Abstract: A Wireless Sensor Network (WSN) is a group of spatially dispersed sensor nodes which are interconnected by using wireless communication. A sensor node also called mote, is an electronic device which consists of a processor along with a storage unit, a transceiver module, a single sensor or multiple sensors, along with an Analog to Digital Converter (ADC) and a power source which normally is a battery. It may optionally include a positioning unit and/or a mobilization unit. Protecting the network from malicious attacks is an important and challenging issue in both wired and wireless networks and the issue becomes even more challenging in the case of wireless sensor networks. We would like to provide solution for the above problem using the dynamic strategy. Proposed solution to determination of the data correlation at each node by way of local computation and propose avoiding transmission of significantly similar data. This can lead to unused time slots at runtime (dynamic slack) which can be traded off for energy savings. The file list is displayed in both sender and the receiver but the file content is present in the sender only. The receiver request the file content by sending the file name then the sender verify the request if the receiver is authentic. Then sender splits the file content into packets and signs each packet by generating the key then encrypts the packets and sends to the receiver. The receiver verifies the packets and then decrypts the message using sender’s public key.