The Cultural Heritage Group regularly receives persons who want to discover some parts of the collections. Last week, two researchers, from the University of Southern California and Uppsala University, visited the manuscript department. In 2011, this international team cracked the « Copiale cipher » a famous encrypted manuscript that deals with a secret society in the XVIII century.
Who hasn’t dreamt of secret method of communication and mysterious encoded documents ? Cryptography is a science based on linguistic and mathematics. The reader who knows me a little might be floored that I’ve decided to write about this topic since I usually faint at the simple evocation of the word mathematics. But my fondness for enigmatic subjects get the better of me against my fear of numbers.
An investigation into our collections became clearly unavoidable and it quickly appeared that the Manuscript department shelters some cryptic documents. Would you like to start with a fleeting medieval excursion ?
Welcome in Vadstena, Östergötland County, a monastery founded by Saint Brigitta – one of the six patron saints of Europe – and soon to be famous as the mother-house of the order she founded in 1346. Sweden is still a Catholic country, we are more than one hundred years before the Reformation. All around Europe, lots of men and women decided to leave in retreat, into a life of prayers, far from the everyday life.
A Musical journey with the Benedictine Monks of Santo Domingo de Silos: http://www.youtube.com/watch?v=RaroIcQ-cnM
Let’s walk wordlessly around the cloister and the scriptorium, the room devoted to the copying of manuscripts by monastic scribes, and open up one manuscript after another, rummage through the papers to find some curiosities. But here is a monk approaching. His name is Störkarus Thurgillus. Wait, he is handing a manuscript, the one that we now keep in the shelves of the Cultural Heritage Group.
He explains that he copied this volume in 1379 that contains religious treatises and sermons. But it’s impossible to talk further with this monk, we should inquire about it somewhere else. This manuscript is one of the very few that is currently known to contain cipher notations. There are indeed only about two dozen in Europe, a minuscule fraction of the medieval manuscripts.
It seems important to notice that nowhere in the medieval sources is any word equivalent to the English « cipher ». They are simply referred to as figures or numbers.
This small encoded note on our manuscript is a valuable proof that ciphers were known in Sweden in the late XIV century. According to the professor David A. King, the cipher might deal with magic and could be used as an invocation or more likely a curse involving devils. The mystery still partly surrounds.
I highly advise you to read the Name of the Rose by Umberto Eco and to watch the excellent adaptation movie by Jean-Jacques Annaud if you wish to extend the travel into the captivating world of medieval libraries and scriptoriums.
It is now time to jump through ages. A time warp to the XVIII century. At that time, cryptographic methods were abundantly used especially by diplomats for whom it was a necessary tool of communication. The different diplomatic representations were trying to hide their political secrets and never-ending plots of all types. Monarchs, ministers, ambassadors, they were all accustomed to refined ciphers.
Postal spying was ever-present and the letters were often unsealed. Thus, the French Countess of Egmont, correspondent of the Swedish king Gustav III, warned him that he should not, on any accounts, trust the postal service : « An even more important precaution is to only write by mail what you want to be publicly known (…) because it is certain that all the letters are unsealed, and even often not properly returned ».
Count Gustaf Philip Creutz, Swedish ambassador at the French court for 17 years, between 1766 and 1783, was exasperated by the bad habit of the Cabinet Noir, the office where the letters of suspected persons (but almost everyone was potentially a suspect !) were opened and read by public officials before being forwarded to their destination. This is why, as much as possible, Creutz sent his letters and dispatches by private route, taking for instance the opportunity of a friend or a close relation’s departure to the homeland. Here is the beginning of a letter he wrote to Gustav III :
« As this is by a sure hand that this letter will be delivered to Your Majesty, I take this opportunity to make him aware of some features that I would not even wish entrust to the postal service despite the cipher (…). I beg Your Majesty to burn this letter. There are spies everywhere and if ever the King here knew the contents of this letter, we should never ever think of France anymore ».
But the travelers were also controlled so cunning was compulsory : « Mr. Kling Sporr on which I can absolutely count will sew this package in his coat lining and so shirk it of all accidents ».
The use of a foreign tongue was also a good way to hide some information. The Count of Creutz often switched between French (most of his letters are written in the language of Molière) and Swedish for political news that he wanted to hide from curious people. It is also possible to mix in one sentence different languages and then encode it. It will be almost impossible to discover the meaning of it without the good interpretation key. Of course, There are thousands of different ciphers, each using different techniques .
A technique, among many others, was to state the opposite of the reality. Pointed by brackets or other signs ascertained in advance, the meaning of the contained was actually diametrically reverse. An example : « The Queen is still ill but will recover soon » was to be understood as « she will pass away soon ». However, the common technique to protect writings from undesired eyes was to represent every letter and some words and proper noun by a number. See the picture, the queen of France was, in this case, encoded by the number 16.
If you don’t know what to do of your spare time, feel free to contact us, you can have a great fun trying to decode some political letters that might contains invaluable undisclosed data. And who knows, your training attempts might help you to be the first to unveil the secret of the Voynich manuscript, the world’s most famous mysterious manuscript.
Note: All the pictures are from our collections. A huge amount of Creutz letters are in the Gustavian Collection in the Manuscript department.
USC Scientist Cracks Mysterious « Copiale Cipher »: http://www.youtube.com/watch?v=Eam0Tk-1FyI
Library in the Name of the Rose: http://www.youtube.com/watch?v=DSh0L_9qok8
The Book That Can’t Be Read, a documentary about the Voynich manuscript: http://www.youtube.com/watch?v=JgALlSPlZC8