Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#2772

  1. A hash function is where you have an input through a hash algorithm and you get a unique output for that exact input. Any change in the input will result in change in the out.

  2. In the bitcoin protocol, hash functions are part of the block hashing algorithm which is used to write new transactions into the blockchain through the mining process. … It’s the need for this large amount of processing power that means new bitcoin get mined over a long period of time, not all at once. - coindesk

  3. Collision resistant means that two different inputs ran through the same hashing algorithm will not result in the same output.

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#2773

1.) Describe hash functions in your own words.

A HASH FUNCTION is the process of converting the input of any length into a fixed size of text using a mathematical function. Any text can be converted in an array of numbers and letters through an algorithm. Input is the message / data that is to be hashed. The hash function is the algorithm used to hash the message / data. The output is called the Hash Value. Simply put…

                          INPUT + HASH FUNCTION = HASH VALUE

             The Hash Value keeps the data's integrity (the input) intact.   It should be impossible to reproduce the same hash value entering different inputs.  Keeping it unique.

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 records/confirms the amount, address, and timestamp to produce a transaction ID or TXID. It then formas a unique hash. This hash is always linked and connected to new blocks. The process is repeated. Always tracking a previous hash to generate a new one while creating an unbreakable dependency forming a hash chain. All this makes blockchain secure, immutable, and transparent.

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.

Collision resistance means that it will be hard to find 2 different inputs and expect the same hash function output, which is an important cryptographic hash property

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#2774
  1. Hash functions are methodologies for converting inputs to unique outputs, but not being able to reverse the process.
  2. Bitcoin utilizes has functions for generating public/private keys, addresses, resolving transactions, and mining.
  3. Collision resistance means that it’s impossible for two unique inputs to have a matching hash output.
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#2775

Elliptic curve function is used to derive public keys. :slight_smile:

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#2776

1.Describe hash functions with your own words
Has functions is a unique fingerprint from input to output.

2.How are hash functions used in cryptocurrencies like bitcoin?
They are used as part of the block hashing algorithm which is used to write new transactions into the blockchain through the mining process

3.What does it mean when we say that hash functions need to be collision resistant?
So it would be hard to find two inputs that hash to the same output

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#2777

  1. Hash functions have a unique input and gives you a unique output that only goes one way. input–>output.

  2. With bitcoin , hashes are used to add new transactional data to the blockchain

  3. Each input is transformed to unique output and the probability of two different inputs transforming to the same output is infeasible , if not impossible.

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#2778

  1. Hash functions are generated - and are the result of - an input; the generation of a value that represents a string of texts using a function to get there. Different from a function, which can go from “result” to “question,” a hash function cannot be retraced back to its original input

  2. Hash functions are used in cryptos like bitcoin to secure the network and allow for the processing of mining new bitcoin. For example, through concatenation, H(k|x) = Y, the random K concatenated with the new block’s hash function X, equals less than the difficulty level of Y. This process gets you a new block and the block reward for new bitcoin. Also helps with security, as simple tampering with information causes massive differences in resulting and verifiable hash rates.

  3. Collision resistant means there is an infeasible probability of having two inputs generate. the same output hash. The chances of them colliding are within the realm of 2^256 possibility.

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#2779
  1. Describe hash functions with your own words

It´s special functions that makes you to inert certain input and receive an output. The output is a fingerprint of the exact input and if input is changed, so is the output.

  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).
    In the bitcoin protocol, hash functions are part of the block hashing algorithm which is used to write new transactions into the blockchain through the mining process.

Hash functions in bitcoin mining, the inputs for the function are all of the most recent, not-yet-confirmed transactions (along with some additional inputs relating to the timestamp and a reference to the previous block).

When changing a small part of the input for a hash function results in a completely different output. This property is crucial to the ‘proof of work’ algorithm involved in mining: to successfully ‘solve’ a block, miners try to combine all of the inputs with their own arbitrary piece of input data in such a way that the resulting hash starts with a certain number of zeroes.

  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).

Collision resistance is a property of cryptographic hash functions: a hash function is collision resistant if it is hard to find two inputs that hash to the same output; that is, two inputs a and b such that H(a) = H(b).

Every hash function with more inputs than outputs will necessarily have collisions. Consider a hash function such as SHA-256 that produces 256 bits of output from an arbitrarily large input. Since it must generate one of 2256 outputs for each member of a much larger set of inputs, the pigeonhole principle guarantees that some inputs will hash to the same output. Collision resistance doesn’t mean that no collisions exist; simply that they are hard to find.

