ROP-4: “Rewrite” vanilla IP-PBS in PEPC framework
Difficulty
Tags
Status
Completed
Created time
Oct 17, 2022
ROP
Involved
Phase
Grantee: Diego Estevez
The PEPC framework was introduced as a generalisation of PBS, where the proposer is able to custom-build their block verification rules, e.g., running a whole or partial PBS auction etc.
We seek to write a proof-of-concept for a vanilla IP-PBS in PEPC, where the proposer accepts bids from builders to construct the whole block. In particular, we are interested in an “end-to-end” implementation, with as much details as possible.
- How are bids gossiped/received from the builders to the proposers?
- Can bids-as-EVM-transactions work?
- How does the proposer commit to a builder in their block?
- How does the committed builder ensure they cannot be griefed? (e.g., honestly releasing their block but not making it to the canonical chain, thereby paying the cost but not earning their revenue)
- Can the mechanism be extended to partial PBS? Inclusion lists?
Deliverables
Diego Estevez received a grant for researching the questions above. We provide here the links to publications with a short context.
- A big open question was the representation of the commitments. Diego has released a library, Emily, to make commitments directly in the EVM. This generic protocol is used throughout the other deliverables.
- Towards writing IP-PBS in the PEPC framework, Diego got interested in using “sequencer commitments” for rollups, which have a more flexible construction than the L1. This led him to hack the OP stack and introduce the ability for sequencer to make these credible commitments.
- Another approach is to “do PEPC out-of-protocol”, to avoid deep changes to the L1 consensus logic. Diego innovated an approach relying on DVT to check the satisfaction of the commitments.
- Finally returning to the question of in-protocol PEPC, Diego extended the PTC design proposed by Mike Neuder to include the ability for proposers to make binding commitments on their block contents, even when built by third-party builders. The validity of the commitments is evaluated by a Commitment Satisfaction Committee (CSC).
