Private key

A private key is a secret cryptographic code that proves ownership of crypto assets and authorizes transactions from a wallet. It is a long, randomly generated number, and it is paired with a public key that others can see and use to send funds to the wallet.

When someone moves assets out of a wallet, the private key signs the transaction. That signature shows the network the request came from the owner, without revealing the key itself. Anyone who holds the private key can control the funds it secures, so it must be kept secret and backed up carefully.

No central authority can reset a lost private key or reverse a transaction signed with it. If the key is lost, the assets it controls can become permanently inaccessible, and if it is stolen, the funds can be moved by someone else. For this reason, keys are often stored offline or protected by hardware devices.