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Questions tagged [hash]

This tag should be used for questions related to hashes. A hash is the output of a hash function, a function which .is a mathematically reproducible but irreversible process that takes in an arbitrary length input and produces a fixed length output. The same input will always result in the same output. Hashing is central to Bitcoin mining as well as the generation of Bitcoin addresses.

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Hash rate of the average PC/Top end PC

Hi I was wondering if anybody had any idea about what the hash rates are like with PCs released fairly recently. I'm sort of looking for figures to use for an average user if they wanted to use their ...
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Signature digital algorithm in bitcoin, to what will it change in the future?

in follow-up to the question: 85202 There, @ugamat wrote ""ECDSA is the first thing that can get vulnerable with quantum computer. signature will need to move to post quantum world much before quantum ...
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ScriptCode field in P2SH-P2WPKH BIP-143 Test Vector

I'm trying to understand the meaning of scriptCode in the context of spending a P2SH(P2WPKH) UTXO. I've already read the following answer to a similar question, but it does not fully address my ...
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How may bitcoins hash algorithm be secured in the future from quantum computing brute forcing?

Other threads already answer very clearly that quantum comps could easily "break" /attack bitcoins chain. Now: Are there any ideas among the bitcoin devs circulating out there, how to save bitcoin ...
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Uniquely identifying a UTXO

I see two ways: Txid + index Txid + script hash Pros of the txid + index: Simple and short Cons of txid + index: It relies on array iteration being deterministic and all third party ...
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Swift implementation of bitcoin transaction creation

Is there a well known and widely used Swift implementation for creating raw Bitcoin transactions and getting their hash (SegWit and Non-SegWit) of signing? If not, is there a reference document that ...
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Hash rate : Algebraic Equation

I recently made a post on stack, Calculate hash rate in IOS, in hopes of deciphering how the hash rate is calculated when benchmarking performance. The reason I wanted to do this is to compare against ...
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where in the source code is the the proof of work checking the blockheader hash and nonce?

Where in the source code do we check whether hash(blockheader*nonce) < Difficulty In fact, the line I found is as follows: https://github.com/bitcoin/bitcoin/blob/v0.17.0.1/src/pow.cpp#L87 My ...
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How specific are ASIC's design? Can they single hash SHA256?

I understand that Bitcoin's ASICs are a highly optimized piece of equipment and, therefore, are also very specific. My question: are they able to do a single (or triple?) SHA-256 hash at all? And, ...
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Trying to understand why hash value is more secure from hash algorithm

I am currently studying in college in the US and was actually curious about bitcoin and cryptocurrencies as a whole. I started looking on free university sites like Stanford university and New York ...
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How does transaction authentication between buyer and seller look for?

I am new to cryptography and would like to understand how a digital signature works between a buyer and a Bitcoin seller. How does transaction authentication between buyer and seller look for? Please ...
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Proof-of-Stake: How to ensure immutability of the blockchain?

In Proof-of-Work, a miner tries to solve PoW puzzle based on the hash of previous block, such that in case of changing block B_i, all blocks after that (blocks B_i+1, B_i+2, ...) are no longer valid ...
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Bitcoin-core how to get all transactions hashes?

Please, can anyone help me how to get all transactions hashes? How to browse all the transactions hashes used in blockchain? P.S. How simply get a list of all transactions IDs (as a simple text list) ...
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Hashing Transactions for Mining

After reading that Mining involves Taking a root hash of a transaction and combining that hash with a nonce it is required to find a number that is equal or below the given target, i was wondering if ...
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Create master public key after HMAC-SHA512

I have that result after hash_pbkdf2 5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570 left 256 bits are: ...
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Newly generated coins

New to BTC world so my question is how and what can I do with newly generated coins what's the process and how to see balance of that in wallet? Can I send those to paper wallet
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Is it possible to accurately map hashing power to network size?

Let's say we have a network with n nodes in it. Is it possible, when the hashing power of the network is calculated after a proof-of-work, to accurately estimate n with an algorithm taking the ...
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in transaction, what is 'hash' data?

i'm studying Bitcoin: A Peer-to-Peer Electronic Cash System Satoshi Nakamoto and this paper introduce a transaction model. (above picture) but i don't understand what is 'Hash' means exactly i ...
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How to determine right address from address hash

I'm using private libbitcoin server and libbitcoin explorer. When I use bx fetxh-transaction, it returns something like: I'm trying to figure out, how to get right address from address_hash. When I ...
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Electrum's “script hash” form with NBitcoin?

I've come across how scripts are hashed in the electrum (stratum) protocol implementation by looking at the docs. I'm using NBitcoin, and I've tried to generate this hash from a segwit address, first ...
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SHA256 vs RIPEMD160 in SegWit

In Pay-To-Witness-Public-Key-Hash (P2WPKH), the RIPEMD160 hash function is used to hash the public key of the recipient in the locking script. On the contrary, Pay-To-Witness-Script-Hash (P2WSH) uses ...
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Merkle hash tree

Does the Merkle hash tree always have to be a binary tree? If not then what will be the advantages if it is ternary, tertiary…or anything else?
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Does hashing of bitcoin addresses cause collisions? [duplicate]

There are 2^256 possible public keys. We generate bitcoin addresses by hashing these public keys using SHA256 and then RIPEMD160. Now, since 160 < 256 won't there necessarily be collisions - ...
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How to convert a bitcoin address to the respective hash160 using bash?

I want to convert a list of bitcoin addresses to their respective hash160 values as illustrated using bash :
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Why is Target < Blockhash?

