# Specular: Towards Secure, Trust-minimized Optimistic Blockchain Execution

arXiv: https://arxiv.org/abs/2212.05219 · HTML: https://mlsanity.com/paper/2212.05219/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 10 Dec 2022.

## Built on by (most cited first, 3 of 3)

- [Game of Trust: How Trustworthy Does Your Blockchain Think You Are?](https://mlsanity.com/paper/2505.14551/) (2025)
- [AGNT2: Autonomous Agent Economies on Interaction-Optimized Layer 2 Infrastructure](https://mlsanity.com/paper/2604.21129/) (2026)
- [OVIG: Optimistic Verification of AI Training Integrity via Gradient Signals](https://mlsanity.com/paper/2606.21045/) (2026)

## Abstract (arXiv)

An optimistic rollup (ORU) scales a blockchain's throughput by delegating computation to an untrusted remote chain (L2), refereeing any state claim disagreements between mutually distrusting L2 operators via an interactive dispute resolution protocol. State-of-the-art ORUs employ a monolithic dispute resolution protocol that tightly couples an L1 referee with a specific L2 client binary--oblivious to the system's higher-level semantics. We argue that this approach (1) magnifies monoculture failure risk, by precluding trust-minimized and permissionless participation using operator-chosen client software; (2) leads to an unnecessarily large and difficult-to-audit TCB; and, (3) suffers from a frequently-triggered, yet opaque upgrade process--both further increasing auditing overhead, and broadening the governance attack surface. To address these concerns, we outline a methodology for designing a secure and resilient ORU with a minimal TCB, by facilitating opportunistic 1-of-N-version programming. Due to its unique challenges and opportunities, we ground this work concretely in the context of the Ethereum ecosystem--where ORUs have gained significant traction. Specifically, we design a semantically-aware proof system, natively targeting the EVM and its instruction set. We present an implementation in a new ORU, Specular, that opportunistically leverages Ethereum's existing client diversity with minimal source modification, demonstrating our approach's feasibility.