Abstract
With a widespread growth in the potential applications of Wireless
Sensor Networks (WSN), the need for reliable security mechanisms for
them has increased manifold. Security protocols in WSNs, unlike the
traditional mechanisms, need special efforts and issues to be
addressed. This is attributed to the inherent computational and
communicational constraints in these tiny embedded system devices.
Another reason which distinguishes them from traditional network
security mechanisms, is their usage in extremely hostile and
unattended environments. The sensitivity of the data sensed by these
devices also pose ever-increasing challenges. We present a layer
based classification of WSN security threats and defenses proposed
in the literature, with special focus on physical, link and network
layer issues.
