The block header is a portion of each block in the block chain that identifies the basic parameters of that particular block such as the block version, the time it was generated, the hash of the previous block, and the hash of the transactions in that block.
Questions tagged [block-header]
125 questions
45
votes
2 answers
Nonce size - Will it always be big enough?
If I understand correctly, the block only has 4 bytes (32 bits) for the nonce.
Is it possible for the difficulty to become high enough that there are no nonce solutions?
If so, then what options does a miner have?
Michael Pickens
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32
votes
9 answers
Why don't the timestamps in the block chain always increase?
The timestamps starting at block 145044 are:
145044: 2011-09-12 15:46:39
145045: 2011-09-12 16:05:07
145046: 2011-09-12 16:00:05 // ~5 minutes before prior block
145047: 2011-09-12 15:53:36 // ~7 & ~12 minutes before 2 prior blocks
145048:…
Mocky
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26
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3 answers
The bitcoin mining algorithm from a programmer's viewpoint
This page: Blocks said mining is actually to solve a mathematical problem, but reading Block hashing algorithm doesn't give much help.
I also tried reading bitcoind source code, but reading code takes much more time than reading documentation:)
And…
Mark Ma
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20
votes
4 answers
How can one embed custom data in block headers?
Some mining pool admins put custom data in block headers, like prayers. How do they do that? Where can I see that data for myself?
herzmeister
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19
votes
3 answers
How would the Bitcoin protocol be impacted if nodes only stored the blocks they cared about?
Right now, full clients of the Bitcoin network store every block ever generated (while "thin" clients instead rely on a node which does so). This greatly increases first-time initialisation for the client, and also has significant implications for…
eMansipater
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19
votes
1 answer
Is it chain of headers rather than a chain of blocks?
We know widely used explanation of the blockchain:
"Every block contains a hash of the previous block". The sentence above implies that since every block contains a hash of the previous block, therefore every block should have a knowledge about…
Nur
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16
votes
3 answers
What is a nonce?
When I see the block info on blockchain, I see that there is a field named "nonce", I could not find any relevant information on web regarding what a nonce is. Please explain what a nonce is what is the purpose of it.
GypsyCosmonaut
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13
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5 answers
Why didn't Satoshi make the nonce space larger?
I know Satoshi isn't around to ask anymore, so this might be futile to ask, but I'm hoping someone might have some insight about this.
Bitcoin mining typically utilizes an extraNonce (bnExtraNonce in the coinbase tx's scriptSig) and a nonce field…
morsecoder
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11
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2 answers
Why are block header bits necessary? (Valid difficulty is already implied by chain history)
Difficulty or target is implied by chain history, so why does it need to be explicit in the header? I suppose it exposes miner-intended-difficulty, but I don't see why that would be relevant without chain context.
So it seemingly represents…
James C.
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11
votes
2 answers
Mining pool performance optimization
What are the main components one should focus on when trying to maximize a mining pool's performance? Assuming the code is pretty optimal (there aren't any inefficiencies), what should a pool owner devote their attention or resources to? I'm…
ThePiachu
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10
votes
1 answer
Whats the process of Creating a Block on the BlockChain
have been mining on pools and blindly going a long for the ride of
> generating a block
Can somebody walk through the process in simple terms of the steps involved in creating a block on the blockchain ?
What determines what transactions get…
BitCoin New Guy
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10
votes
4 answers
Is there a way to use the block chain as entropy in random number generator?
I want to create a transparent gambling/lotto site and use the block chain as entropy for lotto numbers, dice rolls, that kind of thing. Would the transaction hash of the latest transaction be the best way to do this? How often are transaction…
browep
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10
votes
1 answer
How does the bitcoin network recover in case of a hash collision in the block hash?
A Bitcoin client has to download the whole blockchain from the P2P network in order to become a full node.
A full node is able to determine, if a transaction in the network is valid or not.
To download the blockchain, the client queries other peers…
user1861174
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9
votes
1 answer
Calculate hash of block header
I'm trying to calculate the hash of block #502871. This is the block:
{
"result": {
"hash": "00000000000000000020cf2bdc6563fb25c424af588d5fb7223461e72715e4a9",
"confirmations": 35,
"strippedsize": 976261,
"size": 1064277,
…
CamiloARG
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8
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2 answers
Why is the Block Header txn_count field always zero?
According to the Protocol Specification, the txn_count field of a Block Header is always set to 0, why is that? What are the intended future uses of this field?
ThePiachu
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