Leverage Sidechains to Reduce the Workload of Smart Contracts through Parallelization

Recently, blockchain has been evolving rapidly with new innovations, coins, and use cases every day. The platform is getting more congested due to the increase of interest and mainstream adoption, and because most of this activity is on the widely used Ethereum blockchain. This also further increases the costs of using the platform, as the gas prices become higher. Smart contracts are deployed on the Ethereum blockchain and the high usage of these smart contracts is one of the main reasons behind the congestion. We propose a new scheme using sidechains and a middleware to reduce the workload for certain smart contracts, which allows the execution of smart contract transactions in parallel through sidechains. In this way, the sidechains could be leveraged to decrease the congestion on the main blockchain and increase the rate of transactions per second. Furthermore, the sidechains could have their settings, like block time and block gas limit, adjusted to give more optimal results. We implemented a modified version of the ballot contract from the solidity documentation, and our results demonstrated that through the use of two sidechains, the transactions processed per second could be increased from 1.8× to 13.0×, depending on the sidechains settings.