Which protocol is typically used for secure file transfer over a network?

The correct choice for secure file transfer over a network is SFTP. Secure File Transfer Protocol (SFTP) is designed specifically to provide secure file access, transfer, and management functionalities over a secure channel. SFTP operates over the Secure Shell (SSH) protocol, which ensures that data is encrypted during transmission, protecting the confidentiality and integrity of the files being transferred. This is crucial in a network environment where sensitive data is exchanged.

In contrast, standard FTP (File Transfer Protocol) does not provide encryption, making it vulnerable to interception and attacks. HTTP (Hypertext Transfer Protocol), while useful for web page transfers, does not inherently include secure file transfer capabilities unless paired with SSL/TLS to become HTTPS. Meanwhile, SMTP (Simple Mail Transfer Protocol) is intended for sending emails and does not relate to file transfer. Thus, SFTP is the protocol that specifically meets the need for secure file transfer in a network setting.