Wireless Sensor Networks (WSNs) are used in many application areas because of its characteristics of easy installation and deployment of sensor nodes in any place and any form. In most of cases, WSNs are typically deployed in un-trusted environment so that security of data communication becomes the essential demand. Secure data transfer in sensor networks requires complicated consideration, compared to conventional desktop computers with the limited processing power, storage, bandwidth, and energy. In this paper, we provide a secure protocol for WSNs which is not only trying to achieve all major issues in security, but also satisfies the low-power consumption as well. We provide and develop secure protocols for data communication and algorithmic mechanisms which ensure energy-saving processing to maximize the performance of communication.