W E I L I N T A N J O O H Y U N G H A

Y O U N G S O O K I M M A R T I N A C A N E V A R I

WWII cryptography and its relationship to the discipline

“computer science”

Argument

  To break and encode ciphers in the Second World War, automatic electromechanical machines were used with great success; this use of “computer” pioneered early computers

Questions

  What were some examples and common conventions of WWII cryptology?

  What, if any, early computer-based systems were used during WWII for cryptology?

  How such developments affected the emergence of early computers?

  How cryptographic systems and computer systems affected the course of the war?

Introduction to Cryptography

  What is cryptography   “secret writing”   A method by which a message

is encoded by the transposition of letters

  Modern Cryptography is encryption and decryption of information of any sort, from bank passwords to Intelligence briefing

  The Second World War is, perhaps, the period of transition from Classic Cryptography to Modern Cryptography

ULTRA

  Started out as a British designation for decrypted messages   Eventually became the term for all intelligence from cryptography   Recruited young men from universities who would later become

prominent in fields such as computer science   Credited with cracking the German Enigma System and the Japanese

PURPLE system, greatly aiding the European and Pacific theaters of war

  The culmination of its successes were the thousands of decoded messages that came out of its doors on a daily basis

  Pioneered the usage of early computers in forms of Bombes and Punch-card Machines like the Colossus

  Its existence and accomplishments were not known to the enemy   In fact, German intelligence still asserted decades after the war that

their encryption systems were uncompromised

Cryptography in the European theater

  Combined British and American efforts   Both nation had to use certain encryption for communication   Both had their own intelligence groups at communication with

each other

  Much of the War effort depended upon cryptanalysis

  Examples   Helped choose the site for D-Day   Were able to track German U-Boat movement   Decrypted personal messages of the German High Command   Pinpoint German supplies and weaknesses   Increased targets for tactical bombing campaign

Enigma

  The primary German code machine   Transferred encrypted Morse code   Used a set of rotors and a logic board to jumble

messages with sets polyalphabetic substitution   One of the first such coding machines to use

complex mechanical and electrical measures   Had, in theory, 3 x 10^114 combinations with

its rotors and boards   Thought to be impossible to crack

  Was used by every branch the German Armed Forces

  It was nearly completely broken during the war without German knowledge

Cracking Efforts and algorithms

  Messages passed through filters to return randomly

  Weaknesses   Would never return the original   Only operated within 1x10^23   Human and tactical errors   Continued belief in its invincibility   Unified system only as weak as its

weakest link   By using Cribs and intercepted

code books, as well as patterns in strict German use, the combinations were continually narrowed

  Eventually codes had small enough combinations to test

Computers Against the Enigma

  Pioneered by IBM punch card machines, early computers with circuits similar to the Engima were used

  Created Alphabetic sheets for each rotor   Later changed into a computerized

process using “Bombes”   These were giant reconstructed engima

machines with the proper wiring inside   Could then electronically run through

combinations   Each one had processing power equivalent to

perhaps 100 workers, each with their own engima decoding machine

The M4 project

  Use of software to solve the Enigma with current hardware   Tests Rings and Message Keys with 5694000 combinations   Currently having solved several codes   Example

  nczwvusxpnyminhzxmqxsfwxwlkjahshnmcoccakuqpmkcsmhkseinjusblkiosxckubhmllxcsjusrrdvkohulxwccbgvliyxeoahxrhkkfvdrewezlxobafgyujqukgrtvukameurbveksuhhvoyhabcjwmaklfklmyfvnrizrvvrtkofdanjmolbgffleoprgtflvrhowopbekvwmuqfmpwp armfhagkxiibg

  Date: 2006-02-20 11:02:26 Score: 6259047 UKW: B W/0: B241 Stecker: ATBLDFGJHMNWOPQYRZVX Rings: AAAV Message key: VJNA vonvonjlooksjhffttteinseinsdreizwoyyqnnsneuninhaltxxbeiangriffunterwasser gedruecktywabosxletztergegnerstandnulachtdreinuluhrmarquantonjotaneunacht seyhsdreiyzwozwonulgradyachtsmystossenachxeknsviermbfaelltynnnnnnoooviery sichteinsnull Preliminary translation:

  From Looks: Radio signal 1132/19 contents: Forced to submerge during attack, depth charges. Last enemy location 08:30h, Marqu AJ 9863, 220 degrees, 8 nautical miles, (I am) following (the enemy). (Barometer) 1014 Millibar (tendency) falling, NNO 4, visibility 10.

The Lorenz Cipher

  German cipher during late WWII   also known as “Fish” to British cryptanalysts

  More complex than the Enigma

  Used “Pseudorandom Numbers”

To Break Lorenz Cipher

  British cryptanalysts found vulnerability from “Fish”   Like starting phrase “SPRUCHNUMMER”

  However, it was needed to crack cipher texts using “Fish” that   Repeated encryption and decryption   Fast calculation including solving equations

Colossus

  The first electronic-programmable computer   Could read data from paper tape   Could programmed by plugs, cords, and switches

  “Thus a wheel-breaking run on Colossus is merely a means of converging into a pattern from any given data, by crude convergence, and using Colossus as a rapid adding machine.”  From “fish report”

  Computer used to break cipher

Pacific Theater

  Situation and summary   7 December 1941 : Japanese attack on Pearl Harbor   1941-1945 : series of naval battles for control over Pacific

