Angela Dalton

SmokeScreen: flexible privacy controls for presence-sharing

Presence-sharing is an emerging platform for mobile applications, but presence-privacy remains a challenge. Privacy controls must be flexible enough to allow sharing between both trusted social relations and untrusted strangers. In this paper, we present a system called SmokeScreen that provides flexible and power-efficient mechanisms for privacy management. Broadcasting clique signals, which can only be interpreted by other trusted users, enables sharing between social relations; broadcasting opaque identifiers (OIDs), which can only be resolved to an identity by a trusted broker, enables sharing between strangers. Computing these messages is power-efficient since they can be pre-computed with acceptable storage costs. In evaluating these mechanisms we first analyzed traces from an actual presence-sharing application. Four months of traces provide evidence of anonymous snooping, even among trusted users. We have also implemented our mechanisms on two devices and found the power demands of clique signals and OIDs to be reasonable. A mobile phone running our software can operate for several days on a single charge.

Presence-Exchanges: Toward Sustainable Presence-Sharing

Presence-sharing is a promising platform for cooperative location-aware applications, but applications must provide direct benefit to users for their presence information. If not, these services give users strong incentives to free-load to avoid privacy risks and administrative burden. Modeling presence-sharing as an iterated prisoners dilemma shows that it is not sustainable under these conditions. Thus, to create sustainable presence-sharing, we propose introducing a trusted broker to transform the game from a prisoners dilemma to a transactional exchange

Expressive Analytical Model for Routing Protocols in Mobile Ad Hoc Networks

Many routing protocols exist for mobile ad hoc networks. To select the most appropriate protocol, evaluation of candidate protocols must be performed with respect to a specific operating environment, which is not an easy task. However, selecting the best protocol can be a key factor in system behavior, determining whether the system successfully satisfies application requirements. Most of the relevant research in this area relies on simulation studies or empirical analysis to select a routing protocol, requiring an infeasible amount of time and resources for the approaches to be used in real-time decision making. In this paper we describe work toward analytically expressing protocol performance metrics in terms of environment-, protocol- , and application-dependent parameters. This work provides a foundation for adaptive protocol suites that will eventually enable an integrated context-aware communication paradigm.

Countering Intelligent Jamming with Full Protocol Stack Agility

Intelligent jamming (IJ) attacks go beyond applying brute-force power at the physical link, exploiting vulnerabilities specific to protocols or configurations. IJ attackers who can gain a foothold into a network by understanding and exploiting vulnerabilities can operate with a much lower chance of detection and a greater impact on the network. For example, one IJ technique exploits media access control (MAC) layer packet structure to selectively jam packets originating from or destined to a specific user. This project aims to create a moving target in the network protocol stack to mitigate IJ attacks. It introduces protocol agility at all layers of the stack to make such protocol-driven attacks infeasible.

So many sensors, so little data

Future networks are ones in which mobile users are immersed in sensor networks. Application domains such as smart homes, intelligent construction sites, and social networking require users moving through an environment to collect and process data available in that environment. However, even as sensors become increasingly prevalent in our environments, only a handful of applications are available to interact with and process the available sensor data. Poor usability accounts for a good portion of this disparity. In this paper we discuss our directions in creating an architecture for making such sensor data usable by application developers. This has the potential to widen the accessibility of developing mobile applications on embedded sensor networks beyond the niche markets it now enjoys.

Towards adaptive resource-driven routing

In pervasive computing environments, applications find themselves in constantly changing operating conditions. Such applications often need to discover locally available resources on-demand. Communication protocols have been developed that base discovery not on the unique address of the destination but on application-level characteristics of the destination host. Previous work has focused almost exclusively on purely on-demand protocols to achieve these resource connections. However, because the types of resources desired may be common across applications, the discovery and routing tasks can benefit from some degree of proactivity. In this paper, we describe our adaptive approach to incorporating resource advertisement in an application-driven routing protocol. We describe the adaptation mechanism in our protocol that allows the proactive component to dynamically tune its behavior to operating conditions.

Enabling Deliberate Design for Energy Management in Pervasive Systems

This paper argues for explicit consideration of data fidelity during development of context-aware systems. Increasing the amount of data captured, stored, and distributed does not always translate into into increased fidelity, and we can leverage this to avoid unnecessary energy overhead and increase device battery life. We introduce Context-Awareness Fidelity Expression (CAFE) as a framework for deliberately specifying application data fidelity adaptation with the aim of using context-awareness to reduce energy consumption.

SASSI: the sliverware architecture for sensor system integration

Recently, embedded sensor usage has increased thanks to the proliferation of hardware and software addressing resource constraints. While the increased usage is a good start, it is important to adopt good software engineering principles early for many reasons: simplified programming and deployment, improved reuse, and added efficiency. This poster presents SASSI, the Sliverware Architecture for Sensor System Integration, which provides a unique embedded sensor application architecture.