Final answer:
The statement is FALSE because in public key encryption, the private key is used to decrypt a message that was encrypted with the corresponding public key.
Step-by-step explanation:
The assertion that in public key encryption, each site has a private key to encode a message and a public key to decode it is FALSE. In reality, public key encryption works on a principle of key pairs: a public key and a private key. When a message is sent, it is encrypted using the recipient's public key, and it can only be decrypted by the corresponding private key, which is kept secret by the recipient. Conversely, a sender can sign a message with their private key, and anyone with the public key can verify that the message was indeed sent by the holder of the private key. This ensures both security in communication and the ability to authenticate the sender.