| Auth | (Implicit FTPS only) Instructs the server that data-channels should be secure. |
| Auth(SSLFTPSSLVersion) | Switches the control-channel (the connection which carries commands) to secure mode. |
| Auth(SSLFTPSSLVersion, Boolean) | Switches the control-channel (the connection which carries commands) to secure mode. |
| Auth(SSLFTPSSLVersion, SSLFTPSSLVersion, Boolean) | Switches the control-channel (the connection which carries commands) to secure mode. |