A network stream needs to be encrypted. Sara, the network administrator, has selected a cipher which will encrypt 8 bits at a time before sending the data across the network. Which of the following has Sara selected?
A block cipher encrypts data into fixed-length groups of bits, called a block. In this question, the cipher is transmitting the data one block at a time.
In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks, with an unvarying transformation that is specified by a symmetric key. Block ciphers operate as important elementary components in the design of many cryptographic protocols, and are widely used to implement encryption of bulk data.
Even a secure block cipher is suitable only for the encryption of a single block under a fixed key. A multitude of modes of …