What protocol maintains confidentiality of data in transit typically using port 443?

The correct answer, SSL/TLS, is the protocol designed to provide secure communication over a computer network. Specifically, it is used to maintain the confidentiality and integrity of data in transit, encrypting the information exchanged between a client and server. This capability is crucial for protecting sensitive data, such as financial transactions and personal information, from eavesdroppers and attackers. SSL (Secure Sockets Layer) is the predecessor of TLS (Transport Layer Security), but both are often referred to collectively. Port 443 is the standard port used for HTTPS (HTTP Secure), which operates over SSL/TLS to ensure that the data transferred remains confidential and secure.

In contrast, FTP (File Transfer Protocol) primarily serves to transfer files over a network without inherent security measures, while HTTP (Hypertext Transfer Protocol) is the standard web protocol that does not encrypt data, leaving it vulnerable during transmission. SMTP (Simple Mail Transfer Protocol) is employed for sending emails, and while it can operate securely with additional configurations, it does not inherently provide the same level of confidentiality for data in transit as SSL/TLS does.