Secure WCF REST API using C# in ASP.Net

i have this API

http://service.globeali.com/service1.svc/Country

it works fine, the problem is any one can access the URL and see the data which i do not want.

I want the it should be like URI access as facebook and google does, so only those to whom i have given acccess then can see it and that access should be dynamically check like if i have given access to abc.com url so it should check auto whethere the api call is coming from abc.com or not else it should deny it.