Hi Mbenjemia,

Understand that the integration that you describe will be a difficult problem for an experienced developer, and you are unlikely to too find much specific guidance.

That said, the most immediate approach that comes to mind would be to design an alternate membership provider for DNN that links to your existing PHP security token.  Such a provider would inherit the DotNetNuke.Security.Membership.MembershipProvider class.  There are quite a few additional technical hurdles to overcome with this approach, however (E.g. what happens when a DNN user tries to reset their password?  Does this require a call into the PHP application?).

Alternatively, you might consider extending your PHP login functionality to interact with the ASP.NET membership classes and deploy a valid ASP.NET security token on successful authentication.  This would create problems with duplicate member stores though.

It is a moderately difficult task to integrate two disparate membership systems when both exist under the ASP.NET umbrella.  Adding a PHP application to the mix will increase the difficulty significantly.  Good luck!

Brandon