That’s all transactions are—people signing bitcoins (or fractions of bitcoins) over to each other. The ledger tracks the coins, but it does not track people, at least not explicitly. Assuming Bob creates a new address and key for each transaction, the ledger won’t be able to reveal who he is, or which addresses are his, or how many bitcoins he has in all. It’s just a record of money moving between anonymous hands.
Despite having similar needs, there is a good deal of diversity in how chip designers build their hashing engines, says Hanke, who also served as the chief technology officer of a now-defunct mining rig manufacturer called CoinTerra. For example, Bitmain uses pipelining—a strategy that links the steps in a process into a chain in which the output of one step is the input of the next. Bitmain competitor BitFury has chosen not to use that technology.
Bitcoin solves the "double spending problem" of electronic currencies (in which digital assets can easily be copied and re-used) through an ingenious combination of cryptography and economic incentives. In electronic fiat currencies, this function is fulfilled by banks, which gives them control over the traditional system. With bitcoin, the integrity of the transactions is maintained by a distributed and open network, owned by no-one.
Nakamoto is estimated to have mined one million bitcoins[26] before disappearing in 2010, when he handed the network alert key and control of the code repository over to Gavin Andresen. Andresen later became lead developer at the Bitcoin Foundation.[27][28] Andresen then sought to decentralize control. This left opportunity for controversy to develop over the future development path of bitcoin.[29][28]