Homework on Hash Functions - Questions

[Pearce]

1 Hash Functions are complicated mathematical complications, that takes a unique data input of any size and outputs a unique piece of data of fixed size. This is a one-way function and inputs can not be recovered, not even through brute force.

2 Hash functions are used to transform the input data into digest which turn is stored on the block chain. Due to the one way operation of the hash process, this makes the newly hashed data very secure and impossible to hack.

3 Any 2 differant data inputs should not hash to the same output.

[Alderfin]

1. A hash function is an algorithm that converts data of various sizes (input) to a fixed size which is called the hash value.(output)
2. Hash functions are used by miners in order to create new blocks on the blockchain.
3. Collision resistance refers to the inability of two or more inputs resulting in an identical output.

[Joe22]

1. Hash functions take any input, convert it to binary and then into hexadecimal system for encryption.

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.

3. The hash function needs to be collision resistant meaning that it needs to be created as to not produce the same output for two different inputs, if this happens, it makes the hash function susceptible to being hacked by brute force.

[marcos9498]

1. Hash functions are mathematical functions that produce cryptographical strings of encoded information, that is added to the blockchain. This encoded information can not be reversed to determine the original input of the hash function.

2. These functions are essential in Bitcoin because they enable the sending of anonymous information. They also allow new transactions to be written into the blockchain through the mining process

3. For a hash function to be collision resistant means to be hard to find two inputs of the hash function that hash the same output

[kiwi]

1. Describe hash functions with your own words
Hash functions are one-way functions that generate a unique output for each unique input. One-way means that you can feed the hash function an input and get an output, but you cannot find out what the input was if you only had an output.

The job of hash functions is to scramble the input data so that it becomes indecipherable. No matter how long the input data is, the output will always be of the same length. But even if you only made a slight change in the input (such as replacing a lower case letter with a capital letter), the output would change completely and look nothing like it was before.

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 order for a miner to be able to add the next block on the blockchain, they must find the appropriate input which, when put through the hash function SHA-256, gives an output that meets certain criteria such as starting with a certain number of zeros. In the case of bitcoin, the hash function is used to determine which new transactions will be written on the blockchain.

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 function is collision resistant when it is impossible, or nearly impossible, to find two inputs that “collide”, i.e. that give the same output. In other words, it is extremely difficult to find inputs x and y such that f(x) = f(y) after you put it through the hash function.

[urnitemair]

1. Taking a unique piece of data and giving it a unique value.
2. Other cryptos will use them to create unique values pertaining to what that particular crypto does.
3. Collision resistant means that it is difficult to locate two different inputs that produce the same output. In order for something to be collision resistant, it must only have one input produce a unique output.

[Floriano]

1. Hash function, is like a bender : You can throw ingredients, once you mix them, the result contains the nutriment value but it is impossible to reverse the process and retrieve the ingredients.

2. Each block are going through the hash function and and the result of this is written at the beginning of the next block block. Thus making it impossible to “hack”.

3. Collision resistant hash means that the hash function makes it really hard to find collisions. (Two different input that generate the same output.)

[cryptonav]

1. Hash functions are one way computation taking an input such as text and convert it a string of bytes with a fixed length and structure.
2. Hash functions are part of the block hashing algorithm used to write new transactions into the blockchain through the mining process.
3. Hash functions are collision resistant when it is extremely difficult to find two inputs that produce the same output.

[DieterE]

Homework: Hash Functions

1. A hash funktion takes an input and outputs a hash. the special thing about those functions is, you can not construct the function backwards. You can not calculate the input of a hash function , just by knowing the hash. each different input gives a different hash.

2. Hash functions are used to in Bitcoin to generate BTC-Wallet adresses. The “Seed” is the input into the SHA256 and the resulting hash is the wallet address / public key.

3. Because of the pigeonhole principle, which preludes that there are more Hash-function inputs, than there are Hash function outputs, there are cases where two inputs have the same output. collision resistance is a property of a hash function which determines the degree of lickelyhood that such a match between two inputs would occur.

[Fea10]

1. Hash functions input data and get a specific fingerprint or hash. If anything is changed it will alter the fingerprint or hash.

2. Hash functions are used for Securtiy purposes. Hash of transactions make it easy to identify transactions on the blockchain.

3. Being collision resistant means making sure there is not any similar outputs from inputs. If different inputs have the same output it can mean its not collision resistant.

[Halim]

1. Describe hash functions with your own words
   A hash function is a function such that for each unique input, it will give a unique output and you can find the output by inserting a certain input into the hash but the reverse is virtually impossible to accomplish
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 ongoing transactions happening in the blockchain, so really the hash functions output represents a piece of history in which the transaction took place in the block chain
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).
   It means that it is virtually impossible to find two hash outputs that are the same for different inputs.

[Nathan_Burkiewicz]

How are hash functions used in cryptocurrencies like bitcoin?

Bitcoin’s hashing algorithm uses hash functions to write new transactions into the blockchain. These functions are used in the creation of a bitcoin address and during the proof-of-work mining process.

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

Hash functions need to be collision resistant to prevent the possiblity of having two inputs hash to the same digest. If this were possible the result of the hash function is no longer a unique digital fingerprint of its input.

[Saffron]

1. Hash functions encodes a string of information

2. hash functions are used to write new
   transactions into the blockchain

3.Collision resistance is the property of a hash function that it is computationally
infeasible to find two colliding inputs.

[NFT_Luffy]

1. Describe hash functions with your own words

Hash functions are a blockchain algorithm that reads data by giving each input a specific and unique output through a one-way conversion string.

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 hash functions receive inputs of digital media. this input is then blended into a string of binary numbers in which miners have to guess what these binary numbers (1’s and 0’s) are. After a miner guesses the correct input, an alphanumeric string called a hash is then produced.

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 two various inputs can’t equal the same output.

[rjreddog]

1. Describe hash functions with your own words.
   Hash functions are each a unique input of data that produces a unique output of data. Example: The input is the product, and the output is the cost of the product.
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 SHA256 hash function is always a one-way function that cannot be reversed. Therefore, this function is used in Bitcoin for security purposes. The hash of a transaction makes it easy to identify transactions on the blockchain.
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).
   When two hash inputs are generated that hash to the same output then this is considered weak collision resistance. Hash functions that generate more inputs than outputs are considered collision resistant.

[Eserr]

1. A Hash function is a One way to map data of arbitrary size into a fixed size.
   2.Hash functions are used in cryptocurrency as a hashing algorithm to write new transactions. (mining).
2. Hash functions need to be Collision resistant to avoid having functions with the same hash value.

[Cookie1]

1. A computation.
2. A unidirectional computation designed so that output is irreversible and thus secure.
3. It must be difficult to find 2 inputs that hash to the same output, in order to make it more cryptographically secure.

[Brett_Gallinger_II]

1. Describe hash functions with your own words
   They are a one-way function that takes an input and creates a unique output or “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).
   Private/Public key cryptography uses hash functions. I need to learn more detail.

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 should not be 2 (or more) inputs that could create an identical output.

[IntrepidShape]

1. A function that performs a complicated irreversible mathematical operation on the input

2. The content of the input of the function can be verified to be true against the same input but the original content of the input does not have to be provided in verification.

3. This means that you can’t forge some input that would falsely register as true when tested against some other hashed input when really the input was not the same as what you are verifying against.

[evalex]

1. Any data can be changed into 256 bits, it creates a unique code for a data.
2. Used to hash transaction data, creates a specific key, that is unique to that block.
3. Every input is changed into a different and unique output.