Hackathons: Why Co-Location?

This research was supported by the Arts and Humanities Research Council [grant Number AH/J005142/1].This research was supported by the Arts and Humanities Research Council [grant Number AH/J005142/1].This research was supported by the Arts and Humanities Research Council [grant Number AH/J005142/1].This research was supported by the Arts and Humanities Research Council [grant Number AH/J005142/1].In this position paper we outline and discuss co-location as a significant catalyst to knowledge exchange between participants for innovation at hackathon events. We draw on surveys and empirical evidence from participation in such events to conclude that the main incentives for participants are peer-to-peer learning and meaningful networking. We then consider why co-location provides an appropriate framework for these processes to occur, and emphasize the needs for future research in this area

Preserving Co-Location Privacy in Geo-Social Networks

The number of people on social networks has grown exponentially. Users share very large volumes of personal informations and content every days. This content could be tagged with geo-spatial and temporal coordinates that may be considered sensitive for some users. While there is clearly a demand for users to share this information with each other, there is also substantial demand for greater control over the conditions under which their information is shared. Content published in a geo-aware social networks (GeoSN) often involves multiple users and it is often accessible to multiple users, without the publisher being aware of the privacy preferences of those users. This makes difficult for GeoSN users to control which information about them is available and to whom it is available. Thus, the lack of means to protect users privacy scares people bothered about privacy issues. This paper addresses a particular privacy threats that occur in GeoSNs: the Co-location privacy threat. It concerns the availability of information about the presence of multiple users in a same locations at given times, against their will. The challenge addressed is that of supporting privacy while still enabling useful services.Comment: 10 pages, 5 figure

Emerging patterns of leadership: co-location, continuity and community

"Local leaders have taken hold of the opportunity created by co-location not just to deal with an immediate problem, but also to transcend that with an even better offer to children and their families." - Page 1

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