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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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23 views

What would be the effect on the number of leading zeros hash generation if bitcoin increase its nonce size from 32 to 60 or 100 bits?

If Bitcoin increases its nonce size from 32 bits to double or triple the size, how will it affect the speed of getting the right hash with the required number of zeros?
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26 views

How to transfer hash power from one pool to another

Is it possible to transfer hash power from one pool to another? If yes, how?
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38 views

How do more leading zeroes make it more difficult to find a block?

A couple of articles describing the process of mining do say that the more miners are in the network, the more 0 numbers are included in the encoded hash of the particular block. I cannot find an ...
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30 views

How get the public key to hex script? like command decodescript of bitcoin core

If I want to recreate the command decodescript of bitcoin core? how is the process for decode the script P2PK? So I'm writing for personal exercise the Bitcoin script decompiler, form moment I have a ...
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16 views

How are the requirements of the hash for mining a new block determined?

How are the requirements of the hash for mining a new block determined? Is it published or a message is sent?
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48 views

How to sign an Altcoin transaction manually with 2 inputs and 2 outputs

So i'm working with the altcoin denarius which has the following raw TX structure. This is a transaction I am try to sign: Original: ...
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32 views

BIP32 HD Wallet vs HMAC vs Hashing

I've been working on a website which will be caring out various cryptographic operations. On the website users can post Ads. Each Ad has a monotonically increasing unique ID. For each Ad, I would like ...
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31 views

Bitcoin Module - Hash512-EVP_ByteToToken

Is there any standalone software modules created which allow the user to complete the following: 1. Enter in passphrase 2. Enter a given salt 3. Enter the number of rounds I am looking ...
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1answer
43 views

How many hash calculation is needed to reach one BTC?

What I am asking for is a formula and it's source of numbers to put in there and calculate how many hashes must be calculated to get 1 bitcoin today(or every other day in future)? For example, if I ...
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1answer
13 views

When changing transaction data in a block change the hash of previous block?

If i only manually change the data on the block without touching/modifing the already calculated hash, then hash on the block its still valid because its already saved and was not touched ... so, ...
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1answer
43 views

How exactly does the network know if the miner has put forth a valid proof of work?

If all that the miner needs to do is find a hash with a certain number of leading 0's of the block's header, couldn't they just find a random hash with the required number of 0's that isn't ...
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2answers
306 views

Is verification of a blockchain computationally cheaper than recreating it?

One of the advantages of cryptocurrencies like Bitcoin that is often repeated is how hard it should be to manipulate past transactions. The reason that is often stated is that you would have to re-...
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1answer
21 views

How is the PRIVATE KEY actually created in the first place?

How is the "Private Key" created in the first place? I understand that once you have your wallet, you will also gain access to your public key and private key... But in order to have a wallet ...
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29 views

Method to create P2SH address

I am trying to create a htlc smart contract manually by writing a script and finding the hex using the btcc compiler. Now node A has to create a transaction using that hex and lock money in that p2sh ...
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1answer
16 views

Doubt regarding hashing function in Merkle trees

From what I read, say in a block, there are 4 transactions. The hash value of transactions A and B are combined together to get the hash AB. Same goes for transactions C and D to get hash CD. Later AB ...
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38 views

OP_EQUAL not working properly

I went to https://siminchen.github.io/bitcoinIDE/build/editor.html to try some bitcoin scripting and I wrote this script: <1PUzZ61FSVTn12CafJC85Vy1ts3BoFcXdU> OP_HASH160 <...
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20 views

Is the current hashcash proof of work system vulnerable to attack by quantum computer? [duplicate]

I've been caught up in the post-quantum cryptography scene for a little while now, and understand that the RSA or ECC cryptography inherent in a cryptocurrency network can be easily broken by a ...
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52 views

Is this a collision attack or a 2nd-preimage attack?

This question revolves around Bitcoin Optech newsletter #51 (1) and an email thread from the bitcoin-dev mailing list (2). I asked the same question in a reply-email of the newsletter and the response ...
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52 views

What happens if I send a XRP transaction to a blank TAG when I was supposed to send to a specifc TAG?

I sent XRP to a blank TAG while I was supposed to send to the éxchange's TAG. The address is the one from the exchange but the TAG was left blank. The exchange says that they can't recover the money. ...
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32 views

19 out of 24 words of BIP39 passphrase (brute-force last 5?) [duplicate]

I have managed to lose 5 words of my 24 word Ledger Nano S recovery phrase. I have words 1-19 but I am missing words 20-24. I have significant holdings on the wallet so would very much like to recover ...
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13 views

Public key vs Bitcoin address [duplicate]

As i've read on many websites and papers, the bitcoin address is made by hashing the public key. And i've read that that's done because we don't want the public key to be public until money is spent. ...
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1answer
36 views

How chaining the blocks protect against altering data?

I am confused with the block chaining, as i know a block header contains a reference to the previous block header hash with the merkle root and other fields. This header hash is related (computed) to ...
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2answers
880 views

What is preventing me from simply constructing a hash that's lower than the current target?

I just started learning about Bitcoin, and something I can figure out is why miners have to use a random process (hashing a nonce) to get lower than the target. For example, if the target is ...
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38 views

How difficult is it to confirm a Bitcoin Block?

If I have done the math right to come up with this hash, to confirm a true block and this is a confirmed hash. You can look it up here Bitcoin Block #570240 ...
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15 views

Hash rate of the average PC/Top end PC [duplicate]

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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1answer
51 views

Signature digital algorithm in bitcoin, to what will it change in the future?

in follow-up to the question: 85202 There, @Ugam Kamat wrote ""ECDSA is the first thing that can get vulnerable with quantum computer. signature will need to move to post quantum world much before ...
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1answer
135 views

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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46 views

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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43 views

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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19 views

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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1answer
86 views

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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1answer
75 views

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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1answer
158 views

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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2answers
34 views

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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32 views

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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64 views

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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2answers
299 views

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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1answer
38 views

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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1answer
66 views

Create master public key after HMAC-SHA512

I have that result after hash_pbkdf2 5B56C417303FAA3FCBA7E57400E120A0CA83EC5A4FC9FFBA757FBE63FBD77A89A1A3BE4C67196F57C39A88B76373733891BFABA16ED27A813CEED498804C0570 left 256 bits are: ...
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1answer
59 views

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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22 views

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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1answer
36 views

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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1answer
53 views

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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2answers
108 views

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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2answers
114 views

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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20 views

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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149 views

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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60 views

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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1answer
58 views

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 ...