_______encryption is a form of cryptosystem in which encryption and decryption are performed using the same key

The two types of attack on an encryption algorithm are cryptanalysis based on properties of the encryption algorithm,                   which involves trying all possible keys. ( and brute- force which)

One of the simplest and best-known polyalphabetic ciphers is ____ cipher. In this scheme, the set of related monoalphabetic substitution rules consists of the 26 Caesar ciphers with shifts of 0 through 25. Each cipher is denoted by a key letter which is the ciphertext letter that substitutes for the plaintext letter a

A  ......cipher processes the input one block of elements at a time producing an output block for each input block whereas a  .........cipher processes the input elements continuously   producing output one element at a time.

The earliest known and simplest use of a substitution cipher was called the ________  cipher and involved replacing each letter of the alphabet with the letter standing three places further down the alphabet

The best known multiple letter encryption cipher is the ______ which treats diagrams in the plain text as single units and translates these units into ciphertext diagrams.

A ____ cipher is an encryption/decryption scheme in which a block of plain text is treated as a whole and used to produce a ciphertext block of equal length

The most widely used encryption scheme is based on the ______ adopted in 1977 by the National Bureau of Standards as Federal Information Processing Standard 46.

A _____ encryption is a form of crypto system in which encryption and decryption are performed using a public key and a private key.

Asymmetric encryption transforms plain text into ____ using one of two keys and an encryption algorithm.