Stream cipher - A cryptographic system that treats plaintexts as a series of bits with
a binary sequence generator and encrypts them one bit at a time (or byte/word unit).
Stream ciphers are mainly used in wireless communication devices because they
can be designed quickly and are actually faster than any block cipher. Block ciphers
use large block data, but stream ciphers generally use bits, a small unit of plaintext.
Encryption is generally generated by combining plaintext with a keystream with a bit-
by-bit exclusive OR operation.
Block cipher - Block cihper refers to a method of performing encryption in units of
blocks corresponding to bundles of bits. While encryption on a 1-bit basis is a stream
