Sunday, November 13, 2011

Mysterious 'Copiale Cipher' cracked

The mysterious cryptogram, bound in gold and green brocade paper, reveals the rituals and political leanings of an 18th-century secret society in Germany. The manuscript seems straight out of fiction: a strange, handwritten message in abstract symbols and Roman letters meticulously covering 105 yellowing pages hidden in the depths of an academic archive.

A role in revolution?

The rituals detailed in the document indicate the society had a fascination with eye surgery and ophthalmology, though it seems members of the society were not eye doctors.

“This opens up a window for people who study the history of ideas and the history of secret societies,” said computer scientist Kevin Knight of the USC Viterbi School of Engineering, part of the international team that finally cracked the cipher. “Historians believe that secret societies have had a role in revolutions, but all that is yet to be worked out, and a big part of the reason is because so many documents are enciphered.”

To break the cipher, Knight and colleagues Beáta Megyesi and Christiane Schaefer of Uppsala University in Sweden tracked down the original manuscript, which was found in the East Berlin Academy after the Cold War and now is in a private collection. They transcribed a machine-readable version of the text, using a computer program created by Knight to help quantify the co-occurrences of certain symbols and other patterns.

“When you get a new code and look at it, the possibilities are nearly infinite,” Knight said. “Once you come up with a hypothesis based on your intuition as a human, you can turn over a lot of grunt work to the computer.”

The approach — presented to the Association for Computational Linguistics in a paper called The Copiale Cipher (PDF) — treated the encrypted text as a foreign language and used techniques similar to those employed by Babelfish and Google Translate to derive the text.

The secret of the Roman and Greek letters

With the cipher, the code-breaking team began not even knowing the language of the encrypted document. But because they had a hunch about the Roman and Greek characters distributed throughout the manuscript, they isolated these from the abstract symbols and attacked it as the true code.

“It took quite a long time and resulted in complete failure,” Knight said.

After trying 80 languages, the cryptography team realized the Roman characters were “nulls” intended to mislead the reader. It was the abstract symbols that held the message.

The team later tested the hypothesis that abstract symbols with similar shapes represented the same letter or groups of letters. Eventually, the first meaningful words of German emerged: “Ceremonies of Initiation,” followed by “Secret Section.”

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 first 16 pages describes an initiation ceremony for an unidentified secret society.

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.

What next?

Knight now is targeting other coded messages, including ciphers sent by the Zodiac Killer, a serial murderer who sent taunting messages to the press and has never been caught. Knight also is applying his computer-assisted code-breaking software to other famous unsolved codes such as the last section of “Kryptos,” an encrypted message carved into a granite sculpture on the grounds of CIA headquarters, and the Voynich Manuscript, a medieval document that has baffled professional cryptographers for decades.

Past Horizons. 2011. "Mysterious 'Copiale Cipher' cracked". Past Horizons. Posted: October 28, 2011. Available online:

No comments: