apt-key list
/etc/apt/trusted.gpg
--------------------
pub   1024D/437D05B5 2004-09-12
uid                  Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
sub   2048g/79164387 2004-09-12

pub   1024D/FBB75451 2004-12-30
uid                  Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>

pub   1024D/6A423791 2006-09-26 [expires: 2009-09-25]
uid                  Opera Software Archive Automatic Signing Key <hostmaster@opera.com>
sub   2048g/BEAEDCB7 2006-09-26 [expires: 2009-09-25]

pub   1024D/0C5A2783 2006-11-23
uid                  Medibuntu Packaging Team <admin@lists.medibuntu.org>
uid                  The Medibuntu Team <medibuntu@sos-sts.com>
sub   2048g/16C7105A 2006-11-23

pub   1024D/B6EE20E8 2007-06-07 [expires: 2012-06-05]
uid                  Fabien Tassin <fta@ubuntu.com>
uid                  Fabien Tassin <fta@sofaraway.org>
uid                  Ubulette <fta+ubuntu@sofaraway.org>
sub   4096g/A2F54B72 2007-06-07 [expires: 2012-06-05]