How to publish artifacts in Travis CI?

I would like to use Travis CI for my open-source project. The issue that Travis doesn't provide any ways to publish produced artifacts (though, they have this in their future plans).

What are workarounds to publish/upload artifacts somewhere? I'm allowed to execute any scripts on a CI machine.

Simple upload will work, but there is security issue: anyone will be able to upload something in the same way as all sources are public.