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#2780

  1. Describe hash functions with your own words
    Its used in common security related apllications, each unique input is a unique output, a fingerprint

  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 as part of the block hashing algorithm which is used to write new transactions into the blockchain through the mining proces.

  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).
    Collision resistant is that each input has it unique output, that 2 inputs can’t have the same output

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#2781

  1. Hash functions use the concept of a normal function to create an output(fixed number of characters) from the input that cannot be reversed, whereas a normal function can be worked out backwards if you know what the function is.

  2. They are used to secure information with bitcoin transactions. The hash also makes the transaction identifiable and unique. They are also used in bitcoin mining to be compared to the random nonces that are generated in order to add blocks.

  3. If a hash function is collision resistant it means that it is hard to find another hash that collides with it. Much like the birthday paradox if there are more hashes then it would make it easier to find a collision.

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#2782

Homework on Hash Functions - Questions

  1. Describe hash functions with your own words
    Is a digital fingerprint by which a unique input will always create the same unique output. It should always be a one way function. If an output is given it is too complex to figure out what was the input.

  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).
    Bitcoin uses SHA-256, a secured hashing algorithm. This hash function is used to create its blockchain. Each new block has its own unique hash from transactional data and creates a linked list referencing all previous blocks back to the genesis block.
    "In the bitcoin protocol, hash functions are part of the block hashing algorithm which is used to write new transactions into the blockchain through the mining process. It’s the need for this large amount of processing power that means new bitcoins get mined over a long period of time, not all at once.-Coindesk Feb 19, 2017

  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).
    Its hard to find two inputs that link to the same single output under the application of the hash function. Output is a fixed size but inputs can be different sizes, so it should be astronomically hard to find two distinct inputs that produce the same exact output. Thus the hash function can be collision resistant.

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bcc41d030844579fd7ac5bac5c1dd5d01060×1060 52.2 KB

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#2783

Soon the hash of The Milky Way Galaxy will collide with Andromeda…

It will produce an astronomical collision forming Milkomeda or Milkdromeda :alien::metal:

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#2784
  1. Describe hash functions with your own words
  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).
  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)

Hash functions work by inputting data and outputting a different cryptic set of data.
This is used in Bitcoin in 256 bits. Collision resistance means two different things not getting the same hash.

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#2785
  1. Hash functions are unique one way functions that uses unique inputs to create unique outputs (fingerprints)
  2. Using hash functions in crypto currencies allows data to be secure as the algorithm uses the inputted data and the timestamp and then adds the hash of the previous transaction to encrypt all data. Thus the extremely sensitive information is no longer visible.
  3. Collision resistant means that it is highly unlikely for 2 different inputs to end up with the same hash but it is also not impossible.
2 Likes
#2786
  1. Hash functions take a unique input and produce a unique output.
  2. Hash functions are used in the mining process of Bitcoin. A hash function is used to write a new transaction to the blockchain.
  3. Collision resistant is when two different inputs don’t get the same output.
2 Likes
#2787

1. Describe hash functions with your own words
A Hash function is a oneway function which converts any string of data into a fixed length 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).

  • Creating adresses
  • Creating Private keys
  • Creating Public Keys
  • Mining

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).
Collision resistant means, that the probability of 2 inputs having the same output should be almost impossible. Therefore, each Input has to have it’s own output!

2 Likes
#2788

Homework on hash functions.

  1. Hash function takes a group of characters (called keys) and maps it to a value of certain length (called a hash value or hash) which is a representation of the original string of characters.

  2. Hash functions are part of the Bitcoin algorithm which are use to write new transactions in to the blockchain through many processes. These processes require huge amount of processing power for bitcoin to be mined over a long period of time, instead of all at once.

  3. Hash function needs to be collision resistant means, it should be hard to find two inputs of a hash function that will result in the same output (ie input a and b such that H(a) = H(b)). This gives an added security to the system.

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#2789

hash functions create unique identifiers for any sting of data.
that should not be able to be changed output to input.
.

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#2790

1 hash creats a fingerprint for data.
2 hash functions are used in bitcoin to create a hash for each block to verify data passed to next block

3 colliision resistant because there is no colloisin proof.
always a chance.lol

2 Likes
#2791

[quote=“ivan, post:1, topic:8430”]

  • Describe hash functions with your own words
    I think the differente functions of hashing goes for input to output, but the thing is that you can go from A to B, but not B to A; the another thing I’ve learned is that HASHING is a very unique thing, it always gives unique codes, since input to output, always, it’s like the cornea or the fingerprint.
  • 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).
    I think it’s because de SHA-256, it creates a heavy number that goes with the cryptocurrencies.
  • 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 it’s very difficult to be on the same input or output that other transaction.
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