Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#5281

[quote=“ivan, post:1, topic:8430”]

  • Describe hash functions with your own words
    Hash functions is algorithm upon bitcoin exists. Each unique input gives us unique output. We can not go from output into input, it is not possible to reverse. It is only one way function.
  • How are hash functions used in cryptocurrencies like bitcoin?
    Bitcoin mining.
  • What does it mean when we say that hash functions need to be collision resistant?
    Collision resistant means it is difficult to find 2 inputs that gives the same output.
1 Like
#5282
  1. Describe hash functions with your own words
    Hash functions are one-way mathematical functions that translate any word string in fixed size alphanumeric string.
  2. How are hash functions used in cryptocurrencies like bitcoin? (Try to research this on your own, we will cover this later in the course but challenge yourself and see if you can find information on this already )
    Miners use the SHA-256 function to calculate the hash of the block header and compare this value to the Nonce. If the hash value is below of the nonce value, the network rewards the node. So using the hash functions allows to reward the miners that belong to the infrastructure
  3. What does it mean when we say that hash functions need to be collision resistant? (We didn’t use the term “collision resistant” in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, that’s how you learn best).
    It means that the hash functions don’t allow to generate the same output from two different inputs
1 Like
#5283
  1. Describe hash functions with your own words

each unique input gives a unique output, a digital fingerprint. It is a one way function, because it is impossible to start with the output and get the orginal input.

  1. How are hash functions used in cryptocurrencies like bitcoin? (Try to research this on your own, we will cover this later in the course but challenge yourself and see if you can find information on this already now).

Hash functions write new transactions trough mining crypto.

  1. What does it mean when we say that hash functions need to be collision resistant? (We didn’t use the term “collision resistant” in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, that’s how you learn best)

any input into a hash, cannot produce the same hash twice. So it is a unique identifier. It is hard to find two inputs with the same output.

1 Like
#5284

  1. Describe hash functions with your own words
    Linear conversion of a string of data which can be digitd letters or even media files translated into a alphanumeric string of a set size. It’s basically giving every unique input a unique fingerprint which will always be the same if the input is the same so it’s possible to verify is anything has be changed.

  2. How are hash functions used in cryptocurrencies like bitcoin? (Try to research this on your own, we will cover this later in the course but challenge yourself and see if you can find information on this already now).

They are used for verification of data and confirmation of signatures / public keys

  1. What does it mean when we say that hash functions need to be collision resistant? (We didn’t use the term “collision resistant” in the lecture, but you will easily find this on Google, we add this question intentionally to make you research informati

It prevents two different inputs from having the same output

1 Like
#5285

hi everyone,

  1. A hash function takes a digital input, makes a (complicated) computation, and gives a fingerprint unique to that input. Change the input slightly and you get a different output. It is a one-way mechanism. You can not derive the input from output.
  2. To mine bitcoin miners has to take transactions data and find the number (by trying one by one, there are various possibilities, so it is a lottery) the number which added to that transactions data, and used as input of the hashing function, will give as output the specified target.
  3. It means that taking two different inputs, it is extremely unlikely that the function returns the same output. So it is extremely hard to find two inputs giving the same output.
1 Like
#5286
  1. Hash functions are a computation that translate any data into a unique digital fingerprint or hash that are indecipherable.
  2. The hash or unique fingerprint created by a cryptocurrency transaction generates a block on the blockchain ledger that is both immutable and secure. These transaction blocks are linked together to form chain that can be viewed or traced.
  3. In cryptography a hash function that is collision resistant means that it is difficult to find two inputs that generate the same two outputs.
1 Like
#5287

  1. Hash Functions are a function that gives each unique input its own output and you cannot go from output to input. This makes Hash Functions 1 way functions.

  2. Hash Functions are used in cryptocurrencies such as bitcoin through block hashing and creating public keys.

  3. It mean that we cannot have 2 inputs that have the same output.

2 Likes
#5288

  1. It takes an input of any value (up to 130k characters with SHA-256 on the test tool in the course, not sure if this is the real limit) and converts it into a digital fingerprint of a fixed size. The slightest change in the input will change the output entirely. It is not possible to figure out the input with just an output.

  2. Hash functions were not invented for cryptocurrencies, but the algorithm is widely used to solve the next block in the chain if I understand it correctly. Miners use computer power to find the correct input to generate a hash that ends with a number of zeroes.

  3. A Hash Function is collision-resistant if it is hard to find several inputs that generate the same output.
    There will always be a risk of this in cryptographic hash functions due to the pigeonhole principle. There are simply more input variations than output variations, that being said it is not easy to stumble upon such collision and is yet to be found with SHA 256.

1 Like
#5289

  1. Describe hash functions with your own words
    Hash Functions are functions that convert input value to a hash value, Each unique input will give a unique output.

  2. How are hash functions used in cryptocurrencies like bitcoin?
    Hash functions are used in cryptocurrency to perform secured transactions, The algorithm use by bitcoin is the SHA-256(secure hash algorithm) which was invented by the national security agency(NSA). this convert an input to an output but can’t go from output to input which means it’s a one way function.

