Cryptanalysis = Codebreaking - PowerPoint Presentation

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Cryptanalysis = Codebreaking - PPT Presentation

Cryptanalysis Codebreaking Terry Bahill Emeritus Professor of Systems Engineering University of Arizona Tucson AZ 857041622 terrysiearizonaedu Copyright 19972019 Bahill References David Kahn ID: 772086

2019 bahill dreyfus 2018 bahill 2019 2018 dreyfus telegram words code amp mexico proof abstraction levels level codebreaking ciphertext

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Method for success Most codes are broken using the scientific method and serendipity Sir Francis Bacon was the father of the scientific method, which is based on unbiased observation and induction 3 10/23/2019 © 2018 Bahill

So what? Breaking this code allowed me to compute trajectories of a foul ball that injured a spectator on a different diamond This helped me to conclude that the design of the ballfields was negligent 7 10/23/2019 © 2018 Bahill

ADFGX cipher* (WWI, Fritz Nebel) A D F G X A n b x r u D q o k d v F a h s g f G m z c l t X e i p j w 10/23/2019 © 2018 Bahill 11 plaintext t e r r y CODETEXT GX XA AG AG ? Find the row first, then the column One of 25! possible alphabet assignments We transmit GXXAAGAG?? --. -..- -..- .- .- --. .- --.?? Your assignment, should you choose to accept it, is to write your first name in the ADFGX cipher and give it the person on your right or left. Then decode the name that they gave you.

A brief history of codebreaking 12 10/23/2019 © 2018 Bahill Where When Who For Whom Italy 15 & 16th centuries Alberti, Soro, Argentis Pontifical Secretary Dato, Council of Ten in Venice, Pope Clement VII, Several other popes France 17 & 18th centuries Rossignol Cardinal Richelieu, Louis XIII, XIV and XV England 17 & 18th centuries Wallis Earl of Nottingham, King of Prussia France World War I Army & Navy Government and military leaders USA and England World War II Turing, Rochefort, Army & Navy Roosevelt, Churchill, some cabinet members, some flag rank officers

Translation viewpoint Viewpoint Name: Translation Purpose: to allow English speakers to read German messages Stakeholders: translators, U. S. President, a few cabinet members, a few generalsConcerns: jargon, dialects, technical words, secrecyLanguages: English and GermanModeling Methods: write words on paper, use sound recorders, use computers 14 10/23/2019 © 2018 Bahill

Percent occurrence of individual letters* a b c d e f g h 8 1.5 3 4 13 2 1.5 6 i j k l m n o p6.5 0.5 0.5 3.5 3 7 8 2q r s t u v w x0.25 6.5 6 9 3 1 1.5 0.5y z2 0.25 This table is updated based on message traffic.* 17 10/23/2019 © 2018 Bahill

What is the missing term in this sequence? 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ?, 1, 1, 19W is the answer. What is the question?

Letter pairs (in English) Vowels e associates with many other letters a, i and o avoid each other, but of these io is the most common and ae is the rarestConsonants80% of the letters that precede n are vowelsh precedes vowels ten times as often as it follows them: he is common but eh is rare 19 10/23/2019 © 2018 Bahill

The Zimmerman telegram Date: January 16, 1917 From: Arthur Zimmerman, German Foreign Minister in Berlin *To: German ambassador in Washington* D.C.To be forwarded to the German ambassador in Mexico, to be given to the Imperial Minister of Mexico, to be given to the President of Mexico 28 10/23/2019 © 2018 Bahill

