Many applications, such as broadcasting stock quotes and videoconferencing require data source authentication of the received multicast traffic. Multicast data source authentication must take into consideration the scalability and the efficiency of the underlying cryptographic schemes and mechanisms, because multicast groups can be very large and the exchanged data are likely to be important in volume (streaming). Besides, multicast data source authentication must be robust enough against packet loss because most of multicast multimedia applications do not use reliable packet delivery. In this paper, we propose a hybrid hash-chaining scheme in conjunction with an adaptive and efficient data source authentication protocol which tolerates packet loss and guarantees non-repudiation of media-streaming origin. We have simulated our protocol using NS-2, and the simulation results show that the protocol has remarkable features and efficiency compared to other recent data source authentication protocols.