The current work looks closer at the problem of receiver access control within the Protocol Independent Multicast (PIM) protocol - specifically PIM Sparse Mode - and proposes a practical solution to this problem for PIM-SM. The proposed solution has a number of benefits. The approach adheres to the basic IP multicast model and maintains the “anonymous-receiver” principle of the model, thereby maintaining the scalability of the original model. In accordance to the basic model, PIM routers in the domain need not maintain or propagate any host identification in-formation. The solution makes use of the authentication-key arrangement of the PIM Working Group (IETF) [1] and adheres to it. Finally, the distributed decision-making approach adopted allows routers (other than the RP) to decide whether a new branch of the distribution tree is to be created towards a given receiver, thereby relieving the RP from being the sole decision-point and making the overall solution scalable.