The Zimmerman telegram (as decoded January 17, 1917) Most secret for your Excellency’s personal information and to be handed on to the Imperial Minister in (?Mexico) with Telegram No. 1 (…) by safe route. We propose to begin on the 1st February unrestricted submarine warfare. In doing so, however, we shall endeavor to keep America neutral. (?) If we should not (succeed in doing so) we propose to (?Mexico) an alliance upon the following basis: [joint] conduct of the war. [joint] conclusion of peace. (…) Your Excellency should for the present inform the President [of Mexico] secretly (?that we expect) war with the U.S.A. (possibly) (…) (Japan) and at the same time to negotiate between us and Japan. (Please tell the President) that (…) or submarines (…) will compel England to peace in a few months. Acknowledge receipt. Zimmerman 29 10/23/2019 © 2018 Bahill

The Zimmerman telegram (as published by the Associated Press, March 1, 1917) We intend to begin on the first of February unrestricted submarine warfare. We shall endeavor in spite of this to keep the United States of America neutral. In event of this not succeeding, we make Mexico a proposal of alliance on the following basis: make war together, make peace together, generous financial support, and an understanding on our part that Mexico is to reconquer the lost territory in Texas, New Mexico and Arizona. The settlement in detail is left to you. You will inform the President [of Mexico] of the above most secretly, as soon as the outbreak of war with the United States of America is certain and add the suggestion that he should, on his own initiative, invite Japan to immediate adherence and at the same time mediate between Japan and ourselves. Please call the President’s attention to the fact that the ruthless employment of our submarines now offers the prospect of compelling England in a few months to make peace. Zimmerman 30 10/23/2019 © 2018 Bahill

Basic process Plaintext Algorithm Ciphertext Key ExamplePlaintext = CaesarAlgorithm = substitute a different letter for the current letterKey = shift 4 A B C D E F G H I J K L M N O P Q R S T U V W X Y ZC > GA -> EE -> IS -> Y A -> E R -> X 32 10/23/2019 © 2018 Bahill

What are codes? Codes are processes using words, letters, numbers and other symbols substituted for other words, letters, numbers and symbols, that are designed to deliberately conceal information from interlopers The following are not codes: allegories, parables, apocalypses, revelations, mystery books, metaphors, riddles, and languages such as Egyptian hieroglyphs and Mayan glyphs Some people say codes substitute one word for another and cyphers substitute one letter for another 33 10/23/2019 © 2018 Bahill

The Dreyfus Affair On November 1, 1894 a French newspaper said that a French army officer, Captain Alfred Dreyfus, in the pay of Germany or Italy, gave secret military information to Germany. 37 10/23/2019 © 2018 Bahill

Dreyfus: ciphertext (telegram) On November 2, Panizzardi, the Italian military attaché in Paris, sent the following telegram to his chief in Rome: “Commando stato maggiore Roma 913 44 7836 527 3 88 706 6458 71 18 0288 5715 3716 7567 7943 2107 0018 7606 4891 6165 Panizzardi” 41 10/23/2019© 2018 Bahill

Dreyfus: find the codebook The French intercepted his telegram. First they had to find the codebook that was used. The intermixing of one-, two-, three- and four-digit groups suggested the Baravelli commercial code, which produced 913 44 7836 527 3 88 706 6458 71 ... us le rimprovera nar i te ren pensato sara ...or an alternative hypothesis ofuss -re narr j 43 10/23/2019 © 2018 Bahill

Dreyfus: codebook level Both alternatives were gibberish, which meant that they could not skip the ciphertext level. They had to find Panizzardi’s cipher. They presumed that Dreyfus’ name would be in the telegram.45 10/23/2019 © 2018 Bahill

Dreyfus: codebook level* “Dreyfus” can be coded using the Baravelli codebook like this dr Table III, page 2, line 27e Table 1, line 1y Table II, group 9, line 8 fus Table III, page 3, line 06So in plaintext Dreyfus would be 227 1 98 30646 10/23/2019 © 2018 Bahill

Dreyfus: codebook level They were looking for Dreyfus, 227 1 98 306. The telegram had a similar sequence of three, one, two and three-digit groups, namely 527 3 88 706But the first digit of each group was different. So Panizzardi must have enciphered the left most digit of each group. 47 10/23/2019 © 2018 Bahill

