Qishi Wu

A Survey of Game Theory as Applied to Network Security

Network security is a complex and challenging problem. The area of network defense mechanism design is receiving immense attention from the research community for more than two decades. However, the network security problem is far from completely solved. Researchers have been exploring the applicability of game theoretic approaches to address the network security issues and some of these approaches look promising. This paper surveys the existing game theoretic solutions which are designed to enhance network security and presents a taxonomy for classifying the proposed solutions. This taxonomy should provide the reader with a better understanding of game theoretic solutions to a variety of cyber security problems.

On computing mobile agent routes for data fusion in distributed sensor networks

The problem of computing a route for a mobile agent that incrementally fuses the data as it visits the nodes in a distributed sensor network is considered. The order of nodes visited along the route has a significant impact on the quality and cost of fused data, which, in turn, impacts the main objective of the sensor network, such as target classification or tracking. We present a simplified analytical model for a distributed sensor network and formulate the route computation problem in terms of maximizing an objective function, which is directly proportional to the received signal strength and inversely proportional to the path loss and energy consumption. We show this problem to be NP-complete and propose a genetic algorithm to compute an approximate solution by suitably employing a two-level encoding scheme and genetic operators tailored to the objective function. We present simulation results for networks with different node sizes and sensor distributions, which demonstrate the superior performance of our algorithm over two existing heuristics, namely, local closest first and global closest first methods.

Ultrascience net: network testbed for large-scale science applications

UltraScienceNet is an experimental wide area network testbed to enable the development of networking technologies required for next-generation large-scale scientific applications. It provides on-demand dedicated high-bandwidth channels for large data transfers, and also high-resolution high-precision channels for fine control operations. In the initial deployment its data plane consists of several thousand miles of dual 10 Gb/s lambdas. The channels are provisioned on demand using layer 1 and 2 switches in the backbone and multiple service provisioning platforms at the edges in a flexible configuration using a secure control plane. A centralized scheduler is employed to compute future channel allocations, and a signaling daemon is used to generate the configuration signals to switches at appropriate times. The control plane is implemented using an out-of-band virtual private network, which encrypts the switching signals, and also provides authenticated user and application access. Transport experiments are conducted on a smaller test connection that provides us useful information about the basic properties and issues of utilizing dedicated channels in applications.

CHEETAH: circuit-switched high-speed end-to-end transport architecture testbed

We propose a circuit-switched high-speed end-to-end transport architecture (CHEETAH) as a networking solution to provide high-speed end-to-end circuit connectivity to end hosts on a dynamic call-by-call basis. Not only is it envisioned as a complementary service to the basic connectionless service provided by todays Internet; it also relies on and leverages the presence of this service. Noting the dominance of Ethernet in LANs and SONET/SDH in WANs, CHEETAH circuits consists of Ethernet segments at the ends and Ethernet-over-SONET segments in the wide area. In this article we explain the CHEETAH concept and describe a wide-area experimental network testbed we have deployed based on this concept. The network testbed currently extends between Raleigh, North Carolina, Atlanta, Georgia, and Oak Ridge, Tennessee, and uses off-the-shelf switches. We have created CHEETAH software to run on end hosts to enable automated use of this network by applications. Our first users of this network testbed and software is the terascale supernova initiative (TSI) project researchers, who plan to use this network for large file transfers and remote visualizations.

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.

Control Plane for Advance Bandwidth Scheduling in Ultra High-Speed Networks

A control-plane architecture for supporting advance reservation of dedicated bandwidth channels on a switched network infrastructure is described including the front-end web interface, user and token management scheme, bandwidth scheduler, and signaling daemon. A path computation algorithm for bandwidth scheduling is proposed based on an extension of Bellman-Ford algorithm to an algebraic structure on sequences of disjoint non-negative real intervals. An implementation of this architecture for UltraScience Net is briefly described.

Supporting Distributed Application Workflows in Heterogeneous Computing Environments

Next-generation computation-intensive applications in various fields of science and engineering feature large-scale computing workflows with complex structures that are often modeled as directed acyclic graphs. Supporting such task graphs and optimizing their end-to-end network performances in heterogeneous computing environments are critical to the success of these distributed applications that require fast response. We construct analytical models for computing modules, network nodes, and communication links to estimate data processing and transport overhead, and formulate the task graph mapping with node reuse and resource sharing for minimum end-to-end delay as an NP-complete optimization problem. We propose a heuristic approach to this problem that recursively computes and maps the critical path to the network using a dynamic programming-based procedure. The performance superiority of the proposed approach is justified by an extensive set of experiments on simulated data sets in comparison with existing methods.

Fusion of threshold rules for target detection in wireless sensor networks

We propose a binary decision fusion rule that reaches a global decision on the presence of a target by integrating local decisions made by multiple sensors. Without requiring a priori probability of target presence, the fusion threshold bounds derived using Chebyshevs inequality ensure a higher hit rate and lower false alarm rate compared to the weighted averages of individual sensors. The Monte Carlo-based simulation results show that the proposed approach significantly improves target detection performance, and can also be used to guide the actual threshold selection in practical sensor network implementation under certain error rate constraints.

Secure cell relay routing protocol for sensor networks

Past researches on sensor network routing have been focused on efficiency and effectiveness of data dissemination. Few of them considered security issue during the protocol design time. Security is very important for many sensor network applications. Studies and experiences have shown that considering security during design time is the best way to provide security for routing. In this paper, we present a novel secure cell relay (SCR) routing protocol for sensor networks. SCR routing protocol is resistant to several kinds of attacks on sensor networks, including selective forwarding, sinkhole, wormhole, Sybil, hello flooding attacks, etc. SCR is also an energy efficient routing protocol with acceptable security overhead. SCR routing utilizes the fact that sensor nodes (in most sensor networks) are dense, static and location-aware, to achieve good security, high delivery ratio and low energy consumption, which is confirmed by our simulations.

Complexity analysis and algorithm design for advance bandwidth scheduling in dedicated networks

An increasing number of high-performance networks provision dedicated channels through circuit switching or MPLS/GMPLS techniques to support large data transfer. The link bandwidths in such networks are typically shared by multiple users through advance reservation, resulting in varying bandwidth availability in future time. Developing efficient scheduling algorithms for advance bandwidth reservation has become a critical task to improve the utilization of network resources and meet the transport requirements of application users. We consider an exhaustive combination of different path and bandwidth constraints and formulate four types of advance bandwidth scheduling problems, with the same objective to minimize the data transfer end time for a given transfer request with a prespecified data size: fixed path with fixed bandwidth (FPFB); fixed path with variable bandwidth (FPVB); variable path with fixed bandwidth (VPFB); and variable path with variable bandwidth (VPVB). For VPFB and VPVB, we further consider two subcases where the path switching delay is negligible or nonnegligible. We propose an optimal algorithm for each of these scheduling problems except for FPVB and VPVB with nonnegligible path switching delay, which are proven to be NP-complete and nonapproximable, and then tackled by heuristics. The performance superiority of these heuristics is verified by extensive experimental results in a large set of simulated networks in comparison to optimal and greedy strategies.