Survey Paper: Cryptography Is The Science Of Information Security

Cryptography in the past was used in keeping military information, diplomatic correspondence secure andin protecting the national security. However, the use was limited. Nowadays, the range of cryptographyapplications have been expanded a lot in the modern area after the development of communicationmeans; cryptography is essentially required to ensure that data are protected against penetrations and toprevent espionage. Also, cryptography is a powerful mean in securing e-commerce. Cryptography isused to ensure that the contents of a message are confidentiality transmitted and would not be altered.Confidentiality means nobody can understand the received message except the one who has thedecipher key, and data cannot be changed means the original information would not be changed ormodified; this is done when the sender includes a cryptographic operation called a hash function in theoriginal message. A hash function is a mathematical representation of the information, when anyinformation arrives at its receiver; the receiver calculates the value of this hash function. If the receiver’shash function value is equivalent to the sender’s, the integrity of the message is assured .