Georges Painvin chapter, what are some conditions that seem (1886 - PDF document

10/20/2010 October 12, 2010 Plain p a i n v i n A D F G V X Cipher AD DV VG AX VF VG AX A 8 p 3 d 1 n D l t 4 o a h Z I P I P Z F 7 k b c 5 z A D D D D A G j u 6 w g m V x s v i r 2 V V G V G V X 9 e y 0 f q A X V X V A F V G V G F Plain p a i n v i n Cipher AD DV VG AX VF VG AX A X X A D D A V G V X V A V G F X A � Given the various incidents recounted in this Georges Painvin chapter, what are some conditions that seem (1886 – 1980) favorable to the advancement of military cryptography? � New technologies (e.g. radio) � Easily intercepted messages (e.g. no landlines) � Anxiety, incentive of not dying � Being on the defensive � Failure of old systems � Fresh ideas (drafting new minds into the effort) 1

10/20/2010 The Telegraph The Telegraph Radio Radio st Century Technologies 21 st 21 Century Technologies This was a tough decision, but I I think it was ethical… think it was an ethical one. Yes, Admiral Hall’s decision was ethical… � When the Zimmerman telegram was I think that it was an ethical deciphered by the cryptanalysts of Britain’s decision… Room 40, Admiral William Hall decided not to I think Admiral Hall’s decision was ethical. tell American President Woodrow Wilson about its contents because doing so might let I think this was an ethical decision I think he was acting in on Admiral Hall’s part… the Germans know that Britain was capable the best interest of of breaking their codes. Given the danger Americans. …In the end I believe he posed to America by the unrestricted U-boat chose the lesser of two evils warfare indicated in the telegram, was this The decision… was an by keeping Room 40 a ethical decision on the part ethical of Admiral Hall? secret. of Admiral Hall. 2

10/20/2010 � When the Zimmerman telegram was Ethical Not Ethical deciphered by the cryptanalysts of Britain’s Room 40, Admiral William Hall decided not to • Whole country, way of life at risk. • By not telling the Americans, • Who’s “pulling the trigger”? people would definitely die. tell American President Woodrow Wilson Germany, not England. Telling the Americans wouldn’t • Who’s lying here? Germany, not necessarily save lives. about its contents because doing so might let England. • What England did was as the Germans know that Britain was capable • The good of the many over the unethical as what Germany did— good of the (relative) few. manipulating the Americans for of breaking their codes. Given the danger • Message hasn’t been deciphered their own ends. posed to America by the unrestricted U-boat fully. • Could it be a fake German warfare indicated in the telegram, was this message? ethical of Admiral Hall? � Germany learned that Britain had broken Pros (Share the Story) Cons (Don’t Share) their codes from histories of the First World War written by Winston Churchill and the British Royal Navy. Given that this knowledge prompted Germany to invest in the Enigma machine technology prior to the Second World War, should these histories have been published? What might have motivated Britain to make their code- breaking success known in this fashion? The Enigma Machine 3

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