Secure FTP

One of several secure file transfer protocols is Secure FTP, which, like SSH File Transfer Protocol( SFTP), is also based on Secure Shell. Secure FTP uses an SSH tunnel for the FTP protocol.

The SSH tunnel is used to transfer certain control data of the FTP protocol, such as the authentication of the client and the listing of the directories. The file transfer itself is unencrypted and uses a different port than the SSH tunnel, which uses port number 22.

The difference to the SSH File Transfer Protocol or also to FTP over SSL is that with these transfer methods the transmission channel and the file transfer itself are encrypted, not so with SFTP, where only the transmission channel is secured.