I have REST API and to make it more secure I would like restrict the access to the registered applications or websites only.
Now these client applications could be web app or mobile app under Android/Windows/BlackBerry/Apple etc.
Also I can't ask the client apps to modify there code to store any value being provided by my rest API to get registered. (as these apps may or may not be using database or other persistent media).
WCF REST API should not that the caller is registered with it or not.
Any suggestions how to do it.