Cryptography is the use of codes and ciphers to protect secrets and has been around for centuries. It has its beginnings in ancient Egypt and has played a role in every part of history to its current role in protecting communications across today’s computer networks.
In classical times cryptology was not as sophisticated as it is today, but it had its uses for that time in history. The early Greeks used what was called the Scytale Cipher. It was used between the Greek and Spartan armies and was very popular for its ease of use and the ability to translate a message. (“The Scytale Cipher”, n. d.)
The Scytale cipher is known as a transposition cipher and works by taking a roll of paper or leather, in the case of the Greeks, and wrapping it around a cylinder. The user then proceeds to write the message across the cylinder by placing a letter on each wrap of the paper. This continues until the message is complete. Once complete the paper is unwrapped and the encryption is complete. In order to be decrypted at the other end all that is needed is a cylinder of the same size. (“The Scytale Cipher”, n. d.)
The Romans also used ciphers, most notably the Caesar Cipher. The Caesar Cipher is typically a wheel device with an inner and outer wheel both printed with the alphabet. The Caesar cipher works by substituting a letter of the alphabet with another letter three positions down. This is one of the easiest codes to break since there are only 25 possible solutions. (“Caesar Cipher History”, n. d.)
One of the most significant discoveries of the use of cryptography in ancient times was the Rosetta Stone. The Rosetta Stone was discovered in 1799 by Napoleon’s army while digging fortifications while stranded in ancient Egypt. The stone told of an agreement between Egyptian priests and the pharaoh that occurred on March 27, 196 B. C. The significance of the message was that it was written in three languages - Greek, demotic and hieroglyphics. This provided the key for historians to translate ancient Egyptian hieroglyphs which, at this time, was considered a dead language for over 1500 years. (“History of the Rosetta Stone”, 2014)
During the medieval times the Arabs made significant advances in cryptography and cryptanalysis. The most significant of these was the introduction of the Frequency Analysis technique around 800 AD. This was considered one of the greatest advances in cryptanalysis until the beginning of WWII. (“Medieval Cryptography”, 2014)
Frequency Analysis works on the assumption that in any language certain letters appear with more frequency then others. For example E, T, A, I, O, N, S, H, R, D, L, U are the most common letters used in the English language. In addition to those TH, ER, ON and AN are the most common pairs and SS, EE, TT and FF are the most common repeats. Taking all of that into consideration any monoalphabetic (one alphabet) cipher can be broken by looking for the frequency by which some letters appear and substituting one of...