An international team of computer scientists has cracked a manuscript detailing rituals of an 18th-century German secret society.
The text, known as the Copiale Cipher, is a 105-page book that was written in a combination of elaborate symbols and Roman letters. Previous attempts to decode it had failed, and it was clear that the cipher being used was more sophisticated than most. It is located in the former East Germany and was signed by a “Philipp” in 1866.
Kevin Knight, a computer scientist at the Information Sciences Institute at the University of Southern California, collaborated with two colleagues, Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden. They found that the text was in a sophisticated substitution cipher, which means that the letters one would expect were replaced with symbols.
Such ciphers are common in children’s games –- you might remember the “pigpen cipher” or shifting letters (making an “A” into a “C,” a “B” into a “D” and so on) from grade school. The Copiale manuscript was a step above that. Knight and his team originally thought –- as had many others –- that the visible Roman letters in the text were the coded message. But when they tried replacing those letters with others, all they got was nonsense.
That meant the symbols, or at least some of them, had to be what they were looking for. They tried the same thing on the unknown symbols. Again, they got nonsense, but the nonsense seemed to point to German as the original language.
Knight and his team assumed they were starting with German, as the book is from Germany and “Philipp” is a German spelling. They then looked at the frequency of different symbols and where they occurred together. This technique is centuries old and depends on the fact that different languages have combinations of letters that are allowed (or not). For example, in English, “q” is followed by a “u” in all but a few very rare words (and those are all foreign borrowings). That gave the linguists a few letters, which in turn allowed them to pick out more. Eventually they were able to transcribe the whole text.
The team has only translated the first 16 pages, but what the Copiale cipher revealed was a set of rules and initiation rites for a secret society. Such societies were more common in the 18th and 19th centuries, both as political and social organizations. (Yale’s Skull and Bones society was one of these).
The technique used in the Copiale manuscript, however, has more serious uses than plumbing the secrets of a clandestine society that has long since disbanded. Knight notes that many of his algorithms can be used in machine translation (and often are) and can be applied to other unknown texts and languages
Knight also said he has been very interested in one of the most famous coded texts: the Voynich manuscript, which has also stumped cryptographers and linguists for nearly a century. The Voynich is similar to the Copiale in that it is clearly in a coded text, but nobody is sure what the original language was or about the nature of the cipher.