Report on Cryptography
Contents
Introduction 2
History of Cryptography 2
Modern Cryptography 4
Bibliography 5
Introduction
If you want to keep valuable information a secret, there is two possible solutions: hide the entire existence of the information (Steganographic), or make the information unintelligible (Cryptographic). For the sake of this report we will only look at Cryptography. Cryptography is a technique used to hide the meaning of a message and is derived from the Greek word kryptos which means “hidden” (Mathai). The sender and receiver would agree upon a message scrambling protocol beforehand and agree upon methods for encrypting and decrypting the message or information. Two implementation techniques can be derived from Cryptography namely transposition and substitution.
History of Cryptography
The first recorded use of cryptography for correspondence was by the Spartans who (as early as 400 BC) employed a cipher device called a "scytale" to send secret communications between military commanders (Pell, 2004). Messages were written down the length of the staff, and the papyrus was unwrapped. In order to read the message, the papyrus had to be wrapped around a staff of equal diameter. Without the right staff, it would be difficult to decode the message using the techniques available at that time.
In the famous Greek drama the 'Iliad ', cryptography was used when Bellerophon was sent to the king with a secret tablet which told the king to have him put to death (Cohen, 1995). He had to fight several mythical creatures.
The first inventors of the transposition cipher were the Greeks in the fourth century BC (Pell, 2004). Inventing the Polybius checkerboard, Polybius used this instrument to devise a means of encoding letters into pairs of symbols and elements of the system was common to later encryption systems. It consists of a five by five grid containing all the letters of the alphabet. The letter is converted to a number that represents the row and column number
Introduction 2
History of Cryptography 2
Modern Cryptography 4
Bibliography 5
Introduction
If you want to keep valuable information a secret, there is two possible solutions: hide the entire existence of the information (Steganographic), or make the information unintelligible (Cryptographic). For the sake of this report we will only look at Cryptography. Cryptography is a technique used to hide the meaning of a message and is derived from the Greek word kryptos which means “hidden” (Mathai). The sender and receiver would agree upon a message scrambling protocol beforehand and agree upon methods for encrypting and decrypting the message or information. Two implementation techniques can be derived from Cryptography namely transposition and substitution.
History of Cryptography
The first recorded use of cryptography for correspondence was by the Spartans who (as early as 400 BC) employed a cipher device called a "scytale" to send secret communications between military commanders (Pell, 2004). Messages were written down the length of the staff, and the papyrus was unwrapped. In order to read the message, the papyrus had to be wrapped around a staff of equal diameter. Without the right staff, it would be difficult to decode the message using the techniques available at that time.
In the famous Greek drama the 'Iliad ', cryptography was used when Bellerophon was sent to the king with a secret tablet which told the king to have him put to death (Cohen, 1995). He had to fight several mythical creatures.
The first inventors of the transposition cipher were the Greeks in the fourth century BC (Pell, 2004). Inventing the Polybius checkerboard, Polybius used this instrument to devise a means of encoding letters into pairs of symbols and elements of the system was common to later encryption systems. It consists of a five by five grid containing all the letters of the alphabet. The letter is converted to a number that represents the row and column number
Bibliography: Coe, M. G. (2004, Jan 08). Modern Cryptography - Methods and Uses. (A. Cable, Ed.) Retrieved March 03, 2014, from H2G2: http://h2g2.com/edited_entry/A1315919 Cohen, F. (1995). A Short History of Cryptography. Turkey: Istanbul Teknik Universitesi. Retrieved March 03, 2014, from http://web.itu.edu.tr/~orssi/dersler/cryptography/Chap2-1.pdf Mathai, J. (n.d.). History of Computer Cryptography and Secrecy Systems. New York: Fordham University. Retrieved March 03, 2014, from Fordham University: http://www.dsm.fordham.edu/~mathai/crypto.html Norman, A. L. (1997). Cryptography Defined/A Brief History of Cryptography. Texas: Sarah Simpson. Retrieved March 03, 2014, from http://www.laits.utexas.edu/~anorman/BUS.FOR/course.mat/SSim/history.html Pell, O. (2004). Cryptology. Imperial College, Dept. of Computing. London: Imperial College. Retrieved March 03, 2014, from http://www.ridex.co.uk/cryptology/#_Toc439908852 Simanca, S. R., & Sutherland, S. (2002). Modern cryptography. New York: Stony Brook University. Retrieved March 03, 2014, from https://www.math.sunysb.edu/~scott/Book331/Modern_cryptography.html