The Fidesmo dual-interface smartcard might fit the bill: http://shop.fidesmo.com/product/fidesmo-card-dual-interface http://shop.fidesmo.com/product/fidesmo-car

The Fidesmo dual-interface smartcard might fit the bill: http://shop.fidesmo.com/product/fidesmo-card-dual-interface http://shop.fidesmo.com/product/fidesmo-card-dual-interface You would need to buy and install the U2F applet ("card app") onto it. There are other applets available for PGP and for Bitcoin wallets, which can co-exist on the same card AFAIR. Not sure about supported key lengths. I'm not affiliated with Fidesmo or the applet vendors. Any opinions on this product from the HN crowd? E.g., what do you think about the security implications of their user-installable applet model?