Cryptographic Hash Functions

Secret key (symmetric) and public key (asymmetric)

Easy to compute, but almost impossible to reverse; map data of arbitrary size to data of fixed size; efficient computability; deterministic; and non-reversible.

Crytographic hash functions are deliberately made very difficult to reverse, while regular hash functions are not.

<p>Because it is deliberately very difficult to determine the input if you know the hash value.</p> Signup and view all the answers

<p>It demonstrates that similar input does not hash to similar values, which is a key property of cryptographic hash functions.</p> Signup and view all the answers

<p>No, the modulus function is not cryptographically secure because it is reversible and does not satisfy the properties of a cryptographic hash function.</p> Signup and view all the answers

<p>To update the hash object with the given data.</p> Signup and view all the answers

<p>A SHA256 hash value represented as a hexadecimal string.</p> Signup and view all the answers

<p>The inability to find the original input data given its hash value.</p> Signup and view all the answers

<p>In second pre-image resistance, the attacker is given a fixed input, while in collision resistance, the attacker can choose any two inputs.</p> Signup and view all the answers

<p>Because it is harder to find any two inputs with the same hash value than to find an input with a given hash value.</p> Signup and view all the answers

<p>It makes it possible for an attacker to find two different inputs with the same hash value.</p> Signup and view all the answers

<p>To ensure that the sender cannot change the value or statement after committing to it, similar to a sealed envelop.</p> Signup and view all the answers

<p>Binding</p> Signup and view all the answers

<p>To ensure immutability and integrity of the ledger by making any changes to the blocks detectable.</p> Signup and view all the answers

<p>To find a value that, when hashed, produces a hash value starting with a certain number of zeros.</p> Signup and view all the answers

<p>It allows for efficient detection of any changes to the ledger.</p> Signup and view all the answers

<p>Because there is no known efficient algorithm to reverse-engineer the hash function.</p> Signup and view all the answers

<p>To detect errors in file transfers and ensure integrity, authenticity, and hiding of data.</p> Signup and view all the answers

<p>SHA1 has a 160-bit hash and is considered broken, while SHA2 is a family of hash functions with different sizes and is still considered secure.</p> Signup and view all the answers

<p>A general method of breaking input messages into equal-sized blocks and applying a compression function iteratively to produce a hash value.</p> Signup and view all the answers

<p>To ensure that the input message is a multiple of the block size.</p> Signup and view all the answers

<p>A type of attack where an attacker finds two different input messages that produce the same output hash value.</p> Signup and view all the answers

<p>SHA3 has no known attacks and is considered secure, while SHA2 has minor attacks and is considered weak.</p> Signup and view all the answers

<p>To create a hash that can only be created or verified by someone with the key, offering both message authenticity and message integrity.</p> Signup and view all the answers

<p>The key only impacts the last stage of calculating the hash.</p> Signup and view all the answers

<p>To build a MAC function that is provably secure using cryptographic hash functions.</p> Signup and view all the answers

<p>To allow one to commit to a chosen value or statement while keeping it hidden from others, with the ability to reveal the committed value later.</p> Signup and view all the answers

<p>H(k | m1m2… mn+1) is more secure because it prevents message extension attacks, whereas H(k | m) is vulnerable to such attacks.</p> Signup and view all the answers

<p>Key K is used to generate K' and K'', and K', K'', and K are used to calculate the HMAC.</p> Signup and view all the answers