Developments in micro electro mechanical systems (MEMS) and wireless networks are opening a new domain in networking history. Sensors; often called "smart dust" are low cost small tiny devices with limited coverage, low power, smaller memory sizes and low bandwidth, will play a key role in collecting and disseminating data from the fields where ordinary networks are unreachable for various environmental and strategical reasons.
There have been significant contributions to overcome many weaknesses in sensor networks like coverage problems, lack in power and making best use of limited network bandwidth, however; work in sensor network security is still in its infancy stage. This paper is an effort to introduce the security issues in wireless sensor networks, highlight the current research efforts, and to determine the future directions to solve the unresolved issues.
The remainder of this paper is organised in the following way. Section 2 provides a brief overview of wireless sensor networks, their evolution, major research initiatives and future applications. In section 3, security issues and challenges are discussed. Section 4 highlights the related work in sensor networks. Section 5 concludes the paper by posing some questions and future directions.
2. An Overview
Sensor networks are emerging technologies currently being deployed in seismic monitoring, wild life studies, manufacturing and performance monitoring. These sensor nodes are densely deployed in a predetermined geographical area to self-organise into ad hoc wireless networks to gather and aggregate data .
The ad hoc nature of sensor networks poses unique challenges with their security and reliability. Resource constrained sensor nodes in terms of limited memory, low power, limited processing abilities, and low coverage are vulnerable to intrusion, interception, modification and fabrication. Because of these unique challenges traditional security techniques are not enough to meet the security goals of confidentiality, integrity, reliability and availability. Unlike traditional networks, sensor nodes are deployed physically in open areas where there is added risk of intervention with people and environment . Therefore, new security measures are needed to address the unique sensor networks security challenges.
Advent of small cheap sensors, equipped with tiny memory and processing power of aggregation to reduce the load of data and provide more useful information has transformed the traditional networks to very smart networks. David Culler, a computer scientist at the University of California, Berkley, has been working for few years towards development of sensors says, "Low-power wireless sensor networks are spreading what the future of computing is going to look like" .
Research in sensor networks was started over two decades ago in defence applications. Researchers at Carnegie Mellon University (CMU)...