If you want to restrict who can install your packages, one way to do this in Pacman is to put caches on machines which have to be accessed via ssh. You then just use the standard SSH addressing of a directory on your machine to specify cache locations as in
% pacman -get youssef@atlas.bu.edu:/atlasgrid/caches:Pythonor
% pacman -get gsiftp://atlas.bu.edu/atlasgrid/caches:PythonOf course, if you don't have your SSH and/or grid certificate set up in the usual way, you will get an error message.
These kinds of caches are a convenient way of providing increased security and/or restricted access in situations, for example, where licenses are involved.