Named for one of just two non-coded inscriptions in the document, this mysterious manuscript is 105 pages long and is bound in gold and green brocade paper. The manuscript consists of roughly 75,000 characters. These characters are handwritten very neatly but consist of a perplexing mix of upper- and lower-case Roman letters, along with a large assortment of more abstract symbols (see sample pages above). In total, the Cipher contains 90 distinct characters, including 26 unaccented Roman letters. Adding to the confusion is the lack of spacing between words.

This opens up a window for people who study the history of ideas and the history of secret societies", says Dr Knight. He cites several modern examples of challenging ciphers, such as the communications from the still-unidentified Zodiac Killer to the California police in the 1960s and 1970s, and the Kryptos sculpture, located on grounds of the C.I.A. headquarters in the United States, which has been only partly decoded.

Dr Knight also points out that there are other such ancient enciphered texts, particularly the famous Voynich Manuscript, a 240-page volume that has confounded cryptographers for centuries. This document was recently dated back to the early 1400s.