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The History of Codebreaking, Part I: The Pre-Computing Era (Preview Edition) Jason Hale.

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Presentation on theme: "The History of Codebreaking, Part I: The Pre-Computing Era (Preview Edition) Jason Hale."— Presentation transcript:

1 The History of Codebreaking, Part I: The Pre-Computing Era (Preview Edition) Jason Hale

2 Cipher – Early Techniques - Pen and paper techniques - Language knowledge and statistical techniques Long been recognized by governments as an important tool in support of diplomacy and military action, and have set up organizations devoted to intercepting and decrypting messages of other powers.

3 Early Adopters of Cryptography Al-Kindi: 9th Century Muslim Arab Scientist, was responsible for the first known recorded explanation of cryptoanalysis (Wikipedia) Julius Caesar – 1 st Century B.C.

4 Conventional Cryptograhy PlaintextABCDEFGHIJKLMNOPQRSTUVWXYZ CiphertextDEFGHIJKLMNOPQRSTUVWXYZABC Simple Substitution Cipher Caesar’s Cipher Using this scheme, the plaintext, "SECRET" encrypts as "VHFUHW." To allow someone else to read the ciphertext, you tell them that the key is 3.

5 R S T L N ER S T L N E Since 1988, the most commonly chosen letters (R,S,T,L,N,E) are given to the contestant automatically.

6 Frequency Analysis Caesar's Cipher is so vulnerable to frequency analysis. One-to-one relationship between each letter. If a sufficiently large ciphertext is given, the plaintext can be found out by frequency analysis R S T L N ER S T L N E

7 Frequency Analysis

8 Frequency Analysis: Digraphs DigraphCount DigraphFrequency th5532 th1.52 he4657 he1.28 in3429 in0.94 er3420 er0.94 an3005 an0.82 re2465 re0.68 nd2281 nd0.63 at2155 at0.59 on2086 on0.57 nt2058 nt0.56 ha2040 ha0.56

9 Diplomacy

10 The Zimmerman Telegram – WW I - 1917 U.S. : NO code-breaking ability. - Germany to Mexico, in Code 7500 and 13042 - Intercepted in Britain and decoded by British Naval Intelligence “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”

11 1930’s Europe Germany: Secretly Rearming USSR: Threatening France, Poland, Britain, others: Spying to see what Germany would do.

12 ENIGMA: Germany’s Cipher

13 ENIGMA: Weaknesses

14 France’s Efforts: The ENIGMA Spy

15 Poland’s Efforts: The Bomba

16 Britain’s Efforts: Bombe

17 Britain’s Efforts: Collusus

18 Britain’s Efforts: Alan Turing

19 Significance of Breaking Enigma Responsible for the Outcomes of Some Individual Battles: - the decimation of the Italian Fleet at Matapan in March 1941 - the sinking of the Scharnhorst in December 1943 - helped Britain to defeat the U-boats in the Atlantic between October and November 1941 (evasive routing). (untold merchant ships were saved from sinking, even as number of Uboats increased in 41-42. - Contributed to the outright defeat of U-Boats in the Atlantic in 43-44. - Overlord would probably have had to been delayed 2 years without defeating the U-Boats

20 Defining characteristics of five first operative digital computers ComputerShown workingBin ary Ele ctr oni c ProgrammableTuring complete Zuse Z3ZuseZ3May 1941YesNoBy punched film stockfilm stockYes (1998)1998 Atanasoff-Berry ComputerAtanasoff-Berry Computer Summer 1941Yes No Colossus December 1943 / January 1944 Yes Partially, by rewiringNo Harvard Mark I/IBM ASCCHarvard Mark I/IBM ASCC 1944No By punched paper tapeNo ENIAC1944NoYesPartially, by rewiringYes 1948NoYesBy Function Table ROMROMYes

21 After the War - British Secrecy: - 1945 Collusus machines ordered destroyed by Winston Churchill - Existence Classified until 1970 American companies continued building and improving computers for commercial and especially military use. - ENIAC – Artillery Tables; H-BOMB (1946 – 1955) Aberdeen Proving Grounds - EDVAC - $500,000 binary computer (1951-1960) US. Ballistics Laboratory US National Security Agency (NSA) – Established 1952

22 NSA has the world's largest supercomputing facility. Some of the earliest supercomputers were designed and built for the National Security Agency. The Cray XMP-22 was the first Cray supercomputer ever delivered to a customer site – NSA. NSA is believed to be the U.S.’ largest employer of mathematicians.

