Deck 11: Cryptographic Hash Functions

Question 1

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.

Answer 1

True

Question 2

Hash functions can be used for intrusion and virus detections.

Answer 2

True

Question 3

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

Answer 3

False

Question 4

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 5

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

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

Question 6

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

Question 7

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

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

Question 8

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

Question 9

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 10

The cryptographic hash function is not a versatile cryptographic algorithm.

Question 11

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

Question 12

Encryption hardware is optimized toward smaller data sizes.

Question 13

Whirlpool is a popular cryptographic hash function.

Question 14

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

Question 15

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

Question 16

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 17

The most widely used hash function has been the Whirlpool.

Question 18

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

Question 19

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 20

The principal object of a hash function is __________ .

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

Question 21

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 22

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 23

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

Question 24

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

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 Hx),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 Hy)= Hx)is 0.5?" is a reference to the __________ .

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

Question 27

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

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

Question 28

The Secure Hash Algorithm was developed by the ___________ .

A)ITIL
B)IEEE
C)ISO
D)NIST

Question 29

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

Question 30

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

Question 31

SHA-1 produces a hash value of __________ bits.

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

Question 32

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

Question 33

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

Question 34

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

Question 35

Message authentication is achieved using a __________ .

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

Question 36

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

Question 37

__________ 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 38

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 39

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 40

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 41

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

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