Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 24 of 24

Full-Text Articles in Physical Sciences and Mathematics

Spice: Secure Proximity-Based Infrastructure For Close Encounters, Aarathi Prasad, Xiaohui Liang, David Kotz Nov 2017

Spice: Secure Proximity-Based Infrastructure For Close Encounters, Aarathi Prasad, Xiaohui Liang, David Kotz

Dartmouth Scholarship

We present a crowdsourcing system that extends the capabilities of location-based applications and allows users to connect and exchange information with users in spatial and temporal proximity. We define this incident of spatio-temporal proximity as a \em close encounter. Typically, location-based application users store their information on a server, and trust the server to provide access only to authorized users, not misuse the data or disclose their location history. Our system, called SPICE, addresses these privacy issues by leveraging Wi-Fi access points to connect users and encrypt their information before it is exchanged, so only users in close encounters have …


Demo: Wanda, Securely Introducing Mobile Devices, Timothy J. Pierson, Xiaohui Liang, Ronald Peterson, David Kotz Jun 2016

Demo: Wanda, Securely Introducing Mobile Devices, Timothy J. Pierson, Xiaohui Liang, Ronald Peterson, David Kotz

Dartmouth Scholarship

Nearly every setting is increasingly populated with wireless and mobile devices – whether appliances in a home, medical devices in a health clinic, sensors in an industrial setting, or devices in an office or school. There are three fundamental operations when bringing a new device into any of these settings: (1) to configure the device to join the wireless local-area network, (2) to partner the device with other nearby devices so they can work together, and (3) to configure the device so it connects to the relevant individual or organizational account in the cloud. The challenge is to accomplish all …


Location Privacy For Mobile Crowd Sensing Through Population Mapping, Minho Shin, Cory Cornelius, Apu Kapadia, Nikos Triandopoulos, David Kotz Jun 2015

Location Privacy For Mobile Crowd Sensing Through Population Mapping, Minho Shin, Cory Cornelius, Apu Kapadia, Nikos Triandopoulos, David Kotz

Dartmouth Scholarship

Opportunistic sensing allows applications to “task” mobile devices to measure context in a target region. For example, one could leverage sensor-equipped vehicles to measure traffic or pollution levels on a particular street or users' mobile phones to locate (Bluetooth-enabled) objects in their vicinity. In most proposed applications, context reports include the time and location of the event, putting the privacy of users at increased risk: even if identifying information has been removed from a report, the accompanying time and location can reveal sufficient information to de-anonymize the user whose device sent the report. We propose and evaluate a novel spatiotemporal …


Privacy In Mobile Technology For Personal Healthcare, Sasikanth Avancha, Amit Baxi, David Kotz Nov 2012

Privacy In Mobile Technology For Personal Healthcare, Sasikanth Avancha, Amit Baxi, David Kotz

Dartmouth Scholarship

Information technology can improve the quality, efficiency, and cost of healthcare. In this survey, we examine the privacy requirements of \emphmobile\/ computing technologies that have the potential to transform healthcare. Such \emphmHealth\/ technology enables physicians to remotely monitor patients' health, and enables individuals to manage their own health more easily. Despite these advantages, privacy is essential for any personal monitoring technology. Through an extensive survey of the literature, we develop a conceptual privacy framework for mHealth, itemize the privacy properties needed in mHealth systems, and discuss the technologies that could support privacy-sensitive mHealth systems. We end with a list of …


Recognizing Whether Sensors Are On The Same Body, Cory Cornelius, David Kotz Jun 2011

Recognizing Whether Sensors Are On The Same Body, Cory Cornelius, David Kotz

Dartmouth Scholarship

As personal health sensors become ubiquitous, we also expect them to become interoperable. That is, instead of closed, end-to-end personal health sensing systems, we envision standardized sensors wirelessly communicating their data to a device many people already carry today, the cellphone. In an open personal health sensing system, users will be able to seamlessly pair off-the-shelf sensors with their cellphone and expect the system to ıt just work. However, this ubiquity of sensors creates the potential for users to accidentally wear sensors that are not necessarily paired with their own cellphone. A husband, for example, might mistakenly wear a heart-rate …


Anonysense: A System For Anonymous Opportunistic Sensing, Minho Shin, Cory Cornelius, Dan Peebles, Apu Kapadia, David Kotz, Nikos Triandopoulos Feb 2011

Anonysense: A System For Anonymous Opportunistic Sensing, Minho Shin, Cory Cornelius, Dan Peebles, Apu Kapadia, David Kotz, Nikos Triandopoulos

