A Two-Stage PBFT Architecture With Trust and Reward Incentive Mechanism

Abstract

Consensus algorithm is an essential ingredient of any blockchain system. Many different consensus mechanisms such as Practical Byzantine Fault Tolerance (PBFT), Proof-of-Work (PoW), Proof-of-Stake (PoS), and their many derivatives have been proposed over the years, but the complementary problems of performance and resilience to malicious behavior of the nodes have yet to be resolved in a satisfactory manner. In this work, we propose a consensus mechanism that integrates PoS with PBFT, which can effectively deal with dishonest nodes, both individual validators and leaders, whilst maintaining high performance. Our model incentivized truthful behavior by using trust score and reward mechanisms as crucial components of the block validation and ordering processes. The performance of the proposed scheme is evaluated using an analytical model that employs a semi-Markov process, defined by an ergodic multidimensional Markov chain with a finite number of states. The results show the efficiency of the proposed model in consensus-based decision making, even under a high likelihood of dishonest node behavior.