This lesson's interactive features are locked, please to keep using them
Block vs. Stream
Block Cipher
A block cipher is a deterministic algorithm operating on fixed-length groups of data, called blocks. Block ciphers are an example of symmetric encryption.
Popular block ciphers include:
Stream Cipher
In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding character of the keystream, to give a character of the ciphertext stream.
Popular stream ciphers include:
Which Is Best?
One isn't necessarily better than the other. Stream ciphers are typically used when a stream of data must be encrypted bit by bit. For example, when encrypting a stream of video data in transit. Block ciphers are more typically used on static data, things like passwords in a password manager (like Passly).