A mysterious sheaf of coded letters tucked away in the National Library of France has turned out to be never-before-seen correspondence from Mary, Queen of Scots.
Cryptographer George Lasry of the DECRYPT Project, a multiuniversity collaboration that attempts to find and decode historical ciphers, and other scientists were combing through the archives at BnF when they came across pages of ciphers mixed in with documents from Italy dating to the early 1500s. The ciphered letters were believed to be Italian. But as the researchers began to try to crack the code, they realized that the deciphered words would have to be in French for them to make sense.
“Working on the decryption was like working on an onion that you needed to peel,” Lasry says. “The cipher was quite complex, and we worked in phases.” Most of the 57 letters had never been seen before Lasry and his colleagues’ discovery. But seven of them had been intercepted and decoded by Walsingham’s network, so deciphered copies were in the U.K.’s National Archives. These matching copies helped confirm beyond a doubt that Mary was the writer, Lasry says.
Wonderfully fortunate discovery.