Public & Private Keys, Simply Explained

Underneath every wallet are two related pieces of cryptography: a public key and a private key. Think of the public key as similar to an account number you can safely share with anyone so they can send you funds, and the private key as similar to the password that actually authorizes spending them — except a private key must never be shared with anyone, ever.

When you send cryptocurrency, your wallet uses your private key to create a digital signature proving the transaction really came from you, without ever revealing the private key itself. The rest of the network can check that signature using your public key, confirming it's genuine, all without you ever having to hand over your actual password-equivalent.

In practice, most wallets represent your private key as a recovery phrase: a sequence of 12 or 24 ordinary-looking words, generated when you first set up the wallet. That phrase is the master key to your funds — anyone who obtains it can access and move everything in the wallet, and if you permanently lose it with no backup, the funds are typically gone for good.

The piece of information that must never be shared and is used to authorize spending is called your ____ key.

What is a private key used for?

It's generally safe to share your wallet's recovery phrase with a website that asks for it to help you.