PEPC-DVT: PEPC with no changes to the consensus protocol

[diego]

Thanks @mikeneuder for all the questions!

@mikeneuder

• It is a very cool use of DVT, but is there anything particular about DVT that this design hinges on? Would a simple multisig solve the same problem but without the need for DVT?

I agree with this point. In fact, PEPC-DVT could be framed in terms of BLS Multi-Signatures, as this new article explores in the context of blinded signatures that would make PEPC-DVT private.

@mikeneuder

• I am curious about the timing of commitments especially in the presence of reorgs. Like could a proposer make a commitment to a builder, but then reorg the chain so that it looks like they didn’t make that commitment to trick the enforcement committee into signing their block? I guess in general these commitment schemes seem super latency sensitive, so I am curious about the games proposers could play with them.

With respect to this question, my solution was that the commitments enforced (deemed “active”) were only the ones introduced by transactions already finalized. The tricky part here is how to find this out on-chain if we want to delegate all the logic of checking commitments to a smart contract (such that the DVT client only has to make a call to this contract passing the block). In the worst case, the DVT client could be the one that makes sure to only consider commitments finalized. By only considering finalized ones, we prevent the protocol from considering a commitment that may later be excluded.