Igor Bilogrevic

Learn More
Location-Sharing-Based Services (LSBS) complement LocationBased Services by using locations from a group of users, and not just individuals, to provide some contextualized service based on the locations in the group. However, there are growing concerns about the misuse of location data by third-parties, which fuels the need for more privacy controls in such(More)
Cellular mobile networks are used by more than 4 billion users worldwide. One effective way to meet the increasing demand for data rates is to deploy femtocells, which are lowpower base stations that connect to the mobile operator through the subscriber’s residential Internet access. Yet, security and privacy issues in femtocell-enabled cellular networks,(More)
Personal and contextual information are increasingly shared via mobile social networks. Users' locations, activities and their co-presence can be shared easily with online "friends", as their smartphones already access such information from embedded sensors and storage. Yet, people usually exhibit selective sharing behavior depending on contextual(More)
In this paper, we investigate the feasibility of keystroke inference attacks on handheld numeric touchpads by using smartwatch motion sensors as a side-channel. The proposed attack approach employs supervised learning techniques to accurately map the uniqueness in the captured wrist movements to each individual keystroke. Experimental evaluation shows that(More)
Location check-ins contain both geographical and semantic information about the visited venues, in the form of tags (e.g., “restaurant”). Such data might reveal some personal information about users beyond what they actually want to disclose, hence their privacy is threatened. In this paper, we study users’ motivations behind location check-ins, and we(More)
WiFi base stations are increasingly deployed in both public spaces and private companies, and the increase in their density poses a significant threat to the privacy of connected users. Prior studies have provided evidence that it is possible to infer the social ties of users from their location and co-location traces but they lack one important component:(More)
Abstract Over the past few years, online service providers have started gathering increasing amounts of personal information to build user profiles and monetize them with advertisers and data brokers. Users have little control of what information is processed and are often left with an all-or-nothing decision between receiving free services or refusing to(More)
Mobile devices are increasingly being used to store and manage users’ personal information, as well as to access popular third-party context-based services. Very often, these applications need to determine common availabilities among a set of user schedules, in order to allow colleagues, business partners and people to meet. The privacy of the scheduling(More)
Contextual information about users is increasingly shared on mobile social networks. Examples of such information include users’ locations, events, activities, and the co-presence of others in proximity. When disclosing personal information, users take into account several factors to balance privacy, utility and convenience – they want to share the “right”(More)
Revocation of public-key certificates is an important security primitive. In this paper, we design a fully distributed local certificate revocation scheme for ephemeral networks — a class of extremely volatile wireless networks with short-duration and short-range communications — based on a game-theoretic approach. First, by providing(More)