HTTP Basic auth on specific Drupal paths?
I think you are looking for Sharing authentication with HTTP-Auth which describes using the Drupal user tables to supports Apaches http auth system. You will probably have to hard-code the paths in your menu, or within your page content. Then set up Apache to use http auth on the particular directories.

EDIT:

To use this technique in the Drupal environment, you would define http auth for individual directories in the apache Auth.conf file like:

&lt;Directory /usr/local/webroot/d7.example.com/folder&gt;
...Auth directives ...
&lt;/Directory&gt;


where /usr/local/webroot/d7.example.com is your drupal root. This allows you to protect individual directories, while maintaining drupal authentication for your site.