The PGP authentication option uses the same key pairs and key certificates as the PGP program. New keys and key-certificates can be created with PGP. PGP makes the authentication option easy to implement as the key handling, public-key encryption/decryption and generation/verification of digital signatures are taken care of by this program.
The public keys will automatically be transferred if one or both of the parties does not already have the required public key. This allows ``caching'' of keys. A server with many clients, for example, can choose to store only the most frequently used public keys.