ABSTRACT
Cryptography, when applied to network security, describes the art of coding information into secrets that are transmitted over a public channel to an intended receiver. The latter is the only entity capable of recovering the initial information from the secrets. That is, any entity can get the encrypted information, i.e., the ciphertext. However, it will not be able to recover the original content of the message, namely, the plaintext, unless it gets the key that has been used for encryption. Cryptography has been used for a long time to provide security properties such as data confidentiality, data integrity, and data origin authentication.
