Why don't you use oauth? If I understand what you're wanting to do, it solves exactly this type of problem.
Google: data oauth Robert On Jun 30, 2011 11:49 AM, "Nikolay Sohryakov" <nikolay.sohrya...@gmail.com> wrote: -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.