Bitcoin WikiWallets & custody

Private key

Updated 9 October 2026StubRandom article

In plain words

The secret number that authorises spending. Whoever has it controls the coins.

Glossary on the Learn page Watch: How Bitcoin works in 5 minutes (CuriousInventor) (2014)

See also

Seed phrase
A seed phrase is a list of 12 or 24 ordinary words that can recreate all the keys of a wallet. Whoever has the words has the bitcoin, so write them on paper or metal and never type them into a website.
Hardware wallet
A hardware wallet is a small device that keeps your private keys offline and signs transactions inside itself. Even if your computer is infected, the keys never leave the device.
Address
What you share to receive bitcoin. Modern ones start with bc1. Use a new one each time for privacy.
Public key / xpub
Derived from the private key; an xpub lets software see all your addresses but not spend.