+.. _sec_pkg_authentication:
+
+What means "The following signatures couldn't be verified..."?
+--------------------------------------------------------------
+
+When you start using this repository, you probably get warning messages
+like this::
+
+ The following signatures couldn't be verified because
+ the public key is not available.
+
+Or you will be asked questions like this over and over::
+
+ WARNING: The following packages cannot be authenticated!
+ ...
+ Install these packages without verification [y/N]?
+
+This is because your APT installation initially does not know the GPG
+key that is used to sign the release files of this repository. It is easy to
+make APT happy again. The simplest way is to install the ``neurodebian-keyring``
+package that is available from the NeuroDebian repository. Alternatively:
+
+1. Get the key. Either download the `repository key from here
+ <_static/neuro.debian.net.asc>`_
+ or fetch it from http://wwwkeys.pgp.net (2649A5A9).
+
+2. Now feed the key into APT by invoking::
+
+ apt-key add #file#
+
+ Where `#file#` has to be replaced with the location of the key file you just
+ downloaded. You need to have superuser-privileges to do this (either do it
+ as root or use sudo).
+
+
+How can I cite NeuroDebian?
+---------------------------
+
+Please cite the following paper:
+
+ Halchenko, Y. O. & Hanke, M. (2012). `Open is not enough. Let’s take the
+ next step: An integrated, community-driven computing platform for neuroscience
+ <http://www.frontiersin.org/Neuroinformatics/10.3389/fninf.2012.00022/full>`_.
+ *Frontiers in Neuroinformatics*, 6:22.
+