Empirical Analysis of TEE-Enabled Rollup Designs
Layer 2 (L2) rollups have become the dominant scaling solution in Ethereum. At the core of these systems lies the rollup sequencer, a component that orders, executes, and submits L2 transaction blocks to the main Ethereum blockchain. The centralization of this sequencer introduces security risks, including censorship and malicious manipulation of transactions to extract maximum extractable value (MEV). Trusted execution environments (TEEs) provide strong hardware-enforced confidentiality and integrity guarantees for code and data. TEEs are strong candidates for strengthening security and ensuring verifiable neutrality in rollup sequencer operations, but multiple TEE-based designs are possible, offering different trade-offs among modularity, performance, and security guarantees. Among them, the separation of proposer and builder logic (PBS) into independent services is a strong contender against the monolithic approach that bundles all sequencer logic. Despite several proposed theoretical frameworks, there is a lack of experimental evaluation of the practicality and security trade-offs of integrating TEEs into rollup sequencers. This work addresses this gap through a comprehensive empirical study of TEE-enabled rollup designs under both PBS and monolithic sequencer models. Our experimental evaluations show that the impact of TEEs on rollup performance is small and that PBS does not significantly amplify it. We also show that PBS can lead to significant performance improvements by enabling more specialized, efficient builder logic implementations.