IntroductionWith the growing popularity of mobile devices and recent developments in wireless communication, wireless sensor networks are one of the next fields of interest from a research perspective. Sensor networks consist of "smart nodes" with limited resources in terms of memory, energy and computing power. These nodes communicate wirelessly and transmit their information to the master node usually called sink node or base station. these sensor nodes consist of their own sensors, processor, radio transceiver, energy resource usually a battery which provides them with sensing, processing and communication capabilities. The first implementation of wireless sensor networks was for military applications, but nowadays these networks are used in environmental applications, medical applications, home appliances, and various other commercial and consumer applications. In wireless sensor networks, sensor nodes are densely distributed and work collaboratively to monitor the specific task and then communicate with each other or with a base station. The topology of sensor networks can vary from the simple flat model to the multihop clustering model. These networks have low memory, low bandwidth, low power and large-scale nodes and the various other factors that influence the design of sensor networks are: fault tolerance, scalability, manufacturing cost, operating environment, hardware constraints etc. Therefore, the design of these networks must meet all these factors. However, due to the wireless nature of these networks and the absence of tamper-resistant hardware, they make them vulnerable to various types of attacks, and these attacks are possible at almost every level of the OSI layer. Since these networks are physically weak, it involves... middle of paper ......or network traffic on communication channels without the knowledge of the sending and receiving party. As in wireless sensor networks, publicly accessible wireless signals are transmitted and the attacker can easily insert themselves between the communication channel ranges.3: Jamming: These types of attacks are performed by deploying a large number of nodes which can cause intense noise in the network and occupying the network channels, making the transmission means unavailable for the other nodes. These types of attacks rarely occur because these jamming devices are easily detectable as sensor nodes detect noise that is much larger than normal noise in the network. MAC layer: At this layer the attacker tries to disrupt the various coordination rules and produces the malicious traffic. They also attempt to spoof identities at the MAC layer.