We propose an efficient multicast source authentication protocol called efficient multi-tree-chains scheme (EMTC),which shows more loss resistibility,less communication cost,and no delay at receivers. The EMTC scheme is based on combination of single Chain scheme and Hash Tree Chains scheme,and integrates the advantages of both. In this scheme,stream is firstly divided into blocks with n packets,and each block consists of m clusters,everyone of which contains a tree of packets. All clusters are chained together. Through EMTC,packets of one cluster can be authenticated by any packet of the previous cluster. Compared to other multicast authentication protocols,the proposed scheme has the following advantages: dramatically improves the resistance to burst packets loss; ② low computation and communication overhead; ③ imposes low delay on the sender side and no delay on the receiver side. The proposed EMTC scheme is based on combination of single chain scheme and hash tree (EMTC), which shows more loss resistibility, less communication cost, and no delay at receivers. Chains scheme, and integrates the advantages of both. In this scheme, stream is first divided into blocks with n packets, and each block consists of m clusters, everyone of which contains a tree of packets. Compared to other multicast authentication protocols, the proposed scheme has the following advantages: dramatically improves the resistance to burst packets loss; ② low computation and communication overhead; ③ imposes low delay on the sender side and no delay on the receiver side.