Robo-FTP User's Guide > Appendix > Security > Connecting to Secure Sites > SFTP

Secure File Transfer Protocol (SFTP) is a method of transferring files between a client and server over a secure, encrypted connection (as opposed to regular FTP, which functions over an insecure connection).

The security in SFTP comes through its integration with the SSH (or Secure Shell) protocol. SSH provides an encrypted transport layer over which the SFTP commands are executed, and over which files are transferred. Regular FTP connections usually utilize port 21 for connections, while SSH servers use port 22.

Robo-FTP supports both password and private key authentication for SFTP connections.

When negotiating a connection with a remote SFTP server, Robo-FTP requires SSH2 and chooses ciphers in the following order: AES (any type) > Triple DES > Blowfish. Robo-FTP selects the key exchange algorithm from the following set in order of preference...

1.diffie-hellman-group-sha256

2.diffie-hellman-group14-sha1

3.diffie-hellman-group1-sha1

In other words, if the server supports diffie-hellman-group-sha256 Robo-FTP will use that. If not, it will use diffie-hellman-group14-sha1, etc.

Related command(s): FTPLOGON