gpgerror --- solution

Sudo apt-get update

is Giving this error

W: GPG error: http://ppa.launchpad.net raring Release: The following signatures were invalid: BADSIG 6A9653F936FD5529 Launchpad PPA for atareao
W: GPG error: http://ppa.launchpad.net raring Release: The following signatures were invalid: BADSIG 80AE77E42C5522E3 Launchpad PPA for Birdie Team

Solution    http://www.ubuntugeek.com/how-to-fix-the-ubuntu-gpg-error-badsig.html