Private Key

A private key is a secret code that allows you to spend bitcoin sent to its matching public key. When someone sends bitcoin to your public key, only the private key can create the digital signature needed to move those coins. Because access to the private key means control over your bitcoin, it’s essential to keep it secure and never share it.

Most Bitcoin wallets handle private key generation and storage for you, making it easier to sign transactions safely. Importantly, while a private key can generate its public key, the process can’t be reversed—knowing the public key won’t reveal the private key. This one-way relationship forms the backbone of Bitcoin’s cryptographic security.