I think that protected access may need some elaboration, especially since Kathy said that the details of access control were exam bait.
The simple case is protected access to a static member x of class A in package P. Code in class A, code in any other class in package P, and code in any subclass S of class A can access member x in all the normal ways.
The interesting case is where x is an instance member of class A in package P. Code in class A and code in any other class in package P can still access member x normally. Code that is within a subclass S of A but that is not in package P can only access member x using a reference of subclass S or of a subclass of S. this, explicit or implied, is considered a reference of subclass S. super is not.
The key point is that references of any supertype of S, including A, will not work.
Since an interface can never be a subtype of a class, that would mean that you can't access a protected member from outside its package using an interface name.
There is a very good exposition of this topic in K&B pages 75-81.