[PublicKey]s and [PrivateKey]s are generated in matched pairs in PublicKeyEncryption. The PublicKey can decrypt anything encrypted with its PrivateKey and visa-versa, but the public key is unable to decrypt anything it encrypts itself and the private key is unable to decrypt anything it encrypts itself. This enables the creation of a [Signature], in which a [CryptographicHash] of a message is created, encrypted with the private key and appended to the message. Anybody with the public key can decrypt the signature and run the cryptographic hash of a message (without the appended signature) and check that they are the same, but only someone with the private key could have created it. This is the basis of all PublicKey [Cryptography]. 

  

 Standards for the use of [PublicKey]s include [SSL] [X509] and [OpenPGP], systems include: [OpenSSL], [SSH], PGP and [GPG].