MECHANICAL CIPHER SYSTEMS IN THE SPANISH CIVIL WAR

We present a brief study of the mechanical cipher systems used in the Spanish Civil War (1936–1939). This research is based on original documents obtained from various archives. We do not address the manual methods of ciphering that were more frequently used in the fighting nor the mechanisms of simple ciphering, methods like the strip cipher, the R cipher or the RF cipher [10]. We make a brief description of the cipher device used by the Nationalist army, more commonly known as the “Clave Norte” or “North Key”.