Final answer:
Public key encryption uses a paired public and private key, where the sender encrypts the message with the recipient's public key, and the recipient decrypts it with their private key.
Step-by-step explanation:
The correct statement regarding public key encryption is: 'Public key encryption uses a private and public key.' This describes the method by which public key encryption operates. When a sender wants to send an encrypted message to a recipient, the sender will use the recipient's public key to encrypt the message. Upon receiving the message, the recipient will then use their private key to decrypt it. This ensures that only the intended recipient, who possesses the correct private key, can read the message.
A digital certificate, which is often mentioned in the context of public key encryption, serves as proof of ownership of a public key and does not show that the keys themselves are encrypted. Moreover, public key encryption does not require both computers to have the same key; that is a characteristic of symmetric encryption, which uses the same key for both encryption and decryption.