Wireless Sensor Networks (WSNs) are a collection of sensor nodes scattered over the area for data collection. But the main problem is it is in danger to the node clone. To identify node clone proposing distributed hash table which a fully decentralized, key-based caching and checking system. Next introducing distributed detection protocol provides good communication performance for large sensor networks. Sensor-MAC a new MAC protocol explicitly designed for wireless sensor networks for reducing energy consumption. The authors' protocol also has good scalability and collision avoidance capability.