Wireless Sensor Networks (WSNs) are expansive networks comprised of small, self-configured, and spatially dispersed devices. These devices are characterized by their small size, affordability, and low power consumption. Sensors gather and transmit data through wireless communication channels in a WSN. Due to the critical need for robust and secure communications within the realm of Wireless Sensor Networks (WSNs), we design a novel authentication protocol between nodes in Wireless Sensor Networks to ensure security. The proposed protocol remains impervious to interceptions and attacks by using a combined approach of public key cryptography and symmetric key cryptography. The proposed protocol is simple and its security analysis through Scyther proves it to be secure.