ShardCons - A Sharding Based Consensus Algorithm for Blockchain

Abstract

Blockchain, the foundation of Bitcoin, has received extensive attentions in recent days. Blockchain-based applications are springing up, covering numerous fields including financial services, reputation system, Internet of Things (IoT), Healthcare systems, Supply Chain Management and so on. Blockchain serves as an immutable ledger which allows transactions to be securely accomplished via point-to-point connections in a distributed system without the need for a third-party. Since it is decentralized, consensus algorithms keeps hold the integrity of the transactions which are added in the chain. Consensus algorithms are the primary root of the blockchain technology and a good consensus algorithm can guarantee the fault tolerance and security of the blockchain systems. In this article, authors present a novel consensus algorithm for public blockchain which shards the miners based on their performance. Once the sharding of miners is done, the best miner from each shard is chosen to form a Super shard of miners, and then from Super shard, one miner is randomly chosen as a winner miner who will mine the next block in the blockchain network. For sharding, performance history of miners will be maintained in each miner and re-sharding will be done at regular intervals in order to bring fairness in the system. The proposed sharding based consensus algorithm solves one of the main problem of public blockchain which is scalability issue. This performance based consensus algorithm also ensures more fairness, avoids starvation, improves the trust among the miners and enhances the overall performance of the blockchain network.