dpkg -l | grep policykit
ii  plainbox-secure-policy                                      0.25-1                                                    all          policykit policy required to use plainbox (secure version)
ii  policykit-1                                                 0.105-14.1                                                amd64        framework for managing administrative policies and privileges
ii  policykit-1-gnome                                           0.105-2ubuntu2                                            amd64        GNOME authentication agent for PolicyKit-1
ii  policykit-desktop-privileges                                0.20                                                      all          run common desktop actions without password