Date Added: Feb 2012
Wireless Sensor Network is consisting of number of limited sensor devices which are communicated over the wireless media. There are a lot of its application in military, health and industry. As sensor devices are resource restricted, the networks exposed to different types of attacks and conventional techniques against these attacks are not desirable due to the resource constrained nature of these kinds of networks. Therefore, security in WSNs is a challenging task due to inheritance limitations of sensors and it becomes a good topic for researchers. In this paper, the authors focus at secure hierarchal routing protocols in wireless sensor networks and represent selected approaches which focusing at this matter.