Tanveer A. Zia

Security Issues in Wireless Sensor Networks

Due to inherent limitations in wireless sensor networks, security is a crucial issue. While research in WSN security is progressing at tremendous pace, no comprehensive document lists the security issues and the threat models which pose unique threats to the wireless sensor networks. In this paper we have made an effort to document all the known security issues in wireless sensor networks and have provided the research direction towards countermeasures against the threats posed by these issues.

A Secure Triple-Key Management Scheme for Wireless Sensor Networks

Key management is critical to meet the security goals to prevent the sensor networks being compromised by an adversary. Due to ad-hoc nature and resource limitations of sensor networks, providing a right key management is challenging. Traditional key management schemes based on trusted third parties like a certification authority are impractical due to unknown topology prior to deployment. In this paper we present a secure triple-key management scheme to provide resilience security against attacks in sensor networks.

Reputation-based trust management in wireless sensor networks

Wireless sensor networks are promising future of many sensitive applications such as healthcare, defence, habitat monitoring and early bushfire detection. These networks are prone to security attacks due to their wireless and deployment nature. It is very likely that after deployment of the network, sensor nodes are left unattended which causes serious security concerns. Insecure wireless communication aggravates the inherent vulnerabilities of wireless sensor networks. This paper is to study the reputation and trust management and setting a scene to integrate the trust in a security framework to ensure the reliability, integrity and trustworthiness of data sensed by the sensor nodes.

A Synopsis of Simulation and Mobility Modeling in Vehicular Ad-hoc Networks (VANETs)

Vehicular communication is considered to be a backbone for many critical safety applications. In order to achieve a better implementation of any vehicular communication scenario, an efficient, accurate and reliable simulator is essential. Various open source and commercial simulating tools are available for this purpose. One of the key issues in this regard is the selection of a reliable simulator which implements all standard algorithms and paradigms giving accurate results. In this paper, we first present IEEE standard and protocols for vehicular communication, IEEE 802.11p and IEEE 1609.x, also known as WAVE protocol stack. The paper then discusses the necessary requirements for a generic discrete event simulator which can be used to simulate Vehicular Ad-hoc Networks. Since not all the network simulators can be used in the scenario of vehicular communication, we highlight the key features of some network simulators in the context of vehicular ad-hoc networks. The paper also highlights some of the implementation limitations in these simulators. Furthermore, the paper presents a discussion on traffic simulators by emphasizing on the underlying mobility models used in order to generate the realistic traffic patterns. A comparative study of both network and traffic simulators show the pros and cons of these simulation tools. The paper suggests the appropriate choice of a network simulator to be used as a VANET simulator.

An Efficient Privacy Preserving Data Aggregation Scheme with Constant Communication Overheads for Wireless Sensor Networks

Providing efficient data aggregation while preserving data privacy in wireless sensor networks (WSNs) is a challenging problem. Existing security schemes either incur high communication and computational overheads or simply fail to counter attacks when nodes are compromised. In this paper, we present a multidimensional privacy preserving data aggregation scheme for WSNs which is efficient and provides strong security. The scheme not only provides efficient countermeasure against passive and active privacy compromising attacks, coalition attacks from malicious base station and captured sensor nodes, but also is robust to data loss. In addition, the proposed scheme provides data aggregation with constant communication overheads, so that the transmission cost can be significantly reduced which makes it suitable to be used in large scale WSNs. To the best of our knowledge, our scheme is the first one that addresses the privacy and efficiency issues in WSNs all at once.

