Mohammad Reza Rohbanian - Department of Information Technology, Shiraz University, Tehran, Iran
Mohammad Rafi Kharazmi - Department of Information Technology, Shiraz University of Technology, Shiraz, Iran
Alireza Keshavarz-Haddad - Department of COMMUNICATION AND ELECTRONICS, Shiraz University, Shiraz,
Manije Keshtgary - Department of Computer Engineering & IT, Shiraz University of Technology, Shiraz, Iran

Wireless sensor network comprises of small sensor nodes with limited resources. Clustered networks have been proposed in many researches to reduce the powerconsumption in sensor networks. LEACH is one of the most interested techniques that offer an efficient way to minimize the power consumption in sensor networks.However, due to the characteristics of restricted resources and operation in a hostile environment, WSNsare subjected to numerous threats and are vulnerable toattacks. This research proposes a solution that can be applied on LEACH to increase the level of security. InWatchdog-LEACH, some nodes are considered as watchdogs and some changes are applied on LEACH protocol for intrusion detection. Watchdog-LEACH isable to protect against a wide range of attacks and it provides security, energy efficiency and memory efficiency. The result of simulation shows that in comparison to LEACH, the energy overhead is about 2% so this method is practical and can be applied to WSNs.

LEACH, Wireless sensor networks,clustered, Watchdog-LEACH, security