Towards Saving Blockchain Fees via Secure and Cost-Effective Batching of Smart-Contract Invocations
Yibo Wang, Kai Li, Yuzhe Tang, Jiaqi Chen, Qi Zhang, Xiapu Luo, Ting Chen
Abstract
This paper presents <small>iBatch</small> , a middleware system running on top of an operational Ethereum network to enable secure batching of smart-contract invocations against an untrusted relay server off-chain. <small>iBatch</small> does so at a low overhead by validating the server's batched invocations in smart contracts without additional states of user nonces. The <small>iBatch</small> mechanism supports a variety of policies, ranging from conservative to aggressive batching, and can be configured adaptively to the current workloads. <small>iBatch</small> automatically rewrites smart contracts to integrate with legacy applications and support large-scale deployment. We built an evaluation platform for fast and cost-accurate transaction replaying and constructed real transaction benchmarks on popular Ethereum applications. With a functional prototype of <small>iBatch</small> , we conduct extensive cost evaluations, which shows <small>iBatch</small> saves <inline-formula><tex-math notation="LaTeX">$14.6\%\sim {}59.1\%$</tex-math></inline-formula> Gas cost per invocation with a moderate 2-minute delay and <inline-formula><tex-math notation="LaTeX">$19.06\%\sim {}31.52\%$</tex-math></inline-formula> Ether cost per invocation with a delay of <inline-formula><tex-math notation="LaTeX">$0.26\sim {}1.66$</tex-math></inline-formula> blocks.