This paper presents SEQMRAN, a novel secure efficient QoS multicast route discovery protocol for mobile ad hoc networks. The protocol relies entirely on a new one-time signature mechanism, HORSEI, with very efficient signing and verifying, and we do this by improving the HORSE protocol through the introduction of intermediate hash joints. The main purpose of SEQMRAN is to provide source authentication for QoS multicast routing discovery messages in MANET by constructing multicast tree with QoS and authentication constrains in mobile ad hoc networks. The performance measure of SEQMRAN is evaluated using network simulator NS2. The results represent that SEQMRAN produces less end-to-end packet latency than RSA public key encryption based secure routing scheme, and it is a feasible approach to securing multicast routing with multiple QoS constrains for mobile ad hoc networks.