In Wireless sensor Network, providing security in a cost of efficient way is the major problem because of resource limited sensor devices. Therefore, we need to consider the energy of the sensor node while providing security. The wireless sensor network with mobile sink is vulnerable to replication attack. To avoid replication attack, the dynamic polynomial pool based key pre-distribution scheme is already present. But in that, the energy of the sensor node is not considered. Our proposed scheme provides security with the awareness of sensor node residual energy. The sensed information is encrypted using the RSA algorithm. The key generated by RSA algorithm is dynamically changed for each and every packet. The Energy based dynamic key generation algorithm is used to generate the dynamic key while the sensor node is in the demand to transmit the data packet.  The mobile sink aware of residual energy of sensors, therefore, based on the residual energy of the sensor, the marble sink sends a data request. As the key is dynamically changed, the adversary cannot introduce replicated node in the network.

Keywords : RSA;Residual energy;security;sink