1.Each unique input gives a unique output.
2They are used to write new transactions into blockchain through mining.
3.If it wasn’t collision resistant we could find multiple messages that produce the same hash which would destroy its value.
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Hash functions are one way functions, where a unique input gives a unique output, and where you can go from input to output but is not posible to reverse it.
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Hash functions are used to write new transactions into the blockchain through the mining process. Bitcoin uses the “SHA-256” hash algorithm to generate verifiably “random” numbers in a way that requires a predictable amount of CPU effort.
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Hash functions are usually designed to be collision resistant, this meansif it is hard to find two inputs that hash to the same output.
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Hash functions are an output that is like a fingerprint where, unless it has been broken, you are not able to know or understand the input based on the output.
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Hash functions are a way to hide the imput data. Not matter what data or how large the amount of data you will get the same size, or fixed, output depending on what type of hash you use. This secures input data.
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It is collision resistant if it is hard to find two inputs that hash the same output.
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- Hash function convert a string of data to an unique fixed length hexadecimal string
- It is used for signature on blocks produced, that data is not changed
- It means it is possible to get strings the same, but it is very very hard, probably will never happen
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- Has functions are based on complex math formulas which cause that the outputs are calculated from inputs in that way the inputs shall be impossible to recover from outputs. Moreover hash function should have features such as avalanche effect (slight change on inputs cause significant change on the output) and high computation rate (outputs should be calculated fast).
- Hash functions are used in connecting blocks and provide form of block validation because each block has a hash of the previous block.
- It means that two different inputs cannot lead to the same output.
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1.Hash function is a set of data. For each input, that is given, it will give an unique output for it. This is called the digital fingerprint.
2.A hash function in Bitcoin is used to hash transactions in each block.
They are very secure, because each transaction has a unique output in blockhain.
3. Collision resistance is the property of a hash function that it is computationally infeasible to find two colliding inputs. This property is related to second preimage resistance, which is also known as weak collision resistance
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- Describe hash functions with your own words
A hash function turns a random input of data (keys) into a string of bytes with a fixed length and structure (hash value) The hash of a transaction makes it easy to identify transactions on the blockchain. It is essentially a mechanism to secure and identify the block data. - 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 the Hash function is used to hash transaction data. Also mining and finding a nonce requires finding a number that generates a specified hash in combination with data unique to that block. - 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).
The collision resistance property requires that two different input messages should not hash to the same output. No two blocks should have the same hash.
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Hash functions are algorithms that produce unique outputs (digital fingerprints) for unique inputs.
Hash functions are used in the consensus/verification mechanisms of bitcoin. Proof of Work is based on this hash function.
The term “collision resistant” refers to the difficulty/likelihood of finding an identical output for two unique inputs. A collision resistant function has a very low probability of that identical output ever occurring.
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1 and 2. Hash functions are a method of encryption. You take information from a transaction, and this is inputted into the function, and the output is that is produced will be a hash function; an alphanumeric value that could have up to 256 digits.
- Hast functions are collision resistant meaning that it is very difficult to find 2 inputs that work together to produce the correct hash function.
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unique mathematical output
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used to write transactions into the blockchain while securely producing unique outputs
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to be secure from blockchain/hash attacks the hash functions need to have consistently different outputs
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Hash function gives any given input a unique fingerprint and is irreversible as in input to output and not the other way around.
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SHA-256 is the primary hash function of BTC and has a unique hash value, high hashing speed and secure hash function, bitcoin is a digital ledger of hashes that utilises proof of work combined with SHA-256 to obtain mathematical traceability and unbreakability.
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Meaning that it is hard to find 2 inputs that hash to the same output in other words every input has a unique fingerprint.
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A hash function is taking a unique input and receiving a unique output. Once an output has been achieved there is no way to reverse this to find the input.
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Bitcoin uses a hash algorithm known as SHA-256 which is very secure even by today’s standards. Each unique input will produce a unique output that ranges from zero to a max 256 alphanumeric number.
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A collision occurs when two different inputs create the same output, this has been a huge issue especially with the MD-suite (Message Digest) of hashing algorithms. If a hashing algorithm is susceptible to collisions then that reduces its security and makes it easier to brute force as the number of unique possibilities becomes greatly reduced.
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A function that take inputs of variable lengths to return outputs of a fixed length which is unique in nature.
Use of hash function in Bitcoin is to
-generate the Bitcoin address.
-pass transaction information anonymously
-create a new block in blockchain.
collision resistant means that no two different input hashes should map to the same output hash.
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- translation of words, letters and sign into a special unique code
- for example to create unique btc adress or form mining new blocks
- a unique input can only create one unique output, not possible to create same output with other imput
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Hash functions are a type of algorithm that accept any input and produce an irreversible output of a fixed length.
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Each new block contains a hash of the previous block (including all of it’s content) creating a chain of hashes. This hashing of hashes makes altering the blockchain nearly impossible.
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Collision resistant means that it is extremely likely that each input will produce its own unique output/hash.
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Hash functions are complicated algorithms when making a transaction on blockchain used by miners.
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They are used to create a specific number/alphabetic sequence when performing a transaction on the BTC blockchain.
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It is when a hash function is hard to find the same hash or output for 2 different inputs.
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Hash functions translate data into an alphanumeric string of predetermined size.
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Hash functions are used to encrypt the Bitcoin blockchain. BTC uses sha256, which is one of the most robust hash encryptions currently used. The creator of sha256 was not Satoshi Nakamoto, but the U.S. NSA.
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Collision resistance is a property of cryptographic hash algos which prevent 2 inputs from producing the same output. BTC transactions are processed and recorded on the blockchain, which is sha256 encrypted, so because of the collision resistance property , only one input or transaction, may produce the output.
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A hash function is a one way digital finger print with a unique input and output that can never reversed.
A hash function in bitcoin is how information is stored and checked by the miners to prove that the information on the ledger is correct it dose this using SHA-256.
The hash functions are so astronomically difficult that to get two people to come up with the same hash essentially colliding are so vast its almost impossible.
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A hash function is a function that is a way of encripting inputs such as text, numbers or possibly media files into a string algorithm to represent it, that cannot be reversed
To encrypt using hash takes a larger string of variables and consolidates it into an encrypted code no one else can recognise, or decrypt
They cannot be broken or partial information inserted into the string
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- Describe hash functions with your own words
ANS-it is a computation formula where inputs of any form like (digits,letters and media files) are translated in to an alpha numeric strings of codes as an output.
2.How are hash functions used in cryptocurrencies like bitcoin?
ANS-transactions are taken as an input and they run through the hashing algorithm(SHA-256) to give the miners the desired output of a fixed length every 10 minutes.
3.What does it mean when we say that hash functions need to be collision resistant?
ANS-this is a property of cryptographic hash functions to proof that its almost impossible to find two random inputs that has the same hash output.
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