COLDCARD Paranoid Guide

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