SFTP (Secure File Transfer Protocol)
When you transfer with FTP, the password and sensitive information can be transmitted over the network. However the SFTP, or secure FTP encrypts both commands and data so that the file transfer is much more secured. When using SFTP connection, Private Key and Passphrase can be used to strengthen the security.
If you are running a server and you wish to give access to only specific group of people or to a person, then you can providee Private Key to only those who are allowed. In this way, those permitted people can use the Private Key that is saved in their PC to connect your server more securely. Also, Passphase can be used to protect your Private Key.
So, please keep your Private Key in a safe place. If your Private Key is lost, you will lose access until your server provider re-generates the key.
