iBatch: Saving Ethereum Fees via Secure and Cost-Effective Batching of Smart-Contract Invocations

TL;DR

iBatch is a middleware system that enables secure, cost-effective batching of Ethereum smart-contract calls, reducing transaction fees significantly while maintaining security and flexibility.

Contribution

This work introduces iBatch, a novel middleware for secure batching of smart-contract invocations on Ethereum, with adaptive policies and automatic smart contract rewriting.

Findings

saves 14.6%-59.1% Gas per invocation

reduces Ether cost by 19.06%-31.52%

achieves batching with moderate delay of 2 minutes

Abstract

This paper presents iBatch, 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. iBatch does so at a low overhead by validating the server's batched invocations in smart contracts without additional states. The iBatch mechanism supports a variety of policies, ranging from conservative to aggressive batching, and can be configured adaptively to the current workloads. iBatch automatically rewrites smart contracts to integrate with legacy applications and support large-scale deployment. For cost evaluation, we develop a platform with fast and cost-accurate transaction replaying, build real transaction benchmarks on popular Ethereum applications, and build a functional prototype of iBatch on Ethereum. The evaluation results show that iBatch saves 14.6%-59.1% Gas cost per invocation with a moderate 2-minute delay and 19.06%-31.52% Ether cost per invocation with a delay of 0.26-1.66 blocks.