First official state cryptographer

Cicco Simonetta (1410-1480) was a longstanding state secretary in the duchy of Milan, one of the most meticulously informed cities in the late medieval period, especially under Francesco Sforza (1401-1466). Responsible for the Milanese secret chancery and its ciphers in the second half of the fifteenth century, Simonetta has been remembered in posterity as the first known professional cryptologist employed in state administration. In 1474, he published his Regulae extraendis litteras zifferatas sive exempio ("Rules for deciphering enciphered documents without a key").