Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#4480
  1. Describe hash functions with your own words

A) A hash function is a one way function where you can put in an input and it will give you a unique 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).

A) A Hash function is used in Cryptos to get digital signatures. With each hash being able to produce its own unique key for any form of data, it allows these cryptos to keep data and transactions secure, safe, and efficient.

  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).

A) Since certain cryptographic hash functions like SHA-256 can only have 256 digits. This means that mathematically speaking the chances of getting two different inputs with one same output is slim to none. This makes us collision resistant because you will never have two inputs collide into one same output

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#4481

  1. Hash functions convert an input into a hash number (not decimal), based on a function which does not enable to find out the input from an output (reverse)

  2. It allows to access a public key (output), without being able to discover the private key (input)

  3. The don’t allow two different inputs to generate the same output

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#4482
  1. Hash functions are functions that give you a completely unique output for any unique input, and you shouldn’t be able to find the input using the output
  2. Hash functions are used in cryptocurrencies to cover new transactions and make it so that bitcoin cannot simply be copied and pasted
  3. If hash functions are not collision resistant, it means that the outputs from two different inputs may not be completely unique, which would make the code easier to crack and would make verification by hash less reliable
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#4483
  1. Describe hash functions with your own words

Special functions where you insert something you get an unique fingerprint. if you change something in the input (ie the fingerprint) then the output will change too. + It is one directional meaning there is no way to find out the input. If this happens then the hashfunction has been broken. And is considered solved. in other words you will need another better hashfunction!

  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).

We are talking about private and public fingerprints ie 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 information on your own, that’s how you learn best).

It is one directional meaning there is no way to find out the input. If this happens then the hashfunction has been broken. And is considered solved. in other words you will need another better hashfunction!

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#4484

1 Hash Functions are one-way functions where a given input is transformed through a complicated mathematical algorithm to a unique output

2 Hash functions used in cryptocurrencies like bitcoin are used to run the consensus mechanism and to reward miners

3 When we say that hash functions need to be collision resistant it means that the hash function is made in a way that it is hard to find two inputs that hash to the same output

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#4485
  1. hash functions are one-directional functions. With each unique input, it gives a unique output.
  2. In bitcoin, they are used for storing transaction data in the mining process
  3. Hash functions need to be collison resistant because collison resistance means that it is difficult to find two input that hash the same output and this is important for hash functions to maximize security
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#4486

  1. Describe hash functions with your own words
    It is function where each unique input gives unique output, and this can be only produced one way. Once it could be reversed it is no longer safe to use it.

  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 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).
    If a hash function is not collision-resistant then an adversary can break the function with little effort. 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. Every hash function with more inputs than outputs will necessarily have collisions.

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#4487
  1. Describe hash functions with your own words

Hash functions are very special in that they give you a unique output from the data you input. They are one-way functions(i.e. Can only work from input to output but can never go from output to input) They cannot be manipulated as the data you input will give you a unique digital fingerprint. If the input data is slightly changed the output will be totally different and the digital fingerprint would also be totally different.

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

Hash functions in crypto currencies are used to write new transactions into the block chain and this is done through the mining process.

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

It means that two different inputs don’t have the same hash output. If they do, that would be a collision. However the chance of that happening are virtually impossible as it is imperative for a Hash to have a strong collision resistance. Otherwise security becomes an issue. So to summarise collision resistance is a very important part of Hash Functions.

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#4488
  1. Describe hash functions with your own words

Hash function is a one way of hashing input data to a digital fingerprint with no reverse. it means you can not reverse it to get the data back.

  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 an essential part of, not only of the bitcoin protocol, but of information security as a whole. A common use of this kind of hash function is to store passwords. In the bitcoin protocol, hash functions are part of the block algorithm which is 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).

