As defined by the Velocity Network Foundation, a cryptographic key used in pair with a Public Key, a Private Key is kept secret and known only to its owner. The Private Key is used to decrypt data that was encrypted with the corresponding Public Key or to create digital signatures that can be verified with the Public Key. The security of the Private Key is crucial for ensuring encrypted communications remain confidential and digital signatures can be trusted.

While the private key is used to decrypt data or create digital signatures, public keys are designed to be shared openly, allowing others to send encrypted messages or verify the authenticity of signed data. Security relies on the fact that, while the public key can be widely distributed, the corresponding private key remains confidential and known only to its owner.