Hesiri Weerasinghe

Preventing Cooperative Black Hole Attacks in Mobile Ad Hoc Networks: Simulation Implementation and Evaluation

A black hole attack is a severe attack that can be easily employed against routing in mobile ad hoc networks. A black hole is a malicious node that falsely replies for any route requests without having active route to specified destination and drops all the receiving packets. If these malicious nodes work together as a group then the damage will be very serious. This type of attack is called cooperative black hole attack. In S. Ramaswamy et al. (2003), we proposed a solution to identifying and preventing the cooperative black hole attack. Our solution discovers the secure route between source and destination by identifying and isolating cooperative black hole nodes. In this paper, via simulation, we evaluate the proposed solution and compare it with other existing solutions in terms of throughput, packet loss percentage, average end-to-end delay and route request overhead. The experiments show that (1) the AODV greatly suffers from cooperative black holes in terms of throughput and packet losses, and (2) our solution proposed in S. Ramaswamy et al. (2003) presents good performance in terms of better throughput rate and minimum packet loss percentage over other solutions, and (3) our solution can accurately prevent the cooperative black hole attacks. The example findings are: (1) the proposed scheme presents 5 - 8% more communication overhead of route request; and (2) The secure route discovery delay slightly increases the packet loss percentage.

An Enhanced Multi-Channel MAC for the IEEE 1609.4 Based Vehicular Ad Hoc Networks

This paper proposes a multi-channel MAC scheme for Vehicular Ad Hoc Networks (VANETs), which dynamically adjusts the intervals of Control Channel (CCH) and Service Channels (SCHs). Markov modeling is conducted to optimize the intervals based on the traffic condition. The scheme also introduces a multi-channel coordination mechanism to provide the contention-free access in SCHs. Theoretical analysis and simulation results show that the proposed scheme is able to help IEEE 1690.4 MAC improve the saturation throughput of SCHs significantly, while maintaining the prioritized transmission of critical safety information on the CCH.

Human Perception of Haptic Force Direction

In this paper we investigate the accuracy of human perception of haptic force direction applied to the hand. Haptic interfaces are commonly used in many applications and understanding the limitations of human perception would facilitate the design of these interfaces and the associated applications. The literature contains work related to force perception; however, none of which address the issue of the accuracy of haptic force direction perception. We discuss the design and implementation of the experiment used to evaluate the accuracy. Also presented are results related to training effects, fatigue and accuracy across angular regions

Verifying position and velocity for vehicular ad‐hoc networks

In the near future, vehicle-to-vehicle and vehicle-to-roadside infrastructure communications will enable numerous applications, such as collision avoidance, traffic management, location-based services, and infotainment for the automobile field. Position and velocity play important roles in these applications such as collision avoidance. Forged position or velocity information will make a severe impact on both performance and security of the vehicular ad-hoc network (VANET). The main challenges in developing secure position and velocity schemes for VANETs are the highly dynamic environment and cost constraints. In this paper, we propose a position and velocity verification scheme. Then via ns-2, we simulate the proposed scheme in various vehicular mobility environments including rural, urban and Manhattan. Finally, we evaluate the proposed scheme for both position and velocity verifications with automotive grade differential global positioning system (DGPS) and intentionally induced errors as well. The performance evaluation results show that (1) our scheme is very precise in both position and velocity verifications and (2) the proposed scheme is very robust in position verification for rural, urban and Manhattan scenarios even if the introduced errors are in the order of 10 m. Copyright

ESAP: Efficient and scalable authentication protocol with conditional privacy for secure vehicular communications

Security mechanisms such as authentication, message integrity, and non-repudiation are extremely important features for both vehicle-to-vehicle and vehicle-to-infrastructure communications in vehicular ad hoc networks. This paper proposes an Efficient and Scalable Authentication Protocol (ESAP) that provides anonymity and conditional privacy for vehicular ad hoc networks based on the self-generated certificates. The proposed ESAP provides all required security services such as authentication, message integrity, non-repudiation and revoking malicious vehicles in an efficient and scalable manner while supporting user anonymity, location privacy and conditional privacy. Moreover, accuracy of this protocol does not depend on the availability of Road Side Units.

Analysis of key management in wireless sensor networks

A multitude of wireless sensor networks exist today in various fields, each having a specific objective in mind. Based on the objectives for each network, the security concerns can be different, dependent on such factors as the level of secrecy of the data being captured, the amount of computation done to the captured data, and the criticality of the data being available when needed. This paper aims to identify the various types of WSNs in existence today, review some of the key management schemes proposed by the community, and map each type of WSN to a set of these key management schemes that would be ideal to handle the security requirements for that network. Through our research, we aide in solving the question as to whether or not there exists any specific security concerns which are prevalent in a majority of WSNs in use today.

Data centric adaptive in-network aggregation for wireless sensor networks

This paper presents and evaluates a data centric adaptive in-network aggregation algorithm for wireless sensor networks. In-Network data aggregation is used in wireless sensor networks to reduce the power consumption of sensor nodes. The accuracy of the aggregated results is highly sensitive to delays in the measurements. All existing methods use fixed time limit to accept delayed information for aggregation. The proposed method dynamically calculates the delay limit by using the historical behavior of each sensor. The presented simulation results illustrate the advantage of the developed algorithm.

Enhancement of IEEE 802.11 modules in ns-2 and performance evaluation with error rate

Ns-2 is being widely utilized to evaluate the wired and wireless networks on many research activities. The ns-2.33 distribution version includes an extension of IEEE 802.11 module which improves the core functions of 802.11 MAC and PHY protocols. Although this extension version provides well-designed MAC and PHY functions, it has some significant shortcomings in handling packet errors. When a packet error rate, one of the most important performance parameters in wireless network simulations, applies to the extension, a simulation program is interrupted with some fatal errors. Besides, as the packet errors are handled on the PHY layer in this version, MAC layer loses its own right of treating the packet errors. In this paper, we modify the extension version to correct the mentioned problems and verify the behavior of our modified version by simulation work. And also, we perform the ns-2 simulation to investigate the impact of error rate on IEEE 802.11p-based vehicular ad-hoc networks.