<p>By definition, by altering the block, the hash would have to be altered too. Thus the hash ensures the block can't be tampered with, and the miner safely receives his reward.</p>

<p>To modify the block, the attacker would have to recompute a new valid hash within the difficulty, i.e. mine the block again after the original miner, which would clearly not be part of the main chain by that point and thus basically ignored.</p>

CC BY-SA 3.0
2017-07-08T12:50:43.993Z
ahhhhh - of course. For some reason I thought of the mining reward as outside of the list of transactions. Thank you very much!
Emil L.
CC BY-SA 3.0
2017-07-08T12:52:54.470Z
Nope the mining reward is the first transaction in the block, known as the coinbase transaction. Glad I could help :)
meshcollider
CC BY-SA 3.0
2017-07-08T12:49:12.247Z
2017-07-08T12:49:12.247Z
meshcollider
<p>With my still rather limited knowledge of bitcoin, I was wondering how the correct origin of proof of work is ensured. Specifically, when a miner successful computes a valid hash and is to broadcast this to others, how can he be sure that others do not alter the block now that they know the hash, rewarding themselves instead of the original successful miner?</p>

<proof-of-work>
How the first succesful miner is ensured his reward
Emil L.
# How the first succesful miner is ensured his reward

(Asked by: username_0 on 2017-07-08)

With my still rather limited knowledge of bitcoin, I was wondering how the correct origin of proof of work is ensured. Specifically, when a miner successful computes a valid hash and is to broadcast this to others, how can he be sure that others do not alter the block now that they know the hash, rewarding themselves instead of the original successful miner?

**Tags:** proof-of-work


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## 1 answers

### Answer by username_1 on 2017-07-08. Score: 4 | Accepted answer

By definition, by altering the block, the hash would have to be altered too. Thus the hash ensures the block can't be tampered with, and the miner safely receives his reward.

To modify the block, the attacker would have to recompute a new valid hash within the difficulty, i.e. mine the block again after the original miner, which would clearly not be part of the main chain by that point and thus basically ignored.

> **Comments:**
> **username_0**: ahhhhh - of course. For some reason I thought of the mining reward as outside of the list of transactions. Thank you very much!  
> **username_1**: Nope the mining reward is the first transaction in the block, known as the coinbase transaction. Glad I could help :)  

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