Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#4159

  1. Describe hash functions with your own words
    *Hash functions are mathematical algorithms that are linear functions used to create encrypted keys that cannot be reversed engineered.

  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).
    *When we use linear hash functions on Bitcoin it provides the blockchain’s consensus protocol the ability to confirm transactions and make them irreversible. This in return makes it infeasible to hack the system or be manipulated.

  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 need to be collision resistant so that when nodes are working on consensus of the information being added to the blockchain all other nodes in the system are not tricked into confirming the information because it has the same signature.

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#4160

  1. Describe hash functions with your own words
    Hash functions work by taking an input no matter how big or small into the hash and getting a fixed 256bit output. You can not derive the input from 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).
    A cryptographic hash function is a mathematical algorithm that maps data of arbitrary size to a bit array of a fixed size . It is a one way function , that is a function which is practically infeasible to invert.

  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 no two inputs should create the same output.

  4. A hash function is said to be collision-resistant because it is infeasible to find two different inputs to hash to the same output.

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#4161

1- hash functions are one way functions that take an input and produce an output. These functions are not easily reproduced and by being secure act as a point of security for the collection of data.
2-hash functions are used in cryptocurrencies to store data and timestamp transactions from previous blocks. this level of security prevents fraud and maintains the integrity of the blockchain.
3- collision resistant means that two hash functions will not have the same output unless they are the exact same input. It is very hard to find two inputs that have the same output as any adjustment can alter the output completely.

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#4162
  1. Describe hash functions with your own words

A hash function is a function that converts an input of any size to a unique output of a fixed length of bits.

  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 function are used to write new transactions into the blockchain through the mining process.

  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 has to be impossible for two unique inputs to produce the same output.

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#4163
  1. Hash functions are unique addresses that can be an input string that returns an output string.
    2.Hash functions are used in Bitcoin to create a unique address for individuals on the Blockchain in the healthcare space. This hash could serve as an identifier instead of a social security number.
  2. Collision resistant means that an input produces two outputs. A hash function must be collision resistant because hash functions produce a unique fingerprint.
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#4164
  1. A hash function takes input data of any size and turns it into an output with a set number characters.
  2. Hash functions are used to code information and verify it.
  3. Collision resistant means that every variation of input has to produce a different output.
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#4165

  1. A hash function take an input key map it to a hash value called hash.

  2. Hash functions are used in a bitcoin blockchain to write new transaction into the blockchain through the mining process.

  3. Hash function are collision free which means it is very difficult to find two identical hashes for two different messages.

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#4166
  1. Describe hash functions with your own words

A hash function is the combination of two or more mathematical functions that converts a numerical input value into another numerical value. The input to the hash function is of arbitrary length but output is always of fixed length.

  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 used in cryptocurrencies like bitcoin, to secure information that cannot be taken by theft or without the permission or the will of the owner of the information.

  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).

The need for collision resistance of hash functions describes the need to not generate the same answer for two non-identical inputs of an hash.

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#4167

Hash function is a function that is meant to take input and create an output from it. It is like a code, which means that we are not supposed to crack it (there are some that have been cracked tho and therefore they have lost their value)
Hash function take the input and generate a UNIQUE, fingerprint-like output and is a one way street, meaning you can give an output from input but you can not do vica versa.
In cryptocurrencies like bitcoin we use hashes to generate numbers that requier a predictable amount of CPU effort. Generating equal to or a smaller number than the target wins the “mining lottery”
Hash functions need to be collision resistant in order to produce a unique fingerprint for each input. In case on collision, 2 different inputs could produce the same output in which case hash loses it’s “fingerprint quality”.

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#4168 
Describe hash functions with your own words  Hash Function is an algorithm in which you can go from input to output using a set of parameters, but you cannot reverse the process and go from output to input maintaining the integrity and security of the information being converted into a hash.

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 part of the algorithm that adds new transactions to the blockchain after the stringent verification protocol is completed during mining.

