Secure P2P backup system

Abstract

Peer-to-peer (P2P) networking is gaining ground as one of the most popular networking paradigms over the past few years. This increase in popularity is mostly due to the number of applications running on top of such networks enabling nodes (called peers) to collaborate between each other to perform specific tasks. Perhaps the most popular of them are file sharing applications like Napster and Kazaa. However, motivated by the potential large amount of unused disk space on peers in a P2P network, a new set of P2P applications have emerged lately. These are distributed storage (or backup) applications. This dissertation describes the implementation of a secure P2P backup system using the Microsoft .NET Framework. This system essentially enables peers connected to a P2P network to exploit their unused disk space in order to securely backup their files on each others' disks. Each peer shares an amount of unused disk space to be used by other peers on the network. A version control mechanism allows the system to keep track of different file versions that a peer backups. Moreover, version control enables the system to suppress already backed-up files (or parts of them) from being backed-up again. This, together with file sharing between peers, allows the system to make efficient use of the available bandwidth. The system makes use of a job scheduler in order to execute pre-defined automated backup jobs periodically. Finally, the system also allows peers to restore previously backed-up files from the P2P network. The information maintained by the version control module enables the system to reconstruct and validate the restored files.