Ocean

  American efforts   U.S. Navy's Combat Intelligence Unit : OP–20–G(738 naval

personnel)   Cryptography a key factor   Examples

  Knowledge of fleet movements, strike plans, supply routes etc.   Decoded messages led to the successful assassination of

Yamamoto, the commander in chief of the Japanese Navy

PURPLE

  Main cryptographic machine used by the Japanese navy before and during World War II

  One of the few machines that used stepping switches as its cryptographic element

  Like the German Enigma, decrypted by US Navy intelligence during the war without Japanese knowledge

PURPLE Algorithms

  Outline   Divide alphabet into two groups(6 letters, 20

letters)   Stepping switch connects input and output

terminals, resulting in 25 unrelated cipher alphabets

  Random ‘letter-by-letter’ encipher   Theoretically, almost impossible to decipher

without knowledge of keying information   How it was cracked

  Based on intelligence information, deciphering machine built in 1941 by William Friedman(ECM Mark III)

  Technology involved?   IBM punch-card tabulating machines   Electromechanical system of rotors

Impact on History of Information

  Advancements in both encryption and decryption throughout the war   The Enigma machine, for example, went from 3 to 8 rotors

over the course of the war

  Showcased the advantages and vulnerability of long distance radio transmissions

  Sowed the roots for the information age   Paved the way for the massive changes in

communication methods during the Cold War   Helped win the war – thereby shaping the world as

we know it

Early Computer Systems

  Early Computers sought to do basic mathematical and logical operations that were previously performed by people, not unlike the Bombes of WWII cryptography

  The developments of electrical circuitry, at first in devices such as the Enigma machine, made possible the advent of electronic as opposed to mechanical machines

  Many experts of computer science had backgrounds in cryptology, for example; Arnold Dumey, the inventor of hashing and the UPS delivery code, worked for the service during WWII as a cryptologist

  Postwar Computer systems used input from punch cards nearly identical to those used by WWII cryptography machines

Future Questions

  Did more of the early computer scientists have backgrounds in cryptography?

  Though the German intelligence network did not use mechanical means to decrypt intelligence, how did it nonetheless use cryptography to capture information during the war, especially during the first two years?

  How much knowledge of Japanese ciphers did US intelligence have prior to 1941? To what extent did the American government know about the attacks on Pearl Harbor?

Summary and Conclusions

  Cryptology and Cryptanalysis played vital roles in the Allied victory of WWII   “We owe to the arm of General Menzies [the head of SIS and

distributer of ULTRA files] that we won the war” – Winston Churchill

  Advances in technologically based intelligence and intelligence warfare eventually led to the creation of early computers   “The electrical currents and moving rotors of World War II’s

Enigmas and Sigabas[ECM Mark II] have yielded to computers,…” – R. A. Ratcliff, Delusions of Intelligence

Sources and Citations

  Wilford, Timothy, Pearl Harbor redefined : USN radio intelligence in 1941, Lanham, Md. : University Press of America, c2001. http://oskicat.berkeley.edu/record=b14263460~S1

  Parrish, Thomas (Thomas D.), The ultra Americans : the U.S. role in breaking the Nazi codes, New York : Stein and Day, 1986. http://oskicat.berkeley.edu/record=b12195816~S1

  Ratcliff, R. A. (Rebecca Ann) Delusions of intelligence : Enigma, Ultra and the end of secure ciphers, Cambridge ; New York : Cambridge University Press, 2006. http://oskicat.be.rkeley.edu/record=b15328981~S1

  Smith, Michael, The emperor's codes : the breaking of Japan's secret ciphers, New York : Arcade Pub. : Distributed by Time Warner Trade Pub., 2001. http://oskicat.berkeley.edu/record=b13551028~S1

  Lewin, Ronald. The other Ultra, London : Hutchinson, 1982. http://oskicat.berkeley.edu/record=b12936842~S1   CRYPTOLOGY IN WORLD WAR II, Nation Museum of the US Air Force, visited July,20,2009

http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=9722   M4 Message Breaking Project, The M4 Project is an effort to break 3 original Enigma messages with the help of distributed

computing, visited July 20,2009 http://www.bytereef.org/m4_project.html   World War II, United States Breaking of Japanese Naval Codes, visited on July 20, 2009

http://www.espionageinfo.com/Vo-Z/World-War-II-United-States-Breaking-of-Japanese-Naval-Codes.html   Pearl Harbor, Japanese Attack on, visited on July, 20, 2009

http://www.espionageinfo.com/Pa-Po/Pearl-Harbor-Japanese-Attack-on.html   Albert W. Small, The Special Fish Report (December, 1944)   Allen W. M. Coombs, The Making of Colossus (Annals of the History of Computing, Vol. 5 (No. 3), 1983, pp.253?259)   Enigma machine, From Wikipedia, the free encyclopedia, visited on July 29, 2009 http://en.wikipedia.org/wiki/Enigma_machine   Oral and Personal Histories of Computing at Cornell, visited on July 29,2009

http://www2.cit.cornell.edu/computer/history/pictures.html   Arnold Dumey, From Wikipedia, the free encyclopedia, visited on July 29, 2009 http://en.wikipedia.org/wiki/Arnold_Dumey   Frode Weierud’s CryptoCellar, visited on July 30, 2009 http://cryptocellar.org/simula/purple/index.html

The End

  Questions?   Comments?