Bitcoin

Overview
Bitcoin is

"a virtual currency scheme based on a peer-to-peer network. It does not have a central authority in charge of money supply, nor a central clearing house, nor are financial institutions involved in the transactions, since users perform all these tasks themselves. Bitcoins can be spent on both virtual and real goods and services. Its exchange rate with respect to other currencies is determined by supply and demand and several exchange platforms exist. The scheme has been surrounded by some controversy, not least because of its potential to become an alternative currency for drug dealing and money laundering as a result of its high degree of anonymity."