The Copiale cipher is an encrypted manuscript consisting of 75,000 handwritten characters filling 105 pages in a bound volume. It is thought to date to between 1760 and 1780,
In April 2011, it was decoded with the help of modern computer techniques by Kevin Knight of the University of Southern California, along with Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden.
The plaintext letters of the message were found to be encoded by accented Roman letters, Greek letters and symbols, with unaccented Roman letters serving only to represent spaces. The researchers found that the initial portion of 16 pages describes an initiation ceremony for an unidentified secret society related to Freemasonry. The document describes an initiation ritual in which the candidate is asked to read a blank piece of paper, and on confessing inability to do so, is given eyeglasses and asked to try again, and then again after washing the eyes with a cloth, followed by an "operation" in which a single eyebrow hair is plucked...