Defense R and D Canada

Ottawa, Canada

Defense R and D Canada

Ottawa, Canada

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Bu S.,Carleton University | Yu F.R.,Carleton University | Liu P.X.,Carleton University | Tang H.,Defense R and D Canada
IEEE International Conference on Communications | Year: 2011

Continuous authentication is an important prevention-based approach to protect high security mobile ad-hoc networks (MANETs). On the other hand, intrusion detection systems (IDSs) are also important in MANETs to effectively identify malicious activities. Considering these two approaches jointly is effective in optimal security design taking into account system security requirements and resource constraints in MANETs. To obtain the optimal scheme of combining continuous authentication and IDSs in a distributed manner, we formulate the problem as a partially observable distributed stochastic system. We present structural results for this problem in order to decrease computational complexity, making our solution usable in large networks. The policies derived from structural results are easy to implement in practical MANETs. Simulation results are presented to show the performance of this method for the proposed scheme. © 2011 IEEE.


Changiz R.,Carleton University | Halabian H.,Carleton University | Yu F.R.,Carleton University | Lambadaris I.,Carleton University | Tang H.,Defense R and D Canada
Proceedings - IEEE/IFIP International Conference on Embedded and Ubiquitous Computing, EUC 2010 | Year: 2010

Cooperative communication makes use of the broadcast nature of the wireless medium where adjacent nodes overhear the message transmitted by the source and assist in the transmission by relaying the overheard message to the destination. Although cooperative communication brings in significant benefits, it also raises serious security issues to wireless mobile networks. For example, there exists a possibility that a node refuses to cooperate when it is selected for cooperation or deliberately drop the received packets. In wireless mobile networks with cooperative communication, trust management is an important mechanism to monitor such networks for violations of security. In this paper, we propose a trust management method for wireless mobile networks with cooperative communications. Conventional Bayesian methodology is insufficient for the cooperative communication paradigm, as it is biased by the channel conditions and relay selection decision processes. Therefore, we modify the conventional trust management method by incorporating not only the relay selection policy but also the dynamic wireless channel conditions among the source, relays and destination. Simulation results are presented to show the effectiveness of the proposed scheme. © 2010 IEEE.


Tang H.,Defense R and D Canada | Yu F.R.,Carleton University | Huang M.,Carleton University | Li Z.,Carleton University
IET Communications | Year: 2012

Cognitive radios (CRs), which are capable of sensing its surrounding environment and adapting its internal parameters, have been considered in mobile ad hoc networks (MANETs). The area of security in CR-MANETs has received far less attention than other areas. However, some distinct characteristics of CRs introduce new non-trivial security risks to CR-MANETs. In this article, the authors study spectrum sensing data falsification (SSDF) attacks to CR-MANETs, in which intruders send false local spectrum sensing results in cooperative spectrum sensing, and it will result in wrong spectrum sensing decisions by CRs. The authors present a novel bio-inspired consensus-based cooperative spectrum sensing scheme to counter SSDF attacks in CR-MANETs. Their scheme is based on recent advances in consensus algorithms that have taken inspiration from self-organising behaviour of animal groups such as birds, fish, ants, honeybees and others. Unlike the existing schemes, there is no need for a common receiver to do the data fusion for reaching the final decision to counter SSDF attacks. The scheme has self-configuration and self-maintenance capabilities. Moreover, in order to further improve the security of CR-MANETs, the authors present an authentication scheme using identity (ID)-based cryptography with threshold secret sharing. Simulation results are presented to show the effectiveness of the proposed schemes. © 2012 The Institution of Engineering and Technology.


