Wireless sensor networks (WSN) have emerged as significant technology that has been adopted in various research fields to monitor the physical environments and collect information from the surroundings. However, WSNs are more vulnerable to attacks owing to their significant characteristics, including dynamicity in network topology and resource constraints. Multiple methods have been investigated to efficiently identify the different types of threats and attacks over the WSN. However, most of the existing works focus on a specific type of attack detection and lack in analyzing their performance. This survey highlights the significant functionalities of WSN, applications, and security requirements. From the viewpoint of security measurements, the authors have classified the survey study as security towards data collections and routing in WSN. Also, various security attacks based on protocol stack layers are classified. Finally, the authors have emphasized the significant security challenges in this research field based on the prior studies followed by the conclusion.
TopIntroduction
From the past decades, there has been tremendous growth in the adoption of wireless devices and infrastructure (Aliu et al., 2013). Wireless sensor networks (WSNs) is core technology in the Internet of Things and plays a significant role to offer optimal services through sensor devices, i.e., smart home, manufacturing as per industry 4.0 vision, smart transportation, environment monitoring, smart grids and many more (Atzori et al., 2010), (Gubbi et al., 2013). A typical WSN contains sink nodes along with multiple distributed sensor nodes which collect and forwards the data packets to perform various tasks. Built-in WSNs provide reliable data delivery for IoT based applications such as smart healthcare applications, which monitors, analyze, and diagnose the illness. In the application, WSNs provides useful information to the physicians and considered as a significant factor for successful diagnosis. However, distributed WSNs are susceptible to network failures owing to signal interference, which could decrease the quality of service (QoS) (Weber, 2010), (Al-Karaki & Kamal, 2004). Therefore, supporting reliable data delivery becomes a challenging problem in WSNs. Many multi-path optimal routing strategies to offer reliable deliveries in the context of WSNs ().
Moreover, the transmission of data packets takes over multiple paths and hops to receivers. So more transmission contentions and signal interferences lead to the additional transmission failures in the network. These efforts go in vain by very small efforts initiated by the malicious nodes by participating into the network. Therefore, study of security in many various dimensions is an essential research domain in WSN.
Though the concern of data privacy and security issues in the area of disasters management is a popular topic (Erdelj & Akyildiz, n.d.) as initially most of the application were related to such application, However, most of the surveillance applications lack the data privacy and security tools; hence it is crucial to evaluate the security concept. Some of the significant challenges to protect and secure the WSNs from the malicious attackers are listed below:
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Energy optimization Indeed, high security with minimum energy consumption policies utilized and strongly influenced by constraints and capabilities of the sensor node.
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The maximum quantity of energy obsessive by the sensor node is during the data transmission. Security is essential to transmit the data securely as well as store the data securely.
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The network topology poses vulnerabilities to the attackers for both active and passive attack as unlike a wired network, where firewall enhances privacy and security, threats in wireless network attains from various directions and may target any sensor node over the network infrastructure.
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Minimal resources: In the WSNs, every sensor nodes contains limited resources, including hardware constraints, energy, processing capability, and memory space. Due to the large scale and distributed topology configuration, processing signals at the receiver end to compensate for attenuation of the signal, the energy consumption by the sensor node communication is very high. Therefore, all previous research studies focus was on energy optimization problem.
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Rekeying: The lifetime of the shared key may expire, and it is essential to re-establish.
The primary motive of this study is to represent a comprehensive research study on WSNs security by considering most prior work in the state of art of threats and attacks in WSNs. The different types of vulnerabilities and threats are identified and introduced operational paradigms for WSNs configuration (Xie et al., 2018). The present study overviews existing security protocols concerning data security and routing security and present a comparative analysis among them.