Recently, I have read some introductions about bitcoin and other p2p currencies. I still don't understand them. I may be unaware of myself, or some do not understand the principle of their specific impact on the national currency.
Issue currency is a kind of special power, generally belong to the central banks of all countries. This kind of power has many benefits. It can control the currency only for macro-control. Issuing currency can also be the same. Of course, the central bank issued a unified currency indeed also avoid a lot of fraud, disputes, reducing the commercial transaction costs due to mistrust. Bitcoin (in theory) replaced the currency system.