5 ms·

I think you have to add that everyone is solving a different puzzle, I.e. if I'm not mistaken, an identifier of the miner (I would guess her public key, I can't

I think you have to add that everyone is solving a different puzzle, I.e. if I'm not mistaken, an identifier of the miner (I would guess her public key, I can't really check right now) is included in the string she hashes (plus they may not all have the same list of pending transactions). otherwise you would still have the problem that if people use the same software for guessing the random string, the fastest would always win.

throwaway7767 13y ago
The block being hashed will include the payout address set by the miner, which will make the block he is working on different than the ones the others are working on. The block includes a nonce, a random number which is changed for each try until one gives a hash < target. That nonce is picked at random independently by the miners, so that also makes the blocks they are working on different.
ufmace 13y ago
True, but not really relevant to this. Even if they were all the same, it wouldn't change things. The fastest would indeed win if all hashing devices started at the same nonce value and all incremented it in the same way. (the nonce is the extra data put into the block solely to make the block's hash meet the requirements) But precisely because of that, there is no reason for any device to try nonces in a deterministic way. maaku's explanation makes clear a very good point - trying any particular hash only tells you whether that one succeeds or fails; it doesn't tell you anything about whether any other value will succeed or fail. Any particular hashing device will maximize its chances of winning/finding a solution by trying nonces in such a way that it is unlikely that any other device is trying the same ones, but that it never tries the same one itself twice. I don't know offhand how many mining algorithms are out there and how they go about picking nonces, but I'd bet they do something like pick a strongly random starting value and then increment it by a fixed, small amount each try. But yes, all of the miner's blocks are generally different. Each block that a miner is working on must have special Coinbase transaction that awards a specific number of new BTC to a chosen address. If you are an independent miner, that would be your address, but pool miners generally use a pool address. I don't actually know how the latest pool mining algorithms work, but I think they all have more elaborate systems for how payouts work.

throwaway7767 13y ago

The block being hashed will include the payout address set by the miner, which will make the block he is working on different than the ones the others are working on. The block includes a nonce, a random number which is changed for each try until one gives a hash < target. That nonce is picked at random independently by the miners, so that also makes the blocks they are working on different.

ufmace 13y ago

True, but not really relevant to this. Even if they were all the same, it wouldn't change things. The fastest would indeed win if all hashing devices started at the same nonce value and all incremented it in the same way. (the nonce is the extra data put into the block solely to make the block's hash meet the requirements) But precisely because of that, there is no reason for any device to try nonces in a deterministic way. maaku's explanation makes clear a very good point - trying any particular hash only tells you whether that one succeeds or fails; it doesn't tell you anything about whether any other value will succeed or fail. Any particular hashing device will maximize its chances of winning/finding a solution by trying nonces in such a way that it is unlikely that any other device is trying the same ones, but that it never tries the same one itself twice. I don't know offhand how many mining algorithms are out there and how they go about picking nonces, but I'd bet they do something like pick a strongly random starting value and then increment it by a fixed, small amount each try. But yes, all of the miner's blocks are generally different. Each block that a miner is working on must have special Coinbase transaction that awards a specific number of new BTC to a chosen address. If you are an independent miner, that would be your address, but pool miners generally use a pool address. I don't actually know how the latest pool mining algorithms work, but I think they all have more elaborate systems for how payouts work.