New decoded letters from Mary Queen of Scots

50 letters from Mary Stewart have been discovered and deciphered
10 February 2023

Interview with 

George Lasry, DECRYPT




‘A stunning piece of research … these discoveries will be a literary and historical sensation.’ The words of University of Cambridge Tudor historian John Guy on work published this week detailing newly-deciphered coded correspondence penned by Mary Stewart - Queen of Scots. History buffs will know of Mary, Queen of Scots’ role in a plot to overthrow her Protestant cousin, Queen Elizabeth I, and restore Catholicism in England. This new find sheds yet more light on the machinations to seize the throne by unpicking the meaning of Mary’s invented graphic symbols by looking for the intricate patterns hidden in the text she wrote in the 1500s. This was a very popular way of keeping messages between trusted allies in the Early Modern era private. Cryptographer George Lasry spends his time poring over national archives in search of documents written in sophisticated codes, “cyphers”, in the hope of solving something of historical significance. James Tytko asked George what it felt like to have contributed so significantly to modern study of this fascinating figure…

George - Surreal. We could not believe our luck and we needed to do a lot of checks to make sure that we are not dreaming or inventing stuff. But eventually we were very much convinced that this is for Mary Queen of Scots and the fact that we can contribute to the history. Folks like us, we are passionate about historical ciphers and we like to crack them. But when we reveal such exciting and new material, it's really, really gratifying.

James - Yes, I can imagine this must be the absolute holy grail for someone with your passion and interest. How long have you been interested in solving ciphers?

George - So I've been always fascinated by history and by the world of intelligence and I'm also a computer scientist. So I like a lot of mathematics and algorithms. So cryptography and cracking ciphers actually combines all of them together. About 10 years ago, I decided to put that hobby and interest into some academic work and I started to crack some historical ciphers and to write papers. And then I wrote a PhD on the subject. So it was very fun, PhD. But nothing of this magnitude. When we look at ciphers, it's kind of a passion and an obsession. <laugh>. When we see a cipher, the moment the cipher is there in front of us, then literally we cannot go to sleep until we solve it.

James - You didn't know what you were working on until you sort of started to translate them. Where did you find them? Why hadn't texts of such historical importance, obviously people didn't know they're of such historical importance, but why hadn't they been looked at and cracked before?

George - So first there is evidence that some of those letters existed. There are, for example, other letters that are referenced, specific letters which are missing. So historians had an idea that something is missing here, but no one knew where to find them. And we find them really by chance because we are part of a project which is called the DECRYPT Project. It's a project involving multiple universities in Europe to collect and then digitize and transcribe and decipher documents in cipher that we have in national archives, like in the Bibliotheque Nationale de France or in Germany and Italy and so on. And we just collect ciphers and if they're not yet deciphered, then you will crack the code. But we do that systematically. And also if you look at one of those samples, all you see are graphical signs. There is nothing to hint about who wrote them to whom, and the date.

James - How sophisticated were cyphers from this Tudor period. And what did you have to therefore do to be able to crack them?

George - If we look at ciphers we use in France or in England, the one that Mary Stewart used was by way to communicate with our ambassador, the French ambassador to England, Michel de Castelnau. So it's more direct, it's not the strongest one, but it's a good one. It's a secure one. For an historical codebreaker, we used the computer in the process. So it took us less time. Still the work required not just a computer to give us a head start, but also a lot of manual analysis of the text. A lot of linguistic analysis, a lot of textual analysis.

James - I see. So now is where you sort of pass the baton onto the historians to get their teeth into it. So we, I suppose the significance really of this find is sort of yet to be revealed in a way.

George - Yes, we did go over all the texts and we summarized them in our paper. So we know more or less the subject that they're talking about. But only historians which are deeply knowledgeable about the matter will be able to give us the full significance of each one of those details that we have. We have many names. Some of them are known to historians and some of them are not known. Events are reflected in various ways, sometimes very, very colourful. And we have about 50,000 words. 50 letters with 50,000 words. Sometimes even if you find one letter from someone like Mary Stewart, that's a celebration for the historical community. But 50 letters and some of them are very long. It's a real gold mine. We think.

James - So interesting. And has this satisfied, George, your appetite for cryptography for the foreseeable future or I can almost imagine the answer to this question already. Are you more energized than ever?

George - Yes, and unfortunately it's, it's an addiction. And it's not something that you can <laugh> you can put on the side. And we still have a lot of stuff to work on. I'm very much in doubt if any of them will be at the magnitude of deciphering 50 letters from Mary Stewart.


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