1. CRYPTOGRAPHY

2. 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 Gary C. Kessler

3. 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?v=bNoOYeS0gs0

4. HISTORY 1895 – Changed Cryptology— Communications were open for anyone’s inspection

5. TYPES From “An Overview of Cryptography” by Gary C. Kessler, 28 July 2014, http://www.garykessler.net/library/crypto.html Gary C. Kessler

6. THE POLYBIUS SQUARE 12345 1ABCDE 2FGHIJ 3KLMNO 4PQRST 5UVWXY/Z Ciphertext: 45232444 2444 11 441513431545 32154444112215 Go to http://www.braingle.com/brainteasers/codes/polybius.php for other types of ciphershttp://www.braingle.com/brainteasers/codes/polybius.php

7. 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.

8. ACTIVITIES http://www.austincc.edu/lrosen/1314/webact2/webact2.htm http://illuminations.nctm.org/Lesson.aspx?id=1926 http://jwilson.coe.uga.edu/EMAT6680Fa09/KimS/EMAT6690/3rd%20Write%20up/Project- Code/ProjectCoding.html http://www.sosmath.com/matrix/coding/coding.html