Always be Two Steps Ahead of Your Enemy [article]

Thorsten Götte, Vipin Ravindran Vijayalakshmi, Christian Scheideler
2021 arXiv   pre-print
We investigate the maintenance of overlay networks under massive churn, i.e. nodes joining and leaving the network. We assume an adversary that may churn a constant fraction α n of nodes over the course of 𝒪(log n) rounds. In particular, the adversary has an almost up-to-date information of the network topology as it can observe an only slightly outdated topology that is at least 2 rounds old. Other than that, we only have the provably minimal restriction that new nodes can only join the
more » ... via nodes that have taken part in the network for at least one round. Our contributions are as follows: First, we show that it is impossible to maintain a connected topology if adversary has up-to-date information about the nodes' connections. Further, we show that our restriction concerning the join is also necessary. As our main result present an algorithm that constructs a new overlay – completely independent of all previous overlays – every 2 rounds. Furthermore, each node sends and receives only 𝒪(log^3 n) messages each round. As part of our solution we propose the Linearized DeBruijn Swarm (LDS), a highly churn resistant overlay, which will be maintained by the algorithm. However, our approaches can be transferred to a variety of classical P2P Topologies where nodes are mapped into the [0,1)-interval.
arXiv:1810.07077v2 fatcat:bjepdfhbwfhufn3bgi3kud667e