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This paper presents Open Data Kit (ODK), an extensible, open-source suite of tools designed to build information services for developing regions. ODK currently provides four tools to this end: Collect, Aggregate, Voice, and Build. Collect is a mobile platform that renders application logic and supports the manipulation of data. Aggregate provides a(More)
Establishing secure links between pairs of directly connected sensor nodes is an important primitive for building secure wireless sensor networks. This paper systematically identifies two important security requirements of pairwise key setup in wireless sensor networks, namely opaqueness and inoculation. Transitory master key schemes, such as the LEAP(More)
Technology offers the potential to objectively monitor people's eating and activity behaviors and encourage healthier lifestyles. BALANCE is a mobile phone-based system for long term wellness management. The BALANCE system automatically detects the user's caloric expenditure via sensor data from a Mobile Sensing Platform unit worn on the hip. Users manually(More)
In this paper we present FireWxNet, a multi-tiered portable wireless system for monitoring weather conditions in rugged wildland fire environments. FireWxNet provides the fire fighting community the ability to safely and easily measure and view fire and weather conditions over a wide range of locations and elevations within forest fires. This previously(More)
While sensor network deployment is becoming more commonplace in environmental, business, and military applications, security of these networks emerges as a critical concern. Without proper security, it is impossible to completely trust the results reported from sensor networks deployed outside of controlled environments. Much of the current research in(More)
The ability to collect data is key to the success of many organizations operating in the developing world. Given the weaknesses of current tools and the surge in mobile phone growth, there's an opportunity for mobile and cloud technologies to enable timely and efficient data collection. This paper discusses Open Data Kit (ODK), a suite of tools that enable(More)
In 2007, approximately 30% of US adults were obese, with related health care costs exceeding 100 billion dollars. Clearly, the obesity epidemic represents a growing societal concern. One challenge in weight control is the difficulty of tracking food calories consumed and calories expended by activity. This paper presents a system for automatic monitoring of(More)
People often misplace objects they care about. We present a system that generates reminders about objects left behind by tagging those objects with passive RFID tags. Readers positioned in the environment frequented by users read tags and broadcast the tags' IDs over a short-range wireless medium. A user's personal server collects the read events in(More)
The irregularities of a low cost wireless communication interface, changing environmental conditions, in-situ deployment and scarce resources make management, monitoring and troubleshooting performance of a sensor network a challenging task. In this paper we present the design of a decentralized fault diagnosis system for a wireless sensor network. Our(More)
We analyze three new consumer electronic gadgets in order to gauge the privacy and security trends in mass-market UbiComp devices. Our study of the Slingbox Pro uncovers a new information leakage vector for encrypted streaming multimedia. By exploiting properties of variable bitrate encoding schemes, we show that a passive adversary can determine with high(More)