In ubuntu 10.04, when I apt-get install vlc I get this warning:

 WARNING: The following packages cannot be authenticated!
  liba52-0.7.4 libavutil49 libgsm1 libschroedinger-1.0-0 libavcodec52
  libavformat52 libcddb2 libdvbpsi5 libdvdread4 libdvdnav4 libebml0 libenca0
  libfaad2 libiso9660-7 liblua5.1-0 libmad0 libmatroska0 libmodplug0c2
  libmpcdec3 libmpeg2-4 libpostproc51 libqtcore4 libqtgui4 libsdl-image1.2
  libswscale0 libtar libtwolame0 libvcdinfo0 vlc-data libvlccore2 libvlc2
  libass4 libdca0 libupnp3 libx264-85 vlc-nox libxcb-keysyms1 vlc
Install these packages without verification [y/N]?

Why is this happening and is it safe to install these packages without verification? I'd appreciate any help.

2 Answers 2


I am guessing you added a VLC repository to your apt sources file (maybe when VLC 1.0 was released). The packages are be listed as not authenticated because you may not have added the PPA key for the VLC repository.

As stated in the link above, to find all missing key IDs in your sources.list file run:

sudo apt-get update

To add a PPA key from the key ID gathered:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <key id>

As the purplepixel stated, it is safe to install these packages without authentication as long as you trust the repository the packages are coming from. Check your /etc/apt/sources.list file to see what repositories you are using and verify that you trust all of them.


As far as I know, VLC is in a separate repository in Ubuntu right now, and this just means that your apt hasn't imported the key (you haven't explicitly trusted it). As long as you're not downloading the software off some obscure mirror and are just using the Ubuntu defaults, you'll be fine to install VLC.

  • 1
    I believe VLC is actually accessible from the main Ubuntu repository. VLC does have its own repository for more recent versions, which is probably what officespace is using. Jun 11, 2010 at 1:04

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .