ssh implements the RSA authentication protocol automatically. The user creates his/her RSA key pair by running ssh‐keygen(1). This stores the private key in $HOME/.ssh/identity and the public key in $HOME/.ssh/identity.pub in the user’s home directory. The user should then copy the identity.pub to $HOME/.ssh/authorized_keys in his/her home directory on the remote machine (the authorized_keys file corresponds to the conventional $HOME/.rhosts file, and has one key per line, though the lines can be very long). After this, the user can log in without giving the password. RSA authentication is much more secure than rhosts authentication.