Multi-hop Byzantine Reliable Broadcast Made Practical

Abstract

We revisit Byzantine tolerant reliable broadcast with honest dealer algorithms in multi-hop networks. To tolerate Byzantine faulty nodes arbitrarily spread over the network, previous solutions require a factorial number of messages to be sent over the network if the messages are not authenticated (e.g. digital signatures are not available). We propose modifications that preserve the safety and liveness properties of the original unauthenticated protocols, while highly decreasing their observed message complexity when simulated on several classes of graph topologies, potentially opening to their employment.

Multi-hop Byzantine reliable broadcast with honest dealer made practical

“…The results are presented in Figures 7 and 8 (notice that scale of the graphics in Figure 7 are logarithmic). Starting with the Multi-Random policy, it can be seen in Figures 7 that, while for some graphs the Multi-Random policy acts smoothly, the random regular (confirming the results achieved in our preliminary work [3]) the multipartite wheel graphs and the k-diamond, there exist topologies where the broadcast latency and message complexity may conspicuously increase (k-pasted-tree). It follows that on some kind of graphs the selections of paths that the Multi-Random policy may take are not equivalment with respect the protocol progression and that additional criterion have to be considered in the selection.…”

“…In a preliminary work [3], we focused on random network topologies, we defined two modifications to the state of art protocols, we proposed one preliminary message selection technique, and we carried out a performance analysis in the scenario where all processes are correct. In this work, by extensive simulations for variously shaped networks and considering active Byzantine processes spreading spurious messages over the network, we show that our modifications enable to keep the message complexity close to quadratic (in the size of the network).…”

“…Thus, we consider and evaluate two selection policies: (i) Multi-Random and (ii) Multi-Shortest . The Multi-Random is an extension of the forwarding policy proposed in [3].…”