Comparison of single- and multiple entry point PBFT for IoT blockchain systems

Abstract

This work deals with problem of deployment of Practical Byzantine Fault Tolerance (PBFT) consensus algorithm in Internet of things (IoT) applications requiring strict order among records linked in blockchains at multiple geographical points. Due to the needs of reliability and coverage of larger geographical areas it becomes necessary to extend current PBFT systems with single entry node towards multiple entry nodes. In this work we model PBFT systems with single and multiple entry points and compare their performance. We have implemented multiple entry system using CSMA/CA algorithm over fully connected P2P networks. We have compared two systems with four orderers against increasing system load and against increasing geographical coverage. Our results indicate that system with four entry points has double capacity over the system with single entry point.