## blockchain. How worked at the beginning?

-1

I would know some things about the creation of a blockchain for cryptocurrency (I let assume for simplicity Bitcoins). I red online that miners verify the blockchain, and when they verify a block, they earn Bitcoins. Here are my questions:

1) At the dawn of Bitcoins, so when the blockchain didn't have block, how people/miners could earn Bitcoins? If there weren't block, who released Bitcoins?

2) What problem miners solve to earn Bitcoins?

3) If two (or more) miners solve the same problem, will all be paid?

0

1. At the beginning there was the Genesis block. This Block is hardcoded in the Bitcoin Software.

2. In Bitcoin miners hash a block (which pays them the mining reward when accepted) with double-SHA-256. They modify the block sightly until they find a hash that starts enough zero bits. The amount of zero bits is defined by the difficulty.

3. When two miners find a valid block at roughly the same time and broadcast it a small fork occurs. The next miner that finds a valid block resolves this, as his block is based on only one of the two. The longest chain of blocks is valid here. The other block is then called an orphan block.

for the answer number 1, I realise that there is a Genesis block, but in this case, at the very beginning, miners just connect to the network, verify the genesis and earn 25 bitcoins? – BossShell – 2017-12-03T14:24:59.643

no. The 50 bitcoin (started at 50, halved to 25, and now to 12.5) from the Genesis block are unspendable. A Miner would build a new block and pay 50 bitcoin to himself. This new block references the Genesis block. – 0xb10c – 2017-12-03T14:40:05.133

How a miner can build a new block (that it should be a set of transactions), if nobody (at the dawn of Bitcoins) have Bitcoins and so there aren't transaction to verify? Sorry for these questions, but I didn't find good answers on internet – BossShell – 2017-12-03T14:47:49.473

Well you have at least one transaction in it. The coinbase transaction where the miner pays the new 50 bitcoin to himself. Some miners sometimes still mine emtpy blocks with only the coinbase transaction.

– 0xb10c – 2017-12-03T14:54:49.260

Yeah, I didn't figure it. can i say that at the beginning it was really easy to mine bacause of the few transactions? Is it correct? – BossShell – 2017-12-03T14:59:35.493

incorrect. The difficulty does not depend on the amount of transactions. It depends on the network hashrate.

– 0xb10c – 2017-12-03T15:48:25.853

Who generate the Target? A single node, choosen randomly, that will distribute the number to the world, or something else? – BossShell – 2017-12-03T16:02:45.457

– 0xb10c – 2017-12-03T16:05:48.257