An adaptive reputation-based byzantine fault tolerance consensus mechanism for node performance evaluation and leader selection in permissioned blockchain system

Permissioned blockchains are increasingly adopted in enterprise environments due to their controlled access and role-specific permissions. However, the widely used Practical Byzantine Fault Tolerance (PBFT) protocol suffers from inefficiencies in round-robin leader selection and lacks integrated mechanisms for node performance evaluation. These weaknesses lead to reduced throughput, higher latency, and scalability constraints, particularly under Byzantine fault conditions. This study aims to overcome PBFT’s leader selection and performance assessment limitations by proposing an Adaptive Reputation-Based Byzantine Fault Tolerance (ARepBFT) protocol. The hypothesis is that by integrating dynamic reputation scoring with adaptive multi-criteria leader selection, the consensus process can achieve higher efficiency and reliability, while maintaining Byzantine fault tolerance in permissioned blockchain systems. Using Design Research Methodology (DRM), ARepBFT integrates two key modules: CRepScore, a credit-based system for continuous node performance evaluation, and RepTOPS-Lead, which applies the TOPSIS decision-making method for leader selection. The protocol was implemented in the NS-3 simulator with embedded consensus logic and evaluated against PBFT and Random Cluster PBFT (RC-PBFT) under varied node counts, transaction loads, and Byzantine fault ratios. ARepBFT demonstrated consistent performance advantages over PBFT and RC-PBFT in throughput, latency, and scalability. Under varying node and transaction configurations, ARepBFT achieved up to 24% higher throughput and 19% lower latency. This mechanism has also improved performance under Byzantine node stress tests and reduced the selection of abnormal leaders. These results affirm ARepBFT’s adaptive strength in maintaining Byzantine fault tolerance in dynamic blockchain environments. The research advances PBFT by introducing an adaptive, performance-aware consensus protocol, contributing theoretically to the field of Byzantine fault tolerance and practically to enterprise blockchain deployment. The results have implications for sectors requiring secure, scalable, and reliable distributed systems, supporting broader societal adoption of trustworthy decentralized technologies.