Originally posted at ouhos.org, the now-discontinued blog of the OU History of Science Collections. Neither this post nor any of its content should be taken as an official communication of the University of Oklahoma.
This recently-acquired manuscript is a report to the French Ministry of War about methods of encryption, composed circa 1790:
BAROILLET. Rapport du Comité des Fortifications, sur une méthode d’écrire en chiffres et sur l’instrument approprié à cet objet, proposés par le citen Baroillet. [France, c. 1790]
Baroillet presented the Ministry of War with an instrument containing moving parts which he called a Kinographe, accompanied by an explanatory Mémoire. Corrected in the scribe’s hand in many places, this manuscript may be the first draft of the Mémoire. After a short exposition of various methods of encryption, Baroillet proposed a method of date-dependent encryption using the Kinographe for messages sent via semaphore towers
. The Committee on Fortifications approved of Baroillet’s Kinographe, but offered no precise description of the Kinographe device which, naturally, had to be kept secret.
Cryptographic material from the French Revolution is very rare, although cryptology played an important role in the diplomatic and military history of the period.
