Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#3999

  1. Describe hash functions with your own words:
    Hash Functions are a universal translator for all computers that utilizes alphanumeric - one directional calculations to affirm transactions onto the public ledger known as Blockchain. The translation process compresses any amount of information into a secure (SHA-256) 256-bit, fixed alphanumeric code that is then validated by the collective network of global CPUs. Each input creates a unique output.

  2. How are hash functions used in cryptocurrencies like bitcoin?
    Hash Functions are a component of the “Block Hashing Algorithm” in the Bitcoin protocol. The main objective is to encrypt the communication so that only the ledger and intended recipient can decipher the information. The block hashing algorithm 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?
    Collision Resistant refers to an aspect of the hash function that makes the output secure in that it cannot be “reverse engineered”, through a forced collision - running a calculation in reverse in an effort to discover the inputs. CR means that it is difficult to find two different inputs that produce the same output or calculated encryption result. The Bitcoin protocol and aspect of CR is required to be Cryptographically Secure and usable in the block chain technology / ecosystem.

RJR
2021-03-01T05:00:00Z

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#4000

1, Describe hash functions with your own words

  • Hash functions, any take inputs of any length, to return outputs of a fixed length. Each input will always get its own unique output.

2, How are hash functions used in cryptocurrencies like bitcoin?

  • Hash functions provide digital fingerprints and keeps Bitcoin secure by encrypting transactions data through SHA-256.

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

  • It means you can not get the same output with different inputs.
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#4001

  1. Describe hash functions with your own words
    A mathematical process to convert arbitrary data into a standardized output, which cannot be reverse-engineered.

  2. How are hash functions used in cryptocurrencies like bitcoin?
    A bitcoin address is the hashed output of the public key.

  3. What does it mean when we say that hash functions need to be collision resistant? The likelihood of two unique inputs resulting in the same output is negligible.

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#4002

Homework on Hash Functions - Questions

1. Describe hash functions with your own words

Hash functions are 1 way algorithms, when you have marihuana and you put it in a grinder- bullet to bottom layer will catch the crystals, once you have collected enough crystals you can make has HASH, it is almost impossible to bring the hash into its original marihuana state/form
.
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).

With Bitcoin you have a public address and for that address you have 1 private key. there is no way to derive the private key from the public address.

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).

There can only be 1 answer in the hash function to have x out come and not more than 1. if its more than 1 then its is considered not secure.

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#4003
  1. Describe hash functions with your own words
  • Hash functions are algorithms that take an input and mathematically convert it into a unique output, also called the has value.
  1. How are hash functions used in cryptocurrencies like bitcoin?
  • Hash functions act as the “engraver”, forging a cryptographic ledger of the transactions onto the cryptocurrency’s 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).
  • hash functions need to be collision-resistant, meaning that two input values of the function cannot have the same output.
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#4004
  1. Hash functions take any input of any length and turns them into a string of letters and numbers of a specific length as a totally unique string.
  2. They are used as the “name” or “fingerprint” of each block, and contain the list of all transactions on the block as well as the hash of the previous block.
  3. Each output has only one input, multiple inputs do NOT generate the same hash output.
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#4005
  1. A function that allows a very high level of privacy/security.
  2. They are used to create new blocks to add to the blockchain. (Transactions+previous has+nonce) are hashed to try to get a result lower than the target in order to create a new block.
  3. It means that it is computationally infeasible to find two colliding inputs.
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#4006

Describe hash functions with your own words-
a hash function takes a group of characters(input) and turns it into a unique code/key(output) like a fingerprint for all characters that were input and can not be reversed. You can not use the code/key to figure out what characters were input.

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 Funtions are what is used to create new transactions within the bitcoin blockchain.

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 was not collision resistant it would mean it possible to get the same output, they need to be collision resistant so there are far less copies of one Hash capable of being found

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#4007

A hash function is an algorithm that takes an input and creates an alphanumeric distinctive output.

Hash functions are used in crypto to confirm transactions and act as previous block identifiers which ultimately provide the ability to add new blocks to the blockchain.

Hash functions being collision resistant means that it is very difficult to identify two inputs that result in the same output.

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#4008

  1. A hash function is a one-way function that produces a digital fingerprint or hash by transferring binary input to hexadecimal 256 bit output using the SHA-256 hash function.

  2. Hash functions such as SHA-256 are the foundational to blockchain technology! They take an input of any length and return an output of a fixed length. This means While using SHA-256 no matter how large or small the input, it will allways return a hash of 256 bits. This is important when dealing with large amounts of data or transactions as in the case with bitcoin. You only have to remember the hash! Another Function of SHA-256 is that if you change any “iota”(from the greek mean smallest part) of the input data eg (. To !) it will change the Entire hash. The pointer links each block and is a hash of the previous block, hence the term block “chain”. So Say a hacker decides to hack block 2 it will because of the hash/ chain it change the hash of block 1 which helps with the immutability of the chain. Determining the input from the output is also Infeasible because with a brute force attack you could guess your whole life and you still won’t be able to do it, even if you had 4 lifetimes. It is not impossible but its just not feasible.

  3. Two inputs resulting in the same hash is called a collision. Collision resistant means that each input will have its own unique hash! No hash function is completely collision free but like with the brut force it takes so long it is inconsequential and extremely rare when using SHA-256.

