Bitcoin is the first virtual peer-to-peer currency that allows a false-proof exchange of digital coins over the Internet. The decentral structure of Bitcoin enables one to avoid high transaction fees that are demanded by banks, credit card companies or clearing houses. The average fee of a Bitcoin transaction is just 0.016%. In contrast, for an overseas bank transfer of 200$ from the USA a fee of 6% is charged. Besides Bitcoin, there are 750 other cryptocurrencies, whereas Bitcoin is dominating the market with a market share of 80%. The only requirement for accessing the Bitcoin network is a functioning Internet connection.