Protocol enforced Proposer commitments (PEPC)

• proposed by Barnabe Monnot
• Initial proposal here
• PEPC FAQ here

State of PBS -

1. Out of protocol PBS
2. Enshrined PBS
3. PEPC

Out of protocol PBS

The Builder API, which is a module in all consensus-layer clients, allows proposers to offer their signature to builders, but this module is not part of the Ethereum consensus rules, nor is the abstraction of a builder ever instantiated. It also has trusted entities like relayers.

Enshrined PBS (ePBS)

ePBS makes PBS part of the protocol. ****ePBS involves instantiating the “Proposer” and “Builder” abstractions in the consensus rules of Ethereum, as well as a specific allocation mechanism, for instance, a full block in exchange for a signature. In its current form in ePBS, we can have only type of contract between Proposers and Block builders that is - a full block containing a payment to the proposer, in exchange for a signature from the proposer to make the block valid.

PEPC

PEPC asks the question why can’t proposer and builders have other type of (more flexible) contracts between them which are protocol enforced.

• Proposers can make any programmable contract with the builders, including partial blocks, commitment to ordering etc.
• Commitments are enforced by the protocol and so enshrined

PEPC FAQ proposes to split PBS in two layers -

• The market structure: Validators enter into agreements with outside parties (”builders”), and there is a legal system (consensus rules) which guarantees the fair exchange between them.