Public keys and addresses explained
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 4 min
In short
A public key is computed from your private key and lets anyone verify your signatures. An address is a shorter encoding of that public key, and it is safe to share. Private key, public key and address are derived in that order, one way only.
Key points
- An address is a receiving handle you can share freely
- You cannot work back from an address to the key
- Address formats differ from chain to chain
- Same-looking address, wrong network, lost funds
Definition
A public key is a verification value derived one-way from the private key; an address is a compact encoding of it used as a destination identifier.
Think of an address as an account number: you hand it to whoever is paying you, and sharing it does not put your funds at risk. The private key is closer to your card plus its PIN, and never leaves your hands.
Formats differ by chain. Bitcoin addresses start with 1, 3 or bc1; Ethereum addresses are 42 characters starting 0x. Networks that copied Ethereum's format — Arbitrum, Base, BNB Chain — produce visually identical addresses, which is exactly why people send to the right address on the wrong network.
Many wallets generate a fresh address for each receipt. Reusing one address concentrates your entire receiving history at a single public point, making it easier to link activity to a person. For exchange deposits, always use the address the exchange displays for that specific asset.
Watch out for
- · Always paste addresses, then check the first and last few characters by eye
- · Clipboard-hijacking malware that swaps addresses is real
- · Send to an unsupported network and even an exchange may be unable to recover it