23 Snow White by the Brothers Grimm. Retold by Jennifer Greenway. Illus. by Erin Augenstine. Kansas City, MS: Ariel Books, 1991.



26 How ENIGMA Worked Hitting a key on the Enigma keyboard released an electric current which ran to a series of scrambling elements – including a plugboard and three wheels. The scrambling elements diverted the current away from its original course. The current would then hit a 'reflector' end disk which would send the current back through the same scrambling elements again, though on a different course, and the current would finish up by lighting a bulb marked with one of the letters of the alphabet if a German wanted to send a message saying 'Hitler ist in Wilhelmshaven', the Enigma operator would tap the H key on his keyboard and write down on his notepad which bulb on the Enigma's lightboard lit up. The way the plugboard and the wheels were set determined what cipher text was produced. The plugboard looked like a telephone switchboard. The settings lists which Schmidt passed to the French Secret Service specified how all Enigma operators and receivers during a particular quarter should set the plugs connecting the plugboard sockets.

27 How ENIGMA Worked The wheel order to be used by all Enigma operators, which might be, say, wheel 1 on the right, wheel 3 in the middle, and wheel 2 on the left, was, like the plugboard socket connections, specified in the settings lists provided by Schmidt. The wheel on the right turned anti-clockwise one twenty-sixth of a revolution each time a keyboard key was pressed. This meant that if an Enigma operator pressed the H key on the keyboard twice consecutively, the current would go into the right wheel's right face at a different point on each occasion, it would follow a different pathway through the wheels, and it would usually light up a different letter Another element regulated by these settings lists was the ring, marked with the twenty-six letters of the alphabet, which was around the rim of each wheel. The ring could be rotated relative to the inner core of the wheel, and then fixed into position with a catch. The settings at which the rings were fixed were referred to as the Ringstellung by the Germans. If the ring setting on a wheel was, say, A, the ring had to be rotated manually until the A on the ring was opposite the Ringstellung marker, which was a red dot on the catch on some Enigma machines. The letters around the ring – visible through a window above the wheel once the wheel was in its working position inside the Enigma machine – were used by message senders to describe the position of the wheel to message receivers.

28 How ENIGMA Worked The rings also had another function. A notch on each ring ensured that the wheel placed on its left turned one twenty-sixth of a revolution whenever the ring reached a particular position in its cycle. This position was different for each of the three wheels. So, for example, when wheel 1 was placed on the right, the ring on wheel 1 ensured that the middle wheel turned one twenty-sixth of a revolution anti-clockwise if Q was showing through the window above the right wheel when a keyboard key was tapped. The middle wheel was turned as the right wheel turned so that R rather than Q was showing through the window above the right wheel. (The 'turnover positions' for wheels 2 and 3 were at E and V respectively.) The middle wheel would then remain in the position to which it had turned until the keyboard keys were tapped twenty-five more times, by which time the right wheel would have rotated one complete revolution. At this point Q would once again be showing through the window above the right wheel, and the ring around the right wheel would then ensure that the middle wheel turned another. one twenty-sixth of a revolution when the next keyboard key was tapped. Following the same principle, the left wheel would be turned one twenty-sixth of a revolution each time the middle wheel passed its 'turnover position'. After the three wheels were set to a particular position, they would only return to their original position after the keyboard keys had been tapped about 17,000 times

29 Breaking the ENIGMA CODE In Poland, ? Langer was trying to contruct their own Enigma machine in 1932, using their own information from the Enigma they had inspected, using the manuals that Schmidt had supplied to the French, and several code settings. By 1938, the code was still not broken, by the French, and so the French planted some info in their Abwher contacts that the cipher had been broken, to see if the Germans would switch to another one that was easier to break, or to force the Polish Cipher Bureau to reveal more about how close they might be to breaking the code. In fact, Langer and the Polish had broken the code, and had been using it to read German messages for over 5 years, but had neglected to keep their promise to inform the French when they broke it.

