Need a Module or create a module for this
I have the following scenario:
1. Authenticated users can view a list of confidential documents (filenames in plaintext). Download is not allowed.
2. Authenticated users can click "Request" button and write a reason to submit a document request. The request will be sent to manager for approval (either by email or in Drupal).
3. Manager review the request and approval/reject the request. User can only download after request is approved.
It seems that module download_access is close to what I need. But it seems that no development has been going on. So I plan to write a module to cater this.
But I wonder is it possible to turn on and off a download link using condition checking modules (e.g. rules, actions and trigger, etc)? Any one has tried this before?

Deleted
Sorry, it isn't what your looking for...
Warm regards from sunny México!
Pepe
:-)
Security Through Obscurity?
Are you trying to use access control around file downloads or only hide the download link until the user is approved?
Security
It is better access control than simply hide the download link but it is an option too.
Stopping downloads is impossible
Stopping downloads is impossible. If the user can view the content then they can copy it. Aside from that everything else you want done is certainly possible.
Instead of using the condition checking modules it may be easier to set a true/false flag in a SQL table and activate/deactivate the link from within the module's admin controls. The only other way I can think of is making a custom content type using CCK and basing the activation on the node's publication status.