Copiale Cipher Decoded After 260 Years Reveals Secret Oculist Society

The Copiale cipher, a 105-page manuscript dating from 1760 to 1780, remained undecipherable for over 260 years until a team led by University of Southern California computer scientist Kevin Knight and Uppsala University linguists Beata Megyesi and Christiane Schaefer cracked it in the early 2010s. The manuscript uses 88 unique symbols, including one shaped like an eye, and was first converted into machine-readable code. Researchers discovered it was a homophonic cipher substituting multiple symbols for single German letters, revealing the text was written by a secret society of ophthalmologists called the Oculists. The society met in the 1740s and may have been Freemasons, whose rites were banned by Pope Clement XII. The manuscript describes an initiation ritual where the inductee must read a blank paper, try with eyeglasses, wash his eyes, and undergo a symbolic eyebrow plucking. The Oculists appear to have been dedicated to knowledge rather than sinister aims. The cipher was found in Germany and is available as a two-part PDF.