Java EE (Java Enterprise Edition) General Discussion

Hi,
I am developing a application in which I have used fascade design pattern. I have one main session bean and have several entity bean .

To the client I only want that the user can only lookup the main session bean and no other bean should be exposed

In my main session bean however I lookup other entity beans.
In my desc file I give the JNDI name for all the beans , so in this case all my beans are exposed with JNDI name

How should I restrict the client to access only the main session bean