Test Review

The most important symmetric algorithms, all of which are block ciphers, are the DES, triple DES, and the __________.

AES

The _________ was issued as a federal information-processing standard and is intended to replace DES and 3DES with an algorithm that is more secure and efficient.

Advanced Encryption Standard (AES)

For general-purpose block-oriented transmission you would typically use _______ mode.

CBC

For general-purpose stream-oriented transmission you would typically use _______ mode.

CFB

______ mode is typically used for a general-purpose block-oriented transmission and is useful for high-speed requirements.

CTR

A ______________ is an attack model for cryptanalysis in which the cryptanalyst gathers information, at least in part, by choosing a ciphertext and obtaining its decryption under an unknown key.

Chosen-ciphertext attack

"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.

Cipher Block Chaining (CBC)

A ______________ is an attack model for cryptanalysis where the attacker is assumed to have access only to a set of ciphertexts.

Ciphertext-only attack

___________ takes a plaintext block of 64 bits and a key of 56 bits to produce a ciphertext block of 64 bits.

DES

The purpose of the __________ is to enable two users to securely reach agreement about a shared secret that can be used as a secret key for subsequent symmetric encryption of messages.

DSS algorithm

Public-key encryption was first publicly proposed by __________ in 1976.

Diffie and Hellman

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

Electronic Codebook (ECB)

The __________ has the advantage that encryption and decryption operations are very similar, even identical in some cases, requiring only a reversal of the key schedule.

Feistel structure

__________ is a term that refers to the means of delivering a key to two parties that wish to exchange data without allowing others to see the key.

Key distribution technique

The ______________ is an attack model for cryptanalysis where the attacker has samples of both the plaintext and its encrypted version then he can use them to expose further secret information after calculating the secret key.

Known-plaintext attack

The __________ protects both a message's data integrity as well as its authenticity, by allowing verifiers (who also possess the secret key) to detect any changes to the message content.

MAC value

__________ is a procedure that allows communicating parties to verify that received or stored messages are authentic.

Message authentication

__________ are the alternative techniques that have been developed to increase the security of symmetric block encryption for large sequences of data.

Modes of operation

The National Bureau of Standards is now the ______________.

National Institute of Standards and Technology

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

OFB

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

RC4

__________ is a block cipher in which the plaintext and ciphertext are integers between 0 and n-1 for some n.

RSA

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

SSM

____________ has a key length of 168 bits, utilizing three 56-bit DES keys.

Triple DES

If the analyst is able to get the source system to insert into the system a message chosen by the analyst, then a ________ attack is possible.

chosen-plaintext

It is possible to convert any block cipher into a stream cipher by using the _______________ mode.

cipher feedback (CFB)

Unlike ECB and CBC modes, ________ mode requires only the implementation of the encryption algorithm and not the decryption algorithm.

counter (CTR)

A __________ is created by using a secure hash function to generate a hash value for a message and then encrypting the hash code with a private key.

digital signature

A ____________ is any function that can be used to map data of arbitrary size to data of fixed size.

hash function

The purpose of a __________ is to produce a "fingerprint" of a file, message, or other block of data.

hash function

Combined one byte at a time with the plaintext stream using the XOR operation, a __________ is the output of the pseudorandom bit generator.

keystream

A _____________ is a small block of data generated by a secret key and appended to a message.

message authentication code

A ________ is a key used between entities for the purpose of distributing session keys.

permanent key

A _________ protects against an attack in which one party generates a message for another party to sign.

strong hash function