Which protocol is used for secure file transfer over SSH? The answer is SFTP.
SFTP stands for SSH File Transfer Protocol. It is an application-layer protocol that provides file transfer, directory listing, remote file management, and related operations over a secure channel, most commonly an SSH version 2 connection.
SFTP is not simply traditional FTP encrypted by SSH. It was designed as a separate protocol by the IETF’s SECSH working group and usually operates as an SSH subsystem, commonly using TCP port 22. The underlying SSH connection supplies encryption and authentication.
SFTP is often confused with SCP, another SSH-based transfer method. SCP is chiefly designed for copying files, while SFTP supports richer operations such as resuming transfers, browsing directories, deleting remote files, and preserving file attributes. FTPS is different again: it is FTP secured with TLS rather than SSH.