The one-time card numbers generated by the old AMEX Blue system were great for shopping on sites you didn't trust. Too bad that they dumped that and the card reader system around 2002-2003? I really liked it and felt much more confident using it. Seems like it would have cut down on fraud a lot more than many systems in use.
That said, I really don't know why anyone would want to try and write their own payment integration gateways nowadays. There are so many good alternatives out there. Why not use them? You should focus on what you love, not payment processing. If you're just selling simple goods, you can easily setup a store on Shopify, Weebly, WIX, etc. Let them handle the fraud stuff. Sure, you might be on the hook for a few bad charges here and there, but at least you didn't waste hours writing payment code.