Cryptography

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Cryptography
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DEFINITION

• Cryptography is the science of writing in secret
  code
• The earliest documented use began around 2,000
  B.C in Egypt (Hieroglyphics)
• Encryption has been used during warfare. Most
  recently it has been applied to cyber-security.

From An Overview of Cryptography by Gary C.
Kessler, 28 July 2014, http//www.garykessler.net
/library/crypto.html
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HISTORY

• 1835-- Samuel Morse invented the Morse Code
• 1843-- Construction of experimental telegraph
  line from Washington to Baltimore (40 miles)
• http//www.youtube.com/watch?vbNoOYeS0gs0

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HISTORY

• 1895 Changed Cryptology
• Communications were open for anyones inspection

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TYPES
From An Overview of Cryptography by Gary C.
Kessler, 28 July 2014, http//www.garykessler.net
/library/crypto.html
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The Polybius Square
1 2 3 4 5
1 A B C D E
2 F G H I J
3 K L M N O
4 P Q R S T
5 U V W X Y/Z
Ciphertext 45232444 2444 11 441513431545
32154444112215
Go to http//www.braingle.com/brainteasers/codes/p
olybius.php for other types of ciphers
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The Enigma Machine

• The machine was like a typewriter, with the rotor
  replaced.
• It combined substitution and rotation ciphers
  such that the code was difficult to break.
• The machine could decode as well as encoding
  messages.

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ActivitIES
http//www.austincc.edu/lrosen/1314/webact2/webact
2.htm
http//illuminations.nctm.org/Lesson.aspx?id1926
http//jwilson.coe.uga.edu/EMAT6680Fa09/KimS/EMAT6
690/3rd20Write20up/Project-Code/ProjectCoding.ht
ml
http//www.sosmath.com/matrix/coding/coding.html