WWII cryptography and its relationship to the...
Transcript of WWII cryptography and its relationship to the...
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