When i try to install or update any packages I get: Untrusted packages could compromise your system's security. You should only proceed with the installation if you are certain that this is what you want to do. I strongly suspect this is related to the error i get on update: $ sudo aptitude update Get: 1 http://ftp.us.debian.org wheezy InRelease [208 kB] Get: 2 http://debian.lcs.mit.edu wheezy InRelease [208 kB] Ign http://ftp.us.debian.org wheezy InRelease Hit http://ftp.us.debian.org wheezy/main amd64 Packages/DiffIndex Hit http://ftp.us.debian.org wheezy/contrib amd64 Packages/DiffIndex Hit http://ftp.us.debian.org wheezy/non-free amd64 Packages/DiffIndex Hit http://ftp.us.debian.org wheezy/contrib Translation-en Hit http://ftp.us.debian.org wheezy/main Translation-en Hit http://ftp.us.debian.org wheezy/non-free Translation-en Get: 3 http://debian.lcs.mit.edu wheezy-updates InRelease [116 kB] Ign http://debian.lcs.mit.edu wheezy InRelease Ign http://debian.lcs.mit.edu wheezy-updates InRelease Hit http://debian.lcs.mit.edu wheezy/main Sources/DiffIndex Hit http://debian.lcs.mit.edu wheezy/main amd64 Packages/DiffIndex Hit http://debian.lcs.mit.edu wheezy/main Translation-en Ign http://ftp.us.debian.org wheezy/contrib Translation-en_US Ign http://debian.lcs.mit.edu wheezy-updates/main Sources/DiffIndex Ign http://debian.lcs.mit.edu wheezy-updates/main amd64 Packages/DiffIndex Ign http://ftp.us.debian.org wheezy/main Translation-en_US Ign http://ftp.us.debian.org wheezy/non-free Translation-en_US Hit http://debian.lcs.mit.edu wheezy-updates/main Sources Hit http://debian.lcs.mit.edu wheezy-updates/main amd64 Packages Ign http://debian.lcs.mit.edu wheezy/main Translation-en_US Ign http://debian.lcs.mit.edu wheezy-updates/main Translation-en_US Ign http://debian.lcs.mit.edu wheezy-updates/main Translation-en Fetched 531 kB in 1s (304 kB/s) W: GPG error: http://ftp.us.debian.org wheezy InRelease: Unknown error executing gpgv W: GPG error: http://debian.lcs.mit.edu wheezy InRelease: Unknown error executing gpgv W: GPG error: http://debian.lcs.mit.edu wheezy-updates InRelease: Unknown error executing gpgv I have tried reinstalling the key ring: sudo aptitude reinstall debian-archive-keyring (which surprisingly doesn't cause a warning).