Deck 11: Cryptographic Hash Functions

Question 1

Limited characteristics make it impossible for hash functions to be
used to determine whether or not data has changed.

Answer 1

False

Question 2

the Secure Hash Algorithm design closely models, and is based on, the hash function __________ .

A)MD5
B)FIPS 180
C)RFC 4634
D)MD4

Answer 2

D

Question 3

Big-endian format is the most significant byte of a word in the
low-address byte position.

Answer 3

True

Question 4

It is possible to use a hash function but no encryption for message
authentication.

Question 5

A weak hash function is sufficient to protect against an attack in
which one party generates a message for another party to sign.

Question 6

the most widely used hash function has been the Whirlpool.

Question 7

the way to measure the resistance of a hash algorithm to
cryptanalysis is to compare its strength to the effort required for a
brute-force attack.

Question 8

A good hash function has the property that "the results of applying
the function to a large set of inputs will produce outputs that are
evenly distributed and apparently random".

Question 9

A ___________ is an algorithm for which it is computationally infeasible to find either (a) a data object that maps to a pre-specified hash result or (b) two data objects that map to the same hash result.

A)cryptographic hash function
B)strong collision resistance
C)one-way hash function
D)compression function

Question 10

the cryptographic hash function requirement that guarantees that it is impossible to find an alternative message with the same hash value as a given message and prevents forgery when an encrypted hash code is used is the ___________ .

A)collision resistant
B)pseudorandomness
C)preimage resistant
D)second preimage resistant

Question 11

Whirlpool is a popular cryptographic hash function.

Question 12

the principal object of a hash function is __________ .

A)data integrity
B)compression
C)collision resistance
D)mapping messages

Question 13

It can be shown that some form of birthday attack will succeed
against any hash scheme involving the use of cipher block
chaining without a secret key, provided that either the resulting
hash code is small enough or that a larger hash code can be
decomposed into independent subcodes.

Question 14

Virtually all cryptographic hash functions involve the iterative use
of a compression function.

Question 15

Hash functions can be used for intrusion and virus detections.

Question 16

the cryptographic hash function is not a versatile cryptographic
algorithm.

Question 17

Hash functions are commonly used to create a one-way password
file.

Question 18

the SHA-512 algorithm has the property that every bit of the hash
code is a function of every bit of the input.

Question 19

A ___________ accepts a variable length block of data as input and produces a fixed size hash value h = H(M).

A)hash resistance
B)hash value
C)hash function
D)hash code

Question 20

Encryption hardware is optimized toward smaller data sizes.

Question 21

If collision resistance is required the value _________ determines the strength of the hash code against brute-force attacks.

Question 22

An ideal hash algorithm will require a cryptanalytic effort __________ the brute-force effort.

A)less than or equal to
B)greater than or equal to
C)less than
D)greater than

Question 23

A hash function that satisfies the properties of variable input size, fixed output size, efficiency, preimage resistant and second preimage resistant is referred to as a __________.

A)strong hash function
B)collision resistant function
C)weak hash function
D)preimage resistant function

Question 24

the most important and widely used family of cryptographic hash functions is the __________ family.

Question 25

the effort required for a collision resistant attack is explained by a mathematical result referred to as the ___________ .

A)Whirlpool
B)birthday paradox
C)hash value
D)message authentication code

Question 26

"Given a hash function H, with n possible outputs and a specific value H(x), if H is applied to k random inputs, what must be the value of k so that the probability that at least one input y satisfies H(y) = H(x) is 0.5" is a reference to the __________ .

A)authentication code
B)collision resistant
C)big endian
D)birthday attack

Question 27

the Secure Hash Algorithm was developed by the ___________ .

A)ItIL
B)IEEE
C)ISO
D)NISt

Question 28

When a hash function is used to provide message authentication, the hash function value is often referred to as a ___________ .

Question 29

the compression function used in secure hash algorithms falls into one of two categories: a function specifically designed for the hash function or an algorithm based on a ___________ .

Question 30

A __________ is an attack based on weaknesses in a particular cryptographic algorithm.

Question 31

the two categories of attacks on hash functions are __________ attacks and cryptanalysis.

Question 32

__________ are measures of the number of potential collisions for a given hash value.

A)MACs
B)Primitives
C)Hash codes
D)Preimages

Question 33

Message authentication is achieved using a __________ .

A)DES
B)MDF
C)SHA
D)MAC

Question 34

A hash function that satisfies the properties of variable input size, fixed output size, efficiency, preimage resistant, second preimage resistant and __________ is referred to as a strong hash function.

Question 35

SHA-1 produces a hash value of __________ bits.

A)224
B)160
C)384
D)256

Question 36

__________ is a mechanism or service used to verify the integrity of a message.

A)Message authentication
B)Data compression
C)Data mapping
D)Message digest

Question 37

the kind of hash function needed for security applications is referred to as a __________ hash function.

Question 38

Requirements for a cryptographic hash function include ___________ which is the one-way property.

Question 39

three new versions of SHA with hash value lengths of 256, 384, and 512 bits are collectively known as __________ .

A)SHA-3
B)SHA-1
C)SHA-2
D)SHA-0

Question 40

the __________ resistant guarantees that it is impossible to find an alternative message with the same hash value as a given message.

Question 41

the evaluation criteria for SHA-3 are security, ___________, and algorithm and implementation characteristics.

Question 42

A message authentication code is also known as a __________ hash function.

Question 43

SHA-1 is very similiar in structure and in the basic mathematical operations used to __________ and SHA-0.

Question 44

the hash algorithm involves repeated use of a __________ function, f, that takes two inputs (an n-bit input and a b-bit block) and produces an n-bit output.

Question 45

the hash value of a message in the __________ application is encrypted with a user's private key.