Empirically comparing the performance of blockchain’s consensus algorithms

Blockchain-based audit systems suffer from low scalability and high message complex-ity. The root cause of these shortcomings is the use of “Practical Byzantine Fault Toler-ance” (PBFT) consensus protocol in those systems. Alternatives to PBFT have not been used in blockchain-based audit systems due to the limited knowledge about their func-tional and operational requirements. Currently, no blockchain testbed supports the execution and benchmarking of different consensus protocols in a unified testing environment. This paper demonstrates building a blockchain testbed that supports the execution of five state-of-the-art consensus protocols in a blockchain system; namely PBFT, Proof-of-Work (PoW), Proof-of-Stake (PoS), Proof-of-Elapsed Time (PoET), and Clique. Performance evaluation of those consensus algorithms is carried out using data from a real-world audit system. These results show that the Clique protocol is best suited for blockchain-based audit systems, based on scalability features.