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#4009
  1. Hash functions are functions that accept a value and produces a unique string that maps back to the original set of input value(s).
  2. In Bitcoin, hash functions are used to reach consensus when new blocks are added. If one node happens to tamper with the ledger, the hash will be different to the hash on other nodes on the bitcoin blockchain and as such will reject the tampered ledger.
  3. A collision resistant hash is one where two different inputs do not generate the same hash output.
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#4010
  1. Describe hash functions with your own words

A hash function is a cryptographic algorithm that allows you to take a piece of data of any size and encode it so that the length of the output (hash) is always the same. A hash function is designed to only work one way, that is, you can’t (or shouldn’t be able to) ‘un-hash’ something, or it should take too much compute power to do it.

Changing even a tiny bit of an input for a hash function will completely alter the hash of the input.

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

Bitcoin uses the SHA-256 hash algorithm in the process by which miners add blocks to the blockchain. The inputs for the hash function are the most recent transactions not yet confirmed or added to the blockchain, and the previous block. Miners must find a hash for that data that is below the target difficulty.

Because every block is also a hash of the previous block, changing the input for one historical transaction would show up in all subsequent blocks require you to remine all those subsequent blocks. Hashing is therefore vital to the proof of work concept and the security of the network.

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

Collision resistance is the property of a hash that makes it so that it is difficult to find two or more inputs that would result in the same hash.

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#4011
  • Describe hash functions with your own words
    Hash functions have unique inputs that are then computed into unique outputs that only transfer in one direction from input to output.
  • 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 is simply a digital ledger of hashes that utilizes proof of work combined with SHA-256 to obtain mathematical traceability and unbreakability. The process through which this is ensured is called Bitcoin mining that utilizes Bitcoin hashes generated through SHA-256 function at various steps of 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).
    [/quote]

When two inputs hash to the same output, that’s known as a collision. We never want to see a collision they are the first sign that a hash function is broken.

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#4012

  1. It is a mathematical process that converts an input of any given size into and output of a determined size.

  2. In Bitcoin, hash functions are used to store transaction’s info into new blocks. In order to do this, computers try to combine all the info with the aim of getting hash with specific number of zeros in front.

  3. It means that a hash function output shouldnt be obtained with two different inputs.

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#4013

  1. Hash functions take an input(s) and hash this to create an output. It should not be possible to reverse the function to infer the original input.

  2. SHA.256 is used by Bitcoin in the PoW algorithm used by the miners and in the creation of bitcoin addresses.

  3. Collision Resistance means the likelihood that 2 different inputs could result in the same output. Whilst this can’t be ruled out it should be EXTREMELY unlikely in order for a hash function to be used effectively.

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#4014

1/ hash functions are one way functions; when computed by function, one input gives only one output: in fact, it’s mathematical defintion of a basic function.

2/ in a BTC transaction, there are data, like adress, public key, signatures, …, once hashed, that could be used for validating the transaction, in making it unique and unchangeable.

3/? = impossible to use the same amount of BTC, located in one adress in the blockchain, for 2 or more transactions

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#4015

  1. A hash function is an algorithm that takes an input and creates a unique code (like a digital fingerprint) of a specific length. It is a one way function, meaning you cannot work out what the input was based on the output.

  2. In cryptocurrencies, transactions are hashed together in blocks of information which each have a unique code and are also hashed to the previous blocks. If any changes are made to any of the blocks then the entire chain would become invalid.

  3. Collision resistance means that no two inputs should create the same output.

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#4016
  1. A hash function is a mathematical equation that takes any input, a set of data, and converts it into a specified set of bits (of a specific/constant length) that are unique only to that particular input. And more importantly, another quality of a true hash function is that it cannot be reversed.
  2. Hash Functions in cryptocurrency are used as part of an algorithm to help write new transactions into the blockchain through mining. As inputs are the new, yet to be confirmed transactions in a cryptosystem, miners try to combine all inputs with their own random data so that the hash produced starts with a particular number of zeros. Different currencies require a different number of zeros at a given particular time to complete a block, which also requires a great amount of computing power to accomplish. This process, known as “proof-of-work,” allows for the miner to “earn” their reward of a “cryptocurrency.”
  3. To say that hash functions need to be collision-resistant, implies that they possess the quality of making it difficult for two different inputs to have the same output, more specifically, that it is very tough, nay impossible, for two inputs to yield the same resultant hash. When this happens, the hash function is said to be collision-resistant.
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#4017
  1. Is a mathematical operation that causes a unique output for each input.
  2. This functions are used to write new transactions into the blockchain and confirmed by different blocks.
  3. Collision Resistance is how likely is that two different inputs produce different outputs, very very unlikely and difficult but in the end, possible.
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#4018

1Describe hash functions with your own words
Hash Functions are one way functions that for one unique input produces one unique output. We can not go from the output to input. The result of the hash function is a hexadecimal key.
2How 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 in bitcoins are using in transaction and mining. In the mining the inputs for the hash are the unconfirmed transactions and data related to the previous transaction. To solve the block, miners try to combinate all the inputs with their own random data so that hash produced starts with a particular number of zeros. This requires a great amount of computer processing. The miner that first solves de problem earns a reward in criptocurrency.
3What 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 a property of criptographic hash functions and it means that is hard to find the same output for two diferente inputs x and y

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