Código Púrpura
Na Galipedia, a wikipedia en galego.
Na historia da criptografía, 97-shiki oobun Inji-ki (九七式欧文印字機) (Máquina de impresión do sitema 97 para caracteres europeos ("System 97 Printing Machine for European Characters")) ou Angooki B-gata (暗号機B型) ("Máquina de cifrado de tipo B"), chamada PURPLE (Púrpura) polos Estados Unidos, foi unha máquina de criptografía diplomática usada por Xapón durante a Segunda Guerra Mundial. A máquina era un dispositivo electromecánico.
A información sobre as desencriptacións foron eventualmente chamadas Magic dentro do goberno dos EE.UU.
O nome clave "PURPLE" era usado polos criptoanalistas estadounidenses para referirse á máquina, referido o material producido por varios sitemas; antes houbo a RED máquina usada pola Japanese Foreign Office (oficina extranxeira xaopnesa), e purple (púrpura) era a seguinte cor dispoñible. Os xaponese tamén usaron CORAL e JADE. PURPLE era a sucesora mellorada, da máquina criptográfica RED, que os americanos chamaron "M machine". PURPLE e RED foron deseñados polo capitán da Navy xaponesa Risaburo Ito[1]. O creador principal de PURPLE era Kazuo Tanabe.
Índice |
[editar] Puntos Febles
Nas operacións, a máquina criptográfica acetaba carateres de entrada escritos a máquina (letras latinas) e producia texto cifrado de saída, e viceversa cando se descifran mensaxes. O resultado era un criptosistema excelente. En realidade, erros operacionais, principalmente en claves opcionais, fixo o sistema menos seguro do que podería ser. Os xaponeses crían que tiña unha gran eficacia irrompible en todas partes e posteriormente, na guerra. Esta seguridade foi "rota" por un equipo da armada estadounidense dedicada ós signos de intelixencia (US Army Signals Intelligence Service), dirixidos por William Friedman. O equipo foi dirixido por Frank Rowlett.
Os Estado Unidos obtiveron partes de PURPLE desde a Embaixada Xponesa en Alemaña tras a derrota de Alemaña no 1945 (ver imaxe) e discovered that the Japanese had used precisely the same "stepping switch" in its construction that Leo Rosen of SIS had chosen when building a "duplicate" (or Purple analog machine) in Washington in 1939 and 1940. The "stepping switch" was a common type of unit used in high-tech telephone-company exchanges in countries like the United State, Canada, the U.K., and Japan that had good dial-telephone systems in their large cities. These fast switches were at the heart of the systems.
Aparentemente, todas as outras máquinas PURPLE das embaixadas xaponesas e consulados arredor do mundo (países do eixe, Washington, London, Moscow, e en países neutrais) e en Xapón mesmo, foron destruidas e enterradas na area xaponesa. As tropas americanas que ocuparon Xapón entre 1945 e 1952 procuraron calquera parte que quedara da máquina.
A máquina PURPLE foi usada por primeira vez en Xapón en Xuño de 1938, pero criptoanalistas estadounidenses e británicos xa conseguiran descifrar algúns mensaxes antes do ataque a Pearl Harbor. US cryptologists decrypted and translated the 14-part Japanese diplomatic message breaking off relations (ominously) with the United States at 1 PM Washington time on 7 December 1941 before the Japanese Embassy in Washington could do so. Difficulties at the Embassy were a major reason the diplomatic "note" was delivered late.
[editar] Outros Factores
Durante a Segunda Guerra Mundial, o embaixadora xaponés en Berlín, who was a military man, avidly studied German military developments and deployments and reported on them at length back to Tokyo via PURPLE-enciphered messages sent via radio. A good example of this was that he reported on the emplacement of the Atlantic Wall fortifications that the German Wehrmacht was building along the coasts of France and Belgium. Thus, unaware to himself, he was reporting to the Allies all about German military preparations against the forthcoming D-Day invasion of Western Europe. All that time, the Americans and the British were reading every report that the Japanese ambassador was sending in PURPLE to Tokyo.
The decrypted PURPLE traffic, and Japanese messages generally, was the subject of acrimonious hearings in Congress post-WW-II in connection with an attempt to decide who, if anyone, had allowed the disaster at Pearl Harbor to happen and whom therefore should be blamed. It was during those hearings that the Japanese learned, for the first time, that the PURPLE cypher machine had indeed been broken.
[editar] Lectura adicional
An account of the WW-II cryptographic struggle is Battle of Wits, by S. Budiansky, which is not too overwhelmingly long or technical. Combined Fleet Decoded by J. Prados has, in somewhat dispersed form, a complementary and fuller account of Japanese cryptography specifically, much of it from sources on the Japanese side. Both are recent enough to reflect much of the release of information that had been kept secret since the war.
[editar] Referencias
- Freeman, Wes., Geoff Sullivan, and Frode Weierud, "PURPLE Revealed: Simulation and Computer-Aided Cryptanalysis of Angooki Taipu B", Cryptologia 27(1), January 2003. pp 1–43.
- Ronald W. Clark, "The Man Who Broke Purple: the Life of Colonel William F. Friedman, Who Deciphered the Japanese Code in World War II", September 1977, Little Brown & Co, ISBN 0316145955.
- Frank Rowlett, "The Story of Magic, Memoirs of an American Cryptologic Pioneer", 1998, Aegean Park Press, ISBN 0894122738. First-hand account of the breaking of Purple.
- ↑ Robert J. Hanyok, "Before Enigma: Jan Kowalewski and the Early Days of the Polish Cipher Bureau (1919–22)", Appendix B in Władysław Kozaczuk and Jerzy Straszak, Enigma — How the Poles Broke the Nazi Code, 2004, ISBN 078180941X, p. 93
[editar] Links Externos
- A Máquina PURPLE -Información e emulador da máquina PURPLE (para Windows)
- PURPLE, CORAL, and JADE
