Cryptogram of Olivier Levasseur

The cryptogram of Olivier Levasseur (also known as La Buse cryptogram) is a 17-line pigpen cipher allegedly created by 18th-century French pirate Olivier Levasseur, and first attested by French historian and librarian Charles de La Roncière in his 1934 paperback novel Le Flibustier Mystérieux: Histoire d'un trésor caché.

La Roncière claimed the cryptogram and the treasure to which it purportedly refers originated from a raid on the Portuguese cargo ship Nossa Senhora do Cabo in 1721 by a group of pirates including Levasseur, Jasper Seagar and Captain John Taylor. On board the Nossa Senhora was a large amount of valuable cargo, along with the Viceroy of Goa, who was later released for ransom. With a share of the loot and currency, Levasseur went into hiding for nine years until he was captured in July 1730, when he was executed. A popular legend claims that immediately before his execution, Levasseur threw a piece of paper into the watching crowd and shouted French: "Mes trésors à qui saura comprendre", lit. 'My treasures to those who will know how to understand'. The written cryptogram supposedly ended up in the possession of La Roncière, who then decrypted it in his 1934 novel. Though the 1721 raid of Nossa Senhora by Levasseur and his associates is well attested by historians, no concrete evidence for the treasure's existence has ever been uncovered, despite many searches and investigations, which suggests the cryptogram may have been an invention of La Roncière for his novel.