01 May 2014 / Investopedia – If you’ve ever wondered where Bitcoin comes from and how it goes into circulation, the answer is that it gets “mined” into existence. Bitcoin mining serves to both add transactions to the block chain and to release new Bitcoin. The mining process involves compiling recent transactions into blocks and trying to solve a computationally difficult puzzle. The first participant who solves the puzzle gets to place the next block on the block chain and claim the rewards. The rewards incentivize mining and include both the transaction fees (paid to the miner in the form of Bitcoin) as well as the newly released Bitcoin.
Security of the Network
Bitcoin mining is decentralized. Anyone with an internet connection and the proper hardware can participate. The security of the Bitcoin network depends on this decentralization since the Bitcoin network makes decisions based on consensus. If there is disagreement about whether a block should be included in the block chain, the decision is effectively made by a simple majority consensus, that is, if greater than half of the mining power agrees.
If an individual person or organization has control of greater than half of the Bitcoin network’s mining power, then they have the power to corrupt the block chain. The concept of someone controlling more than half of the mining power and using it to corrupt the block chain is known as a “51% attack”. How costly such an attack would be to carry out depends largely on how much mining power is involved in the Bitcoin network. Thus the security of the Bitcoin network depends in part on how much mining power is employed….. Read more
http://www.investopedia.com/articles/investing/043014/what-bitcoin-mining.asp
