Jim Sanborn, contains four encrypted messages. Three out of these four messages have been cracked. The fourth section, known as K4, remains unsolved for over three decades.
Top-notch cryptographers despite their best efforts couldn’t crack it. Though Sanborn has released subtle clues over the years, the CIA, NSA, and amateur codebreakers still couldn’t decipher it.
4. The Beale Cipher
Thomas Beale, who reportedly buried $65 million in gold and jewels in Virginia in 1820, left behind three ciphers: one detailing the treasure’s location. Only the second cipher was solved. The first and third—containing the location and names of heirs—are still unsolved.
Treasure hunters still scout for one of the USA’s greatest lost fortunes in the Appalachian foothills, trying to use the code.
5. The Tamam Shud Puzzle: A Dead Man, and a Cryptic Note
The year 1948 saw a well-dressed man found dead on Somerton Beach in Australia. A scrap of paper with the Persian phrase “Tamam Shud” (“ended” or “finished”) was found. A book with a strange code—believed to be connected to the man’s identity and possibly espionage—was recovered by police.
Somerton Man’s true identity and the code he left behind remain a world-class mystery though exhumations, DNA tests, and cryptographic analysis were done in the right earnest.
6. Linear A, the Uncrfacked Script
The Minoans of Crete used a script called Linear A before Greek civilisation. Though Linear B, which was deciphered as ancient Greek, Linear A has never been cracked.
According to historians, it could represent a lost Indo-European language. The enduring mystery fuelled debate among linguists and archaeologists. Decoding it may completely reshape the history of ancient Europe.
7. Rohonc Codex, Hungary’s Most Mysterious Book
The Rohonc Codex, a handwritten book of unknown origin, remains Hungary’s mysterious book. It features over 400 symbols and illustrations, many of which describe religious scenes, battles, and architecture.
Why These Codes Are Still Unsolved?
Despite the advent of AI, some codes remain uncracked because:
- Not much context (like the Rohonc Codex)
- Very short to describe (like Zodiac Z13)
- Made to confuse or created without real solutions
- Use of extinct or private languages
Even today, top codebreakers battle with patterns in a sign of how powerful true encryption still is.
In a world of surveillance, many codes still are uncracked. These cryptic ciphers are living puzzles.