Which public key encryption system is used to verify the authenticity of an e-mail sender and encrypt e-mail data during transmission?

The option referring to PGP (Pretty Good Privacy) is the correct choice for the question regarding a public key encryption system used to verify the authenticity of an email sender and encrypt email data during transmission. PGP employs a combination of symmetric and asymmetric encryption techniques to secure email communications.

When an email is sent with PGP, it uses the sender's private key to create a digital signature, which allows the recipient to authenticate the sender’s identity. This digital signature confirms that the email has not been altered during transmission. Additionally, PGP encrypts the email body, ensuring that only the intended recipient, who possesses the corresponding private key, can decrypt and read the message.

PGP’s dual functionality of authentication and encryption makes it a popular choice for securing email communications. This specific use case aligns with the requirements laid out in the question, highlighting its effectiveness in ensuring both authenticity and data security.

In contrast, other options like SSL (Secure Sockets Layer) and HTTPS (Hypertext Transfer Protocol Secure) are protocols primarily designed to secure data over networks and do not directly relate to email encryption or sender verification. S/MIME (Secure/Multipurpose Internet Mail Extensions) is also a strong contender for email security, but PGP is specifically