Bitcoin is a peer-to-peer payment system and digital currency introduced in 2009 by developer Satoshi Nakamoto. Unlike other currencies, Bitcoins are created by solving math puzzles called mining. There are finite number of bitcoins – 21 million – and All are expected to be mined by 2014. In a key development in 2011, BitPay, a payment processor that allows e-commerce merchants to accept bitcoins, begins operating. BitPay allows both users and senders to remain anonymous by transferring bitcoins between digital wallets that can be set up on computers and mobile phones. The program tracks each bitcoin to prevent counterfeiters
