Above all, the most important thing to know about Bitcoin is that it is completely independent of your computer or any digital hardware. You could destroy all your hardware and as long as you have your seed phrase, you have your Bitcoin. That is absolutely true.

My best shot at explaining Bitcoin from bottom to top. Best explanation ever:

Or on Spotify:

Practical Summary

• Bitcoin is not digital currency, it’s mathematical currency.
• Your seed phrase equals your money. Your computers and thumb drives can all die and you still have it.
• You can buy metal tags to write your seed phrase on.
• A public key is an account number.
• A private key verifies your identity as the owner of the corresponding public key and gives you permission to spend the balance of the public key’s account.
• A public key is generated from a private key mathematically. The reverse cannot be done. A private key cannot be generated from a public key. This is the nature of the one-way math problem described in the podcast.
• You could stop there and own Bitcoin in a single account, but then your balance and all your transactions are public and linked to the single public key account number.
• A single private key public key pair would represent a wallet with a single account.
• A wallet can be a collection of multiple connected key pairs that together represent the balance of the wallet and the ability to spend it.
• A seed phrase generates multiple private keys, nearly unlimited, and each private key generates its corresponding public key.
• Like the private key cannot be generated from the public key, the seed phrase cannot be generated even from all the corresponding private keys. The keys generated from a seed phrase appear random and unrelated unless you have the seed phrase – another one-way math problem.
• The seed phrase is everything and is designed to be written down by humans completely off computers. The seed phrase represents the security of your balance.
• The extended public key is the key to just your public keys, so the full balance of the wallet, but not the ability to spend the balance.
• The extended public key represents the privacy of your balance.

Setup I Recommend

• I recommend sparrow wallet on a completely offline laptop.
• Write down your seed phrase in multiple secure places. Possibly commit the seed phrase to memory by repetition.
• I also recommend using a passphrase in addition to the seed phrase.
• Laptops have a camera, which is helpful for using QR codes.

To Receive Bitcoin

To receive, simply generate a receive code (public key) from your Sparrow wallet and send Bitcoin to that code from an app like Coinbase. Sparrow wallet creates a QR code to send to. It’s self-explanatory when using a phone app, usually called transfer Bitcoin.

To Spend Bitcoin

1. Use BlueWallet on your phone to create a partially signed Bitcoin transaction from an online wallet of a public key with a balance.
2. Transmit the PSBT to the offline laptop wallet using a QR code. Cobang is a linux app to read QR codes with the computer’s camera.
3. Sign the PSBT with Sparrow.
4. Send the signed transaction back to the phone with a QR code.