Why is security necessary in WSN? Due to the broadcast nature of the transmission medium
wireless sensor networks are vulnerable. There are another reason of vulnerability of WSNs are
nodes are often placed in a hostile or dangerous environment and they are not physically safe.
Most of the threats and attacks against security inwireless sensor networks are almost similar to
their wired counterparts while some are exacerbatedwith the inclusion of wireless connectivity.
WSNs are usually more vulnerable to various security threats because the unguided transmission
medium is more susceptible to security attacks, butalso through traffic analysis, privacy violation,
physical attacks and so on.
Attacks on WSNs can be classified from two different levels of views
1. Attack against security mechanisms
2. Attack against basic mechanisms (like routing mechanisms)
In many applications the data obtained by the sensing nodes need to be authentic [5]. A false or
malicious node could intercept private information in the absence of proper security or could send
false messages to nodes in the network. Different possible attacks can be categorized as follows