SFTP, a Data Transmission Protocol
SFTP stands for Secure File Transfer Protocol that is a comparatively new protocol developed by the Internet Engineering Task Force (IETF) in the 1990s. Being an extended version of SSH 2.0, SFTP allows the transfer of different files and other data using a connection that was secured with the help of the Secure Shell (SSH) protocol. SFTP ensures file transfer over SSH and use with VPN applications and Transport Layer Security (TLS). Running over SSH, the SFTP protocol supports authentication functionality and complete security of SSH.
The data and commands are encrypted to prevent transferring sensitive information such as passwords over the network. The functionality of SFTP resembles that of FTP because both of them provide communication over a secure connection but some differences still exist.
Unlike FTP which is text-based, SFTP is designed to be packet-based for sending small amounts of data, what makes it faster since less information is transferred. With SFTP, all file transfers are done in-line using the main Control Connection so there is no need to make a separate Data Connection for performing transfers. That provides a single secure connection through firewalls.
SFTP is naturally secure because it runs over SSH and, unlike FTP, the encryption can't be turned off or triggered with AUTH commands and that's a great advantage for system administrators willing to improve corporate security policies.`
Due to the robust request protocol, the majority of SFTP versions can deliver more detailed information about the transferred files, such as the time, date, permissions, size, and other data which is not typically available to FTP.
SFTP allows to perform a wide range of operations on remote files and acts somewhat like a remote file system protocol. The SFTP protocol allows such operations as resuming from halted transfers, remote file removal, and directory listing.
Designed to be more platform-independent, SFTP is available on most platforms.