<blockquote>
  <p>I was under the impression that even an individual could, if he completes the proof of work first, cause the addition of the block to the blockchain? What am I missing here?</p>
</blockquote>

<p>That it could happen that 2 blocks are found at the same time. Which usually causes the network to split into two chains, ( One part of the network is going to build/find a new hash based on block y, and the other part of the network is trying to find a new valid hash based on block X.).</p>

<p>Whoever finds Block Z first creates the longest chain and thus invalidating the shorter one. ( Miners who build on block Y find block Z so now block X ( which is the shortest chain) gets orphaned )= now invalid.</p>

<p>The same principle applies to a 51% attack, since you have majority hashpower you will always (hypothetically) find a valid hash faster then the other chain which has 49% hashpower.</p>

<p>In that case, no individual ( unless the individual owns 51% of the hashpower) is going to be able to "mine" a block/(or rather, - get a block added to the longest/valid chain).</p>

<p>Your title is something else then your question, </p>

<blockquote>
  <p>Do multiple miners contribute to mining the same block even if they are not in the same pool</p>
</blockquote>

<p>Well, yes, if there's only 1 chain, every miner is going to be building upon that chain, which means they'll all be looking for a block ( or rather a hash) that is going to be valid on that chain ( basically the next block?)</p>

<p>I wouldn't use contribute though, it's not like they share their hashpower, but they do indeed share the same goal. -> Finding a block with a valid hash that is valid on the current chain.</p>

CC BY-SA 3.0
2018-03-26T17:10:53.620Z
2018-03-26T17:10:53.620Z
Jan Janssen
<p>Assuming that this is reliable, according to an <a href="https://www.investopedia.com/terms/1/51-attack.asp" rel="nofollow noreferrer">article on investopedia on the 51 percent attack</a>:</p>

<blockquote>
  <p>51% attack refers to an attack on a blockchain – usually bitcoin's, for which such an attack is still hypothetical – by a group of miners controlling more than 50% of the network's mining hashrate, or computing power. <strong>The attackers would be able to prevent new transactions from gaining confirmations</strong>, allowing them to halt payments between some or all users. </p>
</blockquote>

<p>Does the above bold line imply that all the miners are required to provide their confirmation for a transaction to be added to the blockchain? <p>I was under the impression that even an individual could, if he completes the proof of work first, cause the addition of the block to the blockchain? What am I missing here?</p>

<mining-theory><majority-attack>
Do multiple miners contribute to mining the same block even if they are not in the same pool
rahs
# Do multiple miners contribute to mining the same block even if they are not in the same pool

(Asked by: username_0 on 2018-03-26)

Assuming that this is reliable, according to an [article on investopedia on the 51 percent attack](https://www.investopedia.com/terms/1/51-attack.asp):

> 51% attack refers to an attack on a blockchain – usually bitcoin's, for which such an attack is still hypothetical – by a group of miners controlling more than 50% of the network's mining hashrate, or computing power. **The attackers would be able to prevent new transactions from gaining confirmations**, allowing them to halt payments between some or all users.

Does the above bold line imply that all the miners are required to provide their confirmation for a transaction to be added to the blockchain?

I was under the impression that even an individual could, if he completes the proof of work first, cause the addition of the block to the blockchain? What am I missing here?

**Tags:** mining-theory, majority-attack


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## 1 answers

### Answer by username_1 on 2018-03-26. Score: 0 | Accepted answer

> I was under the impression that even an individual could, if he completes the proof of work first, cause the addition of the block to the blockchain? What am I missing here?

That it could happen that 2 blocks are found at the same time. Which usually causes the network to split into two chains, ( One part of the network is going to build/find a new hash based on block y, and the other part of the network is trying to find a new valid hash based on block X.).

Whoever finds Block Z first creates the longest chain and thus invalidating the shorter one. ( Miners who build on block Y find block Z so now block X ( which is the shortest chain) gets orphaned )= now invalid.

The same principle applies to a 51% attack, since you have majority hashpower you will always (hypothetically) find a valid hash faster then the other chain which has 49% hashpower.

In that case, no individual ( unless the individual owns 51% of the hashpower) is going to be able to "mine" a block/(or rather, - get a block added to the longest/valid chain).

Your title is something else then your question,

> Do multiple miners contribute to mining the same block even if they are not in the same pool

Well, yes, if there's only 1 chain, every miner is going to be building upon that chain, which means they'll all be looking for a block ( or rather a hash) that is going to be valid on that chain ( basically the next block?)

I wouldn't use contribute though, it's not like they share their hashpower, but they do indeed share the same goal. -> Finding a block with a valid hash that is valid on the current chain.


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