Undeciphered historical codes and ciphers

illustrated codex hand-written in an unknown writing system

serial killer in California

word square containing a five-word Latin palindrome

Kryptos is a sculpture by the American artist Jim Sanborn located on the grounds of the Central Intelligence Agency (CIA) headquarters, the George Bush Center for Intelligence in Langley, Virginia.

1948 unsolved death of an unidentified man in Somerton, South Australia

French pirate

a set of three ciphertexts

Enciphered letter written by English composer Edward Elgar

American outsider artist (1909–1964)

church buiilding in Naples, Italy

a death in Germany in 1984, which was considered a supposedly unsolved criminal case until 2025

Sequence of letters – O U O S V A V V, between the letters D M – carved on the 18th-century Shepherd's Monument in the grounds of Shugborough Hall in Staffordshire, England

unbroken cipher

Unsolved encrypted message associated with unsolved homicide

Wikimedia list article

U.S. American murder