What is a Public Key?

A public key is a cryptographic address derived from your private key that allows others to send cryptocurrency to you. Think of it like your email address—you can share it publicly so people know where to send funds, but they can’t access your account with it alone.

How Public Keys Work

The Key Pair System

  • Private key: Your secret password (never share)
  • Public key: Derived from private key (safe to share)
  • Address: Often a shortened/hashed version of public key

Cryptographic Relationship

  1. Private key generates public key mathematically
  2. Public key cannot reverse-engineer private key
  3. This one-way relationship is the foundation of crypto security

Public Key vs Wallet Address

While related, they’re not identical:

AspectPublic KeyWallet Address
LengthLong (256+ characters)Shorter (26-42 characters)
FormatRaw cryptographic outputEncoded/hashed version
UsageTechnical operationsReceiving funds

Most users interact with wallet addresses, which are derived from public keys.

Why Public Keys Matter

Transaction Verification

  • Proves ownership without revealing private key
  • Enables digital signature verification
  • Secures the entire blockchain network

Safe Sharing

  • Can be posted publicly without risk
  • Required for receiving any cryptocurrency
  • Used to verify transaction authenticity

Best Practices

  • Always verify addresses when sending (double-check first and last characters)
  • Use QR codes to avoid typing errors
  • Generate new addresses for privacy when possible

Exchanges like Coinbase and Kraken manage public keys automatically through custodial wallets.