A public/private key pair is
|“||pair of mathematically related keys used in asymmetric cryptography for authentication, digital signature, or key establishment. As the name indicates, the private key is used by the owner of the key pair, is kept secret, and should be protected at all times, while the public key can be published and used be the relying party to complete the protocol or invert the operations performed with the private key.||”|
Every digital certificate has a pair of associated cryptographic keys (a public-private key pair). This pair of keys consists of one private key and one public key. The public key is part of the owner's digital certificate and is available for anyone to use. The private key, however, is protected by and available only to the owner of the key. This limited access ensures that communications that use the key are kept secure.