Lesson Three Code makers and breakers

Transcription

1 Lesson Three Code makers and breakers Teachers Materias Code Makers and Breakers Lesson Pan Further Information Lesson Materias Aan Turing and Enigma images Codes to Break Downoad this resource 21

2 Lesson Three: Codemakers and breakers AIM To expore the activity of spies and the use of code breaking from Word War Two the Cuban missie crisis and beyond. LESSON OUTCOMES A students wi be abe to expain the origins of code breaking and how codes work. Some students wi be abe to evauate the chaenges faced by code breakers during the Cuban missie crisis. A few students wi be abe to consider the egacy of code breaking and its impact on the modern word. CONCEPTS TO EXAMINE Code breaking, secrecy, prejudice and discrimination, egacy, inteigence. OERIEW Students wi discover the history of code breaking and its significance on events such as the Cuban missie crisis. They wi be abe to earn how code breaking works, and create their own codes. The esson wi enabe students to consider the mora diemmas of code breakers. The cass wi examine code breakers egacy. Students can debate the need for secrecy, inteigence gathering and security in the context of the modern word. EQUIPMENT NEEDED - Pens - Timeine of Cuban missie crisis (page 12) - List of codes to break - Code breakers PowerPoint (onine) - Countdown cock SUGGESTED TIME This is a one hour esson, but can de differentiated to run over a period of two essons examining each activity in more detai. ROOM LAYOUT - For group work. - First activity needs space for students to form a debate ine. SKILLS - Numeracy - Literacy - ICT - Enquiry - Cooperation and team work 22

3 INSTRUCTIONS Starter Using Code Breakers PowerPoint teacher to use the debate ine side to consider students views of secrecy. Pose the question to the students Does secrecy protect peace? If they think it protects peace they stand on one side of the room, if they think it doesn t protect peace they stand on the other side of the room. If they are somewhere in the midde they stand somewhere in the midde. Teacher to then encourage students through questioning to expain why they have the opinion that they do make sure an appropriate number of responses from each side of the viewpoint is examined. Main activities Put a picture of Aan Turing or Gordon Wechman on the board. Ask students who they think they are. Then put a picture of the Enigma machine on the board ask students what they think it is. Expain to students using the PowerPoint the historic overview of code breakers at Betchey Park and eading to the Cod War. Spit cass into USA and Soviet Union. Roepay activity with a task: Give students a ist of codes to break for USA and codes to break for Soviet Union. (There are two sets of codes to use these can be used for two sets of groups, or aternatives to extend the code breaking portion of this esson to fi an hour). They have ten minutes to break each set of codes and must work together in order to do this. Countdown the ten minutes using a countdown cock. The majority of codes to crack require knowedge from the further information page they operate on a Caesar cipher, whereby you repace etters with numbers or other etters. The first one to break the code and compete the action required by the code is responsibe for saving the word if the codes are not broken within ten minutes the Presidents of the Soviet Union and the USA wi aunch nucear weapons at each other and both teams wi ose. At end of activity feedback with the students reating to the probems that they faced as a team, and how they worked together to break the codes or how they coud improve their work in the future. Students now to create their own codes. They must have a cipher and a way of the code being decrypted when it reaches its destination. The two teams of USA and Soviet Union stay in pace. Using the timeine of the Cuban missie crisis students pick a significant event in which they woud not want the other team to find out about. They then create a code for it. At the end of the aotted time, students pass the codes to each other and try to break them. PLENARY Students to discuss what they think the egacy of the code breakers during the Cuban missie crisis is in today s word. Do they think codes sti exist? How do they think codes can be used? Are the use of codes a good think? What do they think coud be some of the probems with secrecy and inteigence gathering? DIFFERENTIATION - For the debate ine activity give students prompt cards to hep them discuss the arguments for and against. - Give students part of the cipher for the ist of codes - Give students cues to hep them break the codes - Give students a cipher to make their own codes - Use computers to make a cipher either to crack the codes or make their own 23

4 EXTENSION - For the debate ine activity, students coud be asked Does the use of codes keep our word safe? or other questions on this theme. - Students coud argue against their own view to improve their debating skis. - Students can discuss the egacy of the code breakers, incuding Aan Turing and Gordon Wechman ENRICHMENT - Take students to Betchey Park on a trip to find out more about code makers and code breakers - Watch a fim The Imitation Game to earn more about Aan Turing. - Compete the roe pay or code breaking activities outside the cassroom using props, and creative expression. - Read about Gordon Wechman and the invention of The Coud in computer technoogy - Make and use QR codes to create other forms of codes, these can be done using students mobie phones. 24

