paper tape. Unlike Enigma, Typex I machines were linked to teleprinters while Typex II machines could be if required. Enigma messages had to be written, enciphered, transmitted (by Morse), received, deciphered, and written again, while Typex messages were typed and automatically enciphered and transmitted all in one step, with the reverse also true. See also Cryptanalysis of the Enigma Cryptanalysis of the Lorenz cipher Mercury (Typex Mark X)—a Typex descendant used for on-line traffic. Notes References Martin Campbell-Kelly, ICL: A Business and Technical History, Oxford University Press, 1990. Dorothy Clarkson, "Cypher Machines: Maintenance and Restoration Spanning Sixty Years", Cryptologia, 27(3), July 2003, pp. 209–212. Cipher A. Deavours and Louis Kruh, "Machine Cryptography and Modern Cryptanalysis", Artech House, 1985, pp. 144–145; 148–150. Ralph Erskine, "The Admiralty and Cipher Machines During the Second World War: Not So Stupid after All". Journal of Intelligence History 2(2) (Winter 2002). Ralph Erskine, "The Development of Typex", The Enigma Bulletin'' 2 (1997): pp. 69–86 Kruh and Deavours, "The Typex Cryptograph" Cryptologia 7(2), pp. 145–167, 1983 Eric Morgon, "The History of Communications Security in New Zealand", Part 1 (PDF).Possibly related page as html External links A series of photographs of a Typex Mk III Jerry Proc's page on Typex Typex graphical simulator for Microsoft Windows Virtual Typex online simulator Crypto Museum page on Typex Cryptographic hardware Rotor machines World War II military equipment of the United Kingdom