How the first succesful miner is ensured his reward 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?
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.