A scalable multi-layer PBFT consensus for blockchain

Li, W., Feng, C., Zhang, L. , Xu, H. , Cao, B. and Imran, M. A. (2021) A scalable multi-layer PBFT consensus for blockchain. IEEE Transactions on Parallel and Distributed Systems, 32(5), pp. 1146-1160. (doi: 10.1109/TPDS.2020.3042392)

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Practical Byzantine Fault Tolerance (PBFT) consensus mechanism shows a great potential to break the performance bottleneck of the Proof-of-Work (PoW) based blockchain systems, which typically support only dozens of transactions per second and require minutes to hours for transaction confirmation. However, due to frequent inter-node communications, PBFT mechanism has a poor node scalability and thus it is typically adopted in small networks. To enable PBFT in large systems such as massive Internet of Things (IoT) ecosystems and blockchain, in this paper, a scalable multi-layer PBFT based consensus mechanism is proposed by hierarchically grouping nodes into different layers and limiting the communication within the group. We first propose an optimal double-layer PBFT and show that the communication complexity is significantly reduced. Specifically, we prove that when the nodes are evenly distributed within the subgroups in the second layer, the communication complexity is minimized. The security threshold is analyzed based on faulty probability determined (FPD) and faulty number determined (FND) models respectively. We also provide a practical protocol for the proposed double-layer PBFT system. Finally, the results are extended to arbitrary-layer PBFT systems with communication complexity and security analysis. Simulation results verify the effectiveness of the analytical results.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Imran, Professor Muhammad and Zhang, Professor Lei and Xu, Mr Hao
Authors: Li, W., Feng, C., Zhang, L., Xu, H., Cao, B., and Imran, M. A.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:IEEE Transactions on Parallel and Distributed Systems
ISSN (Online):1045-9219
Published Online:03 December 2020
Copyright Holders:Copyright © 2020 IEEE
First Published:First published in IEEE Transactions on Parallel and Distributed Systems 32(5): 1146-1160
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
304481Resource Orchestration for Diverse Radio SystemsLei ZhangEngineering and Physical Sciences Research Council (EPSRC)EP/S02476X/1ENG - Systems Power & Energy