I think that cryptocurrency has to come up with a more efficient sort of block chain scheme in terms of the concept of the code and its logical working. Unfortunately they have to mine the ledger from the very first transaction in time forwards to today’s transactions, over and over again everyday, always starting back at the beginning of time, which in examination does not have to be done if viewed right. But that is how it all began and others use this same sort of model for their block chains but there are some variations. At some point the mining of Bitcoin will become so difficult and slow no one knows what will happen then. And if technology can not keep up in terms of hardware that can mine the block chain fast enough as it grows then a crunch point will be reached and who knows what will happen. Bitcoin will be the first to reach that point so whatever happens then will show us the future of other cryptocurrency. I study crypto mining and am interested in trying it myself, and so understand the issues with the size and difficulty of mining the Bitcoin block chain versus the present speed of the technology used in the data mining hardware. Bitcoin at present is the hardest to mine and yes due to all of the mining hardware it consumes allot of electrical power, and so cryptocurrency is not what we would call the greenest concept.