SpacePay

Private Key

Quick Answer

A private key is a cryptographic secret giving full control over a blockchain address. Anyone with the private key can move all funds — losing it means permanent loss of access.

Full Definition

A private key is a cryptographic secret that gives the holder full control over a blockchain address and the ability to sign transactions. It must be kept absolutely secure — anyone with the private key can move all funds from the associated address. Private keys are typically 256-bit numbers represented as 64 hexadecimal characters or encoded as seed phrases (12-24 words). Losing a private key means permanently losing access to the associated funds.