Enabling Concurrency on Smart Contracts Using Multiversion Ordering

Blockchain-based platforms, such as Ethereum, allow transactions in blocks to call user-defined scripts named smart contracts. In the blockchain network, after being generated by a miner, a block will be validated many times by the peers who accept it. Hence by enabling concurrency on smart contracts, especially validation, we can improve the efficiency and the throughput of those platforms. By introducing multiversion transaction ordering, this paper presents a concurrent scheme called MVTO to run smart contracts concurrently. First, the miners are able to use any concurrency control technique to discover a conflict-serializable schedule. Then, validators use MVTO to verify the block by replaying this schedule concurrently and deterministically. The evaluation shows that this mechanism achieves approximately 2.5x speedup in the block validation using a thread pool with 3 threads.