Repository signature verification issues in ubuntu are becoming annoying, I’m getting this after apt-get update :
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.ubuntu.com natty-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/natty-updates/Release
W: Some index files failed to download. They have been ignored, or old ones used instead.
here is a quick fix :
$ sudo apt-get clean
$ cd /var/lib/apt
$ sudo mv lists lists.old
$ sudo mkdir -p lists/partial
$ sudo apt-get clean
Should be enough, but still getting error like :
W: GPG error: http://archive.ubuntu.com natty-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key
Try another clean
$ sudo apt-get clean
$ sudo aptitude -o Acquire::http::No-Cache=True -o Acquire::BrokenProxy=true update
Test now
$ sudo apt-get update
$ sudo apt-get upgrade
Fixed !