Mastercard is Building Fingerprint Scanners Directly Into Its Cards (fastcompany.com)
Mastercard said on Thursday it's beginning trials of its "next-generation biometric card" in South Africa. In addition to the standard chip and pin, the new cards have a built-in fingerprint reader that the user can use to authenticate every purchase. From a report: Impressively, the new card is no thicker or larger than your current credit and debit cards.
I think the point is that they're making it much harder for a typical wallet thief to go to town on your credit card before you can report it stolen. By the time they create a false print, it may be too late.
A hash is not enough. Fingerprint matching is a notoriously fuzzy process because fingers deform under pressure, they get damaged (cuts, burns), etc. The matching process works by doing a "good enough" comparison between the newly-acquired image and a pre-digested "template" computed from the enrolled image.
A friend of mine works for one of the companies involved in the Mastercard pilot. As I understand it, their card is powered by the chip reader, which already supplies power to the EMV chip.