Resumen
In this article the features of Crypto Currencies, which are not backed by governments, are investigated with regards to their specialties, usage areas and current structures. In this context the newly invented crypto currencies are compared with currency types that were in use in different periods of history. A similarity between Crypto Currencies and Free Banking Era Banknotes is noticed and thus investigated in details. The possible risks and outcomes with regards to the future usage of crypto currencies are analyzed and elaborated.