Thank you for going to the effort of coming back to respond! I appreciate the detailed critique. There's a lot to think about here, but one thing that comes imm

Thank you for going to the effort of coming back to respond! I appreciate the detailed critique. There's a lot to think about here, but one thing that comes immediately to mind is that this: > Payment must need some signature: it could be a PIN, it could be that the payer hands money to the payee. It cannot be that the recipient approaches a card. ...could be easily solved with a button on the card (like my FIDO2 key has), or, in the case of the NatWest trial, a fingerprint scanner[1] on the card itself. This would stop the card from being (accidentally/maliciously) charged by NFC through a wallet or pocket. Unfortunately, it doesn't look like NatWest continued the trial - for the moment, at least, that makes gives them the privilege of being both 'the first' and 'the last' UK bank to unveil biometric credit cards! [1]: https://www.natwestgroup.com/news-and-insights/feature-content/our-updates/2011-2020/natwest-first-uk-bank-to-unveil-biometric-credit-card.html https://www.natwestgroup.com/news-and-insights/feature-conte...