What you are proposing, while great for the consumer, will not happen any time soon, due to the inertia of millions of merchants and their existing POS terminal

What you are proposing, while great for the consumer, will not happen any time soon, due to the inertia of millions of merchants and their existing POS terminals, and also due to the fact that very few people have smartphones. Also, how widespread is the problem of people handing over their credit cards to pay for something, and the merchant types in a bigger amount than you want to pay? It doesn't happen, or happens negligibly often. The bigger problem is not that merchants get to ask for as much money as they want when you are there at the store paying for something, but that they now have your credit card number and can, if they are malicious, use it later, or sell it on the black market. In comparison to your proposal, the new card being proposed can work today without any merchant making any change to their equipment. And this new card will become very useful once they add something akin to SecureID: That is, after every swipe of the card, the credit card number automatically changes to a new one. This is done on the card, and on the credit card issuer server, so that when the user makes their next purchase, both the card and the card issuer agree what number is being used. This would make it useless for people to steal credit card numbers. And having this built-in to your credit card, instead of having to go online every time, like some existing systems, makes it extremely convenient and easily adopted by users. Basically, this would mean no change on the part of users, no change on the part of the merchants, and only change on the part of the card issuers (they need to upgrade their servers and issue new cards), which is great because it is the card issuers that are most impacted by credit card fraud, so they are the most motivated to make a change.