|In this paper, we propose an e±cient multi- cast source authentication protocol based on a novel layered hash-chaining scheme. Our protocol tolerates packet loss and guarantees non-repudiation of media-streaming origin. Furthermore, our protocol allows receivers to make the deci- sion regarding the authentication information redundancy degree depending on the quality of reception in term of packet loss ratio. This novel technique allows to save band- width since the packet loss distribution over a large scale network is likely to be not uniform. We have simulated our protocol using NS-2, and the simulation results show that the protocol has remarkable features and e±ciency com- pared to other recent source authentication protocols.