When Cryptography and Artificial Intelligence join forces to serve Historians

Sometimes, in an archive box, historians suddenly come across an encrypted document that has remained unchanged since it was sent. As a result, a great many historical documents remain unexploited because they are incomprehensible. Except in a few rare cases (where the associated encryption table has been preserved elsewhere), they remain helpless in the face of these sources, whose content remains sealed to them. In response to the regular requests for help in my mailbox, I set up the Back In Time project, which straddles three disciplines: AI, cryptography and history. In this presentation, I will discuss the difficulties we encounter: the lack of AI methods capable of transcribing thousands of pages encrypted with glyphs specific to each author, the loss of cryptanalysis techniques over the centuries, and the difficulty of establishing collaborations between the humanities and social sciences and the hard sciences.