Most hash functions are not really collision resistant. But it basically means that you get the same output for two or more different inputs

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#4489
  1. A hash function is a one way function and is irreversible. A hash function comprises of a unique input which produces a unique output. A unique identifier.
  2. Hash functions are used to mine blocks. Large computation power is used to run a hashing algorithm/s until all data is verified and added to the chain.
  3. A hashing collision involves the same output for a certain piece of input. Technically, collision resistance is not possible where input is greater than output. But a hashing algorithm is considered ‘Collision Resistant’ if collision, is of a certain improbability.
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#4490

  1. A hash function takes any bit of data and converts it into 256 bits. This process is impossible to reverse and provides a unique outcome for your data.

  2. In Bitcoin the Hash function is used to hash transaction data.

  3. Collision resistant means two different things not getting the same hash

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#4491

  1. Hash functions are a algorithm which takes a small or large input of data and performs a series of bit operations to reduce the data in a one way function to a unique number for the input data. The unique number output is always the same for the same input.

  2. The inventor of Bitcoin used the SHA256 algorithm to compute a hash and then added that hash number to the next block of data to chain the blocks together, so creating an immutable block chain.

  3. Hash functions are designed to be collision resistant meaning there can only be the “birthday” chance of trying a brute force attack on the hash function by trying every combination of numbers in the size of the hash number sequentially in order to guess the correct hash. In other words a the chances of two different inputs computing the same hash (a collision) is extremely highly probabilistic.

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#4492

DESCRIBE HASH FUNCTIONS WITH YOUR OWN WORDS
A hash function is an algorithm that transcribes raw data into an alpha numeric format that is very specific to the original data input in that it is exceptionally character sensitive. This sensitivity will produce a vastly different alpha numeric format if one small character is added, subtracted or altered in some way so that attempts to decode the output in order to interpret raw data produces an impossible amount of data to interpret and for this reason data cannot be decoded in order to alter the original raw data.
HOW ARE HASH FUNCTIONS USED IN CRYPTOCURRIENCIES LIKE BITCOIN?
Hash functions in Bitcoin are used as described in the above answered question although more specific to Bitcoin protocols.
WHAT DOES IT MEAN WHEN WE SAY THAT HASH FUNCTIONS NEED TO BE COLLISION RESISTANT?
A hash function is said to be collision resistant if it is hard to find two inputs that hash to the same output.;

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#4493

  1. Describe hash functions with your own words
    A: Hash functions use different algorithms to solve input and convert it into an unique result, the output. The output can’t be reversed to the function’s 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).
    A: BTC uses SHA-256 algorithm and requires a high end computation device to mine a block. (14 TH/s)

  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: Collision resistant means if it’s hard to find two different hashes outputs, linking to the same input.

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#4494
  1. Describe hash functions with your own words.

Hash functions are unique inputs that give a number fingerprint signature to an output. The input is a one-way path resulting in an identical output, but can never be reversed from output to 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).

The Bitcoin hash function is an integral piece of the hashing algorithm which are used to embed brand 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).

Collision resistant is where two or more different inputs need to have a opposing hash output so to provide a secure digital presence.

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#4495

  1. Hash functions are a process to encrypt an output that can not be traced back to an input.

  2. Hash functions are used in mining to create proof of work and verification of transactions in the blockchain.

  3. Hash functions are collision resistant because it would be extremely difficult (next to impossible) to trace an output back to an input, even if there were 2 different inputs that created exactly the same output.

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#4496
  1. Hash Functions when you input data and it output is unique and i reversible
    2.Bitcoin uses sha 256, which is secured by miners generating hash to altercate a Transaction
  2. in cryptography it is difficult to find two input that hash to give same output
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#4497

Hash function is one way conversion of data and not reversible

Hash function is used in bitcoin in order to hash transactional data

Collision resistant is that you cannot get same output with different input

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#4498

  1. A hash function produces a unique output when given any input and does so in a way that is not solvable in reverse.

  2. Hash functions are used to digitally sign cryptocurrency transactions by hashing transaction data.

  3. A hash function is collision resistant if it is at least as hard to find a collision in outputs than it is to solve the hashing equation.

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#4499

  1. Describe hash functions with your own words
    A single input gives a single output. It is impossible to detect the input starting 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).

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.

  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).

A hash function is collision resistant if it is hard to find two inputs that hash to the same output

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