Public key

A public key is a digital key that can be shared publicly in crypto. It can be used to create a wallet address where you can receive crypto.

What is a public key?

A crypto wallet usually creates two linked keys: a public key and a private key. You can share the public key. The private key must always remain secret.

A public key is a long string of letters and numbers. A wallet address can be derived from this key. You usually share that wallet address with someone who wants to send you crypto.

A public key doesn’t give anyone access to your crypto. Only the private key can do that. You also use the private key to digitally sign a transaction.

An example of a public key

You want to receive crypto from a friend. You send your wallet address to them. This address is created from your public key.

Your friend can send crypto to that address. When you send crypto yourself, your wallet signs the transaction with your private key. The network can use your public key to check that the signature is valid.

Why is a public key important in crypto?

Public keys make it possible to receive crypto and securely verify transactions. That’s why they’re an important part of crypto wallets and blockchains.

In discussions about wallet security, public keys are often mentioned alongside private keys. The main difference is simple: a public key can be shared publicly, but a private key must never be. Anyone with your private key can access your crypto.

A public key also isn’t always exactly the same as the wallet address you share. On some blockchains, a separate wallet address is derived from the public key.