Serious question: In a world where coins are digital and paper money is a mere novelty, how will exchanges or transactions work? It would have to be faster than a handshake, and yet secure. Would they only be on apps in your phone? Could you hide them in a pendant or perhaps a watch? Thoughts?
They will be automatic, at least in shops. You will not need to do much, since with facial recognition they'll know in shop who you are, what's your (public) wallet and everything you want to share. All you will need to do is to check the amount and approve the transaction with your unique seal/key. The amount will be subtracted and if it's not enough in the wallet of that currency, automated exchange from your other (public) wallets will be made to cover the amount.
In the privacy of your home you may still need some sort of computer for the more specific actions. That will be computer, home entertainment and who knows what else, there's plenty of room for innovation.
Just .. why paper money in all this story? That'll be only at the museum, you know?
