bitcoins were invented by aliens silly..... not the CIA
I think (and I know your being funny, here, but truthfully..), that the aliens out there who are more intelligent than us and more advanced, would not use any form of currency at all. Races who use currency are "controlled" races of beings. Beings who are not controlled, use energy to make common exchanges, without a medium like money, in between. Money only facilitates the transfer of energy from being to being, and nothing more. If we could do direct transfer, we do not need money at all. Money only serves to transfer energy or products from the producer to the consumer, and it serves no other higher purpose. Bitcoins will even be irrelevant in the 22st century, i'm sure.
Our drive for money is a direct reflection of our need for energy. When we realize that energy can be harvested (free energy) instead of being produced by the input of a greater amount of energy, then we will begin to move into the area where good and services are produced for other motives entirely, than money.
When that is achieved, then the whole world will work towards a system where each individual contributes energy because they desire to, instead of the need to, in order to survive. At this point, people transfer energy directly, in stead of using money as a medium of exchange.