Halabian H.,Carleton University | Changiz R.,Carleton University | Yu F.R.,Carleton University | Lambadaris I.,Carleton University | Tang H.,Defense R and D Canada
Wireless Networks | Year: 2012

In this paper, we investigate the problem of optimal reliable relay selection in multiuser cooperative wireless networks in the presence of malicious relay nodes. A general discrete time queueing model for such networks is introduced which takes into account the dynamic variations of the channel state, the dynamic malicious behaviour of relay nodes as well as stochastic arrival of data packets into the system. The model consists of a set of mobile users, one destination node and a set of relay nodes which may be either mobile or fixed. The system uses the benefit of cooperative diversity by relaying in the decode and forward mode. We assume that each user either transmits its packets directly to the destination (direct mode) or transmits them with the cooperation of a selected relay node (cooperative mode). It is assumed that a centralized network controller manages the relay selection process in the system. At each time slot, a malicious relay node in the system may behave spitefully and refuse to cooperate with a user deliberately when it is selected to cooperate with that user. A malicious relay node usually acts stochastically to hide its malicious behaviour for longer time. In such a system, at each time slot the network controller should decide whether a user has to cooperate with any relay node or not and if so, which relay node must be selected for cooperation. First, we show that the malicious behaviour of relay nodes makes the stable throughput region shrink. Then, we propose a throughput optimal secure relay selection policy that can stabilize the system for all the arrival rate vectors strictly inside the network stability region. We show that the optimal policy is equivalent to finding the maximum weighted matching in a weighted bipartite graph at each time slot. Finally, we use simulations to compare the performance of the proposed policy with that of four other sub-optimal policies in terms of average queue occupancy (or queueing delay). © Springer Science+Business Media, LLC 2012.


Wang Y.,Carleton University | Yu F.R.,Carleton University | Tang H.,Defense R and D Canada | Huang M.,Carleton University
IEEE Transactions on Wireless Communications | Year: 2014

Game theory can provide a useful tool to study the security problem in mobile ad hoc networks (MANETs). Most of existing works on applying game theories to security only consider two players in the security game model: an attacker and a defender. While this assumption may be valid for a network with centralized administration, it is not realistic in MANETs, where centralized administration is not available. In this paper, using recent advances in mean field game theory, we propose a novel game theoretic approach with multiple players for security in MANETs. The mean field game theory provides a powerful mathematical tool for problems with a large number of players. The proposed scheme can enable an individual node in MANETs to make strategic security defence decisions without centralized administration. In addition, since security defence mechanisms consume precious system resources (e.g., energy), the proposed scheme considers not only the security requirement of MANETs but also the system resources. Moreover, each node in the proposed scheme only needs to know its own state information and the aggregate effect of the other nodes in the MANET. Therefore, the proposed scheme is a fully distributed scheme. Simulation results are presented to illustrate the effectiveness of the proposed scheme. © 2014 IEEE.


Bu S.,Carleton University | Yu F.R.,Carleton University | Liu X.P.,Carleton University | Tang H.,Defense R and D Canada
IEEE Transactions on Wireless Communications | Year: 2011

Continuous user authentication is an important prevention-based approach to protect high security mobile ad-hoc networks (MANETs). On the other hand, intrusion detection systems (IDSs) are also important in MANETs to effectively identify malicious activities. Considering these two approaches jointly is effective in optimal security design taking into account system security requirements and resource constraints in MANETs. To obtain the optimal scheme of combining continuous user authentication and IDSs in a distributed manner, we formulate the problem as a partially observable Markov decision process (POMDP) multi-armed bandit problem. We present a structural results method to solve the problem for a large network with a variety of nodes. The policies derived from structural results are easy to implement in practical MANETs. Simulation results are presented to show the effectiveness and the performance of the proposed scheme. © 2006 IEEE.


