Public Key

A public key is a cryptographic value derived from a private key. It can be shared freely and is used to receive funds and to let others verify that a transaction was genuinely signed by the matching private key.

How it works

Public-key cryptography uses a pair of keys. The private key signs; the public key verifies. A wallet address is typically a shortened, encoded form of the public key. When you receive crypto, the sender is sending it to an address derived from your public key; when you spend, the network checks your signature against that public key to confirm you are authorised.

Why it matters

This one-way relationship is what makes blockchains trustless: you can prove ownership and authorise transfers without ever revealing the secret that controls your funds. Sharing a public key or address is safe; sharing a private key is not.

Example

The address you paste into an exchange’s “withdraw” field is generated from your wallet’s public key.