Digital currency of its creators. "Forbes" writer Tim Worstall has written that the value of bitcoin is largely derived from speculative trading. Bitcoin has also been criticised for its energy inefficient SHA-256-based proof of work. Digital currency Digital currency (digital money, electronic money or electronic currency) is a type of currency available in digital form (in contrast to physical, such as banknotes and coins). It exhibits properties similar to physical currencies, but can allow for instantaneous transactions and borderless transfer-of-ownership. Examples include virtual currencies and cryptocurrencies and central bank issued money accounted for in a computer database (including digital base money). Like
Currency War of 2009–11 a source of contention, concerns over currency war had receded, along with signs that major currencies such as the Renminbi were now much less undervalued than they had been a year previously. Brazil currency had fallen substantially from its peak value against the dollar, allowing Mantega to begin rolling back anti-appreciation measures. In July, the IMF downgraded its assessment of the degree to which the Renminbi is undervalued from "substantially" to "moderately". However, Chinese officials were not pleased, suggesting that their exchange rate is no longer undervalued at all. Whereas in the US, presidential candidate Mitt Romney retains his pledge