A wireless sensor network (WSN) is a special ad hoc network. It consists of a large number of sensors communicating with wireless links to monitor the real-world environment. They have limited energy, computational power, memory, and transmission range. They are widely used in different fields like military operations, environmental monitoring, and healthcare applications. However, the openness and hostility of the deployment space and the resources limitations make these networks vulnerable to several types of attacks and intrusions. So, the WSN security becomes a real challenge. Principally, the attacks in the network aim at damaging the smooth running of the legitimate nodes and cause a dysfunction of the network. Sybil attack is one of the perilous attacks which affects the WSN networks and poses threats to many security goals. This attack makes the sensor node into Sybil node and illegitimately takes and claims multiple identities.
TopIntroduction
In recent years, thanks to advanced technology and more particularly to the evolution of microelectronics and wireless communication, Wireless Sensor Networks (WSNs) (Yick, Mukherjee, & Ghosal, 2008) have experienced considerable growth. For that, these networks are considered as an emerging technology resulting from the progress of the different domains. Their main objective is to offer economically interesting solutions for remote control and data processing. So, currently, they are an integral part of our lives, as they allow the user a better understanding of the environment. Indeed, they are generally deployed to monitor a more or less extensive area of interest, to take regular measurements and to send back alarms to certain nodes responsible for relaying information on a large scale. For this, they are widely used in different fields namely, the military, environmental, medical, home automation, and of course the applications related to the monitoring of critical infrastructures.
Wireless sensor networks (WSNs) are considered as a special type of Ad-hoc networks (Perkins, 2001), in which the nodes are smart sensors. These (also called nano-computers) have limited computing capacity, energy and bandwidth. They are powered by a power source (battery) of limited capacity. They bring an interesting perspective: that of devices capable of self-configuration and self-organization. Typically (see Figure 1), WSNs consist of a potentially large number of randomly deployed sensors in the area of interest also known as the sensing area to monitor a phenomenon and collect its data. The latter are then routed, through a multi-hop routing, to a collection point called collector node (base station or sink) for usual operating purposes. The base station is linked to the network user via the Internet or a satellite.
Figure 1.
Typical architecture of a WSN
A sensor is a measuring instrument with advanced feel features. It makes it possible to generate data relating to its physical environment. Its main role lies in: the recording of a physical quantity (such as temperature, humidity, speed, motion, pressure, etc.) observed (also called measurand (M) in the model of a measure proposed by the electronics engineer Georges Asch (Asch, 2010), which will later be transformed into a physical quantity of electrical nature (electrical signal) (see Figure 2) This transformation must reflect as perfectly as possible these quantities (Noury, 2002). After scanning in an analog / digital representation, the measured value can be stored, processed, transmitted to be used with other information to meet the needs of a specific application, and the sensors can detect real-world events such as forest fires The main advantages of sensor nodes are: their small size, low cost, fault tolerance, self-organizing ability, and especially their ability to communicate wirelessly (usually a radio channel) (which allows great freedom of movement compared to wired nodes).
Figure 2. Essential function of a sensor (Noury, 2002)