Date Added: Aug 2010
Wireless Sensor Networks (WSNs) consist of low power, low-cost smart devices which have limited computing resources. With a widespread growth of the applications of WSN, the security mechanisms are also becoming a rising big issue. A lot of real-world applications have been already deployed and many of them will be based on wireless sensor networks. These applications include geographical monitoring, medical care, manufacturing, transportation, military operations, environmental monitoring, industrial machine monitoring, and surveillance systems. This paper discusses typical constraints, security goals, threat models and typical attacks on sensor networks and their defensive techniques or countermeasures relevant to the sensor networks, including security methods.