What Is SCP? The Secure Copy Protocol (SCP) from the command line (CLI) (the scp command) to securely copy files and directories between remote hosts without explicitly logging into the remote systems. The scp command uses SSH to transfer data, so it does requires a password or passphrase for authentication. Unlike RCP or FTP, scp encrypts both the file and any passwords exchanged so that anyone snooping on the network cannot view them.