Simple private section of my website

I have a simple website. I want to host a file on there that only registered users can download.

Can someone confirm what i'd need to do to achieve this?

Is it just a case of putting it in a directory and making that directory private?

Add http authentication.
OR
Make a php file that "pushes" the file to browser for authenticated users only.
For example.

$id = isset($_GET['id']) ? (int)$_GET['id'] : null;
// a better solution would use a hash instead of id
// check that user is authenticated and file with id=$id exists
// push file to browser with readfile() or mod_xsendfile (better solution).