A secure peer-to-peer backup system

A peer-to-peer (P2P) backup system enables users to save a copy of their data in the free disk space of other peers in order to restore them later in case of hard disk crash, or handling errors... In this paper, we present a new peer-to-peer backup system implemented in the « DisPairSe » project and we concentrate on the security of such a system. Indeed, we provide mechanisms to ensure the integrity and confidentiality of data stored in the P2P network while respecting the anonymity of users. We also propose a solution to encourage peers to contribute to the backup system, to banish the selfish behaviour of a few peers and to give access to authorized nodes only. These solutions are based on the definition of a third trust party in charge of controlling the rights and the behaviour of peers.