Reading package lists... Error!
W: GPG error: http://us.archive.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com quantal Release: The following signatures were invalid: BADSIG 16126D3A3E5C1192 Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>

W: GPG error: http://deb.opera.com stable Release: The following signatures were invalid: BADSIG E585066A30C18A2B Opera Software Archive Automatic Signing Key 2013 <packager@opera.com>
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG D45DF2E8FC91AE7E Launchpad PPA for Geza Kovacs
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG F1773AF13B1510FD Launchpad PPA for GNOME3 Team
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG 2836CB0A8AC93F7A Launchpad Kubuntu Updates
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG B22918DB685D1580 Launchpad PPA for the Shimmer Project
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG A5D712AEE06E6293 Launchpad PPA for upubuntu.com
W: GPG error: http://ppa.launchpad.net quantal Release: The following signatures were invalid: BADSIG EB563F93142986CE Launchpad PPA for Xubuntu Developers
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/quantal/Release

W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/ppa.launchpad.net_noobslab_themes_ubuntu_dists_quantal_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.