A game-theory-based scheme to facilitate consensus latency minimization in sharding blockchain

Abstract

Unbalanced consensus latency in reaching a consensus on transactions occurs due to differences in the ability of different committees to process transactions. As the consensus latency accumulates, the transaction throughput of the sharding blockchain significantly decreases. This article proposes a consensus latency minimization scheme to improve the transaction throughput. According to a time-varying directed graph and a non-cooperative game model solved by a distributed algorithm, we show that the generalized Nash equilibrium for all committees are to balance the differences in consensus latency among various committees and to minimize the consensus latency throughout the whole period. The security of the proposed scheme is analyzed by considering the peaceful equilibrium, and the committee actions asymptotically converge to a generalized Nash equilibrium. Through the comparisons with other baseline algorithms via simulation experiments, we demonstrate that our proposed scheme could result in the optimal consensus latency and throughput. Therefore, the proposed consensus latency minimization scheme effectively avoids the existing problem of the transaction throughput in sharding blockchain and provides a viable and security instrument for the sharding blockchain operator to improve the transaction throughput performance throughout the whole period.