While it's interesting from an accounting perspective, it could revolutionize payments. Imagine if you never gave your credit card number to a merchant, only signed a receipt from them in a way that assured the bank that the transaction was legitimate. PCI would be a non-issue since sensitive information is never exchanged. It also opens all new ways to pay for things, since the transaction could be submitted to the bank by either party (customer pays vs merchant charges).
Sure, but it doesn't need to be. The recipient doesn't need to care if the payment is coming from a bank account or a cryptocurrency (as long as there's a party to convert in between).
