Security of Wireless Sensor Networks: Current Status and Key Issues

Abstract

Due to significant advances in wireless and mobile communication techniques and the broad development of potential applications, Wireless Sensor Networks (WSNs) have attracted great attention in recent years. Nevertheless, WSNs are formed dynamically by a number of powerlimited sensor nodes and themanager nodewith long-lasting power. WSNs are self-organized and autonomous systems consisting of common sensors, manager nodes and back-end data center. Firstly, the common sensors are responsible for transmitting the real-time sensor data of specific monitoring environment to the intermediate collection nodes called manager node. Finally, the back-end data center will receive the sensed data from manager nodes to do further process and analysis. Undoubtedly, all communication between nodes are through the wireless transmission techniques. Furthermore, due to the property of self-organized, without support from the fixed infrastructure and the topology of wireless sensor network changes dynamically, therefore, broadcasting is the general way for communications in WSNs. Wireless sensor network has been widely used in practical applications, such as monitoring of forest fire, detection of military purpose, medical or science areas and even in our home life. However, WSNs are easily compromised by attackers due to wireless communications use a broadcast transmissionmedium and their lack of tamper resistance. Therefore, an attacker can eavesdrop on all traffic, inject malicious packets, replay older messages, or compromise a sensor node. Generally, sensor nodes are most worried about two major security issues, which are privacy preserving and node authentication. Privacy means the data confidentiality is achieved under security mechanism, and hence it allows network communications between sensor nodes and the manager station to proceed securely. In addition, a well-structured authentication mechanism can ensure that no unauthorized node is able to fraudulently participate and get sensitive information from WSNs. As a result, several schemes have been proposed to secure communications in WSNs. In this chapter, we classify them into three classifications based on the cryptographic techniques: symmetric keys, asymmetric keys and one-way hashing functions. The rest of this chapter is organized as follows: In Section 2, we introduce the characteristics and consideration of WSNs. In Section 3, we review some security threats and requirements in WSNs. Section 4 is for the security countermeasure schemes and its classification. Finally, we conclude some future works for the secure networking in WSNs. 17