Network Security And Cryptography PPT Paper Presentation And PDF

                The science of cryptology is the science of secure communications, formed from the Greek words kryptós, "hidden", and logos, "word". During this time when the Internet provides essential communication between tens of millions of people and is being increasingly used as a tool for commerce, security becomes a tremendously important issue to deal with. One essential aspect for secure communications is that of cryptography. But it is important to note that while cryptography is necessary for secure communications, it is not by itself sufficient. Encryption is the science of changing data so that it is unrecognizable and useless to an unauthorized person. Decryption is changing it back to its original form. Data that can be read and understood without any special measures is called plaintext or cleartext. The method of disguising plaintext in such a way as to hide its substance is called encryption. Encrypting plaintext results in unreadable gibberish called ciphertext. You use encryption to ensure that information is hidden from anyone for whom it is not intended, even those who can see the encrypted data. The process of reverting ciphertext to its original plaintext is called decryption.