In this paper, Cluster Based Dynamic Keying Technique for Authentication in Wireless Sensor Networks (WSN) is proposed. The CH enabled by Global Positioning System (GPS) determines a Combined Cost Value (CCV) for each sensor node based on nodes location, node degree and virtual battery power. Since the key to the encryption scheme changes dynamically when there is change in CCV, separate dynamic keys are generated in each cluster by each CH and using RC5 encryption mechanism the source CH forwarding the data along different clusters along the path to the sink are able to verify the authenticity. When the source CH needs to transmit the aggregated data packet to the sink, it splits the packet into shares by threshold secret sharing algorithm and forwards them to the sink using multi-path dispersal routing technique.