Cold Card by Coinkite
A Open, Cheap & Ultrasecure Hardware Wallet!
Coldcard is a Bitcoin hardware wallet, it signs transactions to keep the private keys offline.
What is the Coinkite Coldcard? It’s a Bitcoin hardware wallet, so it signs transactions and can be used offline.
- BIP39 based, which means you can backup the secret words onto paper, and have lots of sub-accounts and unlimited independent payment addresses.
- It knows how to understand transactions, so you can see what you are approving.
- The first PSBT (BIP 174) native wallet which can be used completely offline for it’s entire lifecycle.
But it’s different!
- NO specialized software required. It accepts standard PSBT transaction (BIP 174) stored on an MicroSD card. NO companion ‘app’ on your computer, works with the major wallets already (Electrum, and more to come).
- It’s cheap! Simple packaging, plain design, no fancy boxes, no redundant cables.
- It’s ultrasecure! Real crypto security chip. Your private key is stored in a dedicated security chip, not the main micro’s flash.
- Easy back-up! MicroSD card slot for backup and data storage. This allows truly offline signing, by transferring the unsigned/signed transactions on sneakernet.
- Open source software design runs Micropython and you can change it.
- Full-sized numeric keypad makes entering PIN easy and quick.
- Larger 128×64 OLED screen.
It’s an open platform, and we expect other “apps” in time, like:
- Sign text messages to prove control over private key.
- Participate in multisig wallets, with other signers.
- Encrypt/decrypt secret messages (stored on MicroSD or otherwise).