Secure Access to a PDF File

To all:

Thanks for all your great feedback on SSL VPNs - most appreciated!

Is there a way that I can add access to a pdf file to a website in a secure 
way?  What I was thinking was to require user name and password to access this 
very confidential file.  I was also thinking about requiring the use of tokens 
and/or certificates.

Oh, the fact that I put a link to this document on the website is, in itself, a 
security risk!!  Instead, maybe I should just send recipients a link to access 
this document from a secure server that will then ask for simple but secure 
authentication information.

The user group for this application is pretty low tech so my challenge is to 
come up with something that is secure but really straightforward to use.

Any thoughts on how I would implement this would be most appreciated.

Regards,


Edmond