I am currently trying to validate a blocks hash against its target in python3: This is a block in the Blockcypher testnet, and I am using this formula from the Bitcoin Wiki. block_hash = '...
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Sorry newbie, I dont get the PoS block creation, to much contradiction

I am sorry for the repeat question but I cant find a clear answer. Most of the time PoS isnt explained in detail (only explaining the advantage) and a lot of sources contradict each other and now I am ...
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I am just wondering what are the methods which can hide all the transactions and also able to validate transactions in an block chain?

I am new to block chain and was looking at how block chain work mainly proof of stake based . They check validity by going through all the transactions which is something concerning as everyone can ...
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Why is the nonce bruteforced from 0 to n while mining?

bitcoin noob here. I was wondering why is the nonce increased from 0 to n while searching for a blockhash? Why not start at some other integer > 0 for example? My background is in ethereum-dev, so ...
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Can't we change the block data instead of a nonce?

In the process of solving a hash puzzle, isn't it possible to change the transaction data instead of changing a nonce?
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Natural Language Processing and Blockchain?

This question is about one of the applications of the Blockchain in Artificial Intelligence. I am not very familiar with Natural Language Processing and I see that there is a Blockchain platform ...
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1answer
95 views

Getting transaction id from raw transaction of a multisig address

I am able to get the tx id (or transaction hash) of almost any transaction but the one where the script starts with an "OP_O" (which is, I think, the null dummy introduced here https://github.com/...
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Estimated number of hashes

This is not a duplicate of previous, similar questions I've read on StackExchange, since none of those questions, nor the answers, go into the difficulty theory, as espoused on the Bitcoin Wiki. ...
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Checksum vs. Hash: Differences and Similarities ?

What are similarities and differences between a "checksum" algorithm and a "hash" function? Can they be used instead of each other? Or their usage are different? For example, for verifying the ...
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retrieving an original data from a hash: is it reliable?

Normally, one of the purposes of hashing a string (such as a transaction) is summarizing the data to save the size because of the space limitation. If this proposition is true, now assume we need to ...
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How to protect the latest block in block chain be tampered?

We know for each block in block chain, it has the previous block header hash which make the block be tampered become difficult. If the block is tampered, then all blocks after this tampered block need ...
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1answer
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How come Merkle tree is more efficient when tree branches are not stored in blockchain?

Suppose we have 8 transactions in a block X as follows and we know every node's hash value of the whole Merkle tree (that is, including intermediary nodes such as 45). Then if someone claims ...
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1answer
103 views

General private/public key generation

Not sure if this is the correct forum to ask, but I couldn't find a general one for all cryptocurrencies I wanted to get an idea on how the whole cold-storage private/public key generation works for ...
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1answer
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Can Bitcoin Tech be Used to Protect Journalists [closed]

Over eight Nigerian journalists are currently in police detention because they published investigative news stories that didn't sit well with the government of the day. How can the bitcoin ...
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1answer
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Have all hashes of unlocked difficulty levels of cryptocurrencies been mined?

I'm wondering if all the hashes of a previously unlocked difficulty level of a cryptocurrency, such as 0000000000000000xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx BTC , have been completely ...
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“tx” array inside blocks contains transactions hashes?

When I use the "getblock " command on my bitcoin core client, it returns, beside other things, an array called "tx" with hundreds of hashes. Are these the individual transactions hashes or something ...
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What are the hashes in Unspent outputs?

I am a newbie to Bitcoin. Looking at curl https://blockchain.info/unspent?active=1Cdid9KFAaatwczBwBttQcwXYCpvK8h7FK I guess that the script is the owner's address.I am not sure about this. "...
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When a node receives a transaction, what steps does it do to verify that transaction?

I know that it verifies the block hash by calculating each hash of the contiguous blocks in order, but does it verify the balance of each wallet sending the transactions as well? And does it do the ...
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Mining Theory: What would happen if a block hash collision occured? [duplicate]

To my knowledge, neither SHA256 or scrypt have ever had provable instances of hash collisions occur.. However, if this highly unlikely event was to happen, what would that mean for the state of the ...
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Why A Block have a Merkle root hash? [duplicate]

That is the question, why a block needs to have a Merkle root hash, as Iundestand, once a block is mined the hash value of this block is stored at the header of the next one so, it generates the chain....
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I want to know how I can express a phenomenon found in Merkle Trees mathematically

I want to know how I can express a phenomenon found in Merkle Trees mathematically. If I want to figure out which leaf node in a Merkle Tree has changed I can look at the authentication path to figure ...
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93 views

What does this comment in Chainparams.cpp mean?

There is a comment in the Bitcoin source code under src/chainparams.cpp /** * Build the genesis block. Note that the output of its generation * transaction cannot be spent since it did not ...
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How are Bitcoin Signed Messages generated?

Ledger Nano S and other pieces of Bitcoin software and hardware can sign messages using the private key associated with an address. Doing this, I get the following output: -----BEGIN BITCOIN SIGNED ...
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How would you find the Merkle Root with a Block that contains 6 transactions?

Let's use block #100205 https://www.blockchain.com/en/btc/block/0000000000033d0de6f4ebe93b3b142424cdbecf4bd98b948e856c4a55f09f76 This block contains 6 transactions. After the second level of hashing ...
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Why Does an Online SHA Generator not work for Double Hashing data? [duplicate]

Let's say you use: https://passwordsgenerator.net/sha256-hash-generator/ You plug in data and it produces the first hashed value. If you plug that output in for the second SHA256 it outputs the wrong ...
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How nodes verify if the hash on a P2SH output is from a valid script?

I understand how the validation works if someone wants to spend coins from a multisig address. But what if the receiver makes a mistake and provides an invalid script hash to the sender? Is there ...