W: GPG error: http://security.debian.org wheezy/updates Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553 W: GPG error: http://debian.intergenia.de wheezy Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553 NO_PUBKEY 6FB2A1C265FFB764 W: GPG error: http://debian.intergenia.de wheezy-backports Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8B48AD6246925553
Lösung: apt-get install debian-archive-keyring