Preserving smartphone users' anonymity in Cloudy Days

The mobile cloud computing paradigm involves communications between smartphones and their virtual (software) clones in the cloud. It offers both backup/recovery solutions as well as offload of mobile computations, increasing the communication and computation capabilities of smartphones and making their limited batteries last longer. Unfortunately, in this scenario, the privacy of the users is at stake. The cellular network operator knows how often users contact the cloud, and the cloud provider knows how often users' clones contact each other. We address this privacy problem by providing an anonymous communication protocol, leveraging properties of social networks and ad-hoc wireless networks. Our solution provides anonymous end-to-end communication between two users in the network, and in turn between a user and her clone in the cloud. The proposal copes with an adversary model, where each party observing a portion of the communication (including the cloud provider and the cellular network operator) possibly colludes with others to uncover the identity of communicating users.