Based on the popularity of the application of wireless sensor networks (WSN) in our day- to-day lives, most of the research is going on in this area. Where data transmission of secure data takes the major role. As the information flow rate in the communication system, the integrity should be maintained. In this paper, we have planned a new approach to send the encrypted data from the Cluster head to the base station using the RSA algorithm. The data are sent to the base station based on the demand generated by the base station. Hence, less amount of energy is consumed by the sensor nodes. This approach is simulated using an NS3 simulator and the result is compared with several algorithms. Based on various parameters our approach takes supremacy over those.