A lightweight privacy preserving SMS-based recommendation system for mobile users

In this paper we propose a fully decentralized approach for recommending new contacts in the social network of mo- bile phone users. With respect to existing solutions, our approach is characterized by some distinguishing features. In particular, the application we propose does not assume any centralized coordination: it transparently collects and processes user information that is accessible in any mobile phone, such as the log of calls, the list of contacts or the inbox/outbox of short messages and exchanges it with other users. This information is used to recommend new friend-ships to other users. Furthermore, the information needed to perform recommendation is collected and exchanged be- tween users in a privacy preserving way. Finally, information necessary to implement the application is exchanged trans-parently and opportunistically, by using the residual space in standard short messages occasionally exchanged between users. As a consequence, we do not ask users to change their habits in using SMS. Copyright 2010 ACM.