Step-by-Step Guidelines for Making Smart Contract Smarter

Different from traditional programs, which run on local machines or in the clouds, smart contracts run mostly on miners' devices; moreover, users of smart contracts have to pay fees (i.e., gases in Ethereum) to miners for executing transactions on the blockchain. Lacking of enough experiences in developing smart contracts makes writing low cost and high efficiency smart contracts becoming a very challenging task. In this work, by collating existing approaches and developing new methods for reducing gas consumption, a set of systematical step-by-step guidelines for developing low cost smart contracts is proposed. To prove its usefulness, ZoKrates verifier, a very complicated and costly contract, is used to demonstrate how our scheme can effectively cut the gas consumption down.