D 2 MAC: Dynamic delayed Medium Access Control (MAC) protocol with fuzzy technique for Wireless Body Area Networks

Wireless Body Area Networks (WBAN) have emerged as an extension to conventional wireless sensor networks in recent years to comply with the needs in providing timely and effective response in healthcare as one of the many target applications such networks have. The traffic of a WBAN is diverse due to different monitoring tasks carried on by sensor nodes. It brings difficulty in how to efficiently organize the access to the medium for the dynamic and various generated traffic. This paper analyses the traffic diversity problem in WBAN for healthcare applications and proposes a dynamic delayed Medium Access Control (MAC) algorithm. A fuzzy logic system is used to incorporate both application and protocol related parameters of the real time traffic to make the backoff time produced in IEEE 802.15.4 MAC protocol traffic adaptive. The simulation results demonstrate a significant reliability in packet transmissions and decrease in the latency with no change in energy consumption level.

Evaluation of Overheads in Security Mechanisms in Wireless Sensor Networks

Wireless sensor networks are being used in many commercial and military applications to collect real time and event driven data. Deployment nature of sensor networks makes them vulnerable to security threats. Due to the resource limitations traditional security measures are not enough to protect sensor nodes. Research in sensor network security domains has produced several security solutions. In this paper we have observed three recently introduced security mechanisms (1) TinySec (2) MiniSec, and (3) TripleKeys. We have studied these security mechanisms in terms of packet overheads and compared the packet transmission time, average latency and energy consumption. Our comparison shows that the packet overheads in TripleKeys are lesser compared to other two schemes. We have then used the 38 bytes packet size of TripleKeys for further analysis and calculated the packet delivery ratio, latency and energy consumption. We have observed that packet delivery ratio decreases when we increase the number of nodes while latency and energy increases.

Sparse Density Estimation on the Multinomial Manifold

A new sparse kernel density estimator is introduced based on the minimum integrated square error criterion for the finite mixture model. Since the constraint on the mixing coefficients of the finite mixture model is on the multinomial manifold, we use the well-known Riemannian trust-region (RTR) algorithm for solving this problem. The first- and second-order Riemannian geometry of the multinomial manifold are derived and utilized in the RTR algorithm. Numerical examples are employed to demonstrate that the proposed approach is effective in constructing sparse kernel density estimators with an accuracy competitive with those of existing kernel density estimators.

Addressing the Confidentiality and Integrity of Assistive Care Loop Framework Using Wireless Sensor Networks

In-house healthcare monitoring applications are continuous time-critical applications often built upon Body Area Wireless Sensor Networks (BAWSNs). Our Assistive Care Loop Framework (ACLF) is an in-house healthcare application capable of monitoring the health conditions of aged/patients over a dedicated period of time by deploying the BAWSN as the monitoring component. However, the wireless medium used in the BAWSN for communications is prone to vulnerabilities that could open a door to attackers tampering with or compromising the users data privacy. Hence, it is imperative to maintain the privacy and integrity of the data to gain the confidence and hence, the acceptance of the users of the healthcare applications. Furthermore, in time-critical applications, the vital health conditions must be monitored at regular intervals within their specified critical time. Therefore, the security model proposed for the BAWSN must not incur undue overheads when meeting the critical time requirements of the application. In this paper, we propose and implement a secure adaptive triple-key scheme (aTKS) for the BAWSN to achieve the privacy and integrity of the monitored data with minimal overheads. We then present the performance results of our scheme for the BAWSN, using real-time test-bed implementations and simulations.

Communal Reputation and Individual Trust (CRIT) in Wireless Sensor Networks

Deployment of wireless sensor networks in sensitive applications such as healthcare, defence, habitat monitoring and early bushfire detection requires a careful consideration. These networks are prone to security attacks due to their wireless and deployment nature. It is very likely that after deployment of the network, sensor nodes are left unattended which causes serious security concerns. Insecure wireless communication aggravates the inherent vulnerabilities of wireless sensor networks. Several countermeasures have been proposed in literature to counter the threats posed by attacks in sensor networks; however, security does not come for free. Especially for the resource limited nodes it is very costly to deploy computationally extensive security solutions. This paper studies the notion of trust in wireless sensor networks and proposes a solution based on communal reputation and individual trust (CRIT) in sensor nodes. A very important aspect which determines the viability of this study is the simulation results and performance analysis.