WWII cryptography and its
relationship to the discipline
“computer science”
WEILIN TAN
JOOHYUNG HA
YOUNG SOO KIM
MARTINA CANEVARI
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
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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 Punchcard 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
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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
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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
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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
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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”
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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
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Use of software to solve the Enigma with current hardware
Tests Rings and Message Keys with 5694000 combinations
Currently having solved several codes
Example
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nczwvusxpnyminhzxmqxsfwxwlkjahshnmcoccakuqpmkcsmhkseinjusblkiosxckub
hmllxcsjusrrdvkohulxwccbgvliyxeoahxrhkkfvdrewezlxobafgyujqukgrtvukameurb
veksuhhvoyhabcjwmaklfklmyfvnrizrvvrtkofdanjmolbgffleoprgtflvrhowopbekvwm
uqfmpwp armfhagkxiibg
Date: 2006-02-20 11:02:26 Score: 6259047 UKW: B W/0: B241 Stecker:
ATBLDFGJHMNWOPQYRZVX Rings: AAAV Message key: VJNA
vonvonjlooksjhffttteinseinsdreizwoyyqnnsneuninhaltxxbeiangriffunterwasser
gedruecktywabosxletztergegnerstandnulachtdreinuluhrmarquantonjotaneunacht
seyhsdreiyzwozwonulgradyachtsmystossenachxeknsviermbfaelltynnnnnnooovier
y 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
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Colossus
  The first electronic-programmable computer
  Could read data from paper tape
  Could programmed by plugs, cords, and switches
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“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
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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
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“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
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“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
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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?