vfcBOX: multi-user consistent file sharing.

The emerging of cloud file sharing systems has been motivated by real user needs for data sharing. There are many solutions providing such sharing support all having the common goal of being widely scalable while providing users with consistent shared data. However, offering consistent data is at odds with scalability as it requires many messages and available network bandwith for file transfer. Network bandwidth can be minimized using several techniques such as compression, deduplication[10], delta encoding[9], etc. However, these approaches do not take into account that not all files must be fully consistent at all times for all users. In this paper we further increase the scalability of a cloud file sharing system, called vfcBOX, by taking into account the notion of users interest. This means that vfcBOX considers users' consistency needs regarding shared files, to avoid sending useless (or unnecessary) data through the network. As a matter of fact, some files do not need to be constantly propagated to all users, because some of them do not require such immediacy given the particular semantics of the shared data. vfcBOX uses not only deduplication techniques to minimize network usage but also a consistency model that takes into account the users' interests. The result is a scalable and efficient cloud file sharing system that fulfills users needs regarding data sharing.