1,412 research outputs found
Defending against Sybil Devices in Crowdsourced Mapping Services
Real-time crowdsourced maps such as Waze provide timely updates on traffic,
congestion, accidents and points of interest. In this paper, we demonstrate how
lack of strong location authentication allows creation of software-based {\em
Sybil devices} that expose crowdsourced map systems to a variety of security
and privacy attacks. Our experiments show that a single Sybil device with
limited resources can cause havoc on Waze, reporting false congestion and
accidents and automatically rerouting user traffic. More importantly, we
describe techniques to generate Sybil devices at scale, creating armies of
virtual vehicles capable of remotely tracking precise movements for large user
populations while avoiding detection. We propose a new approach to defend
against Sybil devices based on {\em co-location edges}, authenticated records
that attest to the one-time physical co-location of a pair of devices. Over
time, co-location edges combine to form large {\em proximity graphs} that
attest to physical interactions between devices, allowing scalable detection of
virtual vehicles. We demonstrate the efficacy of this approach using
large-scale simulations, and discuss how they can be used to dramatically
reduce the impact of attacks against crowdsourced mapping services.Comment: Measure and integratio
Mobile Service Clouds: A self-managing infrastructure for autonomic mobile computing services
Abstract. We recently introduced Service Clouds, a distributed infrastructure designed to facilitate rapid prototyping and deployment of autonomic communication services. In this paper, we propose a model that extends Service Clouds to the wireless edge of the Internet. This model, called Mobile Service Clouds, enables dynamic instantiation, composition, configuration, and reconfiguration of services on an overlay network to support mobile computing. We have implemented a prototype of this model and applied it to the problem of dynamically instantiating and migrating proxy services for mobile hosts. We conducted a case study involving data streaming across a combination of PlanetLab nodes, local proxies, and wireless hosts. Results are presented demonstrating the effectiveness of the prototype in establishing new proxies and migrating their functionality in response to node failures.
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂşblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
Efficient Proactive Caching for Supporting Seamless Mobility
We present a distributed proactive caching approach that exploits user
mobility information to decide where to proactively cache data to support
seamless mobility, while efficiently utilizing cache storage using a congestion
pricing scheme. The proposed approach is applicable to the case where objects
have different sizes and to a two-level cache hierarchy, for both of which the
proactive caching problem is hard. Additionally, our modeling framework
considers the case where the delay is independent of the requested data object
size and the case where the delay is a function of the object size. Our
evaluation results show how various system parameters influence the delay gains
of the proposed approach, which achieves robust and good performance relative
to an oracle and an optimal scheme for a flat cache structure.Comment: 10 pages, 9 figure
Seamless Infrastructure independent Multi Homed NEMO Handoff Using Effective and Timely IEEE 802.21 MIH triggers
Handoff performance of NEMO BS protocol with existent improvement proposals
is still not sufficient for real time and QoS-sensitive applications and
further optimizations are needed. When dealing with single homed NEMO, handoff
latency and packet loss become irreducible all optimizations included, so that
it is impossible to meet requirements of the above applications. Then, How to
combine the different Fast handoff approaches remains an open research issue
and needs more investigation. In this paper, we propose a new Infrastructure
independent handoff approach combining multihoming and intelligent
Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3
handoffs are initiated using effective and timely MIH triggers, reducing so the
anticipation time and increasing the probability of prediction. We extend MIH
services to provide tunnel establishment and switching before link break. Thus,
the handoff is performed in background with no latency and no packet loss while
pingpong scenario is almost avoided. In addition, our proposal saves cost and
power consumption by optimizing the time of simultaneous use of multiple
interfaces. We provide also NS2 simulation experiments identifying suitable
parameter values used for estimation and validating the proposed mode
An eco-friendly hybrid urban computing network combining community-based wireless LAN access and wireless sensor networking
Computer-enhanced smart environments, distributed environmental monitoring, wireless communication, energy conservation and sustainable technologies, ubiquitous access to Internet-located data and services, user mobility and innovation as a tool for service differentiation are all significant contemporary research subjects and societal developments. This position paper presents the design of a hybrid municipal network infrastructure that, to a lesser or greater degree, incorporates aspects from each of these topics by integrating a community-based Wi-Fi access network with Wireless Sensor Network (WSN) functionality. The former component provides free wireless Internet connectivity by harvesting the Internet subscriptions of city inhabitants. To minimize session interruptions for mobile clients, this subsystem incorporates technology that achieves (near-)seamless handover between Wi-Fi access points. The WSN component on the other hand renders it feasible to sense physical properties and to realize the Internet of Things (IoT) paradigm. This in turn scaffolds the development of value-added end-user applications that are consumable through the community-powered access network. The WSN subsystem invests substantially in ecological considerations by means of a green distributed reasoning framework and sensor middleware that collaboratively aim to minimize the network's global energy consumption. Via the discussion of two illustrative applications that are currently being developed as part of a concrete smart city deployment, we offer a taste of the myriad of innovative digital services in an extensive spectrum of application domains that is unlocked by the proposed platform
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