Homework on Hash Functions - Questions

Blockchain and Bitcoin 101
#3989
  1. Hash functions take any input variable of any size and outputs a unique and fixed length output.
  2. Hash functions are used in bitcoin by miners trying to solve blocks to be added to the blockchain. They use the hash function to generate verifiably random numbers until the block is solved.
  3. Collision resistance is the highly unlikely probability that any input will have the same output. However, it is not mathematically impossible.
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#3990

Hash functions have unique input, which produces a unique output.

Each bitcoin transaction uses encrypted hashes to identify the transaction, and place the transaction on the blockchain ledger.

Collision Resistant means that no two inputs will create the same output.

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#3991
  1. For a unique input a hash function creates a unique output
  2. Uses SHA-256, PoW function and Miners adding new blocks to the blockchain following successful verification of the hashes within them.
  3. Two distinct values can’t have same output
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#3992
  1. Hash functions take any input and create a unique output with a fixed length.
  2. In BTC, hash functions are used during the mining process to enable security. The input would be your transaction request which is already encrypted. Miners use that as input, hash it, and the output serves as a unique identifier on the blockchain. This is more commonly known as a digital fingerprint and miners can use this to verify the authenticity of the dataset its verifying without the need to decrypt the original input. The quickest miner to update the transaction and verify the ledger (per transaction) gets rewarded.
  3. Collision resistance is the term used to describe an outcome that is mathematically NOT impossible but the likelihood of the outcome occurring is arguably impossible. For a collision to occur, two different inputs would have to hash the same output. Since the output is a fixed quantity of characters, there is a mathematically defined limit of different iterations. However, that number is so large that you have a better chance of winning the lottery multiple times a day every day for more years than your traditional calculator can fit on its screen. (figure of speech)
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#3993

1 - Describe hash functions with your own words

Hash Functions are complex mathematical functions that allow to assign to an input, of variable size, a single output, such as a digital print, of fixed size. Each change in the input would result in a completely different output. It is a one-way function, that is, it is not feasible to start from the output to reach 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).

The cryptographic hash function is a special function class that has several properties ideal for encryption and certain properties need to be in order to be considered secure, such as: Deterministic; Quick Computation; Pre-Image Resistence (“brute-force method” / 2 ^ 128 = 3.402823 x 10 ^ 38 times / 2 ^ 127 = 1.701411 X 10 ^ 38 times); Small Changes In The Input Changes the Hash and Collision Resistant.

Bitcoin uses the SHA-256 hashing algorithm (Secure Hashing Algorithm 256); and

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).

Given two different inputs A and B where H (A) and H (B) are their respective hashes, it is infeasible for H (A) to be equal to H (B).What Is Hashing? [Step-by-Step Guide-Under Hood Of Blockchain]

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#3994

  1. Describe hash functions with your own words
    Hash functions is an one way mathematic algorithm that map an input to a totally unique 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 function use as a cryptography which take the input and generate a hashed value of the output in a way that can’t be reversed. This make cryptocurrencies data integrity, and secure against unauthorized modifications. Bitcoin use hash function to encrypt the transaction so that each transaction is unique and not able to modify and remove.

  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 occurs when two input result to an identical output, hence, a good and trustworthy hashing algorithm just as SHA256 is one that is resistant to these collisions. However, every hash function with more inputs than outputs will necessarily have collisions. Collision resistance does not mean that no collisions exist, just that it is simply that they are hard to find.

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#3995
  1. Irreversible (one-way) data transformation device.
  2. Ensure that a transaction from a wallet can be validated using only the private key in the hash function.
  3. The property that a function is so sensitive/chaotic to its input, that it is impossible to have the same output from different inputs (kinda like 1-1 mapping in mathematics)
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#3996

Q1. Describe hash functions with your own world?
A. Hash functions is a process of encrypting an input data with an output that is unique to the unique input.

Q2. How are hash functions used in cryptocurrency like bitcoin?
A. Bitcoin is on a public irreversible ledger called blockchain. When a transaction is initiated(input) a hash function called SHA-256 takes the unique input data and gives us a encrypted unique output that can not be duplicated without the exact unique input. Giving a trustless public ledger using a mathematical algorithm called SHA-256.

Q3. What does it mean when we say that hash functions need to be collision resistant?
A. To be collision free like SHA-256. Two different input can not give the same output.

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#3997
  1. Describe hash functions with your own words

Hash functions are mathematical functions that take input and generate a unique output.

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

Hash functions are used to encrypt transactions. They are used in the verification of transactions and the addition of blocks to the chain through mining.

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

They need to produce a unique output for each input, ie. two inputs do not produce the same output.

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#3998

1- A hash function is an irreversible function that gives a unique output “digital fingerprint” for a different input.
2- In the bitcoin protocol, hash functions are used in the block hashing algorithm which is used to write new transactions into the blockchain through the mining process. The same goes for other cryptocurrencies.
3- When we say hash functions have to be collision resistant, that means that it should be that no two, or more, inputs result in the same output. That way the output is unique for any input.

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#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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