5 Further information: Code makers and breakers Since human beings were abe to communicate they have attempted to obscure information from each other in different ways, in order to keep certain things secret. One way in which to do this is to create a code. Those making the codes are caed cryptographers. They give the cipher or way to sove the code to the person who is receiving the message. In this way a the codes made in the same way can be read. Without the cipher the message remains secret uness it is broken. Other peope who do not have the cipher consider ways in which to break or crack the code. Code breakers who use ogic, intuition and come up with compex mathematica systems to uncover the secrets in codes are caed cryptanaysts or code breakers. The Greeks and Romans were some of the first civiisations to use sophisticated ciphers to communicate in secret. The schoar Poybius created a system whereby each etter on a grid woud be repaced with a etter from the aphabet in 5x5 grid. A = 1x1 = 2 or N = 3x3 = 9 or T = 4x4 = 16, so the numbers 2, 9, 16 = ANT. Caesar invented a cipher that shifted the etters of the aphabet by a certain number of etters or numbers i.e. A = 2, B = 3, C = 4 or A = B, B = C, C = D. The more compicated the shift of etters/numbers the more chaenging the cipher and the more difficut it is to break the code. These two systems have formed the basis of many codes throughout history. Modern code makers and breakers Codes continued to advance in a simiar way as this unti the invention of the teegraph machine and Morse code. This meant that nations were now abe to transmit codes across arge distances and transmit messages to each other easiy in times of war. However, the codes that they created had to become more compicated as anyone coud isten in and try to work out the cipher for these messages. Codes made by machines started to become more popuar as technoogy improved, as these codes enabed compicated ciphers to be created. To hep cryptanaysts in deciphering messages, cipher machines were deveoped. One of the odest of these was created in the 15th century and caed the Aberti Disc. It heped code breakers by using two discs on top of each other that coud be turned to find the corresponding etter. One of the most famous cipher machines was the Enigma machine made by the Germans the 1920s. This machine ooked ike a typewriter, but each press of a button indicated a ighted etter. The machine used compex wiring and rotors to create a different etter each time. Without the cipher these machines were amost impossibe to crack as they were using so many miions of different etter combinations. In 1932 the first Enigma machine cipher was broken by the Poish Genera Staff s Cipher Bureau. They were abe to do this by receiving inteigence about aspects to do with the cipher, and create a Bombe machine to crack the code. The Enigma machine was then improved upon and new parts were added to make the code more compicated to crack. Aan Turing In Word War Two the Germans were using Enigma to transmit messages between their forces. The British had previousy set up the Government Codes & Ciphers Schoo which Aan Turing had joined. Aan had some ideas about how to decipher the now very compicated Enigma machine if inteigence coud be received reating to parts of the code that were simiar. Aan Turing created a new Bombe machine and from this the British were abe to crack the Enigma machine, and make significant progress in the war. Aan Turing and his team of code breakers are credited with shortening the overa ength of Word War Two. After Word War Two, Prime Minister Churchi asked for the information reating to the discovery of the Enigma codes to be kept secret. Government Codes & Ciphers Schoo became the Government Communications Headquarters (GCHQ). Aan Turing was not recognised for his work, and due to his sexuaity, was sentenced to be chemicay castrated. He committed suicide in 1954 just before his 42nd birthday. In 2009 Prime Minister Gordon Brown apoogised for the appaing treatment of Turing and in 2013 he was posthumousy pardoned. Code breakers in the Cod War GCHQ, Mi5, Mi6 and their counterparts in America, the Centra Inteigence Agency were very active in the Cod War attempting to uncover secrets transmitted and communicated between the USSR and its aies. 25

6 Inteigence gathering is now reated to mutipe aspects of their work, and the data gathered from both codes and sateites images ed to the escaation in the Cod War of the Cuban missie crisis. Mixed messages and a ack of cear communication resuted in some misunderstandings that coud have potentiay ed to the end of the word as we know it. The internet and The Coud that we use today are a resut of the work that mathmaticians ike Gordon Wechman carried out during the Cod War. Cryptographers and cryptanaysts sti work to make and break codes but now have the abiity to use compex computer programmes to assist. They woud say that there is no unbreakabe code, just codes that have yet to be broken. Aan Turing The Enigma Machine 26 Gordon Wechman Turing s Bombe that broke the code

7 Codes to break Make sure to give each part of the codes to students to ensure that they wi be successfu in breaking them. The codes can aso be differentiated by providing cues. The ciphers for the answers and the answers themseves can be found at the end of each country set. Do not give these to the students uness you wish to revea the answers to them. Each word is part of an action that the students must compete to win the game. There are two sets of codes for two countries. This enabes two rounds or 4 groups. USA Part A: No answers 1st word Code to break: 19, 1, 25 2nd word Code to break: 14, 10, 20, 20, 10, 13, 6 3rd word Codeword: Bay of Pigs Code to break: UD B A Y O F P I G S 27

8 4th word Codeword: Hotine Code to break: YQNL H O T L I N E 5th word Codeword: Time to hurry up, the Soviet Union is winning the arms race. Everyone must support the new atomic age. Atom bombs at the ready. Communists can not rue! Haven't you heard they are getting coser? Expansion of the Soviet Union must be stopped. Ready for nucear annihiation? USA Part B: No answers 1st word Code to break: 4, 15, nd word Code to break: 8,16, 22, 7, 24,19 28

