Redmine

We use Redmine internally. Publishing files, builds in example, is a frequently used function.
Our clients usually don't have access to redmine.

We'd like to send links to our clients to securely load files (via https) without giving access to a several files or even the project.

Therefore a plugin which generates a link containing a long random number for a certain file would be great. this link should link to exactly this file.

Does this sound great to you? Has someone seen such plugin/function around?

Best,
jp