Mary, Queen of Scots prison letters finally decoded | Hacker News Reader

Mary, Queen of Scots prison letters finally decoded

theguardian.com

187 pointsTomte29 comments

More in-depth about this, with examples of the encrypted texts:

https://arstechnica.com/science/2023/02/lost-and-found-code-...

it seems that there were plain language versions of some correspondence from Mary to her French contact using those ciphers. However the total number of glyphs is said to be nearly 150,000 ? the article says nothing about combinatorial elements of those glyphs.. it must be that they combine, to get such a big set. also interesting to see that many or most common glyphs like greek were recoded

From figure 3 in the paper linked elsewhere in the thread <https://news.ycombinator.com/item?id=34718588>, it looks like 219 distinct symbols, most with diacritics, like a plus with a dot below it, or a 4 with a dot to the right.

Edit: much further down it is also mentioned "Eventually, we were able to recover the meaning of almost all the 219 distinct symbol types". Wasn't sure if I had counted correctly!

It's basically a substitution cipher, with some elements mapping to the same symbol to defeat frequency analysis and a few special ones like symbols for individual place, month, or person names, or a symbol to delete or duplicate the previous character.

Edit2: figure 13 gives a good overview. There's no combinatorics involved like with modern ciphers.

There were 150,000 non-distinct symbols in the discovered letters that had to be individually mapped out.

> Mary was well-trained in the art of cipher by her mother, Marie >>>de Guise<<<, from a very young age.

Really? :-)

Is this a wordplay on "deguise" = disguise in French?

Letters she sent were decoded at the time. The evidence leading to her being executed was largely based on that. It is a simple substitution cipher so vulnerable to letter frequency analysis. So the article title is either misunderstanding or click-bait. They do appear to have found previously lost letters which is very interesting. But deciphering them is easy.

wow, an entire article and no link to the actual decrypted texts, way to go Guardian.

Presumably they are not yet public?

Gotta protect the lady's privacy. /s

Or maybe it wasn't done, and this is just a claim.

The link is in the article, in the hypertext "Lasry, lead author of the study".

It's quite a good read.

URL: https://www.tandfonline.com/doi/full/10.1080/01611194.2022.2...

This is a nice 38 minute presentation by one of the authors of the study: https://www.youtube.com/watch?v=YRrDr6WfY4Y

It's posted by one of the codebreakers to the Zodiac Killer's code, who gives the introduction.

Am I dense, or is this article and https://arstechnica.com/science/2023/02/lost-and-found-code-... (mentioned by another commenter) almost completely void of details about the cipher? I'm most interested in how Mary was encrypting these letters, but apart from an image or two in the article mentioned above, and this quote "The documents contained only graphical symbols (more than 150,000 in total)", there's nothing.

They do link to the paper at least? https://www.tandfonline.com/doi/full/10.1080/01611194.2022.2...

But yeah, that's annoying.

I think the submission link should be replaced with this. The paper is much more informative and it's surprisingly easy to understand.

The paper is indeed surprisingly easy to follow. Section 4 about the deciphering process is a great read

https://www.tandfonline.com/doi/full/10.1080/01611194.2022.2...

I had the same reaction The Guardian article just says:

"The letters reveal Mary’s distrust of Walsingham and Sir Robert Dudley, Earl of Leicester, who was a favourite of Elizabeth’s. In the letters, many of which were sent to the French ambassador to England, Michel de Castelnau de Mauvissiere, Mary complained about her poor health, the conditions of her captivity, and spoke about her efforts to negotiate with Elizabeth for her release. The letters document her attempts to win over some of Elizabeth’s officials with presents. Mary also expresses her distress about her son, referred to as “mon fils” or my son, later King James VI of Scotland and James I of England, who was taken away from her at the age of one."

The ars article shows an image of an original encryption table used in some other letters by MQS. It's a quite detailed manual. The researchers apparently did consult that and other known tables in their analysis.

Also mentioned,

"... The authors noted that seven of the eight newly decoded letters turned out to have plaintext copies preserved in British archives, adding, "It would seem that the leak from the embassy was quite effective and comprehensive" ..."

, as there were some spies at the time in the French embassy that were leaking the decoded texts.

Btw, there's doi link at the end of the ars article.

The cipher is relatively trivial. The remarkable part is that these are previously unknown letters, primary sources from an important historical event.

It could have been broken long ago if anyone had thought it was interesting. So it's less like deciphering the Voynich Manuscript and more like finding a cache of letters at a yard sale.

The "finally" in the article title is a bit misleading; it implied to me that the cipher was hard to crack.

> Dr John Guy ... said the findings are a “literary and historical sensation” and mark the most important new find on Mary Stuart, Queen of Scots for more than 100 years.

This is why commas are important; I’m pretty sure Mary was not Queen of Scots for that long.

I'm pretty sure that nobody thought that to begin with so even without a comma what is meant is obvious.

The famous humorous example is "I dedicate this book to my parents, Ayn Rand and God." Sometimes an example can be humorous, educational, and technically not actually confusing.

That's funny!

My favourite in this genre comes from Sky News: "Top stories: World leaders at Mandela tribute, Obama-Castro handshake and same-sex marriage date set".

The Quote Investigator found the source of that dedication recently, it had the Oxford comma: https://quoteinvestigator.com/2022/12/29/serial-comma/

"Pretty sure.....", so not totally convinced?

But we do have an accounting of her death:

https://www.youtube.com/watch?v=iLyB08xXoBs

Mary Stuart (Queen of Scots)

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