Dartmouth Scholarship

We describe AnonySense, a privacy-aware system for realizing pervasive applications based on collaborative, opportunistic sensing by personal mobile devices. AnonySense allows applications to submit sensing \emphtasks\/ to be distributed across participating mobile devices, later receiving verified, yet anonymized, sensor data \emphreports\/ back from the field, thus providing the first secure implementation of this participatory sensing model. We describe our security goals, threat model, and the architecture and protocols of AnonySense. We also describe how AnonySense can support extended security features that can be useful for different applications. We evaluate the security and feasibility of AnonySense through security analysis and prototype …


Is Bluetooth The Right Technology For Mhealth?, Shrirang Mare, David Kotz Aug 2010

Is Bluetooth The Right Technology For Mhealth?, Shrirang Mare, David Kotz

Dartmouth Scholarship

Many people believe mobile healthcare (mHealth) would help alleviate the rising cost of healthcare and improve the quality of service. Bluetooth, which is the most popular wireless technology for personal medical devices, is used for most of the mHealth sensing applications. In this paper we raise the question – Is Bluetooth the right technology for mHealth? To instigate the discussion we discuss some shortcomings of Bluetooth and also point out an alternative solution.


On Usable Authentication For Wireless Body Area Networks, Cory Cornelius, David Kotz Aug 2010

On Usable Authentication For Wireless Body Area Networks, Cory Cornelius, David Kotz

Dartmouth Scholarship

We examine a specific security problem in wireless body area networks (WBANs), what we call the ıt one body authentication problem. That is, how can we ensure that the wireless sensors in a WBAN are collecting data about one individual and not several individuals. We explore existing solutions to this problem and provide some analysis why these solutions are inadequate. Finally, we provide some direction towards a promising solution to the problem and how it can be used to create a usably secure WBAN.


A Privacy Framework For Mobile Health And Home-Care Systems, David Kotz, Sasikanth Avancha, Amit Baxi Nov 2009

A Privacy Framework For Mobile Health And Home-Care Systems, David Kotz, Sasikanth Avancha, Amit Baxi

Dartmouth Scholarship

In this paper, we consider the challenge of preserving patient privacy in the context of mobile healthcare and home-care systems, that is, the use of mobile computing and communications technologies in the delivery of healthcare or the provision of at-home medical care and assisted living. This paper makes three primary contributions. First, we compare existing privacy frameworks, identifying key differences and shortcomings. Second, we identify a privacy framework for mobile healthcare and home-care systems. Third, we extract a set of privacy properties intended for use by those who design systems and applications for mobile healthcare and home-care systems, linking them …


Deamon: Energy-Efficient Sensor Monitoring, Minho Shin, Patrick Tsang, David Kotz, Cory Cornelius Jun 2009

Deamon: Energy-Efficient Sensor Monitoring, Minho Shin, Patrick Tsang, David Kotz, Cory Cornelius

Dartmouth Scholarship

In people-centric opportunistic sensing, people offer their mobile nodes (such as smart phones) as platforms for collecting sensor data. A sensing application distributes sensing `tasks,' which specify what sensor data to collect and under what conditions to report the data back to the application. To perform a task, mobile nodes may use on-board sensors, a body-area network of personal sensors, or sensors from neighboring nodes that volunteer to contribute their sensing resources. In all three cases, continuous sensor monitoring can drain a node's battery. \par We propose DEAMON (Distributed Energy-Aware MONitoring), an energy-efficient distributed algorithm for long-term sensor monitoring. Our …


Opportunistic Sensing: Security Challenges For The New Paradigm, Apu Kapadia, David Kotz, Nikos Triandopoulos Jan 2009

Opportunistic Sensing: Security Challenges For The New Paradigm, Apu Kapadia, David Kotz, Nikos Triandopoulos

Dartmouth Scholarship

We study the security challenges that arise in Opportunistic people-centric sensing, a new sensing paradigm leveraging humans as part of the sensing infrastructure. Most prior sensor-network research has focused on collecting and processing environmental data using a static topology and an application-aware infrastructure, whereas opportunistic sensing involves collecting, storing, processing and fusing large volumes of data related to everyday human activities. This highly dynamic and mobile setting, where humans are the central focus, presents new challenges for information security, because data originates from sensors carried by people— not tiny sensors thrown in the forest or attached to animals. In this …


Poster Abstract: Reliable People-Centric Sensing With Unreliable Voluntary Carriers, Cory Cornelius, Apu Kapadia, David Kotz, Dan Peebles, Minho Shin, Patrick Tsang Jun 2008

Poster Abstract: Reliable People-Centric Sensing With Unreliable Voluntary Carriers, Cory Cornelius, Apu Kapadia, David Kotz, Dan Peebles, Minho Shin, Patrick Tsang

