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.