Evolution of Cyptography (Research Paper Sample)

Evolution of Cryptography
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Evolution of Cryptography
Introduction
Cryptography refers to secret writing (Zaid, 2007). It is derived from two Greek words kryptos, which stand for secret, and graphos implies writing. Cryptography can be said to mean the science of secret writing intended for protection of data in a way that only the person whom it is send to can decrypt and read. Cryptography involves two critical and complementing techniques, encryption, and decryption. Encryption is the initial operation conducted on plain text in bid to convert it into an unintelligible plain text depending on the input key. Decryption on the other hand operates on the encrypted text with the intention of retrieving its original form that can be easily comprehended.
The art of secret communication has evolved gradually over the past decades starting from simple encoded confidential messages sent in military communication famously associated with Julio Ceasar. Afraid of the fact that highly confidential military message may fall in the hands of the enemies; Julio encrypted his messages using a technique, which later came to be known as Ceasar cipher. This technique involved an alphabet shift by three such that "A" was translated to "D," "B" to "E" and so on (Zaid, 2007). Today, organizations governments and businesses keep highly sensitive and confidential data, which, if left in the hands of the public, may work against the organization. As such most organizations prefer to keep their data secret by encrypting using a unique algorithm available only to few number of important individuals with the view that the less the number of people with knowledge of the cryptosystem, the lower the chances of attacks (Bruce, 2009).
This paper examines the evolution of cryptography by examining the three development stages that are widely agreed by academicians. These are, ancient, technical and paradoxical period. The famous cryptography techniques employed in each of these periods are also described.
Literature review
Shannon’s theory of diffusion and confusion was developed by Shannon in 1949. In his paper "The Communication theory of secrecy system," he explained two components of encryption to prevent frequency analysis, diffusion, and confusion. He posited that confusion is used to hide the link between plain text and encrypted text and may employ the use of complex substitution method. Diffusion on the other hand is intended to spread the statistics over the text to prevent analysis of cryptanalysts. In 1883, Arguste Kerchoff, a Dutch Linguist came up with the kerchoff principle. He stated the security of a crypto-system must exclusively rely on the secrecy of the key and not the secrecy of the algorithm (Simon, 2008).
Periods of Cryptography
Experts have loosely categorized the cryptography history and development into three significant periods. These are, ancient, technical, and paradoxical.
1 Ancient (Until 1918)
Ancient civilization marked the onset of cryptography. 3500 BC the Sumerians came up with cuneiform writing while hierological writing was also witnessed among the Egyptians. However, the Egyptians did not use cryptography as a way of keeping secrets; rather they used it on tombs of deceased kings and other rulers. The Hebrew community, and in particular the scholars were observed to have employed a form of cryptography known as Atbash cipher, a cryptograph technique done by reversing the alphabet (Zaid, 2007).
Monoalphabetic substitution: This cryptography technique is based on a one-to-one or many-to-many relationship between the original message and encrypted text. For instance, in the Atbash cipher "A" is transformed to "Z" and "B" to "Y.”
Monalphabetic cipher (Bruce, 2009)
Frequency analysis: The 19th century witnessed, the Islam’s discover a more complex and advanced way to replace monoalphabetic cipher. The technique took advantage of written language whereby some letters occur more times than others (Bruce, 2009). The statistical distribution of certain letters was used to generate a relationship based on the mean distribution of letters to obtain underlying mapping functions.
Frequency analysis cipher (Zaid, 2007)
Polyalphabetic substitution cipher: further development was done on monoalphabetic cryptography and its variants, which included the incorporation of dummy variables and between plain text and using key phrases. The inefficiencies associated with these methods led to the adoption of polyalphabetic.
2 Technical period
This period marked the period where mechanical machines were employed in encryption especially during the World War 1. During this period, radio communication had already been adopted in warfare. However air transmitted messages were prone to interception and eavesdropping therefore creating a necessity for a more strong cipher (Bruce, 2009). The development and adoption of the enigma machines as cryptography devices by the Germans turned out to be a step in the right direction in the evolution of cryptography. Created by Arthur Scherbius, the machines had three basic elements in its design that were interconnected by wires. The elements included a keyboard for imputing plain text and a scramble unit (Simon, 2008)
Data encryption Standard (DES)
This came after the invention of computers and digital communication. It was designed by IBM researchers in the 1970s and was used by the US Government as an Official Federal Information processing Standard (FIPS). The two types of cryptography designed were stream cipher and block cipher with the main distinction being that stream cipher transmitted data in bits or bytes while block cipher transmitted data in blocks (Zaid, 2007). Lucifer cipher, an IBM invented algorithm was further strengthened after an analysis conducted by National Bureau of Standards (NBS). DES remained as powerful cryptography technique that was employed as a standard for close to 20 years. However, in 1998, Electronic Frontier Foundation (EFF) was able to expose the weaknesses of DES by breaking it, a situation that had been anticipated by most people who feared that 56-bit size was too short. This led to the introduction of 3-DES.
3 Paradoxical period
For long, the major concern that had proved to be detrimental to the development of cryptography was key distribution. Even the advent of computers that brought digital circuits for cryptography was not able to solve this problem. It was not until 1976 when Whitfield Diffie and Martin Hellman published their research work "New Direction of Cryptography" that cryptography was able to beat this problem. In this paper, two parties sharing information or data had to agree on the key distribution (Bruce, 2008)
Other public Key cryptography invented during this era was R...