Les règles de Cicco Simonetta pour le déchiffrement des écritures secrètes
"Les règles de Cicco Simonetta pour le déchiffrement des écritures secrètes" is a historical text attributed to Cicco Simonetta, a secretary and advisor to the dukes of Milan during the Sforza dynasty, written in the late 15th century. This document presents a collection of rules and guidelines on cryptography, focusing on the methods for decoding secret writings that were becoming more prevalent in Italy during this period. The work reflects the early developments in cryptographic practices, coinciding with a time when encoded communication was increasingly important in political and administrative contexts. The text outlines a series of thirteen rules aimed at helping readers decode messages, highlighting techniques based on the frequency of letters and specific word structures in both Latin and vernacular Italian. Simonetta employs an empirical approach, drawing on his personal experiences within the Milanese chancery to offer practical advice for identifying key letters and patterns within encrypted messages. His strategies emphasize the importance of recognizing vowels and common letter combinations, providing insight into the rudimentary techniques of cryptography of the time. Despite its foundational simplicity, Simonetta’s work serves as an important reference in the history of cryptography, illustrating the nascent understanding of secret writing methods in the late 15th century.