Earliest French Ciphers (1507, 1513, 1521)

Introduction of ciphers in France was later than in Italy or Spain.

While absence of extant ciphertext does not mean there was no cipher, the pursuit of the earliest specimen is not without merit. As of 2023, I thought specimens from ca.1520-1521 might be the oldest (blog post; identified as Antoine Duprat's reports (1521) in Camille Desenclos and George Lasry, "Cryptanalytic and historical challenges with unidentified encrypted documents from the early modern era" (HistoCrypt 2025), 2.2).

But I now see a specimen from 1513 had already been reported in Camille Desenclos (2021), "Le premier essor de la cryptographie en France (1510-1630)" (HAL). It is a letter in cipher from Louis de Solliès to Florimond Robertet, dated 8 July 1513 (BnF Dupuy 261, f.121).

And now, an even earlier instance is given in Camille Desenclos and Sarah Clinet (2025), "Diplomatie et gestion du secret" (Bibliothèque diplomatique numérique (BDN)). It is Robert de Gramont to Georges d'Amboise (ca. 1507) (BnF fr.2930, f.189 (catalogue info)).