Xiaojiang Du

A survey of key management schemes in wireless sensor networks

Wireless sensor networks have many applications, vary in size, and are deployed in a wide variety of areas. They are often deployed in potentially adverse or even hostile environment so that there are concerns on security issues in these networks. Sensor nodes used to form these networks are resource-constrained, which make security applications a challenging problem. Efficient key distribution and management mechanisms are needed besides lightweight ciphers. Many key establishment techniques have been designed to address the tradeoff between limited memory and security, but which scheme is the most effective is still debatable. In this paper, we provide a survey of key management schemes in wireless sensor networks. We notice that no key distribution technique is ideal to all the scenarios where sensor networks are used; therefore the techniques employed must depend upon the requirements of target applications and resources of each individual sensor network.

Internet Protocol Television (IPTV): The Killer Application for the Next-Generation Internet

Internet protocol television (IPTV) will be the killer application for the next-generation Internet and will provide exciting new revenue opportunities for service providers. However, to deploy IPTV services with a full quality of service (QoS) guarantee, many underlying technologies must be further studied. This article serves as a survey of IPTV services and the underlying technologies. Technical challenges also are identified.

An effective key management scheme for heterogeneous sensor networks

Abstract Security is critical for sensor networks used in military, homeland security and other hostile environments. Previous research on sensor network security mainly considers homogeneous sensor networks. Research has shown that homogeneous ad hoc networks have poor performance and scalability. Furthermore, many security schemes designed for homogeneous sensor networks suffer from high communication overhead, computation overhead, and/or high storage requirement. Recently deployed sensor network systems are increasingly following heterogeneous designs. Key management is an essential cryptographic primitive to provide other security operations. In this paper, we present an effective key management scheme that takes advantage of the powerful high-end sensors in heterogeneous sensor networks. The performance evaluation and security analysis show that the key management scheme provides better security with low complexity and significant reduction on storage requirement, compared with existing key management schemes.

Security in wireless sensor networks

Recent advances in electronics and wireless communication technologies have enabled the development of large-scale wireless sensor networks that consist of many low-power, low-cost, and small-size sensor nodes. Sensor networks hold the promise of facilitating large-scale and real-time data processing in complex environments. Security is critical for many sensor network applications, such as military target tracking and security monitoring. To provide security and privacy to small sensor nodes is challenging, due to the limited capabilities of sensor nodes in terms of computation, communication, memory/storage, and energy supply. In this article we survey the state of the art in research on sensor network security.

Transactions papers a routing-driven Elliptic Curve Cryptography based key management scheme for Heterogeneous Sensor Networks

Previous research on sensor network security mainly considers homogeneous sensor networks, where all sensor nodes have the same capabilities. Research has shown that homogeneous ad hoc networks have poor performance and scalability. The many-to-one traffic pattern dominates in sensor networks, and hence a sensor may only communicate with a small portion of its neighbors. Key management is a fundamental security operation. Most existing key management schemes try to establish shared keys for all pairs of neighbor sensors, no matter whether these nodes communicate with each other or not, and this causes large overhead. In this paper, we adopt a Heterogeneous Sensor Network (HSN) model for better performance and security. We propose a novel routing-driven key management scheme, which only establishes shared keys for neighbor sensors that communicate with each other. We utilize Elliptic Curve Cryptography in the design of an efficient key management scheme for sensor nodes. The performance evaluation and security analysis show that our key management scheme can provide better security with significant reductions on communication overhead, storage space and energy consumption than other key management schemes.

Maintaining differentiated coverage in heterogeneous sensor networks

Most existing research considers homogeneous sensor networks, which suffer from performance bottleneck and poor scalability. In this paper, we adopt a heterogeneous sensor network model to overcome these problems. Sensing coverage is a fundamental problem in sensor networks and has been well studied over the past years. However, most coverage algorithms only consider the uniform coverage problem, that is, all the areas have the same coverage degree requirement. In many scenarios, some key areas need high coverage degree while other areas only need low coverage degree. We propose a differentiated coverage algorithm which can provide different coverage degrees for different areas. The algorithm is energy efficient since it only keeps minimum number of sensors to work. The performance of the differentiated coverage algorithm is evaluated through extensive simulation experiments. Our results show that the algorithm performs much better than any other differentiated coverage algorithm.

