This would be more secure than what I proposed, but requires changes that are out of the control of the credit card companies.
For the card to sign the transaction, you need to add some kind of card interface to the users device. Maybe this is what happens with chip cards when you use it at a shop with a card terminal.
For the card to sign the transaction, you need to add some kind of card interface to the users device. Maybe this is what happens with chip cards when you use it at a shop with a card terminal.