Which protocol is used for secure file transfer?

SFTP, or SSH File Transfer Protocol, is specifically designed to provide a secure method for transferring files over a network. It operates over a secure shell (SSH) connection, which means that it encrypts not only the file data being transferred but also the authentication credentials (such as usernames and passwords). This helps to protect sensitive information from being intercepted by unauthorized users.

In contrast, protocols like FTP do not provide encryption, making transmitted data vulnerable to interception. HTTP is primarily used for transferring web pages and does not focus on file transfer security, while SMTP is mainly used for sending emails and not for transferring files. Therefore, SFTP stands out as the appropriate choice for secure file transfers due to its built-in security features.