Ubuntu: How to download a missing GPG key

Here is the tutorials for how to download and add the gpg authentication key in software sources. It is easy and simple way.

Just download and install from the following links

For 10.04

Launchpad-getkeys

For 9.10

Launchpad-getkeys



For execute the programme type the following in terminal

sudo launchpad-getkeys

Now the missing authentication keys are installed. For verify the key go to

System->administration->software source->authentication


From the above picture, all the keys are installed correctly.