I don't think paper money will disappear.
If the currency were to become fully digital, the terrorists would be able to destroy the world's economy by developing a virus that was powerful enough.
And the world economy will never grow to the extent that people around the world have access to the Internet anytime and anywhere.
yeah i got the idea and i agree with that. but maybe it will become fully digital someday, but we must think how to resolve the problem for example as have been said above