Cryptography is an effective way of protecting sensitive information that is stored on media or transmitted through network communication paths.
Although the ultimate goal of cryptography, and the mechanisms that make it up, is to hide information from unauthorized individuals because most protocols can be broken into and the information can be revealed if the attacker has enough time, desire, and resources. Consequently, a more realistic goal of cryptography is to make obtaining the information too work-intensive to be worthwhile to the attacker and this is done through encryption.
The first encryption methods dated back to four thousand years ago and were considered more of an ancient art. As encryption evolved, it was mainly used to pass messages through hostile environments of war, crisis, and for negotiation processes between conflicting groups of people. Throughout history, individuals and governments have worked to protect communication by encrypting it. As time went on, the encryption algorithms and the devices that used them increased in complexity, new methods and algorithms were continually introduced, and it became an integrated part of the computing world. Smith,A(2004)
While cryptography is the science of securing of data, cryptanalysis is the science of analyzing and breaking secure communication. Cryptology embraces both cryptography and cryptanalysis. In order words, it is the coding of plaintext and at the same time decoding it. (Smith 2004)
1.2 STATEMENT OF PROBLEM Cryptography is all about securing information from a third party and also validating the authenticity of the information. The major problem faced in cryptography is that of key management. This is the numeric value used by an algorithm to change information (encryption) and validate the information (digital signatures) making sure the information is secured and visible only to individuals who have the corresponding key to recover the information and verify the authenticity of the information. 1.3 OBJECTIVES OF THE STUDY The aim of this project is to create a web based implementation of CRYPTOGRAPHY HASH FUNCTION algorithm The objectives are as follow: a. To implement the HASH FUNCTION algorithm b. To implement cryptography using SHA5, MD5 and MD45 algorithm. c. To make comparism of SHA5, MD5 and MD45 d. To create a user friendly application. 1.4 SCOPE AND LIMITATION The scope of this study is an examination and implementation of HASH FUNCTION algorithm as a public-key cryptography method with digital signature as authentication for a safe communication on text files only. Other encryption algorithms and authentications are not considered. 1.5 DEFINITION OF TERMS PLAINTEXT or Clear text: The original message that can be read or understood without any special measures. CIPHER TEXT: or the encrypted message algorithm. The method of disguising the plaintext in such a way as to hide its substance is encryption. ENCRYPTION: Is the method of disguising the plaintext in such a way as to hide its substance is encryption DECRYPTION: is the process of getting the original message back is called decryption. To encipher is to transform data into an unreadable format. To decipher is to transfer data into a readable format CRYPTOLOGY: is the study of cryptography and cryptanalysis. CRYPTOGRAPHY: is the science of securing data, CRYPTANALYSIS: is the practice of analyzing and breaking secure communication without a key. A key is the secret sequence of bits and instructions that governs the act of encryption and decryption. CRYPTOGRAPHIC ALGORITHM: is a set of mathematical rules used in encryption and decryption. An application (either a hardware component or programmed code) that provides encryption and decryption is a cryptosystem. CRYPTOSYSTEM: is the strength of cryptography is determined by the length of the key which is in bits. In order words, plaintext is simply binary data (bits)
