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


1
The History of Codebreaking, Part I The
Pre-Computing Era(Preview Edition) Jason Hale
2
Cipher Early 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.
- Pen and paper techniques - Language knowledge
and statistical techniques
3
Early Adopters of Cryptography
Julius Caesar 1st Century B.C.
Al-Kindi 9th Century Muslim Arab Scientist, was
responsible for the first known recorded
explanation of cryptoanalysis (Wikipedia) http//
en.wikipedia.org/wiki/Cryptanalysis http//en.wiki
pedia.org/wiki/Abu_Yusuf_Yaqub_ibn_Ishaq_al-Sabbah
_Al-Kindi
4
Conventional Cryptograhy
Simple Substitution Cipher Caesars Cipher
Plaintext ABCDEFGHIJKLMNOPQRSTUVWXYZ Ciphertext D
EFGHIJKLMNOPQRSTUVWXYZABC
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.
http//library.thinkquest.org/C0126342/ceaser.htm
5
Since 1988, the most commonly chosen letters
(R,S,T,L,N,E) are given to the contestant
automatically.
R S T L N E
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 E
http//library.thinkquest.org/C0126342/ceaser.htm
7
Frequency Analysis
http//www.math.cornell.edu/mec/2003-2004/cryptog
raphy/subs/frequencies.html
8
Frequency Analysis Digraphs
Digraph Count   Digraph Frequency
th 5532   th 1.52
he 4657   he 1.28
in 3429   in 0.94
er 3420   er 0.94
an 3005   an 0.82
re 2465   re 0.68
nd 2281   nd 0.63
at 2155   at 0.59
on 2086   on 0.57
nt 2058   nt 0.56
ha 2040   ha 0.56
http//www.math.cornell.edu/mec/2003-2004/cryptog
raphy/subs/digraphs.html
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
1930s Europe
Germany Secretly Rearming USSR
Threatening France, Poland, Britain,
othersSpying to see what Germany would do.
12
ENIGMA Germanys Cipher
13
ENIGMA Weaknesses
14
Frances Efforts The ENIGMA Spy
15
Polands Efforts The Bomba
16
Britains Efforts Bombe
17
Britains Efforts Collusus
18
Britains 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
Computer Shown working Binary Electronic Programmable Turingcomplete
Zuse Z3 May 1941 Yes No By punched film stock Yes (1998)
Atanasoff-Berry Computer Summer 1941 Yes Yes No No
Colossus December 1943 /January 1944 Yes Yes Partially, by rewiring No
Harvard Mark I/IBM ASCC 1944 No No By punched paper tape No
ENIAC 1944 No Yes Partially, by rewiring Yes
ENIAC 1948 No Yes By Function Table ROM Yes

http//en.wikipedia.org/wiki/ENIAC
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 LaboratoryUS 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
http//disney.go.com/vault/archives/movies/snow/sn
ow.html
Snow White by the Brothers Grimm. Retold by
Jennifer Greenway. Illus. by Erin Augenstine.
Kansas City, MS Ariel Books, 1991.
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How ENIGMA Worked
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.
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
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. 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. 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 BootThe Eye of the Needle
31
First GuyRadio Guy broke several simpler
German ciphers Antoni PalluthThree
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
Frances 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
The Polish Cipher Bureau
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 enigmas were
wired, his team was able to build some replicas.
33
Bletchley Park Role of the British in Breaking
Enigma
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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
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 Germanys 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
theCipher 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.2nd opinion from British.
The ENIGMA Spy
37
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
Germanrearmament, the latter mailed in letters
written in invisible ink. Sometimes he would
sneak over into Belgium, for meetings with
theFrench, to deliver photographs of settings
documents, etc. As he made more and more money,
he and is wife took an a lavish
lifestyleexpensive 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
notmarried. When they encourage him to settle
down, he enlarged his house andbuilt a small
factory producing fat for soap producers. This
was a front, to looklike this was where is money
was coming from. Speaking French to each other,
then denying they knew French when theirchildren
needed help with their homework. In 1936,
informed the French, 2 months in advance, of
Germanys plans invade the Rhineland, thanks to
information from his brother, Rodolf Schmidt,
anArmy General.
The ENIGMA Spy
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 spymastertelegrammed this information
back to France, some of it, the Germans
intercepted and decoded the telegram, and so
they knew that they hada 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 crewLt. Francis
Anthony Blair Fasson and Able Seaman Colin
Grazier swam to the UBoat and recovered some
ENIGMA code books before the U-BOATsank with
them in it Codebreakers needed the books, in
addition to their brains (why? Wouldcomputers
have made a difference?)
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Enigma - Weaknesses
- German U-boat commanders didnt destroy books
and devices before trying to scuttle their
boats.- German Naval Command Didnt 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 wheels 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
Significance of Breaking Other Ciphers
- 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.
44
Enigma
http//home.earthlink.net/nbrass1/enigma.htm Som
e wheelsnot all devices had the same wheels? How
did it operate?How many wheels? (4th 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. http//en.wikipedia.org/wiki/Bomba_28cr
yptography29 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
http//www.nsa.gov/museum/
National Cryptologic Schoolhttp//www.nsa.gov/abo
ut/about00004.cfm
49
Colossus
Colossus - used by the British. an early
electronic digital computer. http//en.wikipedia.o
rg/wiki/Colossus_computer. 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
50
Alan Turing
Alan Turing also worked for the British
code-breaking effort, on the Enigma system
51
ENIAC
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)
52
NSA
1952 National Security Agency established in
the United States, for this purpose. It was
established by
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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