TeeRollup: Efficient Rollup Design Using Heterogeneous TEE

2024-09-23

arXiv.org

AI Summary

Existing Rollup solutions suffer from high on-chain costs, prolonged withdrawal latency, system complexity, or weak trust assumptions—hindering their practical deployment in decentralized applications. This paper proposes TEERollup, a novel Rollup protocol leveraging heterogeneous Trusted Execution Environments (TEEs). Our approach introduces three key innovations: (1) a distributed sequencer architecture natively supporting multiple TEE vendors; (2) a lightweight challenge mechanism to handle TEE failures; and (3) a Data Availability Provider (DAP) layer with a lazy-punishment scheme, enabling system lightweighting without compromising security or availability. Experimental evaluation demonstrates that TEERollup reduces on-chain verification gas overhead by 86% compared to ZK-Rollup and shortens withdrawal latency to several minutes. A prototype has been successfully deployed and validated on the Ethereum Sepolia testnet.

Technology Category

• Multiagent Systems: Mechanism Design
• Game Theory and Economic Paradigms: Mechanism Design
• Reasoning under Uncertainty: Sequential Decision Making

Application Category

• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Security and Privacy: Blockchains and distributed ledgers
• Economics, Online Markets and Human Computation: Trust and reliance of crowd workers and data experts on GenAI

Abstract

Rollups have emerged as a promising approach to improving blockchains' scalability by offloading transactions execution off-chain. Existing rollup solutions either leverage complex zero-knowledge proofs or optimistically assume execution correctness unless challenged. However, these solutions suffer from high gas costs and significant withdrawal delays, hindering their adoption in decentralized applications. This paper introduces TEERollup, an efficient rollup protocol that leverages Trusted Execution Environments (TEEs) to achieve both low gas costs and short withdrawal delays. Sequencers (system participants) execute transactions within TEEs and upload signed execution results to the blockchain with confidential keys of TEEs. Unlike most TEE-assisted blockchain designs, TEERollup adopts a practical threat model where the integrity and availability of TEEs may be compromised. To address these issues, we first introduce a distributed system of sequencers with heterogeneous TEEs, ensuring system security even if a certain proportion of TEEs are compromised. Second, we propose a challenge mechanism to solve the redeemability issue caused by TEE unavailability. Furthermore, TEERollup incorporates Data Availability Providers (DAPs) to reduce on-chain storage overhead and uses a laziness penalty mechanism to regulate DAP behavior. We implement a prototype of TEERollup in Golang, using the Ethereum test network, Sepolia. Our experimental results indicate that TEERollup outperforms zero-knowledge rollups (ZK-rollups), reducing on-chain verification costs by approximately 86% and withdrawal delays to a few minutes.

Problem

• Blockchain Scalability
• Rollup Solutions
• Decentralized Applications

Innovation

• Trusted Execution Environments
• Rollup Solution
• Data Availability Providers