- Hash functions takes a certain input and produces a unique output or fingerprint. Change anything in the input and you get a completely different output.
- Hash functions are used in cryptocurrencies to track new transactions into the blockchain through the mining process. The transactions are taken as input and run through a hashing algorithm. Bitcoin uses SHA-256 which gives an output of a fixed length.
- Hash functions that are collision resistant means it is hard to find 2 inputs that hash to the same output.
- Hash functions are functions which transform specific input to an output using some algorithm. Special characteristics are that every input leads to a different output and also you cannot determine the input based on the output.
- Hash functions in bitcoin are used for hashing the blocks in the blockchain. E.g. every block contains the hash of the previous block. They are also used in the mining of new blocks.
- Collision resistant means that it is infeasible that the hashed outputs of two values will be the same
- Describe hash functions with your own words
Hash functions is using a unique input to generate a unique output or digital fingerprints. - 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).
Miners input the transactions of any length into sha256 to get a fixed length output. - What does it mean when we say that hash functions need to be collision resistant? (We didnât use the term âcollision resistantâ in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, thatâs how you learn best).
Hash functions needs to be collision resistant so that way 2 different inputs wonât give you the same output.
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A hash function is a function that converts data into a fixed value. In a hash function, data gets added into the function (input) producing an output. The data added will always produce the same output unless the data is changed or altered no matter how small the change. Thus, hash functions are deterministic. Bitcoin uses the hashing algorithm Sha-256 which determines what the fixed length of an output will be. Sha-256 is key to the immutability property of Bitcoin
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Hash functions have given blockchain technology the ability to rely on and allow the participation of autonomous networks in the confirmation and production of transactions within the blockchain. Blockchain has been used in other electronic transactions through a centralized network but it was the coupling of hash functions and blockchain that allowed for a decentralized currency, a cryptocurrency.
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Collision resistant means that the probability of two different networks solving for the same hash at the same time is very small. Hash functions need to be collision resistant in order to maintain a balance in the difficulty that is required for a computer to solve for the target hash. The faster it takes for a system to find the target hash of a block, the more likely it is for a collision to happen. When a collision happens, the difficulty of the hash needs to be adjusted. A bitcoin is hashed about every 10 minutes.
- Describe hash functions with your own words;
Hash functions is computation algorithm , digital information goes only one way⌠It produces a unique output or hash . It is a one way function.
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 Bitcoin hash function called SHA -256 each unique input gives a unique out put .This goes one way and almost impossible to go back from out put to inputâŚ
- What does it mean when we say that hash functions need to be collision resistant? (We didnât use the term âcollision resistantâ in the lecture, but you will easily find this on Google, we add this question intentionally to make you research information on your own, thatâs how you learn best).
It means there is no way to generate the original data from its generated hash. The hash in SHA -256 only function in a linear progression.
Cryptography or hash algorithms are what keep Bitcoinâs blockchains secure . A hash algorithm takes data of any arbitrary size numbers, alphabets media files and transforms it in to a fixed alphanumeric string. the fixed bit size can vary like 64-bit or 128-bit or 256-bit depending what hash function is being used , This fixed size output is what is called a hash .
â My answers â
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Hash functions are functions that output a digital fingerprint of fixed length from a given input data of any length. By being pre-image resistant and by generating a completely different result even with a minimal change in the input, they allow to quickly verify if two pieces of data are identical.
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Bitcoin uses hash functions to write and validate new blocks of transactions: given a difficulty threshold (represented by a number of consecutive zeroes at the beginning of a hash), each miner attempts multiple times to generate the hash of the list of transactions plus a random string, until it starts with a number of zeroes equal or greater then the threshold. Once the âwinningâ hash has been found, the whole network is informed and the block is validated and appended to the blockchain. The miner is then rewarded with a predefined amount of coins.
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Must be infeasible to generate two identical hashes from different inputs.
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A hash function is simply a function that takes an input value, and deterministically computes an output value.
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Hash functions are used in cryptocurrencies like bitcoin to keep it secure and pass transaction information anonymously.
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When we say hash functions need to be collision resistant, we mean that it needs to be computationally impossible to generate the same hash for a different input.
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A hash function mathematically breaks input into binary code and generates a unique âfingerprintâ as the output.
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Bitcoin uses special hash functions called âcryptographic hash functionsâ to give each transaction its own unique code from which you cannot reverse and find the original input. Miners compete to create these hashes to receive newly minted Bitcoin, and are thereby incentivized to secure the blockchain.
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Collision resistant means that for any 2 hashes for example H(A) and H(B), where A and B are 2 different inputs, it is infeasible for H(A)=H(B). Because of this, each individual input will have its own unique hash.
