Cryptography Essay -- Data Encryption

Cryptography is such a broad part of our lives we do not even notice the smallest applications, shopping on eBay or watching satellite television. I bet you even used cryptology when you were in school and did not even know it. Ever write a message in numbers instead of letters? Each letter of the alphabet correlated to its number position in the alphabet. The number sequence 3,16,25,12,20,15,12,15,7,25 equals cryptology. This is a form of cryptology in its most basic form. Webster's dictionary defines Cryptography as : n. 1. The act or art of writing in code or secret characters; also, secret characters, codes or ciphers, or messages written in a secret code. 2. The science which studies methods for encoding messages so that they can be read only by a person who knows the secret information required for decoding, called the key; it includes cryptanalysis, the science of decoding encrypted messages without possessing the proper key, and has several other branches; see for example steganography. [1] Cryptographies main purpose is to hide messages and information. One of the earliest forms of cryptography was the rearranging of letters in messages. This was known as transportation ciphers. A cipher is a system in which plain text, usually the letters, are transposed or substituted according to a predetermined code. Another early form of cryptography was the substitution of letters. One cipher was named after Julius Caesar who was said to have used a 3 letter shift. This involved substituting a letter with another letter in the alphabet three positions away. Caesar used this method to communicate with his generals in wartimes. [2] Cryptography tries to protect the confidential nature in the communications of military leaders ... ...to keep secret. References 1. http://www.webster-dictionary.net/d.aspx?w=Cryptography 2. http://en.wikipedia.org/wiki/Cryptography 3. Eerdmans Commentary on the Bible, James D G Dunn, John W Rogerson, eds., Wm. B. Eerdmans Publishing, 2003, ISBN 0-8028-3711-5 4. Kama Sutra, Sir Richard F. Burton, translator, Part I, Chapter III, 44th and 45th arts. 5. David Kahn, The Codebreakers, 1967, ISBN 0-684-83130-9. 6. http://www.cnn.com/SPECIALS/2001/nsa/stories/crypto.history/ 7. Whitfield Diffie and Martin Hellman, "New Directions in Cryptography", IEEE Transactions on Information Theory, vol. IT-22, Nov. 1976, pp: 644-654. 8. http://www.webopedia.com/TERM/S/SSL.html 9. http://computing-dictionary.thefreedictionary.com/TCP%2FIP+port 10. http://news.com.com/FAQ+Sonys+rootkit+CDs/2100-1029_3-5946760.html?tag=nl 11. http://www.rsasecurity.com/node.asp?id=1158