What technology allows secure transactions over the web?

HTTPS, which stands for Hypertext Transfer Protocol Secure, is the correct choice for enabling secure transactions over the web. It is an extension of HTTP and incorporates a security layer called TLS (Transport Layer Security) or SSL (Secure Sockets Layer). This security layer encrypts the data exchanged between the user's browser and the web server, ensuring that sensitive information, such as credit card numbers and personal details, is protected from interception by unauthorized parties.

When a web address begins with "https://," it indicates that the connection is secured using encryption protocols. This not only helps in safeguarding the privacy and integrity of data but also builds trust between users and websites, as many modern browsers display visual indicators such as a padlock icon in the address bar to signify a secure connection.

In contrast, HTTP alone does not provide any encryption, making it unsuitable for secure transactions. FTP (File Transfer Protocol) is used for transferring files between computers but does not incorporate security features for web transactions. SMTP (Simple Mail Transfer Protocol) is for sending emails, and while it can be secured, it is not relevant for web transactions. Therefore, HTTPS is the essential technology for secure web transactions.