The Secure File Transfer Protocol (SFTP client) will provide secure file transfer functionality over any reliable data stream, SSH in this case. This is the standard file transfer protocol to be used with the SSH2 protocol. Windowless wodSFTP component implements client side of this protocol, which is reliable and easy to use. SFTP is not just some "FTP over SSH" wrapper - it is newer protocol, supported by all SSH2 servers as their subsystem.
SFTP protocol is designed to provide primarily file transfer, but also more general file system access on the remote server - in secure manner. SFTP protocol assumes it is running on secure channel (secure channel is implemented in wodSFTP), thus no plaintext passwords, file or directory contents, or any other information is exposed to the network.