ASP.NET Authentication and Authorization using WCF

Hi,
 
We are in the process of building a distributed application using ASP.NET and WCF. We think, we have two ways of doing authentication and authorization for web site.
 
Create custom membership Provider and expose all the operations as wcf services, at client side call the appropriate methods to authenticate, create the principal object and cache it Create the custom membership provider  and expose the services which can return a custom principle object ( fully loaded with identiy and roles), and at client side, directly receive the principal object.  
In option2 , we have the provision to support multiple sources and can be used to multiple applications.
 
I would like to understand  which is efficient and correct and what is the best way people are following in the industry.
 
 
Thanks
Hari
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