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.

Accepted Answer

This statement is true. The strength of a hash algorithm is typically measured by analyzing its mathematical properties and determining the effort required for an attacker to find a collision or preimage. This can be compared to the effort required for a brute-force attack, which involves trying every possible input until the correct output is found. By comparing these two efforts, one can determine the relative strength of a hash algorithm against cryptanalysis.

Question 2

Hash functions can be used for intrusion and virus detections.

Accepted Answer

Hash functions can be used to detect intrusions and viruses by generating a digital fingerprint or checksum of a file or network traffic. This fingerprint can be compared to known good values to determine if the file or traffic has been modified or tampered with.

Question 3

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

Accepted Answer

Hash functions are designed to generate a unique output for a given input, which means that even a small change in the input data will result in a completely different output. This property of hash functions makes them ideal for verifying the integrity of data, as any change in the original data will result in a different hash. Therefore, hash functions can be used to determine whether or not data has changed.

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 ___________ .

Accepted Answer

Second preimage resistance ensures that it is computationally infeasible to find a different input that has the same hash output as a given input, preventing forgery.

Question 5

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

Accepted Answer

A hash function takes a variable length block of data as input and produces a fixed size hash value. It is used for various purposes such as data integrity checks, authentication, and digital signatures.

Question 6

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

Accepted Answer

In the big-endian format, the most significant byte is stored in the lower address and the least significant byte is stored in the higher address.

Question 7

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

Accepted Answer

The Secure Hash Algorithm (SHA) was originally based on the design principles of MD4, which influenced its structure and operations.

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.

Accepted Answer

A weak hash function can be easily brute-forced, making it vulnerable to attacks where an attacker can generate multiple messages with the same hash value. This means that the attacker can generate a message that matches the hash of the intended message, and therefore trick the other party into signing a fraudulent message. A strong hash function is necessary to protect against such attacks.

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.

Accepted Answer

This statement is true. A birthday attack takes advantage of the probability of two or more people sharing the same birthday in a group, and applies this probability to finding collisions in a hash function. Cipher block chaining without a secret key is vulnerable to this type of attack, especially if the resulting hash code is small or can be decomposed into independent subcodes.

Question 10

The cryptographic hash function is not a versatile cryptographic algorithm.

Accepted Answer

Cryptographic hash functions have various applications in cryptography, including digital signatures, password storage, and message authentication. They are widely used in information security and are considered versatile cryptographic algorithms.

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.

Accepted Answer

The SHA-512 algorithm is designed to be a one-way function that generates a unique 512-bit hash code for any input data. This algorithm uses a message digest technique that combines different mathematical operations such as bitwise logical operations, modular arithmetic and constant addition to ensure that the output hash code is dependent on every single bit of the input data. This means that even a small change in the input data will result in a completely different hash code. Therefore, every bit of the hash code is indeed a function of every bit of the input.

Question 12

Encryption hardware is optimized toward smaller data sizes.

Accepted Answer

Encryption hardware is designed to efficiently handle a wide range of data sizes, from small to very large, ensuring secure data transmission and storage across various applications.

Question 13

Whirlpool is a popular cryptographic hash function.

Accepted Answer

Whirlpool is indeed a popular cryptographic hash function. It was designed by Vincent Rijmen and Paulo S. L. M. Barreto, and is often used for digital signatures and password hashing.

Question 14

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

Accepted Answer

Virtually all cryptographic hash functions, such as SHA-256 and MD5, use a compression function as the main component in their iteration process.

Question 15

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

Accepted Answer

Hash functions are commonly used to create one-way password files, meaning that passwords cannot be easily reversed or decrypted from the hash value. This provides an added level of security to user passwords.

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.

Accepted Answer

A cryptographic hash function is designed to be virtually impossible to reverse-engineer in order to determine the original input data. This makes it difficult to find either a data object that maps to a pre-specified hash result or two data objects that map to the same hash result, which is why it is commonly used in secure digital communications and encryption systems. The other choices may have some similar properties, but they do not offer the same level of security and protection as a cryptographic hash function.

Question 17

The most widely used hash function has been the Whirlpool.

Accepted Answer

The most widely used hash function is SHA-256, followed by SHA-1 and MD5. Whirlpool, while a strong hash function, is not as widely used as these three.

Question 18

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

Accepted Answer

Hash functions can be used for message authentication without the need for encryption. By comparing the hash value of the original message with the hash value of the received message, the receiver can verify the integrity of the message.

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.

Accepted Answer

This is the definition of a good hash function.

Question 20

The principal object of a hash function is __________ .

Accepted Answer

The answer of The principal object of a hash function...

Quiz 11: Cryptographic Hash Functions