Block cipher is an encryption method type in which plaintext is processed in data blocks. The data blocks are encrypted and decrypted independently of each other. Examples of block ciphers are the algorithms AES [please link to glossary term], Blowfish, CAST, IDEA, MARS, Rijndael, RC5, RC6, SAFER, Skipjack, Serpent and Twofish. An alternative to this is the so-called stream ciphers, in which the information stream is continuously encrypted character by character.