Dreyfus: the cipher By November 10 they had discovered Panizzard’s cipher. It was a simple substitution. First plaincode digit 0 1 2 3 4 5 6 7 8 9 First ciphertext digit 1 3 5 7 9 0 2 4 6 849 10/23/2019 © 2018 Bahill

Dreyfus: word level Using what they already knew, on November 3 they produced this guess for a decrypt “Arrested [is] Captain Dreyfus who has not had relations with Germany…” Words inside brackets [ ] were hypotheses. 51 10/23/2019© 2018 Bahill

Dreyfus: sentence level They worked on the cipher and the code and on November 6th improved the decrypt to “If Captain Dreyfus has not had relations with you, it would be wise to have the ambassador deny it officially. [Our emissary is warned.]” The words inside brackets [ ] were hypotheses. 53 10/23/2019© 2018 Bahill

Dreyfus: sentence level When they applied his cipher to the original telegram they got the following plaintext, and using the Baravelli codebook they got they following Italian words: 74 1336 227 1 98 306 5858 31 08 7588 ... Se Capitano Dr e y fus non ha avuto relazione...54 10/23/2019 © 2018 Bahill

Dreyfus: translation Translating this into English we get: “If Captain Dreyfus has not had relations with you, it would be wise to have the ambassador deny it officially, to avoid press comment.” 56 10/23/2019 © 2018 Bahill

Dreyfus: proof level To prove that their decryption was correct, the French had a double agent give an important sounding message to Panizzardi. On November 13 Panizzardi encoded it and sent it to Rome. The French intercepted it and decoded it. Their decrypt matched the original, proving that their cryptanalysis was correct.But Dreyfus was not the spy. 58 10/23/2019 © 2018 Bahill

At times nature can be cruel, but there is also a raw beauty, and even a certain justice manifested within that cruelty. The alligator, one of the oldest and ultimate predators, normally considered the apex predator , can still fall victim to a teamwork strategy, made possible by the tight knit social structure and survival of the pack mentality bred into canines. See the following remarkable photograph courtesy of Nature Magazine. Note that the Alpha dog has a muzzle hold on the gator preventing it from breathing, while another dog has a hold on the tail to keep it from thrashing. The third dog attacks the soft underbelly of the gator. This picture is not for the squeamish 10/23/2019 © 2012 Bahill 61

Dog Pack Attacks Two-year-old Boy 10/23/2019 © 2019 Bahill 63 https://www.pinterest.com/pin/84653667984044857/?utm_campaign=rdpins&e_t=1f4ddb39208440f7bc3aa259debd00b7&utm_content=84653667984044857&utm_source=31&utm_term=7&utm_medium=2004&nic=1a

JN-25 proof level We sent a message stating that, “Water supplies are running low on Midway”The next day we intercepted a Japanese message stating“Water supplies are running low on AF” 64 10/23/2019 © 2018 Bahill

Tasks in the modeling process Describe the system to be modeled State the purpose of the model Determine the level of the model State assumptions and reassess them at every reviewInvestigate alternatives Select tools and languages for the models and simulations Make the model Integrate with models of other systems Gather real-system behavior data Show that the model behaves like the real system Verify and validate the model Explain discoveries not planned in the model’s design Perform a sensitivity analysis of the model Perform a risk analysis Analyze performance of the model Re-evaluate and improve the model Suggest new experiments and measurements for the real system 69 10/23/2019 © 2018 Bahill

The Dreyfus Affair, Final Exam What is the most common letter in the English alphabet? What nationality was Captain Alfred Dreyfus? What nationality was Panizzardi? Are there mentions of codes or cyphers in the Torah or the gospels? Suggest some words that have a and e in that order 10/23/2019 © 2018 Bahill 70

Cryptanalysis = Codebreaking - PowerPoint Presentation

Cryptanalysis = Codebreaking - PPT Presentation

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