Question 1

the types of functions that may be used to produce an authenticator are grouped into three classes: hash function, message authentication code, and ___________ .

Accepted Answer

The answer of the types of functions that may be...

Question 2

the __________ algorithm can be defined as using the cipher block chaining mode of operation of DES with an initialization vector of zero.

Accepted Answer

The answer of the __________ algorithm can be defined as...

Question 3

the appeal of __________ is that its designers have been able to prove an exact relationship between the strength of the embedded hash function and the strength of this form of authentication.
A)MAC
B)HMAC
C)GMAC
D)CMAC

Accepted Answer

HMAC (Hash-based Message Authentication Code) is appealing because its designers have been able to prove an exact relationship between the strength of the embedded hash function and the strength of HMAC as a form of authentication. This makes it a reliable choice for ensuring data integrity and authentication.

Question 4

An alternative authentication technique involves the use of a secret key to generate a small fixed size block of data known as a __________ or MAC that is appended to the message.

Accepted Answer

The answer of An alternative authentication technique involves the use...

Question 5

Attacks on MACs can be grouped into two categories: brute-force attacks and __________ .

Accepted Answer

The answer of Attacks on MACs can be grouped into...

Question 6

Any modification to a sequence of messages between parties, including insertion, deletion, and reordering is a __________ attack.

Accepted Answer

The answer of Any modification to a sequence of messages...

Question 7

the _________ attack is when the attacker is looking for two messages M and M1 that produce the same hash: H(M) = H(M1)
A)birthday
B)chaining
C)MAC
D)hash

Accepted Answer

The birthday attack specifically targets the property of hash functions where the attacker tries to find two different inputs (M and M1) that result in the same hash output (H(M) = H(M1)). This exploits the birthday paradox in probability theory to find collisions in hash functions more efficiently than brute force.

Question 8

the essential elements of any pseudorandom number generator are a __________ and a deterministic algorithm for generating a stream of pseudorandom bits.
A)secret key
B)session key
C)seed value
D)stream encryption function

Accepted Answer

The essential element of any pseudorandom number generator is a seed value, which is used in conjunction with a deterministic algorithm to generate a stream of pseudorandom bits.

Question 9

__________ assures that data received are exactly as sent and that the purposed identity of the sender is valid.

Accepted Answer

The answer of __________ assures that data received are exactly...

Question 10

the MAC function is a __________ function.
A)one-to-many
B)many-to-one
C)one-to-one
D)one-to-two

Accepted Answer

The MAC (Message Authentication Code) function is a many-to-one function because it maps messages of variable length to fixed-length MAC values. This means many different messages can result in the same MAC value, although in practice, a good MAC function makes this occurrence highly unlikely to prevent security issues.

Question 11

When an entire message is encrypted for confidentiality using either symmetric or asymmetric encryption the security of the scheme generally depends on the __________ of the key.

Accepted Answer

The answer of When an entire message is encrypted for...

Question 12

With _________ authentication an opponent would have difficulty generating ciphertext that when decrypted would have valid error control bits.
A)checksum
B)CMAC
C)cipher block chaining
D)internal error control

Accepted Answer

Internal error control involves embedding error detection codes within the ciphertext, making it difficult for an opponent to generate valid ciphertext that decrypts correctly.

Question 13

two MACs that are based on the use of a block cipher mode of operation are Data Authentication Algorithm and __________ .
A)GMAC
B)DMAC
C)tMAC
D)CMAC

Accepted Answer

CMAC is a block cipher mode of operation that is used to provide data authentication. It is based on the CBC-MAC mode of operation, but it uses a different method for calculating the MAC value. CMAC is more efficient than CBC-MAC, and it is also more secure.

Question 14

A __________ takes a variable length message and a secret key as input and produces an authentication code.

Accepted Answer

The answer of A __________ takes a variable length message...

Question 15

Discovery of the pattern of traffic between parties is a __________ attack.

Accepted Answer

The answer of Discovery of the pattern of traffic between...

Question 16

the approach taken by the transport Layer Security protocol and the Wireless transport Layer Security Protocol involve invoking HMAC _________ for each block of output wi.
A)zero times
B)twice
C)three times
D)once

Accepted Answer

The Transport Layer Security (TLS) protocol and Wireless Transport Layer Security (WTLS) protocol invoke HMAC twice for each block of output to ensure data integrity and authenticity.

Question 17

the GCM mode makes use of two functions: __________, which is a keyed hash function, and GCtR.
A)CtR
B)HMAC
C)GHASH
D)CCM

Accepted Answer

GHASH is the keyed hash function used in GCM (Galois/Counter Mode) for authentication.

Question 18

"Release of message contents to any person or process not possessing the appropriate cryptographic key" is a __________ attack.
A)content modification
B)source repudiation
C)disclosure D.sequence modification

Accepted Answer

This describes a "disclosure" attack, where the information is revealed to someone without the necessary cryptographic permissions, compromising the confidentiality of the message.

Question 19

One approach to constructing a MAC is to use a symmetric block cipher in such a way that it produces a __________ output for a variable length input.

Accepted Answer

The answer of One approach to constructing a MAC is...

Question 20

the key algorithmic ingredients of _________ are the AES encryption algorithm, the CtR mode of operation, and the CMAC authentication algorithm.
A)DAA
B)GCM
C)CCM
D)CMA

Accepted Answer

CCM mode (Counter with CBC-MAC) combines the counter (CTR) mode of operation for encryption with the CBC-MAC algorithm for authentication.

Quiz 12: Message Authentication Codes

the types of functions that may be used to produce an authenticator are grouped into three classes: hash function, message authentication code, and ___________ .

the __________ algorithm can be defined as using the cipher block chaining mode of operation of DES with an initialization vector of zero.

the appeal of __________ is that its designers have been able to prove an exact relationship between the strength of the embedded hash function and the strength of this form of authentication.

An alternative authentication technique involves the use of a secret key to generate a small fixed size block of data known as a __________ or MAC that is appended to the message.

Attacks on MACs can be grouped into two categories: brute-force attacks and __________ .

Any modification to a sequence of messages between parties, including insertion, deletion, and reordering is a __________ attack.

the _________ attack is when the attacker is looking for two messages M and M1 that produce the same hash: H(M) = H(M1)

the essential elements of any pseudorandom number generator are a __________ and a deterministic algorithm for generating a stream of pseudorandom bits.

__________ assures that data received are exactly as sent and that the purposed identity of the sender is valid.

the MAC function is a __________ function.

When an entire message is encrypted for confidentiality using either symmetric or asymmetric encryption the security of the scheme generally depends on the __________ of the key.

With _________ authentication an opponent would have difficulty generating ciphertext that when decrypted would have valid error control bits.

two MACs that are based on the use of a block cipher mode of operation are Data Authentication Algorithm and __________ .

A __________ takes a variable length message and a secret key as input and produces an authentication code.

Discovery of the pattern of traffic between parties is a __________ attack.

the approach taken by the transport Layer Security protocol and the Wireless transport Layer Security Protocol involve invoking HMAC _________ for each block of output wi.

the GCM mode makes use of two functions: __________, which is a keyed hash function, and GCtR.

"Release of message contents to any person or process not possessing the appropriate cryptographic key" is a __________ attack.

One approach to constructing a MAC is to use a symmetric block cipher in such a way that it produces a __________ output for a variable length input.

the key algorithmic ingredients of _________ are the AES encryption algorithm, the CtR mode of operation, and the CMAC authentication algorithm.