In a wireless sensor network, the sensors periodically transmit sensed data from a specific environment to a centralized station by wireless communication. Deployment in an open environment leads to the potential of security attacks. A sinkhole attack is a destructive attack aimed at the network layer, where the sinkhole node attracts other nodes by advertising itself as the best path to the base station. Subsequently receiving other sensor node packets and compromising network security. Hence, this work proposes a lightweight, secure method based on the Threshold Sensitive Energy Efficient Sensor Network protocol and watermarking techniques to ensure data integrity during transmission. The homomorphic encryption used in this scheme is to provide fast and efficient and consumes less energy while identifying sensor nodes for the purpose of sinkhole detection and prevention. The proposed work has been evaluated using OMNET++ simulation environment to measure the proposed work performance in the following metrics: delay, packet delivery ratio, throughput, and average energy consumption. Compared with previous works, the proposed work shows better results in these metrics. In addition, the proposed scheme consumes less energy compared with similar works due to the use of lightweight watermarking and authentication techniques. The results show that the proposed scheme enhances security by detecting the sinkhole attacker node before the attack is even activated. In addition, the proposed method ensures the integrity and authenticity of the sensed data while transmitting them from the sensor node until receiving it in the base station, and it can detect any tampering of the data.