I just started using WCF Services with ASP.NET AJAX. I instantiate my WCF service from Javascript and then pass string variables as arguments to my WCF Service method (with an OperationContract signature). I then return a .NET object (defined with a DataContract) which is bound to my custom Javascript class. I'm having trouble authenticating based on the user logged into my web session. However, the WCF web service is a completely different service with no context to the HttpContext.Current object. What is the most secure way to get access to that object?