Dartmouth Scholarship

As sensor technology becomes increasingly easy to integrate into personal devices such as mobile phones, clothing, and athletic equipment, there will be new applications involving opportunistic, people-centric sensing. These applications, which gather information about human activities and personal social context, raise many security and privacy challenges. In particular, data integrity is important for many applications, whether using traffic data for city planning or medical data for diagnosis. Although our AnonySense system (presented at MobiSys) addresses privacy in people-centric sensing, protecting data integrity in people-centric sensing still remains a challenge. Some mechanisms to protect privacy provide anonymity, and thus provide limited …


Anonysense: Opportunistic And Privacy-Preserving Context Collection, Apu Kapadia, Nikos Triandopoulos, Cory Cornelius, Dan Peebles, David Kotz May 2008

Anonysense: Opportunistic And Privacy-Preserving Context Collection, Apu Kapadia, Nikos Triandopoulos, Cory Cornelius, Dan Peebles, David Kotz

Dartmouth Scholarship

Opportunistic sensing allows applications to “task” mobile devices to measure context in a target region. For example, one could leverage sensor-equipped vehicles to measure traffic or pollution levels on a particular street, or users' mobile phones to locate (Bluetooth-enabled) objects in their neighborhood. In most proposed applications, context reports include the time and location of the event, putting the privacy of users at increased risk—even if a report has been anonymized, the accompanying time and location can reveal sufficient information to deanonymize the user whose device sent the report. \par We propose AnonySense, a general-purpose architecture for leveraging users' mobile …


Virtual Walls: Protecting Digital Privacy In Pervasive Environments, Apu Kapadia, Tristan Henderson, Jeffrey Fielding, David Kotz May 2007

Virtual Walls: Protecting Digital Privacy In Pervasive Environments, Apu Kapadia, Tristan Henderson, Jeffrey Fielding, David Kotz

Dartmouth Scholarship

As pervasive environments become more commonplace, the privacy of users is placed at an increased risk. The numerous and diverse sensors in these environments can record contextual information about users, leading to users unwittingly leaving “digital footprints.” Users must therefore be allowed to control how their digital footprints are reported to third parties. While a significant amount of prior work has focused on location privacy, location is only one specific type of footprint, and we expect most users to be incapable of specifying fine-grained policies for a multitude of footprints. In this paper we present a policy language based on …


Risks Of Using Ap Locations Discovered Through War Driving, Minkyong Kim, Jeffrey J. Fielding, David Kotz May 2006

Risks Of Using Ap Locations Discovered Through War Driving, Minkyong Kim, Jeffrey J. Fielding, David Kotz

Dartmouth Scholarship

Many pervasive-computing applications depend on knowledge of user location. Because most current location-sensing techniques work only either indoors or outdoors, researchers have started using 802.11 beacon frames from access points (APs) to provide broader coverage. To use 802.11 beacons, they need to know AP locations. Because the actual locations are often unavailable, they use estimated locations from \em war driving. But these estimated locations may be different from actual locations. In this paper, we analyzed the errors in these estimates and the effect of these errors on other applications that depend on them. We found that the estimated AP locations …


Secure Context-Sensitive Authorization, Kazuhiro Minami, David Kotz Mar 2005

Secure Context-Sensitive Authorization, Kazuhiro Minami, David Kotz

Dartmouth Scholarship

There is a recent trend toward rule-based authorization systems to achieve flexible security policies. Also, new sensing technologies in pervasive computing make it possible to define context-sensitive rules, such as “allow database access only to staff who are currently located in the main office.” However, these rules, or the facts that are needed to verify authority, often involve sensitive context information. This paper presents a secure context-sensitive authorization system that protects confidential information in facts or rules. Furthermore, our system allows multiple hosts in a distributed environment to perform the evaluation of an authorization query in a collaborative way; we …


Policy-Driven Data Dissemination For Context-Aware Applications, Guanling Chen, David Kotz Mar 2005

Policy-Driven Data Dissemination For Context-Aware Applications, Guanling Chen, David Kotz

Dartmouth Scholarship

Context-aware pervasive-computing applications require continuous monitoring of their physical and computational environment to make appropriate adaptation decisions in time. The data streams produced by sensors, however, may overflow the queues on the dissemination path. Traditional flow-control and congestion-control policies either drop data or force the sender to pause. When the data sender is sensing the physical environment, however, a pause is equivalent to dropping data. Instead of arbitrarily dropping data that may contain important events, we present a policy-driven data dissemination service named PACK, based on an overlay-based infrastructure for efficient multicast delivery. PACK enforces application-specified policies that define how …


Design And Implementation Of A Large-Scale Context Fusion Network, Guanling Chen, Ming Li, David Kotz Aug 2004

Design And Implementation Of A Large-Scale Context Fusion Network, Guanling Chen, Ming Li, David Kotz

