Practicability of blockchain technology and scalable blockchain network : sharding

Abstract

Currently, some research has been done in the Blockchain domain on how to improve the efficiency of transmissions in Blockchain ecosystem. The effectiveness of the transmissions within a Blockchain network depends on the execution of appropriate consensus algorithms to ensure the security and fairness of the validation and transmission of transactions. The first consensus algorithm that has been used within a Blockchain ecosystem such as Bitcoin is Proof of Work (PoW). The second generation of consensus algorithm is Proof of Stake (PoS) that has been put into practice in the PeerCoin Blockchain ecosystem. One major issue is that those consensus algorithms are inefficient because they require a significant amount of energy consumption to enable the validation of transactions in a complete Blockchain platform. Therefore, the amount of transactions that can be processed and validated is limited and expensive in terms of time complexity. As a result, scalable approaches need to be designed to sharpen the efficiency ( i.e., with low latency and high throughput) of the Blockchain system. The introduction of the sharding concept has given us the possibility to divide the network into small portions, and to enable the validation of transactions in parallel using the Byzantine-Fault Tolerant (BFT) consensus on those subset of nodes. Sharding the network can significantly improve the Communication Cost per Transaction (CCPT) because each transaction is validated in its specific shard using validator nodes with appropriate proof size. In our implementation, the transaction would follow the shortest path, traversing nodes with small proof sizes minimizing the CCPT. Structuring our Blockchain network, proof sizes are randomly assigned to the nodes to ensure unbiased network structure to stimulate and evaluate our approach to perform a global optimization within a sharded Blockchain network.