COLDCARD Mk4 Firmware v5.1.1: MicroSD 2FA, Tapsigner Import, and More
Coldcard is a Bitcoin hardware wallet, it signs transactions to keep the private keys offline.
“MicroSD card as Second Factor”. Specially marked MicroSD card must be already inserted when (true) PIN is entered, or else seed is wiped. Add, remove and check cards in menu: Settings -> Login Settings -> MicroSD 2FA
Import TAPSIGNER encrypted backup as main or ephemeral seed, for PSBT signing. This is a great way to safely use the key previously held inside a TAPSIGNER, because the COLDCARD can take over the signing that used to be done by the card.
Detached Bitcoin signature files for most exports.