30 Das Boot The Eye of the Needle

31 The Polish Cipher Bureau First Guy Radio Guy – broke several simpler German ciphers – Antoni Palluth Three Mathematician he introduced to Cipher Breaking, moved to Warsaw, To work on ciphers part-time. Rózycki* and Zygalski Marian Rejewski was the first that was asked to work on ENIGMA, and given the manuals.* These manuals (photos of) which were smuggled out of Germany by France’s ENIGMA spy made it clear that an Enigma was used to scramble the letters making up the words in a message before it was sent out in morse code by a radio transmitter if a German wanted to send a message saying 'Hitler ist in Wilhelmshaven', the Enigma operator would tap the H key on his keyboard and write down on his notepad which bulb on the Enigma's lightboard lit up. Schmidt's manuals also explained how an Enigma machine produced the cipher text

32 The Polish Cipher Bureau Rejewski knew that if he was to break the code, he would first have to construct a replica Enigma machine. To do this he worked out a formula which, he hoped, would enable him to discover the wiring inside the wheel which was placed on the right. He believed the settings from Schmidt (in August 32) for Sept-Oct 32 would help him do so. He made some GUESSES, and one of them proved correct, from which he, was able to work out the wiring in the wheels Mathematically, with the help from an example setting and message from the manual. Once he knew how the enigma’s were wired, his team was able to build some replicas.

33 Bletchley Park – Role of the British in Breaking Enigma


35 The American Role in Breaking Enigma Hollywood film U-571 – Gave Americans TOO MUCH credit for capturing ENIGMA technology were able (after May 2003) to produce and manufacture machines which could break the Enigma regularly even after the Germans added the fourth wheel to their cipher machines The British engineers had been unable to design equivalent machinery which was reliable.

36 The ENIGMA Spy Hans Thilo Schmidt German Defence Ministry Cipher Office executive who in 1931 gave the French Secret Service their first clues (for profit) on how to break the Enigma code (2 years before NAZIs assumed power) Was betrayed by his French Spy Master to the Germans and arrested by the Gestapo in March 1943 Poisoned himself with cyanide procured by his daughter Untended, unmarked grave outside of Berlin Average, middle-class guy. Wife and 2 small kids. Economic problems when Germany’s economy tanked. Had affairs with a string of uglier maids and others. Charlotte and Martha, insulting gifts. Loved a lot of women. Inability to resist temptation. (Would never be able to work for the NSA now.) Had access to the safe where cipher machines were stored. Contacted French Secret Service. Sold them manuals that described how the Cipher machines worked. (And documents with their current settings?) Initially 10,000 marks for 2 manuals (2001 equivalent of 2,000 francs) According to the French crypotographers: manuals explained how to encipher a message, but they did not enable a cryptographer to read Enigma messages. 2 nd opinion from British.

37 The ENIGMA Spy They agreed with their French counterparts that Schmidt's documents would not enable them to crack the Enigma. He also provided setting instructions, and information about German rearmament, the latter mailed in letters written in invisible ink. Sometimes he would sneak over into Belgium, for meetings with the French, to deliver photographs of settings documents, etc. As he made more and more money, he and is wife took an a lavish lifestyle—expensive suits, and expensive ski vacations in Switzerland, and other European vacations, which the French were concerned would attract attention in Germany. He continued going to bars in Berlin, as well, as though he were not married. When they encourage him to settle down, he enlarged his house and built a small factory producing fat for soap producers. This was a front, to look like this was where is money was coming from. Speaking French to each other, then denying they knew French when their children needed help with their homework. In 1936, informed the French, 2 months in advance, of Germany’s plans invade the Rhineland, thanks to information from his brother, Rodolf Schmidt, an Army General.

38 The ENIGMA Spy quickly, he should telephone Georges Blun, a French journalist based in Berlin. If Schmidt slipped into the conversation the words 'Uncle Kurt has died', Blun would know that Schmidt needed to see him immediately. Both men would then go to the waiting room in the Charlottenburg railway station in Berlin He passed along the information with a map that showed the nations and timelines that Germany planned to invade: Austria in Fall 38; Check. In Spring 39; Poland in Fall 39. However, when the French spymaster telegrammed this information back to France, some of it, the Germans intercepted and decoded the telegram, and so they knew that they had a leak. Schmidt knew they knew, and the French knew they knew, and so they set up new cautions, such as a new address in Geneva to send his letters to, and a new kind of invisible ink.

