A public key is one half of a cryptographic key pair used in blockchain technology. It functions as your address for receiving cryptocurrency and can be safely shared with anyone — similar to giving someone your email address.
How It Works
A public key is mathematically derived from a private key. While you can generate the public key from the private key, the reverse is computationally impossible. Your wallet address is typically a hashed (shortened) version of your public key.
Public Key vs Wallet Address
While related, they're not identical. The wallet address is derived from the public key through additional hashing. On Ethereum, the address is the last 20 bytes of the Keccak-256 hash of the public key, prefixed with "0x".
Role in Transactions
Receiving: Share your public key (or derived address) so others can send you crypto.
Verification: When you sign a transaction with your private key, anyone can verify the signature using your public key — confirming you authorized the transaction without revealing your private key.