If you have been using ibus-avro for a while, you may have encourtered this error when running apt-get update.

W: GPG error: http://download.opensuse.org ./ Release: The following signatures were invalid: KEYEXPIRED 1366357218

Lets see how to fix that.

1. Open Ubuntu Software Center.

2. From Top bar goto Edit > Software Sources

   

3. Goto Authentication Tab and select the sarimkhan OBS Project key.

   

4. Press Remove and confirm by entering your password.

5. Now open up terminal and add the correcponding key for your OS, for example ubuntu 13.04:

    wget -q http://download.opensuse.org/repositories/home:/sarimkhan/xUbuntu_13.04/Release.key -O- | sudo apt-key add -
   

6. Now you can update your software sources without any problem.

    sudo apt-get update
   

7. Have Fun and keep rocking.