Privacy-Preserving Interest Matching for Mobile Social Networking

[摘要] The success of online social networking has resulted in increased attention to mobile socialnetworking research and applications. In mobile social networking, instead of looking for friendsover the Internet, people look for friends who are physically located close and also based on otherself-defined criteria. For example, a person could find other people who are nearby and whoalso share the same interests with her by using mobile social networking. As a result, they havecommon topics to talk about and may eventually become friends. There are two main approachesin the existing works. One approach focuses on efficiently establishing friendship and ignoresthe protection of private information of the participants. For example, some applications simplybroadcast users’ personal information to everybody and rely on the other users to report thematches. From a privacy point of view, this approach is bad, since it makes the users vulnerableto context-aware attacks. The other approach requires a central server to participate in eachmatchmaking process. For example, an application deploys a central server, which stores theprofile information of all users. When two nearby client devices query the central server at thesame time, the central server fetches the profile information of both devices from the server’sdatabase, performs matching based on the information, and reports the result back to the clients.However, a central server is not always available, so this approach does not scale. In addition, thecentral server not only learns all users’ personal information, it also learns which users becomefriends.This thesis proposes a privacy-preserving architecture for users to find potential friends withthe same interests. The architecture has two matchmaking protocols to prevent privacy leaks.Our protocols let a user learn only the interests she has in common with the other party. Oneprotocol is simpler, but works only if some assumptions hold. The other protocol is more secure,but requires longer execution time. Our architecture does not require any central server that isinvolved in the matchmaking process. We describe how the protocols work, analyze how securethe protocols are under different assumptions, and implement the protocols in a BlackBerryapplication. We test the efficiency of the protocols by conducting a number of experiments.We also consider the cheating-detection and friend-recognition problems.

[发布机构] University of Waterloo

[关键词] Computer Science