Alex Stokes: MEV-Boost, How Does it Work & What’s Missing? - SBC 2022

Summary:
1. MEV-Boost is an off-chain implementation of Proposer-Builder Separation (PBS), which is intended to preserve validator decentralization in Ethereum by separating the proposal and building of blocks to reduce centralizing forces.
2. The PBS framework involves proposers selling block space to builders, who specialize in extracting MEV and wish to buy this space to add value to the network.
3. MEV-Boost addresses the need for a secure network to connect builders to proposers, ensuring that builders produce valid blocks and that the relay provides the availability guarantee.
4. A commit-reveal scheme is used in MEV-Boost to allow for trustworthy communication between proposers and builders. This scheme blinds the payload details until a proposer commits, after which the builder reveals the unblinded payload.
5. Relays play a critical role by ensuring builders produce valid blocks and by releasing blocks when proposers and builders have fulfilled their parts in the network process.
6. MEV-Boost involves a relay monitor to provide checks and balances ensuring that relays function correctly without exhibiting harmful behavior. The system is designed to support multiple relays for fault tolerance and to encourage healthy competition.
7. There remain open questions and potential improvements around decentralizing relays, auction mechanics, and improving the integrity of the system — for which contributions from the community are welcomed.

Key questions the transcript answers:

How does MEV-Boost work?
- MEV-Boost works as an off-chain implementation of Proposer-Builder Separation (PBS) that connects proposers and builders through a commit-reveal scheme. It uses a network of relays to securely facilitate the auction process and ensure the validity and availability of blocks, while also being designed with a sidecar architecture to support client diversity and fallback mechanisms.

What problem does MEV-Boost aim to solve?
- MEV-Boost aims to solve the centralization issue caused by MEV (Maximal Extractable Value) by separating the roles of proposers and builders. This division aims to reduce the incentives for validator centralization and distribute the opportunities to profit from MEV more evenly across the network.

What are the concerns and potential risks associated with MEV-Boost?
- MEV-Boost faces concerns such as builder centralization, reliance on trusted relay networks, vulnerability to various types of faults (like safety and liveness faults), incentive misalignment among participants, and the potential for centralized points of failure. Additionally, the design space is vast and many collective incentive issues need to be considered.

Here are a few memorable quotes:
- "This is like a very big, complex problem. There's many pieces to it."
- "We don't want to be in a world where there's one builder that is essentially the gateway into every validated node."
- "If you have builders colluding with proposers, they can start playing these games..."

Core Takeaway:
The core problem described is the centralizing forces in Ethereum caused by MEV, which can lead to a lack of validator decentralization. Not solving this problem would risk the fundamental decentralized nature of Ethereum, potentially creating a pattern of centralized control by a few entities who are able to extract MEV more efficiently than others.

To address the problem, the top three key ideas presented are:
1. Introduction and implementation of MEV-Boost as an off-chain solution that allows for separation of proposers and builders through a commit-reveal scheme and relay system, which ensures transactions are secure and valid.
2. Ensuring the relay system in MEV-Boost operates with trust and accountability through monitoring systems like the relay monitor, which oversees relay actions and promotes network integrity.
3. Encouraging community involvement to explore, discuss, and contribute to the improvement of MEV-Boost through open-source repositories, as the proposal seeks to continuously evolve and incorporate real-world experiences for a more decentralized relay network.

Tags here: MEV-Boost, Proposer-Builder Separation, MEV, Ethereum, decentralization, relay system, Alex Stokes