Dartmouth Scholarship

In this paper we motivate a Context Fusion Network (CFN), an infrastructure model that allows context-aware applications to select distributed data sources and compose them with customized data-fusion operators into a directed acyclic information fusion graph. Such a graph represents how an application computes high-level understandings of its execution context from low-level sensory data. Multiple graphs by different applications inter-connect with each other to form a global graph. A key advantage of a CFN is re-usability, both at code-level and instance-level, facilitated by operator composition. We designed and implemented a distributed CFN system, Solar, which maps the logical operator graph …


A Sensor-Fusion Approach For Meeting Detection, Jue Wang, Guanling Chen, David Kotz Jun 2004

A Sensor-Fusion Approach For Meeting Detection, Jue Wang, Guanling Chen, David Kotz

Dartmouth Scholarship

In this paper we present a context-sensing component that recognizes meetings in a typical office environment. Our prototype detects the meeting start and end by combining outputs from pressure and motion sensors installed on the chairs. We developed a telephone controller application that transfers incoming calls to voice-mail when the user is in a meeting. Our experiments show that it is feasible to detect high-level context changes with “good enough” accuracy, using low-cost, off-the-shelf hardware, and simple algorithms without complex training. We also note the need for better metrics to measure context detection performance, other than just accuracy. We propose …


A Sensor Fusion Approach For Meeting Detection, Jue Wang, Guanling Chen, David Kotz Jun 2004

A Sensor Fusion Approach For Meeting Detection, Jue Wang, Guanling Chen, David Kotz

Dartmouth Scholarship

In this paper we present a context-sensing component that recognizes meetings in a typical office environment. Our prototype detects the meeting start and end by combining outputs from pressure and motion sensors installed on the chairs. We developed a telephone controller application that transfers incoming calls to voice-mail when the user is in a meeting. Our experiments show that it is feasible to detect high-level context changes with ``good enough'' accuracy, using low-cost, off-the-shelf hardware, and simple algorithms without complex training. We also note the need for better metrics to measure context detection performance, other than just accuracy. We propose …


Dependency Management In Distributed Settings (Poster Abstract), Guanling Chen, David Kotz May 2004

Dependency Management In Distributed Settings (Poster Abstract), Guanling Chen, David Kotz

Dartmouth Scholarship

Ubiquitous-computing environments are heterogeneous and volatile in nature. Systems that support ubicomp applications must be self-managed, to reduce human intervention. In this paper, we present a general service that helps distributed software components to manage their dependencies. Our service proactively monitors the liveness of components and recovers them according to supplied policies. Our service also tracks the state of components, on behalf of their dependents, and may automatically select components for the dependent to use based on evaluations of customized functions. We believe that our approach is flexible and abstracts away many of the complexities encountered in ubicomp environments. In …


Context-Sensitive Resource Discovery, Guanling Chen, David Kotz Mar 2003

Context-Sensitive Resource Discovery, Guanling Chen, David Kotz

Dartmouth Scholarship

This paper presents the “Solar” system framework that allows resources to advertise context-sensitive names and for applications to make context-sensitive name queries. The heart of our framework is a small specification language that allows composition of “context-processing operators” to calculate the desired context. Resources use the framework to register and applications use the framework to lookup context-sensitive name descriptions. The back-end system executes these operators and constantly updates the context values, adjusting advertised names and informing applications about changes. We report experimental results from a prototype, using a modified version of the Intentional Naming System (INS) as the core directory …


Solar: An Open Platform For Context-Aware Mobile Applications, Guanling Chen, David Kotz Jun 2002

Solar: An Open Platform For Context-Aware Mobile Applications, Guanling Chen, David Kotz

Dartmouth Scholarship

Emerging pervasive computing technologies transform the way we live and work by embedding computation in our surrounding environment. To avoid increasing complexity, and allow the user to concentrate on her tasks, applications in a pervasive computing environment must automatically adapt to their changing \em context, including the user state and the physical and computational environment in which they run. Solar is a middleware platform to help these “context-aware” applications aggregate desired context from heterogeneous sources and to locate environmental services depending on the current context. By moving most of the context computation into the infrastructure, Solar allows applications to run …


Solar: Towards A Flexible And Scalable Data-Fusion Infrastructure For Ubiquitous Computing, Guanling Chen, David Kotz Oct 2001

Solar: Towards A Flexible And Scalable Data-Fusion Infrastructure For Ubiquitous Computing, Guanling Chen, David Kotz

Dartmouth Scholarship

As we embed more computers into our daily environment, ubiquitous computing promises to make them less noticeable and to avoid information overload. We see, however, few ubiquitous applications that are able to adapt to the dynamics of user, physical, and computational context. The challenge is to allow applications flexible access to these sources, and yet scale to thousands of devices and sensors. In this paper we introduce our proposed infrastructure, Solar. In Solar, information sources produce events. Applications may subscribe to interesting sources directly, or they may instantiate and subscribe to a tree of operators that filter, transform, merge and …