There are many things that points to number of the beast but there are not the mark of the beast. Otherwise anyone who used for example bar-code (also pointing to 666) would be beyond salvation.
Of course digital or cashless system is not bad. If based on open technology like Bitcoin or alike it would be even much better than current fiat system. Problem is all these good inventions will be misused for totalitarian purposes. Elites will not use Bitcoin of course, they will implement something that they will be able to control and censor.