Exam 2: Classical Encryption Techniques

If both sender and receiver use the same key,the system is referred to as:

__________ techniques map plaintext elements characters,bits)into ciphertext elements.

The best known multiple letter encryption cipher is the __________ which treats digrams in the plaintext as single units and translates these units into ciphertext digrams.

The simplest transposition cipher is the _________ technique in which the plaintext is written down as a sequence of diagonals and then read off as a sequence of rows.

The __________ attack is the easiest to defend against because the opponent has the least amount of information to work with.