Yu F.,Carleton University | Huang M.,Carleton University | Tang H.,Defense R and D Canada
IEEE Network | Year: 2010

Cognitive radios, which are capable of sensing their surrounding environment and adapting their internal parameters, have been considered in mobile ad hoc networks. Secondary users can cooperatively sense the spectrum to detect the presence of primary users. In this article we present a novel biologically inspired consensus-based cooperative spectrum sensing scheme in CR-MANETs. Our scheme is based on recent advances in consensus algorithms that have taken inspiration from self-organizing behavior of animal groups such as birds, fish, ants, honeybees, and others. Unlike the existing cooperative spectrum sensing schemes, such as the OR-rule or the 1-out-of-N rule, there is no need for a common receiver to do the data fusion for reaching the final decision. A secondary user needs only to set up local interactions without a centralized node in CR-MANETs. Simulation results are presented to show the effectiveness of the proposed scheme. © 2006 IEEE.


Li C.,Radiation Protection Bureau | Sadi B.,Radiation Protection Bureau | Wyatt H.,Chalk River Laboratories | Bugden M.,Chalk River Laboratories | And 3 more authors.
Radiation Protection Dosimetry | Year: 2010

Polonium-210 (210Po) is one of the most toxic radionuclides and was used as a poison in the Alexander Litvinenko case. In this study of the metabolism of 210Po in rats, volatile 210Po in excreta was measured, filling a knowledge gap of the previous studies. Five rats were intravenously administrated with 2 kBq and another five with 10 kBq of 210Po (citrate form). They were housed in a glass Metabowlw system for 4 d following the administration. Volatile 210Po from the excreta was collected in a trapping system filled with liquid scintillation cocktail and was measured by liquid scintillation counting. Results showed that the daily excretion of volatile 210Po by the rats is in a very small percentage (0.002-0.009 %) of the administered amounts. However, if the administered amount is large, the excretion of volatile 210Po can be significant. © The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.


Bird J.,Defense R and D Canada | Arden D.,Dale Arden Consulting
IEEE Wireless Communications | Year: 2011

This article describes a method of navigation for an individual based on traditional inertial navigation system (INS) technology, but with very small and self-contained sensor systems. A conventional INS contains quite accurate, but large and heavy, gyroscopes and accelerometers, and converts the sensed rotations and accelerations into position displacements through an algorithm known as a strapdown navigator. They also, almost without exception, use an error compensation scheme such as a Kalman filter to reduce the error growth in the inertially sensed motion through the use of additional position and velocity data from GPS receivers, other velocity sensors (e.g., air, water, and ground speed), and heading aids such as a magnetic compass. This technology has been successfully used for decades, yet the size, weight, and power requirements of sufficiently accurate inertial systems and velocity sensors have prevented their adoption for personal navigation systems. Now, however, as described in this article, miniature inertial measurement units (IMUs) as light as a few grams are available. When placed on the foot to exploit the brief periods of zero velocity when the foot strikes the ground (obviating the need for additional velocity measurement sensors), these IMUs allow the realization of a conventional Kalman-filter-based aided strapdown inertial navigation system in a device no larger or heavier than a box of matches. A particular advantage of this approach is that no stride modeling is involved with its inherent reliance on the estimation of a forward distance traveled on every step' the technique works equally well for any foot motion, something especially critical for soldiers and first responders. Also described is a technique to exploit magnetic sensor orientation data even in indoor environments where local disturbances in the Earth's magnetic field are significant. By carefully comparing INSderived and magnetically derived heading and orientation, a system can automatically determine when sensed magnetic heading is accurate enough to be useful for additional error compensation. © 2011 IEEE.


Sadi B.B.,Radiation Protection Bureau | Li C.,Radiation Protection Bureau | Wyatt H.,Chalk River Laboratories | Bugden M.,Chalk River Laboratories | And 2 more authors.
Radiation Protection Dosimetry | Year: 2011

The metabolic formation of volatile 210Po species in a rat that was intravenously administered with 210Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210Po species. The amount of 210Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210Po species in the faeces. The presence of volatile 210Po in the faeces indicates that the metabolic formation of volatile 210Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210Po species was compared with the daily faecal excretion of 210Po. After 2 h of bubbling, the volatile 210Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210Po-citrate administration. © The Author 2010. Published by Oxford University Press. All rights reserved.

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