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 can translate or convert or map to the same output
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#4169

  1. An algorithm that takes input and gives a number as output unique to the input. Change a single binary digit in the input and you end up with a completely different number as output

  2. Hash functions are used in bitcoin as a part of the block hashing algorithm

  3. We need it to be harder to guess the input.

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#4170
  1. Hash functions are unidirectional functions that represent data in a very unique way. So much so, that they can act as a digital fingerprint and insure the integrity of a data set. Hash functions can take a sequence of data of any length as an input - perform an operation on that data set - and put forth an output of a fixed length.
  2. In bitcoin, hash functions are used to ‘solve’ blocks. The inputs for the has function contain information about not-yet confirmed transactions, info about the timestamp, and a reference to the previous block. Miners then try to combine all of the inputs with their own arbitrary piece of input data in such a way that the resulting has starts with a certain number of zeros.
    -https://www.coindesk.com/bitcoin-hash-functions-explained
  3. Collision resistance in hash functions essentially means that it is unlikely two unequal inputs will produce the same output.
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#4171

  1. The Hash function is a unique one-way function that produced for each input variable a unique output

  2. Hash function is used to create new transactions into the blockchain through the mining process

  3. We say that is collision resistant, when is too difficult to find two different inputs for the same output hash

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#4172

  1. Hash functions is always suppose to be a one way function where each unique input gives you a unique output.

  2. In the bitcoin protocol, hash functions are part of the Bitcoin Hashing Algorithm which is used to write new transactions into the blockchain through the mining process.

  3. In Cryptography context, a collision resistant hash function will ensure difficulty to find 2 inputs that produce the same output which is a very important property.

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#4173
  1. Describe hash functions with your own words
    A. Hash functions are one way functions that irreversible.
  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).
    A. Hash function are 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? (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).
    A. Hash functions have a unique digital fingerprint and thus collision resistant as no two inputs produce the same output and thus do not collide.
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#4174
  1. Describe hash functions with your own words.

Hash functions are complex computations that takes inputted data and creates a linear unique hexadecimal hashes and is used for data integrity.

  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 written in to the protocol’s hashing algorithm and used to create new unique transactions to the block chain.

  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 in hash rates is when two different inputs of data produce the same hash output. Collison resistance makes the hash collision less likely when the bit rate is larger, ex.128 bit vs 256 bit, the probabilities become less apparent as the number of possible hash rate outputs grows.

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#4175
  1. Describe hash functions with your own words

A hash function converts an input of any size to a unique output of a fixed lengths. That output can not be reversed to reveal the orginal input.

  1. How are hash functions used in cryptocurrencies like bitcoin?

  • To write new transactions in the blockchain

  • To create private & public keys

  1. What does it mean when we say that hash functions need to be collision resistant?

A hash function is collision resistant if the probability of two different inputs that result in the same hashing output is extremely unlikely. When this happens it is called a collision, which mean that the hash function is less relibale/secure.

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#4176

  1. Hash Functions are complex functions that convert input to output. SHA-256 is an example of a secure hash function that assigns a unique output for every unique input. Meaning no output or Hash is the same if the input is changed. Another feature of a Hash Function is that it is irreversible or you cannot find the Input given the Ouput.

  2. Hash Functions are part of the algorithm used to add new blocks on the Bitcoin blockchain. A miner’s job is to solve increasingly difficult math equations using unconfirmed transactions as input and arrive with a Hash. This Hash or output of the Hash function is unique and has a digital fingerprint and is assigned a 256-bit alphanumeric code. If the value of the code is equal or less than the target then the miner WINS!

  3. Collision resistant means that no two inputs will produce the same output. This is necessary in the Bitcoin algorithm to ensure that each transaction is unique and cannot be duplicated.

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#4177
  1. Describe hash functions with your own words
  • A hash function is a form of cryptography that turns any input into a hexadecimal string output. This output is unique to the input and can not be used to deduce the 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 are part of the mining process and are used when adding new coins to the blockchain.
  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 the results cannot be the same for different inputs as that can cause data issues. That is why the hash functions used give completely unique outputs per input.
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#4178

  1. Describe hash functions with your own words. | A hash functions is a mathematical equation, in which each unique input has a unique output, as well as the fact that you can go from input to output, but it is impossible to go from output to 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). | Hash functions are used in cryptocurrencies like bitcoin in the mining process, with miners using hash functions to mine the next block.

  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). | For a hash function to be “collision resistant”, it must have a very low to 0% likelihood of a hash being generated that has the same hash as an already existing hash.

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