Certified Ethical Hacker (CEH) Practice Question

OpenPGP uses hybrid encryption. First, the sender's software creates a one-time symmetric session key and encrypts the e-mail body with that key, because symmetric ciphers are faster for large data. To ensure that only the intended recipient can recover this session key, the key is then encrypted with the recipient's public key and included in the message header. Anyone may possess the public key, but only the matching private key-held by the recipient-can decrypt the session key and, in turn, the e-mail. Encrypting the message hash provides integrity and non-repudiation, not confidentiality, and encrypting the entire plaintext with an asymmetric key or sending the sender's private key would be impractical or insecure.