Cognitive femtocell networks: an opportunistic spectrum access for future indoor wireless coverage

Femtocells have emerged as a promising solution to provide wireless broadband access coverage in cellular dead zones and indoor environments. Compared with other techniques for indoor coverage, femtocells achieve better user experience with less capital expenditure and maintenance cost. However, co-channel deployments of closed subscriber group femtocells cause coverage holes in macrocells due to co-channel interference. To address this problem, cognitive radio technology has been integrated with femtocells. CR-enabled femtocells can actively sense their environment and exploit the network side information obtained from sensing to adaptively mitigate interference. We investigate three CRenabled interference mitigation techniques, including opportunistic interference avoidance, interference cancellation, and interference alignment. Macrocell activities can be obtained without significant overhead in femtocells. In this article, we present a joint opportunistic interference avoidance scheme with Gale-Shapley spectrum sharing (GSOIA) based on the interweave paradigm to mitigate both tier interferences in macro/femto heterogeneous networks. In this scheme, cognitive femtocells opportunistically communicate over available spectrum with minimal interference to macrocells; different femtocells are assigned orthogonal spectrum resources with a one-to-one matching policy to avoid intratier interference. Our simulations show considerable performance improvement of the GSOIA scheme and validate the potential benefits of CRenabled femtocells for in-home coverage.

Two Tier Secure Routing Protocol for Heterogeneous Sensor Networks

Research on sensor network routing focused on efficiency and effectiveness of data dissemination. Few of them considered security issues during the design time of a routing protocol. Furthermore, previous research on sensor networks mainly considered homogeneous sensor networks where all sensor nodes have the same capabilities. It has been shown that homogeneous ad hoc networks have poor fundamental performance limits and scalability. To achieve better performance, we adopt a heterogeneous sensor network (HSN) model. In this paper, we present a secure and efficient routing protocol for HSNs - two tier secure routing (TTSR). TTSR takes advantage of powerful high-end sensors in an HSN. Our security analysis demonstrates that TTSR can defend typical attacks on sensor routing. Our performance evaluation shows that TTSR has higher delivery ratio, lower end-to-end delay and energy consumption than a popular sensor network routing protocol.

On efficient deployment of sensors on planar grid

One practical goal of sensor deployment in the design of distributed sensor systems is to achieve an optimal monitoring and surveillance of a target region. The optimality of a sensor deployment scheme is a tradeoff between implementation cost and coverage quality levels. In this paper, we consider a probabilistic sensing model that provides different sensing capabilities in terms of coverage range and detection quality with different costs. A sensor deployment problem for a planar grid region is formulated as a combinatorial optimization problem with the objective of maximizing the overall detection probability within a given deployment cost. This problem is shown to be NP-complete and an approximate solution is proposed based on a two-dimensional genetic algorithm. The solution is obtained by the specific choices of genetic encoding, fitness function, and genetic operators such as crossover, mutation, translocation for this problem. Simulation results of various problem sizes are presented to show the benefits of this method as well as its comparative performance with a greedy sensor placement method.

Improving routing in sensor networks with heterogeneous sensor nodes

Existing routing protocols mainly consider homogeneous sensor networks where all sensor nodes are the same. However, a homogeneous ad hoc network suffers from poor performance limit and scalability. Recent research has demonstrated its performance bottleneck both theoretically and through experiments. Furthermore, recently deployed sensor network systems are increasingly following heterogeneous designs, incorporating a mixture of sensors with widely varying capabilities. To improve network performance, we propose to form heterogeneous sensor networks by deploying a small number of powerful high-end sensors in addition to a large number of low-end sensors. We design an efficient cluster head relay (CHR) routing protocol for heterogeneous sensor networks. Our simulation experiments demonstrate that CHR performs better than two popular sensor network routing protocols.