39 U-33 – German U-Boat was sunk on 12 February 1940 while attempting to lay mines in the Firth of Clyde, one of Britain's busiest estuaries, off the west coast of Scotland 25 members of the crew buried in a German military cemetery at Cannock Chase in Staffordshire, Germany. groups of identical grey granite rectangular gravestones Every year on 12 February, the anniversary of their death, flowers are laid beside their gravestones Max Schiller, a twenty-sixth member of the crew, survived. He was 18. One of the older officers had pleaded with him to sit next to him, because the older Officer thought he was going to die. One of the survivors (which one?) failed to discard two Enigma wheels in his pocket, which were retrieved by the British when he was rescued.

40 U-559 – German U-Boat Was crippled and abandoned in the Eastern Medeterianian, 30 Oct 42 one of the most courageous and significant acts of the Second World War. The HMS Pertard was conducting a search for a German U-Boat U-559 had surfaced and was being abandoned by its crew Lt. Francis Anthony Blair Fasson and Able Seaman Colin Grazier swam to the UBoat and recovered some ENIGMA code books before the U-BOAT sank with them in it Codebreakers needed the books, in addition to their brains (why? Would computers have made a difference?)


42 Enigma - Weaknesses - German U-boat commanders didn’t’ destroy books and devices before trying to scuttle their boats. - German Naval Command Didn’t test to see if Enigma had been compromised, once there was evidence that it might have been. (What evidence?) - Each wheel in the Enigma had a different “turnover position” – it turned over the wheel placed next to it in a different position in the former wheel’s cycle. (DEMO?) All Turing had to do to crack the cipher, “once some of the codebooks were caputred, was to identify the position at which the wheels in the machine were turning over the wheels next to them.” NEED TO UNDERSTAND BETTER. -

43 - U.S. broke the Japanese military code and learned of plans to invade Midway Island. - Believed to have shortened the War in the Pacific by at least one year. Significance of Breaking Other Ciphers

44 Enigma Some wheels—not all devices had the same wheels? How did it operate? How many wheels? (4 th after 1 Feb ’42) – blinded Bletchley Park for 10 and ½ months. First used in 1930 – three years prior to Nazi takeover.

45 U-Boats in WWII d

46 German Blind Eye Paradoxically, the greatest threat to the Allies winning the war at sea was the danger that they would sink too many ships too quickly, thereby alerting the German Naval Command to the possibility that this was because its ciphers were being read. -

47 Bomba Bomba ("Polish for Bomb"): a special- purpose machien designed in October 1938 by Poland's Rejewski to break the German Enigman machine ciphers. ptography%29 There was a new cipher each day, and Bomba could break it in about two hours. They had been breaking the messages for years, but Bomba automated the process. German machine got more sophisticated, but then it started to taking more time.

48 National Cryptologic School

49 Colossus - used by the British. an early electronic digital computer. uter. Operational by 1944. Ten had been constructed by the end of the war. To decipher teleprinter messages which had been encrypted using the Lorenz SZ40/42 machines. Very secret - information not available until late 1970s Colossus

50 Alan Turing also worked for the British code-breaking effort, on the Enigma system Alan Turing

51 1945 or 6: ENIAC - first large scale, digitial, general purpose computer. Designed for calculating artillery firing tables, and was used in the development of the hydrogen bomb. (cost $500,000) ENIAC

52 1952: National Security Agency established in the United States, for this purpose. It was established by NSA 2002 - 50th anniversary, there was speculation that the days when ciphers, or codes, could be broken by mathematical means were numbered. Was instrumental in driving the market for high performance computing in the later 20th century--including the first general purpose computers in the US, and the first "supercomputers", the first parallel computer. Often underwriting the effort. It would take a lot of computing power to break a code, and to dechiper a message, and with the increasing threat of nuclear attack, there was not much time







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