Exam 20: Symmetric Encryption and Message Confidentiality

The _________ is the encryption algorithm run in reverse.

For stream-oriented transmission over noisy channel you would typically use _______ mode.

A ________ cipher processes the input elements continuously,producing output one element at a time as it goes along.

A ________ cipher processes the input one block of elements at a time,producing an output block for each input block.

The most powerful,and most common,approach to countering the threats to network security is ________.

AES uses a Feistel structure.

With ______ encryption each vulnerable communications link is equipped on both ends with an encryption device.

"The input to the encryption algorithm is the XOR of the next 64 bits of plaintext and the preceding 64 bits of ciphertext" is a description of the ________ mode of operation.

Public-key encryption was developed in the late ________.

Stream ciphers are far more common than block ciphers.

If both sender and receiver use the same key the system is referred to as asymmetric.

______ was designed in 1987 by Ron Rivest and is a variable key-size stream cipher with byte-oriented operations.

Plaintext is the scrambled message produced as output.

One desirable property of a stream cipher is that the ciphertext be of the same length as the plaintext.

The _______ module performs end-to-end encryption and obtains session keys on behalf of users.

The ciphertext-only attack is the easiest to defend against.

Cryptographic systems are generically classified by _________.

The exact substitutions and transformations performed by the algorithm depend on the ________.

There are _____ modes of operation defined by NIST that are intended to cover virtually all the possible applications of encryption for which a block cipher could be used.

"Each block of 64 plaintext bits is encoded independently using the same key" is a description of the CBC mode of operation.