policykit-1-gnome software package provides GNOME authentication agent for PolicyKit-1, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install policykit-1-gnome
policykit-1-gnome is installed in your system.
Make ensure the policykit-1-gnome package were installed using the commands given below,
$ sudo dpkg-query -l | grep policykit-1-gnome *
You will get with policykit-1-gnome package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | GNOME |
| Package | policykit-1-gnome |
| Version | 0.105-1ubuntu4 |
| Description | GNOME authentication agent for PolicyKit-1 |
| Sub Section | GNOME |