This paper presents a power-aware secure routing protocol for wireless embedded networks (WENs). We propose an efficient secure relay scheme called ESRS for ad-hoc-based embedded-network communications. ESRS is a two-phase scheme which includes end-to-end secure channel establishment and relay-behavior monitoring. With end-to-end secure channel establishment, the transmitted data will be protected under an end-to-end secure channel. A power-aware secure route will be also provided in this stage. Then attacks of routing are monitored and controlled in the monitoring phase. As the experimental results are shown, ESRS provides an efficient way to relay data securely for ad-hoc-based embedded network communications.