The security issue regarding to worm propagation that exploits geographic proximity of wireless enabled devices has raised attentions in recent years. Early work has modeled worm propagation through directly infecting neighboring nodes, e.g., wireless routers and Bluetooth networks. However, there remains new potential wireless connection topology that can assist the spread of worm in a covert way and threat the cyberspace. In this paper, we study a potential worm epidemic pathway that lies in the densely overlapped wireless metropolitan networks and covers large geographic areas. Specifically, the overlapped footprints of neighboring access points can create hidden connections for worms to propagate across the entire wireless network. We present a novel analytical model to analyze the spread speed of this type of worm. The constraints of the nodes within the overlapped footprints, the boundaries set aside by the access point associations, network topology, and density of both access points and users are considered in the model. We also present methods to obtain estimations about propagation delays in an access point coverage and to generate numerical results based on the model. In evaluation, real maps of access points are used to simulate worm propagation and validate the model. The results call for research on detection and defense solutions against worm propagation in wireless networks.
Mobile ad hoc networks require anonymous communications in order to thwart new wireless passive attacks; and to protect new assets of information such as nodes' locations, motion patterns, network topology and traffic patterns in addition to conventional identity and message privacy. In particular, in wireless ad hoc networks mobile nodes must rely on ad hoc routing to keep network functional for communication. The transmitted routing messages and cached active routing entries leave plenty of opportunities for eavesdroppers. To address the new challenges, several anonymous routing schemes have been proposed recently. However, in various network scenarios, how the different cryptographic operations impact the routing performance remains unclear. In this paper we investigate the impact from cryptographic operations needed for the anonymous features. The overhead considered includes both increased control packet size and prolonged processing delay. The protocols taken into account include ANODR, AnonDSR, ASR, MASK, and SDAR. We present results based on extensive simulation study. We use the standard/unprotected on-demand scheme AODV in the comparison to show how much cost is paid by each anonymous on-demand scheme. Our simulation study shows that various design choices in anonymous routing indeed trade performance with anonymity protection. We conclude that extensive performance study is needed to evaluate the practicality of any enhancement of these proposed schemes and any new anonymous routing schemes
We have observed the laser-assisted dynamic interference in the electron spectra triggered by attosecond pulse trains. The fingerprints of finer interference fringes, much smaller than the laser photon energy, have been clearly identified experimentally. Our measurements are successfully reproduced by theoretical simulations utilizing the numerical solution to the time-dependent Schr\"odinger equation and the strong-field approximation. Further explorations based on the saddle point analysis and a simple quantum model strengthen our finding and reveal the importance of the phase variations of the electron wave packets, which are modulated by the vector potential across the envelope of the strong laser pulse. Our studies show that the dynamic interference can be captured and the electron in the continuum can be effectively manipulated by the current attosecond-controlled multicolor laser approach.
Mobility modelling is an essential component of wireless and mobile networking research. Our proposed Agenda Driven Mobility Model takes into consideration a person's social activities in the form of agenda (when, where and what) for motion generation. The model provides a framework for translating social agendas into a mobile world. Using the data from National Household Travel Survey (NHTS) of the US Department of Transportation, our simulation results suggest that social roles and agenda activities tend to cause geographic concentrations and significantly impact network performance. The model is in a position of better reflecting real world scenarios.
We present a new trust architecture-Situation-Aware Trust-to address several important trust issues in vehicular networks. SAT includes three main components: an attribute-based policy control model for highly dynamic communication environments, a proactive trust model to build trust among vehicles, and prevent the breakage of existing trust, and an email-based social network trust system to enhance trust and to allow the set up of a decentralized trust framework. To deploy SAT, we utilize identity-based cryptography to integrate entity trust, data trust, security policy enforcement, and social network trust, allocating a unique identity, and a set of attributes for each entity. We conclude by presenting research challenges and potential research directions that extend this work.
Location information of users can now be collected from most wireless communication using advanced wireless location tracking techniques. Providing location information can be advantageous in some situations. However, there are instances, where it may be critical to protect the location of the individual. Several protection strategies, such as periodically updating interface identifiers, have been proposed so that an adversary cannot track mobiles in long-term movements. In this paper, we introduce a new strategy, DMAS (Dynamical Mac Assignment with Shuffle), in which the mobile client dynamically exchanges its assigned Mac addresses with others.We present a security analysis to show this scheme can greatly secure a client's location privacy.
As datacenter networks become increasingly programmable with proliferating network functions, network programming languages have emerged to simplify the program development of the network functions. While network functions exhibit high level abstraction over operations on the traffic flow and the interconnections among the operations, the existing languages usually require programming with detailed knowledge about the packet processing patterns at the switches. Such a mismatch between the program abstraction and development details makes developing network functions a nontrivial task. To solve the problem, this paper introduces the easy path programming (EP2) framework. EP2 offers a high-level abstraction to simplify the program design process of the network functions. EP2 also provides a language that captures the common properties of network functions and uses predicates and primitives as basic language components. Specifically, predicates describe when to handle a flow with a global view of the flow dynamics; and primitives describe how to choose a path for a specific flow. Furthermore, EP2 has its own runtime system to support the language and the abstraction model, especially to hide the low level packet-processing behavior at the data plane from the programmers. Throughout this paper, cases are given to illustrate the EP2 abstraction model, language details and benefits. The expressiveness of EP2, the potential overhead of the runtime system and the efficiency of the network functions generated by EP2 are evaluated. The results show that EP2 can achieve comparable performance while reducing programming efforts.
Techniques derived from biological systems explore a new dimension of research in Cognitive Radio Networks (CRNs). In this paper, we address the stability issue of CRN routing, being motivated by the adaptive `Attractor-Selector' model. Our work includes designing a routing protocolnamed Bio-inspired Stable Routing (BioStaR) that increases route stability by maximizing the Spectrum Opportunity (SOP)and also minimizes the channel switching delay and signaling overhead. To the best of our knowledge, this is by far the first bio-inspired CRN routing that takes into account the above mentioned factors. Our simulation results show that this protocol accounts for both higher stability of route and less signaling overhead in spectrum-agile CRN environments.
In this paper, we present a novel routing protocol for wireless ad hoc networks-landmark ad hoc routing (LANMAR). LANMAR combines the features of fisheye state routing (FSR) and landmark routing. The key novelty is the use of landmarks for each set of nodes which move as a group (e.g., a team of co-workers at a convention or a tank battalion in the battlefield) in order to reduce routing update overhead. Like in FSR, nodes exchange link state only with their neighbors. Routes within the fisheye scope are accurate, while routes to remote groups of nodes are "summarized" by the corresponding landmarks. A packet directed to a remote destination initially aims at the landmark; as a gets closer to the destination it eventually switches to the accurate route provided by fisheye. Simulation experiments show that LANMAR provides efficient and scalable routing in large, mobile, ad hoc environments in which group mobility applies.
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