Symmetric Cryptography
Symmetric cryptography provides users with a single key or very closely related keys. The single key is usually shared between two or more people so they can pass secret messages between each other. This digital symmetric key is considered a shared secret between the parties exchanging secret messages. Symmetric cryptography is usually faster for encrypting and decrypting data than asymmetric cryptography.
Symmetric key algorithms include:
 Block ciphers  This method encrypts the data in blocks of a set length.
 Stream ciphers  this method encrypts data using one message bit at a time.
