polkitd — The polkit system daemon
polkitd provides the org.freedesktop.PolicyKit1 D-Bus service on the system message bus. Users or administrators should never need to start this daemon as it will be automatically started by dbus-daemon(1) or systemd(1) whenever an application calls into the service.
polkitd must be started with superuser privileges but drops privileges early by switching to the unprivileged polkitd system user.
See the polkit(8) man page for more information.
Written by David Zeuthen
a lot of help from many others.
Please send bug reports to either the distribution or the polkit-devel mailing list, see the link http://lists.freedesktop.org/mailman/listinfo/polkit-devel on how to subscribe.