Blockchain is the possible destiny of the keeping cash structure, yet not the entire system. Banks will develop their own specific blockchain, and they will use it to cut their costs on trades and to speed them up. Bitcoin and altcoins has some time right now to create and make before banks run live with their own specific upgraded system. They won't tell people that they have developed another blockchain based structure, yet they will pitch that their new system is speedier and more affordable, and that is all what people require, they couldn't think less about the back end. In case that happens, that will be a hard time for cryptos.