CONSENSUS ALGORITHMS BASED BLOCKCHAIN OF THINGS FOR DISTRIBUTED HEALTHCARE

Abstract

The Internet of Things (IoT) consists of smart Things with the evolution of ubiquitous computing. FogComputing (FC) processes and analyzes data of these sensors near to users. However, the ever-increasing numberof Things and the consequent explosion in data traffic has led to fail traditional solutions of centralized storage.Blockchain is a new technology developed as a shared ledger build around a peer-to-peer network to produceunchangeable blocks that contain multiple data. These blocks are linked to previous ones in a sequence calledchain through hash functions. Participants in blockchain selects a leader through one of consensus algorithms whoadds new blocks in the chain to prevent dishonest nodes from creating invalid blocks. In this paper, we proposeIoT based blockchain architecture named blockchain of Things to store medical records in a distributed manner.The architecture is emulated on Fog server Linux-based using Node.js and Postman. Three consensus protocols,namely: Proof of Work (PoW), Proof of Stake (PoS), and Byzantine Fault Tolerance (PBFT) are emulated andcommunicated using WebSocket. The consensus algorithms are evaluated in terms of CPU utilization and memoryusage. The results show that PoS compared to PoW and PBFT is more lightweight and beneficial to IoT application.