  3. What does it mean when we say that hash functions need to be collision resistant?
    Hash functions need to be collision resistance so that it is hard to get the same output for two different input.

2 Likes
#5290
  1. Each unique input gives a unique output. This is calles a unique digital finger print.
  2. One of the main uses of hash functions is to obscure certain data in order to limit their use. Another fundamental use of cryptographic hash functions in the Bitcoin system is in the generation of new coins.
  3. In cryptography, the term “collision resistant” is a situation that occurs when two different inputs produce the same output via a hash function.
2 Likes
#5291

  1. Hash function is taking the data of the input, for example a password could be hashed, and turning it into a series of letters and numbers using a mathematical formula which gives the password a completely unique hashed value. So, the system knows the passwords hashed value but never knows the actual password. If you type it correctly, the hashed value will be accepted by the system and you are granted access.

  2. Hash functions in crypto are used to take all of the most recent and unconfirmed txs data, as well as other things such as the previous blocks hash, time stamp etc and giving a brand new hash.

  3. Collision resistant just means that no 2 different inputs can create the same output, EVER.

1 Like
#5292

  1. A Hash Funktion encrypted Data to a hexidecimal text of random numbers and letters

  2. To hold “user information” or transaction information anonymusly aka pseudonymusly in the network

  3. A collision resistants is when it is hard to find two or more inputs that result in the same output

2 Likes
#5293

  1. Describe hash functions with your own words
    A hash function is a one-way street to blend your string into a predictable, repeatable, mess of a string. It is non-reversible, so the input cannot be hacked with only the output.

  2. How are hash functions used in cryptocurrencies like bitcoin? (Try to research this on your own, we will cover this later in the course but challenge yourself and see if you can find information on this already now).
    Hash functions allow transactions to take place anonymously, verify (mine/validate) transactions, they can also be used to generate a signature, password verification, and preserve message integrity (cryptography, after all).

  3. What does it mean when we say that hash functions need to be collision resistant? (We didn’t use the term “collision resistant” in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, that’s how you learn best).
    According to Wikipedia, collision resistance is a term to describe the difficulty of finding 2 inputs that hash to the same output.

2 Likes
#5294
  1. Describe hash functions with your own words
    It’s a function which calculates unique fingerprint of the unique input data.
  2. How are hash functions used in cryptocurrencies like bitcoin?
    It used to hash new blocks (of the blockchain) of data
  3. What does it mean when we say that hash functions need to be collision resistant?
    There is possibility that the hashing algorithm has equal results/outputs/fingerpints for different inputs.
1 Like
#5295

Homework on Hash Functions - Questions

  1. Describe hash functions with your own words
  • A hash function is a mathematical function that converts a numerical input value into another compressed numerical value.
  1. How are hash functions used in cryptocurrencies like bitcoin? (Try to research this on your own, we will cover this later in the course but challenge yourself and see if you can find information on this already now).
  • Hash functions are primarily used for generating public keys and block hashing. Hash functions are widely used in cryptocurrencies to pass transaction information anonymously.
  1. What does it mean when we say that hash functions need to be collision resistant? (We didn’t use the term “collision resistant” in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, that’s how you learn best).
  • It means that no two inputs should produce the same output, otherwise the blockchain would not be able to work properly as intended.
1 Like
#5296
  1. A hash function is a mathematical computation that takes any input and produces a unique output of an exact size, regardless of the size of the input.
  2. Hash functions are used in cryptocurrencies so that transaction information can be passed securely and anonymously.
  3. Collision resistance implies that it’s difficult to find two x,x that will have the same hash value. In other words, two colliding (non-unique hash values, as they are identical) inputs. Most of the security in Bitcoin relies upon this property.
1 Like
#5297

  1. Has functions are a set of alphanumeric strings that represent an input basically to encrypt information, making it hard/impossible to copy or alter without being broken

  2. Hash functions in Bitcoin are used to generate public keys and block hashing. This is used to ensure secure transactions over the blockchain.

  3. Its difficult to find two inputs that generate the same output

1 Like
#5298
  1. Hash function is when any input gives you unique output , and its one way only, thats why they are using name signature. Its using SHA256 algorithm with base 16 .
  2. Hash function is used to crypt input data, so with only output data people can’t guess it.
  3. collision resistant means different input cannot have same output.
1 Like
#5299
  1. Hash functions are one-way functions where each input will produce a unique hash output.
  2. In order to mine BTC computers attempt to reach a specific number of zeros at the start of the hash output. This takes a tremendous amount of computational power and is essentially a trial and error exercise.
  3. Collision resistance is a required trait of a cryptographic hash algorithm, it would be insecure without it. It essentially means that it is highly unlikely for two different inputs to produce the same hash output (AKA - collision).
1 Like
#5300

  1. A hash function is a mathematical function that can only be solved in a linear unidirectional manner, i.e you can only go from input to output. They are used for cryptocurrency, password security, and message security.

  2. Hash functions are used in cryptocurrency to send information about a transaction in an anonymous manner.

  3. A hash function being collision-resistant means no two input hashes can give the same output hash

1 Like