A paranoid guide for advanced users with a focus on security, privacy, & verification to ensure their self-custodied cold storage wallet is ready for adversarial environments. By following this guide, you will be prepared for storing your keys on a COLDCARD that shall never---in its entire life---be connected to a computer of any kind. It will always get power from COLDPOWER or similar. Sneakernet via MicroSD shall be used for firmware upgrades and PSBT transfers.
This guide covers:
- Checking the tamper-evident bag
- Verifying & updating firmware
- Setting up a PIN
- Verifying the dice roll math
- Generating a seed phrase with 256 bit of entropy by dice rolls
- Creating a passphrase
- Verifying the Sparrow Wallet download
- Air-gapped communication & transacting between COLDCARD and Sparrow Wallet
- Steel plate backup demonstration