A cipher that encrypts data one bit at a time.
Stream ciphers are symmetric key algorithms that generally are much faster for encryption information than block ciphers, which encrypt data in discrete chunks called blocks. Stream ciphers generally work by generating a string of bits called a keystream and then XORing this with the stream of data one bit at a time.
A method for encrypting a data sequence of unlimited length using a key of fixed length. Compare block cipher.