Sensor networks are envisioned to have important applications in military and homeland security. For sensor networks deployed in such hostile environments, security is critical to ensure privacy, integrity, authenticity, and availability of communications. Routing is a fundamental operation in sensor networks. Past researches on sensor network routing focused on efficiency and effectiveness of data dissemination. Few of them considered security during the design phase of the routing protocols. Furthermore, previous researches on sensor networks mainly considered homogeneous sensor networks, i.e., all sensor nodes are the same. Research has shown that homogeneous ad hoc networks have poor performance. We adopt a Heterogeneous Sensor Network (HSN) model for better performance and security. In this paper, we present an efficient secure routing protocol for HSN which takes advantage of the powerful high-end sensors. The security analysis demonstrates that the secure routing protocol can defend typical routing attacks. The simulation shows that the secure routing protocol has better performance than a popular routing protocol - Directed Diffusion.