I've seen prototype NFC cards with E-ink screens and buttons that do exactly this. They can extract enough power from the NFC link to update the e-ink screen.

I've seen prototype NFC cards with E-ink screens and buttons that do exactly this. They can extract enough power from the NFC link to update the e-ink screen. Doesn't solve the problem raised in this article though, which is authenticating the card. The problem is trusting the terminal you are using the card with - because the terminal is responsible for verifying that the card is genuine, a modified terminal can make any card appear as genuine.