1. Enigma Plymstock School History Department

2. The Battle of the Atlantic The Battle of the Atlantic Since the evacuation of the British Army from the beaches of Dunkirk in the summer of 1940, Britain has stood alone. Being an island, Britain is afforded some defence, but all the materials she needs to survive and fight the war must be brought in by sea from the Empire and United States. This would be the longest battle of the war.................. The Battle of the Atlantic The Battle of the Atlantic

3. In 1940, Britain has the largest fleet of merchant ships in the world. but Nazi Germany has the biggest U-Boat fleet in the world

4. Britain is loosing 1 ship every four hours. At this rate Britain will loose the war.

5. Britain's only advantage is the greatest secret of World War Two. At the top secret cryptography school at Bletchley park, 60 miles north of London, British Military Intelligence is reading the ‘unbreakable’ German cipher system Enigma……

6. At least until now………

7. With the largest convoy of military supplies and food now en route from Halifax, Canada, it is vital that the Enigma Code is cracked again so that the location of the Nazi U-Boats can be identified and the convoy re-routed around them. When you correctly broadcast to the U-Boats they will acknowledge their location and will be destroyed by the Royal Navy & Royal Airforce.

8. With 7,000 possible settings, on its two encoding rotor wheels, the Enigma machine was the worlds most advanced encoding machine. It took Britain’s MI5 9 months to crack it using the worlds first electronic computer. Now Admiral Doenitz, Germanys U-Boat Commander, has ordered an extra wheel be attached to his submarines Enigma Machines allowing 159,000,000,000,000,000,000 possible permutations (combinations). You must decode three pieces of Nazi cipher code traffic to identify the three rotor wheel settings.

9. Rotor One – Task One Go to: http://www.pbs.org/wgbh/nova/decoding/simpwave.html The first rotor setting letter can be worked out by deciphering this basic substitution cipher. http://www.pbs.org/wgbh/nova/decoding/simpwave.html The first rotor setting word is: The first letter of the number of vowels in the last word

10. Rotor Two – Task Two Count the number of F's in the following text: ‘FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS’ The second rotor setting letter is: The second letter of the number of letter F’s

11. Rotor Three – Task Three N=14 J=10 E=5 Complete the entire message & show your teacher: 15,14,5,16,5,18,19,15,14,9,19,20,15,1,19,11, 20,15,7,15,20,15,20,8,5,20,15,9,12,5,20,6,18,15,13,25,15,21,18,7,18,15,21,16,20,8,5,6,9, 14,1,12,12,5,20,20,5,18,9,19,15,14,20,8,5,19,20,1,6,6,18,15,15,13,4,15,15,18 The third rotor setting word is will be identified by the message

12. The three letter code will now be the password to open the locked word file THE CODE SHOULD BE ENTERED IN CAPITALS AND IN THE CORRECT ORDER Click here to access file Click here to access file