Patent for improvement in cyphering machines, Germany

Date: 1924 Reference: HW 25/6 Creator: Records created or inherited by Government Communications Headquarters (GCHQ) Catalogue context: Early correspondence relating to the ENIGMA cypher machine, including the patent specification and photographs Categories: Overseas; Second World War Subjects: Intelligence Topics: Military and war Period: Interwar Places: Germany Copyright information: Copyright clearance for publication is not required, except in the case of documents in third-party copyright. Usage terms: https://www.nationalarchives.gov.uk/documents/information-management/use-of-tna-materials.pdf