- Hash functions gives an unique output (digital fingerprint) from every input. Itâs impossible to find input if you have the output. That in what makes hash functions unique.
- In bitcoin hash functions is used in every transaction.
- It means that different inputs canât have same outputs.
- Hash functions are mathematical functions that convert a string of text into a value (in BTC speak - converting to 256 bits).
- Hash functions are used in crytocurrencies like bitcoin to secure the blockchain and ensure immutability (i.e. prevent people from using illegal techniques to solve puzzles)
- Collision resistance means that each input will have its own unique hash (i.e. prevents the 2 inputs âcollidingâ together over the same hash); the BTC ShA 256 isnât completely collision resistant but becasue there are so many numbers available (2^256) it is infeasible 2 inputs will have the same output
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A hash function is a cryptographic one way formula in which a unique input will create a unique output.
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Bitcoin uses a SHA-256 hash protocol, meaning a unique, secure output would always consist of a 256-bit numeral.
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Collision resistance means it is infeasible for 2 inputs to hash the same output number.
H(a) â H(b)
1- hash-functions is a one way function means that you will have output from your input but you can never find out you input from output data, the hash function it self is very complex but the way they work is easy to understand.
2- Bitcoin uses hash-function name SHA-256 and as far as i understand the transactions on every block put in this has-function and there is a pointer in every block that contain hash and the address of previous block ,So if anyone what to change a data (transactions record) he or she should hack the whole block which is some how impossible.
3- it mean that there should be no chance of same output with different input in a hash-functions E.g. the output of A to the hash-function should not be same as the output of B ,However it is possible in some hash-function like SHA-256 but the possibility is very very very low that doesnât matter at all.
- if you give an input you get a hexadecimal digital fingerprint as an output, without possible to get the input from output
- to secure the system
- it should be impossible to generate the same output from an other input
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Hashing is generating a value from a string of text using a mathematical function. A formula makes the hash so it is secured against tampering. Its one way so its not possible to go from output to input
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They make a string of blocks using hash functions where each block looks at the previous. If there is tampering with the data in one block everuthing becomes invalid.
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Itâs almost impossible to get the same output from different input
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Describe hash functions with your own words
Each input will produce a unique output, however it is not possible to produce the input data from the output. The hash function converts a text input (of any length) into binary and hashes it, producing an output of a fixed length in the hash functionâs numerical system. -
How are hash functions used in cryptocurrencies like bitcoin?
Hash functions are part of the block hashing algorithm (proof of work). They keep the blockchain secure. When a block is mined, the hash functions produce a unique fingerprint for the block, and this is referenced in the next block once it has been mined. The public key to your bitcoin wallet is a function of your private key. -
What does it mean when we say that hash functions need to be collision resistant?
It means that it should not be possible to find two different input data sets for the same hashed output.
- Hash function is an algorithm used to generate a unique output with fixed length from a string of data input
- Bitcoin uses SHA256 to generate the random hash for a new block which will then be unlocked by the miners
- A hash function is collision resistant if it is hard to find two inputs that hash to the same output
1). Hash functions are a One-way function. Each has a unique input which results in a unique output, or âfingerprint.â There is no way to figure out what the input is by having the output. If that could be done, bitcoin would not be secure.
2). Hashing is a cryptographic method of converting any string of data into a string of characters with a unique output and a fixed length. The hashing function is used to write new transactions into the blockchain using the mining process. The hashing function results in the security of the blockchain while also allowing for an efficient store of data.
3). If a hash function is NOT collision resistant than the protocols can be broken and will not be secure. It means that given two different inputs it is infeasible that the outputs would be the same or unique.
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A hash function is a function that is easy to compute but very hard to find the inverse of.
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A hash function is used to prove that work was done (to find a small hash) which is how Bitcoin attributes the authorship of the next block in the chain.
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A collision is when two inputs give the same output, and a collision resistant hash function is one that has no collisions.
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Hash functions are mathematical expressions used to generate a unique output (a hexadecimal value or string of numbers and letters that is fixed in size) from a any given input.
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Cryptographic hash functions are used in bitcoin to protect the integrity of the transactions included in blocks.
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Collision resistance is a way to gauge how likely it is for two inputs to produce the same output. To be secure, hash functions need to be highly collision resistant.
- A hash function is a numeric calculation that based on an input, no matter what length it is, will generate a value/key or output of a fixed size, where the smallest change to the input will generate a completely different output.
- Hash functions are part of the block hashing algorithm in the bitcoin protocol, which is used to write new transactions into the blockchain through the mining process (so itâs impossible to copy/paste as I did now
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- It means that there is a very tiny, âalmost zeroâ, chance that a hash output value is equal to another, like if each hashed output value generated âis more like a uniqueâ value.