Advanced Placement (AP) Computer Science

Which protocol is commonly used for secure communication over the Internet?

1. FTP

2. SMTP

3. HTTP

4. HTTPS

The correct answer is: HTTPS

The choice of HTTPS as the protocol commonly used for secure communication over the Internet is accurate because HTTPS, or Hypertext Transfer Protocol Secure, is an extension of HTTP that employs encryption to protect data transmitted between a web browser and a server. It uses SSL (Secure Sockets Layer) or TLS (Transport Layer Security) to provide a secure channel, ensuring that sensitive information, such as passwords and credit card numbers, remains private and is safeguarded against eavesdropping and tampering during transmission. This security feature is essential for various online transactions, such as online banking, shopping, and data entry forms, as it builds trust between users and websites. The padlock icon in web browsers indicates that a website is using HTTPS, further enhancing user confidence. In contrast, the other protocols listed do not prioritize security in their standard operations. For example, FTP (File Transfer Protocol) is mainly used for transferring files but does not inherently provide secure means of data transmission. SMTP (Simple Mail Transfer Protocol) primarily handles email sending without built-in encryption, making it susceptible to interception. HTTP (Hypertext Transfer Protocol) is the fundamental protocol for web traffic but lacks the encryption necessary for secure transactions.