Selfish neighbor selection in peer-to-peer backup and storage applications

In this work we tackle the problem of on-line backup with a peer-to-peer approach. In contrast to current peer-to-peer architectures that build upon distributed hash-tables, we investigate whether an un-coordinated approach to data placement would prove effective in providing embedded incentives for users to offer local resources to the system. By modeling peers as sel sh entities striving for minimizing their cost in participating to the system, we analyze equilibrium topologies that materialize from the process of peer selection, whereby peers establish bi-lateral links that involve storing data in a symmetric way. System stratication, that is the emergence of clusters gathering peers with similar contribution efforts, is an essential outcome of the peer selection process: peers are lured to improve the \quality" of local resources they provide to access clusters with lower operational costs. Our results are corroborated by a numerical evaluation of the system that builds upon a polynomial-time best-response algorithm to the sel sh neighbor selection game.