This article examines the evolution of cryptology as a business trait and a distinct state-controlled and -regulated profession in sixteenth-century Venice. It begins by briefly discussing the systematic development of cryptology in the Renaissance. Following an examination of the amateur use of codes and ciphers by members of the Venetian merchant and ruling classes, and subsequently by members of all layers of Venetian society, the article moves on to discuss the professionalization of cryptology in sixteenth-century Venice. This was premised on specialist skills formation, a shared professional identity, and an emerging professional ethos. The article explores a potential link between the amateur use of cryptology, especially as it had been instigated by merchants in the form of merchant-style codes, and its professional use by the Venetian authorities. It also adds the profession of the cifrista—the professional cipher secretary—to the list of more "conventional" early modern professions.