Unsolved Crypto Mysteries

The Moustier altar inscriptions are two encrypted texts displayed on side altars in a church in Belgium.

A cigarette case from 1909 bears a mysterious engraved inscription.

Ignatius Pollaky, a 19th century private detective, published several encrypted newspaper ads. They have never been solved.

A postcard, sent by football official George Furlong from Luton, England, to his sister Lizzie in 1873, has never been solved.

Five encrypted messages from Nazi spy Walter Köhler are still unsolved.

These two encrypted newspaper ads from 1875 are still unsolved. The second message contains a potential clue.

A copper-and-stone sculpture at the headquarters of the CIA featuring four encrypted messages, one of which remains unsolved.

A code appears to be hidden in the end credits of the 2010 movie Fair Game.