I am very new to DNN and farily new to web dev as a whole.  I'm hoping someone here can at least get me headed in the right direction to do what I'm looking for.

I will have a DNN site that, when users pay for a subscription to the DNN site, will gain them access to another outside site that will be linked to through the DNN site.  The external site is out of my control, but they have requested a simple token of some sort from my site to let them know if the redirected user has actually been provided access to their site.  The token/key, or whatever means is used to authenticate the user to the external site, needs to be dynamic so it cannot be bookmarked, etc.

I've been Google searching for anything related to User Authentication, authentication keys, etc., but I can't find anything to get me started in the direction I need to go.  1.) How can I generate the required authentication key and 2.) How can I get DNN to pass that key along?

As I said, I am just getting my feet wet in DNN and web development as a whole, so I'm not sure if this is a simple two lines of code type of thing, or if it is a highly involved process.  Either way I need to get it figured out relatively soon, so ANY help would be GREATLY appreciated.

Thanks,

CJ