Public key

The cryptographic counterpart to a private key. Used to derive addresses and verify signatures. Safe to share.

A public key is the public counterpart to a private key in Bitcoin's cryptography. It's mathematically derived from the private key, but the operation is one-way — knowing the public key doesn't reveal the private one.

Public keys are used in two ways. First, to derive Bitcoin addresses (via a hash). When you send sats to an address, you're effectively sending them "to whoever can prove they have the private key matching this public key". Second, to verify signatures — anyone can check that a transaction was signed by the legitimate owner without knowing the private key.

Public keys are safe to share. The whole point of public-key cryptography is that the public half can be public. Sharing your public key doesn't let anyone spend your money.

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Wallets & self-custody

How to store Bitcoin so that nobody — not even us — can take it.

Related terms

Glossary

Private key

The cryptographic secret that authorises spending Bitcoin. If someone gets your private key, they can spend your sats.

Glossary

Address

A unique string used to receive Bitcoin. Public, but tied to no name unless you reveal one.

Glossary

Seed phrase

A 12 or 24-word phrase that backs up your entire wallet. Lose it, lose your sats. Share it, lose your sats.

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