Following the installation instructions on the OpenVAS site I stumbled upon some problems importing the required Public Key.

The pgp.net keyservers seem to be not really reliably these so I was unable to use them to retrieve the required Public key for validating the repositories’ packages.

this resulted in the following error:

Reading package lists… Done W: GPG error: http://download.opensuse.org ./ Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY BED1E87979EAFD54 W: You may want to run apt-get update to correct these problems

to resolve this problem just download the key directly  from the repository

wget http://download.opensuse.org/repositories/security:/
OpenVAS:/STABLE:/v4/Debian_5.0/Release.key

and import the key manually

apt-key adv –import Release.key

update your package lists

apt-get update

and it should work without problems.