9 3rd word Codeword: Disarm Code to break: JBI 4th word Codeword: Dipomacy Code to break: XPTSP 5th word AB CD EF GH IJ KL MN OP QR U ST YZ WX 29

10 USA Part A: Answers for teachers 1st word: SAY. Match number to get the correct etter 2nd word: MISSILE. Minus 1 from the number to get the correct etter 3rd word: TO. Write in the aphabet in order starting at J. If the etter has aready been taken in the code word then miss that etter out and enter the foowing etter instead. 4th word: YOUR. Enter the aphabet starting with A in A. If the etter in the aphabet appears in the code word Hotine, skip this etter and carry on to the next etter in the aphabet that does not appear in Hotine. 5th word: TEACHER. Take the first etter of each sentence. 1st word nd word rd word B A Y O F P I G S C D E H I K L M N Q R T U X Y Z 4th word U H O T L I N E W X Y Z 30

11 USA Part B: Answers for teachers 1st word: ALL. Minus 3 to the number to get the correct etter 2nd word: SKETCH. Enter the etters in aphabetica order but backwards starting with entering A under 26. 3rd word: FIE. Put code word in to cypher so D of Disarm equas A. Then enter the aphabet. If a etter is taken in the code word then enter the next etter in the aphabet. 4th word: PEACE. Enter the code word backwards so D for Dipomacy equas Z on the grid. Then enter the rest of dipomacy backwards and then the aphabet starting with B underneath Q. 5th word: SIGNS. The symbos correspond to the borders around the etters. If the symbo has a dot then it s the second etter in that duo of etters. 1st word nd word Z Y X W U T S R Q P O N M L K J I H G F E D C B A 3rd word D I S A R M B C E F G H J K L N O P Q T U W X Y Z 31

12 4th word Z X W U T S R Q N K J H G F E B Y C A M O L P I D 5th word A I Q Y B J R Z C K S D L T E M U F N G O W H P X 32

13 Soviet Union Part A: No answers 1st word Code to break: 20, 5,12, 12 2nd word Code to break: 21, 6, 2, 4, 9, 6, 19 3rd word Codeword: Atomic Code to break: BLI A T O M I C 33

14 4th word Codeword: Power Code to break: RQTD P O W E R 5th word Codeword: My, my time is starting to run out. Isn't it time we stopped these evi capitaists? Space race has begun. So we must work together. Imperiaist Americans must be stopped! Let's get to the moon first! Everyone must support the new atomic age. Soviet Union Part B: No answers 1st word Code to break: 7, 21, 4, 26 2nd word Code to break: 11, 22, 26, 24, 22 34

15 3rd word Codeword: Pacify Code to break: TFOGQNT P A C I F Y 4th word Codeword: Truce Code to break: I J E C U R T 5th word AB CD EF GH IJ KL MN OP QR U ST YZ WX 35

16 Soviet Union Part A: Answers for teachers 1st word: TELL. Match number to get the correct etter 2nd word: TEACHER. Minus 1 from the number to get the correct etter 3rd word: THE. Write in the aphabet in order starting at G, entering B. If the etter has aready been taken in the code word Atomic then miss that etter out and enter the foowing etter in the aphabet instead. 4th word: WORD. Enter the aphabet starting with A in A uness it appears in Power. Skip this etter and carry on to the next etter in the aphabet that doesn't appear in Power. 5th word: MISSILE. Take the first etter of each sentence. 1st word 2nd word 3rd word A T O M I C B D E F G H J K L N P Q R S U W X Y Z 4th word A B C D F G H I J K L M N Q S P O W E R T U X Y Z 36

17 Soviet Union Part B: Answers for teachers 1st word: DRAW. Pus 3 to the number to get the correct etter. 2nd word: PEACE. Enter the etters in aphabetica order but backwards starting with entering A under 26. 3rd word: SYMBOLS. Put code word in to cypher so P of Pacify equas A. Then enter the aphabet. If a etter is taken in the code word then miss it out and enter the next etter in the aphabet. 4th word: ON. Enter the code word backwards so T for Truce equas Z on the grid. Then enter the rest of Truce backwards and then the aphabet starting with A underneath U. If a etter is taken in the code word, miss it out and enter the next etter in the aphabet. 5th word: PAPER. The symbos correspond to the borders around the etters. If the symbo has a dot then it s the second etter in that duo of etters. 1st word 2nd word Z Y X W U T S R Q P O N M L K J I H G F E D C B A 3rd word P A C I F Y B D E G H J K L M N O Q R S T U W X Z 37

18 4th word Z Y X W S Q P O N M L K J I H G F D B A E C U R T 5th word A I Q Y B J R Z C K S D L T E M U F N G O W H P X Now get students to design their own codes! Use the above ciphers or they can make their own. 38